/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2003-2008 Joseph Koshy * Copyright (c) 2007 The FreeBSD Foundation * Copyright (c) 2018 Matthew Macy * All rights reserved. * * Portions of this software were developed by A. Joseph Koshy under * sponsorship from the FreeBSD Foundation and Google, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* needs to be after */ #include #include #include #include #include #include #include #include "hwpmc_soft.h" #define PMC_EPOCH_ENTER() \ struct epoch_tracker pmc_et; \ epoch_enter_preempt(global_epoch_preempt, &pmc_et) #define PMC_EPOCH_EXIT() \ epoch_exit_preempt(global_epoch_preempt, &pmc_et) /* * Types */ enum pmc_flags { PMC_FLAG_NONE = 0x00, /* do nothing */ PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ }; /* * The offset in sysent where the syscall is allocated. */ static int pmc_syscall_num = NO_SYSCALL; struct pmc_cpu **pmc_pcpu; /* per-cpu state */ pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ #define PMC_PCPU_SAVED(C, R) pmc_pcpu_saved[(R) + md->pmd_npmc * (C)] struct mtx_pool *pmc_mtxpool; static int *pmc_pmcdisp; /* PMC row dispositions */ #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) #define PMC_MARK_ROW_FREE(R) do { \ pmc_pmcdisp[(R)] = 0; \ } while (0) #define PMC_MARK_ROW_STANDALONE(R) do { \ KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ __LINE__)); \ atomic_add_int(&pmc_pmcdisp[(R)], -1); \ KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ ("[pmc,%d] row disposition error", __LINE__)); \ } while (0) #define PMC_UNMARK_ROW_STANDALONE(R) do { \ atomic_add_int(&pmc_pmcdisp[(R)], 1); \ KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ __LINE__)); \ } while (0) #define PMC_MARK_ROW_THREAD(R) do { \ KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ __LINE__)); \ atomic_add_int(&pmc_pmcdisp[(R)], 1); \ } while (0) #define PMC_UNMARK_ROW_THREAD(R) do { \ atomic_add_int(&pmc_pmcdisp[(R)], -1); \ KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ __LINE__)); \ } while (0) /* various event handlers */ static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, pmc_kld_unload_tag; /* Module statistics */ struct pmc_driverstats pmc_stats; /* Machine/processor dependent operations */ static struct pmc_mdep *md; /* * Hash tables mapping owner processes and target threads to PMCs. */ struct mtx pmc_processhash_mtx; /* spin mutex */ static u_long pmc_processhashmask; static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; /* * Hash table of PMC owner descriptors. This table is protected by * the shared PMC "sx" lock. */ static u_long pmc_ownerhashmask; static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; /* * List of PMC owners with system-wide sampling PMCs. */ static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; /* * List of free thread entries. This is protected by the spin * mutex. */ static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ static LIST_HEAD(, pmc_thread) pmc_threadfreelist; static int pmc_threadfreelist_entries = 0; #define THREADENTRY_SIZE (sizeof(struct pmc_thread) + \ (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) /* * Task to free thread descriptors */ static struct task free_task; /* * A map of row indices to classdep structures. */ static struct pmc_classdep **pmc_rowindex_to_classdep; /* * Prototypes */ #ifdef HWPMC_DEBUG static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); static int pmc_debugflags_parse(char *newstr, char *fence); #endif static int load(struct module *module, int cmd, void *arg); static int pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf); static void pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp); static int pmc_attach_process(struct proc *p, struct pmc *pm); static struct pmc *pmc_allocate_pmc_descriptor(void); static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); static int pmc_attach_one_process(struct proc *p, struct pmc *pm); static bool pmc_can_allocate_row(int ri, enum pmc_mode mode); static bool pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu); static int pmc_can_attach(struct pmc *pm, struct proc *p); static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); static void pmc_cleanup(void); static int pmc_detach_process(struct proc *p, struct pmc *pm); static int pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags); static void pmc_destroy_owner_descriptor(struct pmc_owner *po); static void pmc_destroy_pmc_descriptor(struct pmc *pm); static void pmc_destroy_process_descriptor(struct pmc_process *pp); static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmc); static struct pmc_process *pmc_find_process_descriptor(struct proc *p, uint32_t mode); static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, uint32_t mode); static void pmc_force_context_switch(void); static void pmc_link_target_process(struct pmc *pm, struct pmc_process *pp); static void pmc_log_all_process_mappings(struct pmc_owner *po); static void pmc_log_kernel_mappings(struct pmc *pm); static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); static void pmc_maybe_remove_owner(struct pmc_owner *po); static void pmc_post_callchain_callback(void); static void pmc_process_allproc(struct pmc *pm); static void pmc_process_csw_in(struct thread *td); static void pmc_process_csw_out(struct thread *td); static void pmc_process_exec(struct thread *td, struct pmckern_procexec *pk); static void pmc_process_exit(void *arg, struct proc *p); static void pmc_process_fork(void *arg, struct proc *p1, struct proc *p2, int n); static void pmc_process_proccreate(struct proc *p); static void pmc_process_samples(int cpu, ring_type_t soft); static void pmc_process_threadcreate(struct thread *td); static void pmc_process_threadexit(struct thread *td); static void pmc_process_thread_add(struct thread *td); static void pmc_process_thread_delete(struct thread *td); static void pmc_process_thread_userret(struct thread *td); static void pmc_release_pmc_descriptor(struct pmc *pmc); static void pmc_remove_owner(struct pmc_owner *po); static void pmc_remove_process_descriptor(struct pmc_process *pp); static int pmc_start(struct pmc *pm); static int pmc_stop(struct pmc *pm); static int pmc_syscall_handler(struct thread *td, void *syscall_args); static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); static void pmc_thread_descriptor_pool_drain(void); static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); static void pmc_unlink_target_process(struct pmc *pmc, struct pmc_process *pp); static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); static struct pmc_mdep *pmc_generic_cpu_initialize(void); static void pmc_generic_cpu_finalize(struct pmc_mdep *md); /* * Kernel tunables and sysctl(8) interface. */ SYSCTL_DECL(_kern_hwpmc); SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "HWPMC stats"); /* Stats. */ SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, &pmc_stats.pm_intr_ignored, "# of interrupts ignored"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, &pmc_stats.pm_intr_processed, "# of interrupts processed"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, &pmc_stats.pm_syscalls, "# of syscalls"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, &pmc_stats.pm_syscall_errors, "# of syscall_errors"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, &pmc_stats.pm_buffer_requests, "# of buffer requests"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW, &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, &pmc_stats.pm_log_sweeps, "# of times samples were processed"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, &pmc_stats.pm_merges, "# of times kernel stack was found for user trace"); SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, &pmc_stats.pm_overwrites, "# of times a sample was overwritten before being logged"); static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, &pmc_callchaindepth, 0, "depth of call chain records"); char pmc_cpuid[PMC_CPUID_LEN]; SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, pmc_cpuid, 0, "cpu version string"); #ifdef HWPMC_DEBUG struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; char pmc_debugstr[PMC_DEBUG_STRSIZE]; TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, sizeof(pmc_debugstr)); SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); #endif /* * kern.hwpmc.hashsize -- determines the number of rows in the * of the hash table used to look up threads */ static int pmc_hashsize = PMC_HASH_SIZE; SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, &pmc_hashsize, 0, "rows in hash tables"); /* * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU */ static int pmc_nsamples = PMC_NSAMPLES; SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, &pmc_nsamples, 0, "number of PC samples per CPU"); static uint64_t pmc_sample_mask = PMC_NSAMPLES - 1; /* * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. */ static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, &pmc_mtxpool_size, 0, "size of spin mutex pool"); /* * kern.hwpmc.threadfreelist_entries -- number of free entries */ SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, &pmc_threadfreelist_entries, 0, "number of available thread entries"); /* * kern.hwpmc.threadfreelist_max -- maximum number of free entries */ static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, &pmc_threadfreelist_max, 0, "maximum number of available thread entries before freeing some"); /* * kern.hwpmc.mincount -- minimum sample count */ static u_int pmc_mincount = 1000; SYSCTL_INT(_kern_hwpmc, OID_AUTO, mincount, CTLFLAG_RWTUN, &pmc_mincount, 0, "minimum count for sampling counters"); /* * security.bsd.unprivileged_syspmcs -- allow non-root processes to * allocate system-wide PMCs. * * Allowing unprivileged processes to allocate system PMCs is convenient * if system-wide measurements need to be taken concurrently with other * per-process measurements. This feature is turned off by default. */ static int pmc_unprivileged_syspmcs = 0; SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, &pmc_unprivileged_syspmcs, 0, "allow unprivileged process to allocate system PMCs"); /* * Hash function. Discard the lower 2 bits of the pointer since * these are always zero for our uses. The hash multiplier is * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). */ #if LONG_BIT == 64 #define _PMC_HM 11400714819323198486u #elif LONG_BIT == 32 #define _PMC_HM 2654435769u #else #error Must know the size of 'long' to compile #endif #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) /* * Syscall structures */ /* The `sysent' for the new syscall */ static struct sysent pmc_sysent = { .sy_narg = 2, .sy_call = pmc_syscall_handler, }; static struct syscall_module_data pmc_syscall_mod = { .chainevh = load, .chainarg = NULL, .offset = &pmc_syscall_num, .new_sysent = &pmc_sysent, .old_sysent = { .sy_narg = 0, .sy_call = NULL }, .flags = SY_THR_STATIC_KLD, }; static moduledata_t pmc_mod = { .name = PMC_MODULE_NAME, .evhand = syscall_module_handler, .priv = &pmc_syscall_mod, }; #ifdef EARLY_AP_STARTUP DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); #else DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); #endif MODULE_VERSION(pmc, PMC_VERSION); #ifdef HWPMC_DEBUG enum pmc_dbgparse_state { PMCDS_WS, /* in whitespace */ PMCDS_MAJOR, /* seen a major keyword */ PMCDS_MINOR }; static int pmc_debugflags_parse(char *newstr, char *fence) { struct pmc_debugflags *tmpflags; size_t kwlen; char c, *p, *q; int error, *newbits, tmp; int found; tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK | M_ZERO); error = 0; for (p = newstr; p < fence && (c = *p); p++) { /* skip white space */ if (c == ' ' || c == '\t') continue; /* look for a keyword followed by "=" */ for (q = p; p < fence && (c = *p) && c != '='; p++) ; if (c != '=') { error = EINVAL; goto done; } kwlen = p - q; newbits = NULL; /* lookup flag group name */ #define DBG_SET_FLAG_MAJ(S,F) \ if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ newbits = &tmpflags->pdb_ ## F; DBG_SET_FLAG_MAJ("cpu", CPU); DBG_SET_FLAG_MAJ("csw", CSW); DBG_SET_FLAG_MAJ("logging", LOG); DBG_SET_FLAG_MAJ("module", MOD); DBG_SET_FLAG_MAJ("md", MDP); DBG_SET_FLAG_MAJ("owner", OWN); DBG_SET_FLAG_MAJ("pmc", PMC); DBG_SET_FLAG_MAJ("process", PRC); DBG_SET_FLAG_MAJ("sampling", SAM); #undef DBG_SET_FLAG_MAJ if (newbits == NULL) { error = EINVAL; goto done; } p++; /* skip the '=' */ /* Now parse the individual flags */ tmp = 0; newflag: for (q = p; p < fence && (c = *p); p++) if (c == ' ' || c == '\t' || c == ',') break; /* p == fence or c == ws or c == "," or c == 0 */ if ((kwlen = p - q) == 0) { *newbits = tmp; continue; } found = 0; #define DBG_SET_FLAG_MIN(S,F) \ if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) /* a '*' denotes all possible flags in the group */ if (kwlen == 1 && *q == '*') tmp = found = ~0; /* look for individual flag names */ DBG_SET_FLAG_MIN("allocaterow", ALR); DBG_SET_FLAG_MIN("allocate", ALL); DBG_SET_FLAG_MIN("attach", ATT); DBG_SET_FLAG_MIN("bind", BND); DBG_SET_FLAG_MIN("config", CFG); DBG_SET_FLAG_MIN("exec", EXC); DBG_SET_FLAG_MIN("exit", EXT); DBG_SET_FLAG_MIN("find", FND); DBG_SET_FLAG_MIN("flush", FLS); DBG_SET_FLAG_MIN("fork", FRK); DBG_SET_FLAG_MIN("getbuf", GTB); DBG_SET_FLAG_MIN("hook", PMH); DBG_SET_FLAG_MIN("init", INI); DBG_SET_FLAG_MIN("intr", INT); DBG_SET_FLAG_MIN("linktarget", TLK); DBG_SET_FLAG_MIN("mayberemove", OMR); DBG_SET_FLAG_MIN("ops", OPS); DBG_SET_FLAG_MIN("read", REA); DBG_SET_FLAG_MIN("register", REG); DBG_SET_FLAG_MIN("release", REL); DBG_SET_FLAG_MIN("remove", ORM); DBG_SET_FLAG_MIN("sample", SAM); DBG_SET_FLAG_MIN("scheduleio", SIO); DBG_SET_FLAG_MIN("select", SEL); DBG_SET_FLAG_MIN("signal", SIG); DBG_SET_FLAG_MIN("swi", SWI); DBG_SET_FLAG_MIN("swo", SWO); DBG_SET_FLAG_MIN("start", STA); DBG_SET_FLAG_MIN("stop", STO); DBG_SET_FLAG_MIN("syscall", PMS); DBG_SET_FLAG_MIN("unlinktarget", TUL); DBG_SET_FLAG_MIN("write", WRI); #undef DBG_SET_FLAG_MIN if (found == 0) { /* unrecognized flag name */ error = EINVAL; goto done; } if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ *newbits = tmp; continue; } p++; goto newflag; } /* save the new flag set */ bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); done: free(tmpflags, M_PMC); return (error); } static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) { char *fence, *newstr; int error; u_int n; n = sizeof(pmc_debugstr); newstr = malloc(n, M_PMC, M_WAITOK | M_ZERO); strlcpy(newstr, pmc_debugstr, n); error = sysctl_handle_string(oidp, newstr, n, req); /* if there is a new string, parse and copy it */ if (error == 0 && req->newptr != NULL) { fence = newstr + (n < req->newlen ? n : req->newlen + 1); error = pmc_debugflags_parse(newstr, fence); if (error == 0) strlcpy(pmc_debugstr, newstr, sizeof(pmc_debugstr)); } free(newstr, M_PMC); return (error); } #endif /* * Map a row index to a classdep structure and return the adjusted row * index for the PMC class index. */ static struct pmc_classdep * pmc_ri_to_classdep(struct pmc_mdep *md __unused, int ri, int *adjri) { struct pmc_classdep *pcd; KASSERT(ri >= 0 && ri < md->pmd_npmc, ("[pmc,%d] illegal row-index %d", __LINE__, ri)); pcd = pmc_rowindex_to_classdep[ri]; KASSERT(pcd != NULL, ("[pmc,%d] ri %d null pcd", __LINE__, ri)); *adjri = ri - pcd->pcd_ri; KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); return (pcd); } /* * Concurrency Control * * The driver manages the following data structures: * * - target process descriptors, one per target process * - owner process descriptors (and attached lists), one per owner process * - lookup hash tables for owner and target processes * - PMC descriptors (and attached lists) * - per-cpu hardware state * - the 'hook' variable through which the kernel calls into * this module * - the machine hardware state (managed by the MD layer) * * These data structures are accessed from: * * - thread context-switch code * - interrupt handlers (possibly on multiple cpus) * - kernel threads on multiple cpus running on behalf of user * processes doing system calls * - this driver's private kernel threads * * = Locks and Locking strategy = * * The driver uses four locking strategies for its operation: * * - The global SX lock "pmc_sx" is used to protect internal * data structures. * * Calls into the module by syscall() start with this lock being * held in exclusive mode. Depending on the requested operation, * the lock may be downgraded to 'shared' mode to allow more * concurrent readers into the module. Calls into the module from * other parts of the kernel acquire the lock in shared mode. * * This SX lock is held in exclusive mode for any operations that * modify the linkages between the driver's internal data structures. * * The 'pmc_hook' function pointer is also protected by this lock. * It is only examined with the sx lock held in exclusive mode. The * kernel module is allowed to be unloaded only with the sx lock held * in exclusive mode. In normal syscall handling, after acquiring the * pmc_sx lock we first check that 'pmc_hook' is non-null before * proceeding. This prevents races between the thread unloading the module * and other threads seeking to use the module. * * - Lookups of target process structures and owner process structures * cannot use the global "pmc_sx" SX lock because these lookups need * to happen during context switches and in other critical sections * where sleeping is not allowed. We protect these lookup tables * with their own private spin-mutexes, "pmc_processhash_mtx" and * "pmc_ownerhash_mtx". * * - Interrupt handlers work in a lock free manner. At interrupt * time, handlers look at the PMC pointer (phw->phw_pmc) configured * when the PMC was started. If this pointer is NULL, the interrupt * is ignored after updating driver statistics. We ensure that this * pointer is set (using an atomic operation if necessary) before the * PMC hardware is started. Conversely, this pointer is unset atomically * only after the PMC hardware is stopped. * * We ensure that everything needed for the operation of an * interrupt handler is available without it needing to acquire any * locks. We also ensure that a PMC's software state is destroyed only * after the PMC is taken off hardware (on all CPUs). * * - Context-switch handling with process-private PMCs needs more * care. * * A given process may be the target of multiple PMCs. For example, * PMCATTACH and PMCDETACH may be requested by a process on one CPU * while the target process is running on another. A PMC could also * be getting released because its owner is exiting. We tackle * these situations in the following manner: * * - each target process structure 'pmc_process' has an array * of 'struct pmc *' pointers, one for each hardware PMC. * * - At context switch IN time, each "target" PMC in RUNNING state * gets started on hardware and a pointer to each PMC is copied into * the per-cpu phw array. The 'runcount' for the PMC is * incremented. * * - At context switch OUT time, all process-virtual PMCs are stopped * on hardware. The saved value is added to the PMCs value field * only if the PMC is in a non-deleted state (the PMCs state could * have changed during the current time slice). * * Note that since in-between a switch IN on a processor and a switch * OUT, the PMC could have been released on another CPU. Therefore * context switch OUT always looks at the hardware state to turn * OFF PMCs and will update a PMC's saved value only if reachable * from the target process record. * * - OP PMCRELEASE could be called on a PMC at any time (the PMC could * be attached to many processes at the time of the call and could * be active on multiple CPUs). * * We prevent further scheduling of the PMC by marking it as in * state 'DELETED'. If the runcount of the PMC is non-zero then * this PMC is currently running on a CPU somewhere. The thread * doing the PMCRELEASE operation waits by repeatedly doing a * pause() till the runcount comes to zero. * * The contents of a PMC descriptor (struct pmc) are protected using * a spin-mutex. In order to save space, we use a mutex pool. * * In terms of lock types used by witness(4), we use: * - Type "pmc-sx", used by the global SX lock. * - Type "pmc-sleep", for sleep mutexes used by logger threads. * - Type "pmc-per-proc", for protecting PMC owner descriptors. * - Type "pmc-leaf", used for all other spin mutexes. */ /* * Save the CPU binding of the current kthread. */ void pmc_save_cpu_binding(struct pmc_binding *pb) { PMCDBG0(CPU,BND,2, "save-cpu"); thread_lock(curthread); pb->pb_bound = sched_is_bound(curthread); pb->pb_cpu = curthread->td_oncpu; pb->pb_priority = curthread->td_priority; thread_unlock(curthread); PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); } /* * Restore the CPU binding of the current thread. */ void pmc_restore_cpu_binding(struct pmc_binding *pb) { PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", curthread->td_oncpu, pb->pb_cpu); thread_lock(curthread); sched_bind(curthread, pb->pb_cpu); if (!pb->pb_bound) sched_unbind(curthread); sched_prio(curthread, pb->pb_priority); thread_unlock(curthread); PMCDBG0(CPU,BND,2, "restore-cpu done"); } /* * Move execution over to the specified CPU and bind it there. */ void pmc_select_cpu(int cpu) { KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); /* Never move to an inactive CPU. */ KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " "CPU %d", __LINE__, cpu)); PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); thread_lock(curthread); sched_prio(curthread, PRI_MIN); sched_bind(curthread, cpu); thread_unlock(curthread); KASSERT(curthread->td_oncpu == cpu, ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, cpu, curthread->td_oncpu)); PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); } /* * Force a context switch. * * We do this by pause'ing for 1 tick -- invoking mi_switch() is not * guaranteed to force a context switch. */ static void pmc_force_context_switch(void) { pause("pmcctx", 1); } uint64_t pmc_rdtsc(void) { #if defined(__i386__) || defined(__amd64__) if (__predict_true(amd_feature & AMDID_RDTSCP)) return (rdtscp()); else return (rdtsc()); #else return (get_cyclecount()); #endif } /* * Get the file name for an executable. This is a simple wrapper * around vn_fullpath(9). */ static void pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) { *fullpath = "unknown"; *freepath = NULL; vn_fullpath(v, fullpath, freepath); } /* * Remove a process owning PMCs. */ void pmc_remove_owner(struct pmc_owner *po) { struct pmc *pm, *tmp; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); /* Remove descriptor from the owner hash table */ LIST_REMOVE(po, po_next); /* release all owned PMC descriptors */ LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { PMCDBG1(OWN,ORM,2, "pmc=%p", pm); KASSERT(pm->pm_owner == po, ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); pmc_release_pmc_descriptor(pm); /* will unlink from the list */ pmc_destroy_pmc_descriptor(pm); } KASSERT(po->po_sscount == 0, ("[pmc,%d] SS count not zero", __LINE__)); KASSERT(LIST_EMPTY(&po->po_pmcs), ("[pmc,%d] PMC list not empty", __LINE__)); /* de-configure the log file if present */ if (po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_deconfigure_log(po); } /* * Remove an owner process record if all conditions are met. */ static void pmc_maybe_remove_owner(struct pmc_owner *po) { PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); /* * Remove owner record if * - this process does not own any PMCs * - this process has not allocated a system-wide sampling buffer */ if (LIST_EMPTY(&po->po_pmcs) && ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { pmc_remove_owner(po); pmc_destroy_owner_descriptor(po); } } /* * Add an association between a target process and a PMC. */ static void pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) { struct pmc_target *pt; struct pmc_thread *pt_td __diagused; int ri; sx_assert(&pmc_sx, SX_XLOCKED); KASSERT(pm != NULL && pp != NULL, ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", __LINE__, pm, pp->pp_proc->p_pid)); KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), ("[pmc,%d] Illegal reference count %d for process record %p", __LINE__, pp->pp_refcnt, (void *) pp)); ri = PMC_TO_ROWINDEX(pm); PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", pm, ri, pp); #ifdef HWPMC_DEBUG LIST_FOREACH(pt, &pm->pm_targets, pt_next) { if (pt->pt_process == pp) KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", __LINE__, pp, pm)); } #endif pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK | M_ZERO); pt->pt_process = pp; LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, (uintptr_t)pm); if (pm->pm_owner->po_owner == pp->pp_proc) pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; /* * Initialize the per-process values at this row index. */ pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? pm->pm_sc.pm_reloadcount : 0; pp->pp_refcnt++; #ifdef INVARIANTS /* Confirm that the per-thread values at this row index are cleared. */ if (PMC_TO_MODE(pm) == PMC_MODE_TS) { mtx_lock_spin(pp->pp_tdslock); LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, ("[pmc,%d] pt_pmcval not cleared for pid=%d at " "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); } mtx_unlock_spin(pp->pp_tdslock); } #endif } /* * Removes the association between a target process and a PMC. */ static void pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) { int ri; struct proc *p; struct pmc_target *ptgt; struct pmc_thread *pt; sx_assert(&pmc_sx, SX_XLOCKED); KASSERT(pm != NULL && pp != NULL, ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, ("[pmc,%d] Illegal ref count %d on process record %p", __LINE__, pp->pp_refcnt, (void *) pp)); ri = PMC_TO_ROWINDEX(pm); PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", pm, ri, pp); KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, ri, pm, pp->pp_pmcs[ri].pp_pmc)); pp->pp_pmcs[ri].pp_pmc = NULL; pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t)0; /* Clear the per-thread values at this row index. */ if (PMC_TO_MODE(pm) == PMC_MODE_TS) { mtx_lock_spin(pp->pp_tdslock); LIST_FOREACH(pt, &pp->pp_tds, pt_next) pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t)0; mtx_unlock_spin(pp->pp_tdslock); } /* Remove owner-specific flags */ if (pm->pm_owner->po_owner == pp->pp_proc) { pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; } pp->pp_refcnt--; /* Remove the target process from the PMC structure */ LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) if (ptgt->pt_process == pp) break; KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); LIST_REMOVE(ptgt, pt_next); free(ptgt, M_PMC); /* if the PMC now lacks targets, send the owner a SIGIO */ if (LIST_EMPTY(&pm->pm_targets)) { p = pm->pm_owner->po_owner; PROC_LOCK(p); kern_psignal(p, SIGIO); PROC_UNLOCK(p); PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, SIGIO); } } /* * Check if PMC 'pm' may be attached to target process 't'. */ static int pmc_can_attach(struct pmc *pm, struct proc *t) { struct proc *o; /* pmc owner */ struct ucred *oc, *tc; /* owner, target credentials */ int decline_attach, i; /* * A PMC's owner can always attach that PMC to itself. */ if ((o = pm->pm_owner->po_owner) == t) return 0; PROC_LOCK(o); oc = o->p_ucred; crhold(oc); PROC_UNLOCK(o); PROC_LOCK(t); tc = t->p_ucred; crhold(tc); PROC_UNLOCK(t); /* * The effective uid of the PMC owner should match at least one * of the {effective,real,saved} uids of the target process. */ decline_attach = oc->cr_uid != tc->cr_uid && oc->cr_uid != tc->cr_svuid && oc->cr_uid != tc->cr_ruid; /* * Every one of the target's group ids, must be in the owner's * group list. */ for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) decline_attach = !groupmember(tc->cr_groups[i], oc); /* check the read and saved gids too */ if (decline_attach == 0) decline_attach = !groupmember(tc->cr_rgid, oc) || !groupmember(tc->cr_svgid, oc); crfree(tc); crfree(oc); return !decline_attach; } /* * Attach a process to a PMC. */ static int pmc_attach_one_process(struct proc *p, struct pmc *pm) { int ri, error; char *fullpath, *freepath; struct pmc_process *pp; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); /* * Locate the process descriptor corresponding to process 'p', * allocating space as needed. * * Verify that rowindex 'pm_rowindex' is free in the process * descriptor. * * If not, allocate space for a descriptor and link the * process descriptor and PMC. */ ri = PMC_TO_ROWINDEX(pm); /* mark process as using HWPMCs */ PROC_LOCK(p); p->p_flag |= P_HWPMC; PROC_UNLOCK(p); if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { error = ENOMEM; goto fail; } if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ error = EEXIST; goto fail; } if (pp->pp_pmcs[ri].pp_pmc != NULL) { error = EBUSY; goto fail; } pmc_link_target_process(pm, pp); if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) pm->pm_flags |= PMC_F_NEEDS_LOGFILE; pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ /* issue an attach event to a configured log file */ if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { if (p->p_flag & P_KPROC) { fullpath = kernelname; freepath = NULL; } else { pmc_getfilename(p->p_textvp, &fullpath, &freepath); pmclog_process_pmcattach(pm, p->p_pid, fullpath); } free(freepath, M_TEMP); if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) pmc_log_process_mappings(pm->pm_owner, p); } return (0); fail: PROC_LOCK(p); p->p_flag &= ~P_HWPMC; PROC_UNLOCK(p); return (error); } /* * Attach a process and optionally its children */ static int pmc_attach_process(struct proc *p, struct pmc *pm) { int error; struct proc *top; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); /* * If this PMC successfully allowed a GETMSR operation * in the past, disallow further ATTACHes. */ if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) return (EPERM); if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) return (pmc_attach_one_process(p, pm)); /* * Traverse all child processes, attaching them to * this PMC. */ sx_slock(&proctree_lock); top = p; for (;;) { if ((error = pmc_attach_one_process(p, pm)) != 0) break; if (!LIST_EMPTY(&p->p_children)) p = LIST_FIRST(&p->p_children); else for (;;) { if (p == top) goto done; if (LIST_NEXT(p, p_sibling)) { p = LIST_NEXT(p, p_sibling); break; } p = p->p_pptr; } } if (error != 0) (void)pmc_detach_process(top, pm); done: sx_sunlock(&proctree_lock); return (error); } /* * Detach a process from a PMC. If there are no other PMCs tracking * this process, remove the process structure from its hash table. If * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. */ static int pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) { int ri; struct pmc_process *pp; sx_assert(&pmc_sx, SX_XLOCKED); KASSERT(pm != NULL, ("[pmc,%d] null pm pointer", __LINE__)); ri = PMC_TO_ROWINDEX(pm); PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", pm, ri, p, p->p_pid, p->p_comm, flags); if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) return (ESRCH); if (pp->pp_pmcs[ri].pp_pmc != pm) return (EINVAL); pmc_unlink_target_process(pm, pp); /* Issue a detach entry if a log file is configured */ if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_pmcdetach(pm, p->p_pid); /* * If there are no PMCs targeting this process, we remove its * descriptor from the target hash table and unset the P_HWPMC * flag in the struct proc. */ KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, ("[pmc,%d] Illegal refcnt %d for process struct %p", __LINE__, pp->pp_refcnt, pp)); if (pp->pp_refcnt != 0) /* still a target of some PMC */ return (0); pmc_remove_process_descriptor(pp); if (flags & PMC_FLAG_REMOVE) pmc_destroy_process_descriptor(pp); PROC_LOCK(p); p->p_flag &= ~P_HWPMC; PROC_UNLOCK(p); return (0); } /* * Detach a process and optionally its descendants from a PMC. */ static int pmc_detach_process(struct proc *p, struct pmc *pm) { struct proc *top; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) return (pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE)); /* * Traverse all children, detaching them from this PMC. We * ignore errors since we could be detaching a PMC from a * partially attached proc tree. */ sx_slock(&proctree_lock); top = p; for (;;) { (void)pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); if (!LIST_EMPTY(&p->p_children)) { p = LIST_FIRST(&p->p_children); } else { for (;;) { if (p == top) goto done; if (LIST_NEXT(p, p_sibling)) { p = LIST_NEXT(p, p_sibling); break; } p = p->p_pptr; } } } done: sx_sunlock(&proctree_lock); if (LIST_EMPTY(&pm->pm_targets)) pm->pm_flags &= ~PMC_F_ATTACH_DONE; return (0); } /* * Handle events after an exec() for a process: * - Inform log owners of the new exec() event * - Release any PMCs owned by the process before the exec() * - Detach PMCs from the target if required */ static void pmc_process_exec(struct thread *td, struct pmckern_procexec *pk) { struct pmc *pm; struct pmc_owner *po; struct pmc_process *pp; struct proc *p; char *fullpath, *freepath; u_int ri; bool is_using_hwpmcs; sx_assert(&pmc_sx, SX_XLOCKED); p = td->td_proc; pmc_getfilename(p->p_textvp, &fullpath, &freepath); PMC_EPOCH_ENTER(); /* Inform owners of SS mode PMCs of the exec event. */ CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { pmclog_process_procexec(po, PMC_ID_INVALID, p->p_pid, pk->pm_baseaddr, pk->pm_dynaddr, fullpath); } } PMC_EPOCH_EXIT(); PROC_LOCK(p); is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; PROC_UNLOCK(p); if (!is_using_hwpmcs) { if (freepath != NULL) free(freepath, M_TEMP); return; } /* * PMCs are not inherited across an exec(): remove any PMCs that this * process is the owner of. */ if ((po = pmc_find_owner_descriptor(p)) != NULL) { pmc_remove_owner(po); pmc_destroy_owner_descriptor(po); } /* * If the process being exec'ed is not the target of any PMC, we are * done. */ if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { if (freepath != NULL) free(freepath, M_TEMP); return; } /* * Log the exec event to all monitoring owners. Skip owners who have * already received the event because they had system sampling PMCs * active. */ for (ri = 0; ri < md->pmd_npmc; ri++) { if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) continue; po = pm->pm_owner; if (po->po_sscount == 0 && (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { pmclog_process_procexec(po, pm->pm_id, p->p_pid, pk->pm_baseaddr, pk->pm_dynaddr, fullpath); } } if (freepath != NULL) free(freepath, M_TEMP); PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", p, p->p_pid, p->p_comm, pk->pm_credentialschanged); if (pk->pm_credentialschanged == 0) /* no change */ return; /* * If the newly exec()'ed process has a different credential * than before, allow it to be the target of a PMC only if * the PMC's owner has sufficient privilege. */ for (ri = 0; ri < md->pmd_npmc; ri++) { if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { if (pmc_can_attach(pm, td->td_proc) != 0) { pmc_detach_one_process(td->td_proc, pm, PMC_FLAG_NONE); } } } KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= md->pmd_npmc, ("[pmc,%d] Illegal ref count %u on pp %p", __LINE__, pp->pp_refcnt, pp)); /* * If this process is no longer the target of any * PMCs, we can remove the process entry and free * up space. */ if (pp->pp_refcnt == 0) { pmc_remove_process_descriptor(pp); pmc_destroy_process_descriptor(pp); } } /* * Thread context switch IN. */ static void pmc_process_csw_in(struct thread *td) { struct pmc *pm; struct pmc_classdep *pcd; struct pmc_cpu *pc; struct pmc_hw *phw __diagused; struct pmc_process *pp; struct pmc_thread *pt; struct proc *p; pmc_value_t newvalue; int cpu; u_int adjri, ri; p = td->td_proc; pt = NULL; if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) return; KASSERT(pp->pp_proc == td->td_proc, ("[pmc,%d] not my thread state", __LINE__)); critical_enter(); /* no preemption from this point */ cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, p->p_pid, p->p_comm, pp); KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); pc = pmc_pcpu[cpu]; for (ri = 0; ri < md->pmd_npmc; ri++) { if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) continue; KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), ("[pmc,%d] Target PMC in non-virtual mode (%d)", __LINE__, PMC_TO_MODE(pm))); KASSERT(PMC_TO_ROWINDEX(pm) == ri, ("[pmc,%d] Row index mismatch pmc %d != ri %d", __LINE__, PMC_TO_ROWINDEX(pm), ri)); /* * Only PMCs that are marked as 'RUNNING' need * be placed on hardware. */ if (pm->pm_state != PMC_STATE_RUNNING) continue; KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); /* increment PMC runcount */ counter_u64_add(pm->pm_runcount, 1); /* configure the HWPMC we are going to use. */ pcd = pmc_ri_to_classdep(md, ri, &adjri); (void)pcd->pcd_config_pmc(cpu, adjri, pm); phw = pc->pc_hwpmcs[ri]; KASSERT(phw != NULL, ("[pmc,%d] null hw pointer", __LINE__)); KASSERT(phw->phw_pmc == pm, ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, phw->phw_pmc, pm)); /* * Write out saved value and start the PMC. * * Sampling PMCs use a per-thread value, while * counting mode PMCs use a per-pmc value that is * inherited across descendants. */ if (PMC_TO_MODE(pm) == PMC_MODE_TS) { if (pt == NULL) pt = pmc_find_thread_descriptor(pp, td, PMC_FLAG_NONE); KASSERT(pt != NULL, ("[pmc,%d] No thread found for td=%p", __LINE__, td)); mtx_pool_lock_spin(pmc_mtxpool, pm); /* * If we have a thread descriptor, use the per-thread * counter in the descriptor. If not, we will use * a per-process counter. * * TODO: Remove the per-process "safety net" once * we have thoroughly tested that we don't hit the * above assert. */ if (pt != NULL) { if (pt->pt_pmcs[ri].pt_pmcval > 0) newvalue = pt->pt_pmcs[ri].pt_pmcval; else newvalue = pm->pm_sc.pm_reloadcount; } else { /* * Use the saved value calculated after the most * recent time a thread using the shared counter * switched out. Reset the saved count in case * another thread from this process switches in * before any threads switch out. */ newvalue = pp->pp_pmcs[ri].pp_pmcval; pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount; } mtx_pool_unlock_spin(pmc_mtxpool, pm); KASSERT(newvalue > 0 && newvalue <= pm->pm_sc.pm_reloadcount, ("[pmc,%d] pmcval outside of expected range cpu=%d " "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); } else { KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, ("[pmc,%d] illegal mode=%d", __LINE__, PMC_TO_MODE(pm))); mtx_pool_lock_spin(pmc_mtxpool, pm); newvalue = PMC_PCPU_SAVED(cpu, ri) = pm->pm_gv.pm_savedvalue; mtx_pool_unlock_spin(pmc_mtxpool, pm); } PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); (void)pcd->pcd_write_pmc(cpu, adjri, pm, newvalue); /* If a sampling mode PMC, reset stalled state. */ if (PMC_TO_MODE(pm) == PMC_MODE_TS) pm->pm_pcpu_state[cpu].pps_stalled = 0; /* Indicate that we desire this to run. */ pm->pm_pcpu_state[cpu].pps_cpustate = 1; /* Start the PMC. */ (void)pcd->pcd_start_pmc(cpu, adjri, pm); } /* * Perform any other architecture/cpu dependent thread * switch-in actions. */ (void)(*md->pmd_switch_in)(pc, pp); critical_exit(); } /* * Thread context switch OUT. */ static void pmc_process_csw_out(struct thread *td) { struct pmc *pm; struct pmc_classdep *pcd; struct pmc_cpu *pc; struct pmc_process *pp; struct pmc_thread *pt = NULL; struct proc *p; pmc_value_t newvalue; int64_t tmp; enum pmc_mode mode; int cpu; u_int adjri, ri; /* * Locate our process descriptor; this may be NULL if * this process is exiting and we have already removed * the process from the target process table. * * Note that due to kernel preemption, multiple * context switches may happen while the process is * exiting. * * Note also that if the target process cannot be * found we still need to deconfigure any PMCs that * are currently running on hardware. */ p = td->td_proc; pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); critical_enter(); cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, p->p_pid, p->p_comm, pp); KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), ("[pmc,%d weird CPU id %d", __LINE__, cpu)); pc = pmc_pcpu[cpu]; /* * When a PMC gets unlinked from a target PMC, it will * be removed from the target's pp_pmc[] array. * * However, on a MP system, the target could have been * executing on another CPU at the time of the unlink. * So, at context switch OUT time, we need to look at * the hardware to determine if a PMC is scheduled on * it. */ for (ri = 0; ri < md->pmd_npmc; ri++) { pcd = pmc_ri_to_classdep(md, ri, &adjri); pm = NULL; (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); if (pm == NULL) /* nothing at this row index */ continue; mode = PMC_TO_MODE(pm); if (!PMC_IS_VIRTUAL_MODE(mode)) continue; /* not a process virtual PMC */ KASSERT(PMC_TO_ROWINDEX(pm) == ri, ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", __LINE__, PMC_TO_ROWINDEX(pm), ri)); /* * Change desired state, and then stop if not stalled. * This two-step dance should avoid race conditions where * an interrupt re-enables the PMC after this code has * already checked the pm_stalled flag. */ pm->pm_pcpu_state[cpu].pps_cpustate = 0; if (pm->pm_pcpu_state[cpu].pps_stalled == 0) (void)pcd->pcd_stop_pmc(cpu, adjri, pm); KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); /* reduce this PMC's runcount */ counter_u64_add(pm->pm_runcount, -1); /* * If this PMC is associated with this process, * save the reading. */ if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); KASSERT(pp->pp_refcnt > 0, ("[pmc,%d] pp refcnt = %d", __LINE__, pp->pp_refcnt)); (void)pcd->pcd_read_pmc(cpu, adjri, pm, &newvalue); if (mode == PMC_MODE_TS) { PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", cpu, ri, newvalue); if (pt == NULL) pt = pmc_find_thread_descriptor(pp, td, PMC_FLAG_NONE); KASSERT(pt != NULL, ("[pmc,%d] No thread found for td=%p", __LINE__, td)); mtx_pool_lock_spin(pmc_mtxpool, pm); /* * If we have a thread descriptor, save the * per-thread counter in the descriptor. If not, * we will update the per-process counter. * * TODO: Remove the per-process "safety net" * once we have thoroughly tested that we * don't hit the above assert. */ if (pt != NULL) { pt->pt_pmcs[ri].pt_pmcval = newvalue; } else { /* * For sampling process-virtual PMCs, * newvalue is the number of events to * be seen until the next sampling * interrupt. We can just add the events * left from this invocation to the * counter, then adjust in case we * overflow our range. * * (Recall that we reload the counter * every time we use it.) */ pp->pp_pmcs[ri].pp_pmcval += newvalue; if (pp->pp_pmcs[ri].pp_pmcval > pm->pm_sc.pm_reloadcount) { pp->pp_pmcs[ri].pp_pmcval -= pm->pm_sc.pm_reloadcount; } } mtx_pool_unlock_spin(pmc_mtxpool, pm); } else { tmp = newvalue - PMC_PCPU_SAVED(cpu, ri); PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", cpu, ri, tmp); /* * For counting process-virtual PMCs, * we expect the count to be * increasing monotonically, modulo a 64 * bit wraparound. */ KASSERT(tmp >= 0, ("[pmc,%d] negative increment cpu=%d " "ri=%d newvalue=%jx saved=%jx " "incr=%jx", __LINE__, cpu, ri, newvalue, PMC_PCPU_SAVED(cpu, ri), tmp)); mtx_pool_lock_spin(pmc_mtxpool, pm); pm->pm_gv.pm_savedvalue += tmp; pp->pp_pmcs[ri].pp_pmcval += tmp; mtx_pool_unlock_spin(pmc_mtxpool, pm); if (pm->pm_flags & PMC_F_LOG_PROCCSW) pmclog_process_proccsw(pm, pp, tmp, td); } } /* Mark hardware as free. */ (void)pcd->pcd_config_pmc(cpu, adjri, NULL); } /* * Perform any other architecture/cpu dependent thread * switch out functions. */ (void)(*md->pmd_switch_out)(pc, pp); critical_exit(); } /* * A new thread for a process. */ static void pmc_process_thread_add(struct thread *td) { struct pmc_process *pmc; pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); if (pmc != NULL) pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); } /* * A thread delete for a process. */ static void pmc_process_thread_delete(struct thread *td) { struct pmc_process *pmc; pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); if (pmc != NULL) pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, td, PMC_FLAG_REMOVE)); } /* * A userret() call for a thread. */ static void pmc_process_thread_userret(struct thread *td) { sched_pin(); pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); sched_unpin(); } /* * A mapping change for a process. */ static void pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) { const struct pmc *pm; const struct pmc_process *pp; struct pmc_owner *po; char *fullpath, *freepath; pid_t pid; int ri; MPASS(!in_epoch(global_epoch_preempt)); freepath = fullpath = NULL; pmc_getfilename((struct vnode *)pkm->pm_file, &fullpath, &freepath); pid = td->td_proc->p_pid; PMC_EPOCH_ENTER(); /* Inform owners of all system-wide sampling PMCs. */ CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if (po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); } if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) goto done; /* * Inform sampling PMC owners tracking this process. */ for (ri = 0; ri < md->pmd_npmc; ri++) { if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { pmclog_process_map_in(pm->pm_owner, pid, pkm->pm_address, fullpath); } } done: if (freepath != NULL) free(freepath, M_TEMP); PMC_EPOCH_EXIT(); } /* * Log an munmap request. */ static void pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) { const struct pmc *pm; const struct pmc_process *pp; struct pmc_owner *po; pid_t pid; int ri; pid = td->td_proc->p_pid; PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if (po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_map_out(po, pid, pkm->pm_address, pkm->pm_address + pkm->pm_size); } PMC_EPOCH_EXIT(); if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) return; for (ri = 0; ri < md->pmd_npmc; ri++) { pm = pp->pp_pmcs[ri].pp_pmc; if (pm != NULL && PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { pmclog_process_map_out(pm->pm_owner, pid, pkm->pm_address, pkm->pm_address + pkm->pm_size); } } } /* * Log mapping information about the kernel. */ static void pmc_log_kernel_mappings(struct pmc *pm) { struct pmc_owner *po; struct pmckern_map_in *km, *kmbase; MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), ("[pmc,%d] non-sampling PMC (%p) desires mapping information", __LINE__, (void *) pm)); po = pm->pm_owner; if ((po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) != 0) return; if (PMC_TO_MODE(pm) == PMC_MODE_SS) pmc_process_allproc(pm); /* * Log the current set of kernel modules. */ kmbase = linker_hwpmc_list_objects(); for (km = kmbase; km->pm_file != NULL; km++) { PMCDBG2(LOG,REG,1,"%s %p", (char *)km->pm_file, (void *)km->pm_address); pmclog_process_map_in(po, (pid_t)-1, km->pm_address, km->pm_file); } free(kmbase, M_LINKER); po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; } /* * Log the mappings for a single process. */ static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) { vm_map_t map; vm_map_entry_t entry; vm_object_t obj, lobj, tobj; vm_offset_t last_end; vm_offset_t start_addr; struct vnode *vp, *last_vp; struct vmspace *vm; char *fullpath, *freepath; u_int last_timestamp; last_vp = NULL; last_end = (vm_offset_t)0; fullpath = freepath = NULL; if ((vm = vmspace_acquire_ref(p)) == NULL) return; map = &vm->vm_map; vm_map_lock_read(map); VM_MAP_ENTRY_FOREACH(entry, map) { if (entry == NULL) { PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " "NULL! pid=%d vm_map=%p\n", p->p_pid, map); break; } /* * We only care about executable map entries. */ if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || (entry->protection & VM_PROT_EXECUTE) == 0 || entry->object.vm_object == NULL) { continue; } obj = entry->object.vm_object; VM_OBJECT_RLOCK(obj); /* * Walk the backing_object list to find the base (non-shadowed) * vm_object. */ for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { if (tobj != obj) VM_OBJECT_RLOCK(tobj); if (lobj != obj) VM_OBJECT_RUNLOCK(lobj); lobj = tobj; } /* * At this point lobj is the base vm_object and it is locked. */ if (lobj == NULL) { PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); VM_OBJECT_RUNLOCK(obj); continue; } vp = vm_object_vnode(lobj); if (vp == NULL) { if (lobj != obj) VM_OBJECT_RUNLOCK(lobj); VM_OBJECT_RUNLOCK(obj); continue; } /* * Skip contiguous regions that point to the same vnode, so we * don't emit redundant MAP-IN directives. */ if (entry->start == last_end && vp == last_vp) { last_end = entry->end; if (lobj != obj) VM_OBJECT_RUNLOCK(lobj); VM_OBJECT_RUNLOCK(obj); continue; } /* * We don't want to keep the proc's vm_map or this vm_object * locked while we walk the pathname, since vn_fullpath() can * sleep. However, if we drop the lock, it's possible for * concurrent activity to modify the vm_map list. To protect * against this, we save the vm_map timestamp before we release * the lock, and check it after we reacquire the lock below. */ start_addr = entry->start; last_end = entry->end; last_timestamp = map->timestamp; vm_map_unlock_read(map); vref(vp); if (lobj != obj) VM_OBJECT_RUNLOCK(lobj); VM_OBJECT_RUNLOCK(obj); freepath = NULL; pmc_getfilename(vp, &fullpath, &freepath); last_vp = vp; vrele(vp); vp = NULL; pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); if (freepath != NULL) free(freepath, M_TEMP); vm_map_lock_read(map); /* * If our saved timestamp doesn't match, this means * that the vm_map was modified out from under us and * we can't trust our current "entry" pointer. Do a * new lookup for this entry. If there is no entry * for this address range, vm_map_lookup_entry() will * return the previous one, so we always want to go to * the next entry on the next loop iteration. * * There is an edge condition here that can occur if * there is no entry at or before this address. In * this situation, vm_map_lookup_entry returns * &map->header, which would cause our loop to abort * without processing the rest of the map. However, * in practice this will never happen for process * vm_map. This is because the executable's text * segment is the first mapping in the proc's address * space, and this mapping is never removed until the * process exits, so there will always be a non-header * entry at or before the requested address for * vm_map_lookup_entry to return. */ if (map->timestamp != last_timestamp) vm_map_lookup_entry(map, last_end - 1, &entry); } vm_map_unlock_read(map); vmspace_free(vm); return; } /* * Log mappings for all processes in the system. */ static void pmc_log_all_process_mappings(struct pmc_owner *po) { struct proc *p, *top; sx_assert(&pmc_sx, SX_XLOCKED); if ((p = pfind(1)) == NULL) panic("[pmc,%d] Cannot find init", __LINE__); PROC_UNLOCK(p); sx_slock(&proctree_lock); top = p; for (;;) { pmc_log_process_mappings(po, p); if (!LIST_EMPTY(&p->p_children)) p = LIST_FIRST(&p->p_children); else for (;;) { if (p == top) goto done; if (LIST_NEXT(p, p_sibling)) { p = LIST_NEXT(p, p_sibling); break; } p = p->p_pptr; } } done: sx_sunlock(&proctree_lock); } #ifdef HWPMC_DEBUG const char *pmc_hooknames[] = { /* these strings correspond to PMC_FN_* in */ "", "EXEC", "CSW-IN", "CSW-OUT", "SAMPLE", "UNUSED1", "UNUSED2", "MMAP", "MUNMAP", "CALLCHAIN-NMI", "CALLCHAIN-SOFT", "SOFTSAMPLING", "THR-CREATE", "THR-EXIT", "THR-USERRET", "THR-CREATE-LOG", "THR-EXIT-LOG", "PROC-CREATE-LOG" }; #endif /* * The 'hook' invoked from the kernel proper */ static int pmc_hook_handler(struct thread *td, int function, void *arg) { int cpu; PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, pmc_hooknames[function], arg); switch (function) { case PMC_FN_PROCESS_EXEC: pmc_process_exec(td, (struct pmckern_procexec *)arg); break; case PMC_FN_CSW_IN: pmc_process_csw_in(td); break; case PMC_FN_CSW_OUT: pmc_process_csw_out(td); break; /* * Process accumulated PC samples. * * This function is expected to be called by hardclock() for * each CPU that has accumulated PC samples. * * This function is to be executed on the CPU whose samples * are being processed. */ case PMC_FN_DO_SAMPLES: /* * Clear the cpu specific bit in the CPU mask before * do the rest of the processing. If the NMI handler * gets invoked after the "atomic_clear_int()" call * below but before "pmc_process_samples()" gets * around to processing the interrupt, then we will * come back here at the next hardclock() tick (and * may find nothing to do if "pmc_process_samples()" * had already processed the interrupt). We don't * lose the interrupt sample. */ DPCPU_SET(pmc_sampled, 0); cpu = PCPU_GET(cpuid); pmc_process_samples(cpu, PMC_HR); pmc_process_samples(cpu, PMC_SR); pmc_process_samples(cpu, PMC_UR); break; case PMC_FN_MMAP: pmc_process_mmap(td, (struct pmckern_map_in *)arg); break; case PMC_FN_MUNMAP: MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); pmc_process_munmap(td, (struct pmckern_map_out *)arg); break; case PMC_FN_PROC_CREATE_LOG: pmc_process_proccreate((struct proc *)arg); break; case PMC_FN_USER_CALLCHAIN: /* * Record a call chain. */ KASSERT(td == curthread, ("[pmc,%d] td != curthread", __LINE__)); pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, (struct trapframe *)arg); KASSERT(td->td_pinned == 1, ("[pmc,%d] invalid td_pinned value", __LINE__)); sched_unpin(); /* Can migrate safely now. */ td->td_pflags &= ~TDP_CALLCHAIN; break; case PMC_FN_USER_CALLCHAIN_SOFT: /* * Record a call chain. */ KASSERT(td == curthread, ("[pmc,%d] td != curthread", __LINE__)); cpu = PCPU_GET(cpuid); pmc_capture_user_callchain(cpu, PMC_SR, (struct trapframe *) arg); KASSERT(td->td_pinned == 1, ("[pmc,%d] invalid td_pinned value", __LINE__)); sched_unpin(); /* Can migrate safely now. */ td->td_pflags &= ~TDP_CALLCHAIN; break; case PMC_FN_SOFT_SAMPLING: /* * Call soft PMC sampling intr. */ pmc_soft_intr((struct pmckern_soft *)arg); break; case PMC_FN_THR_CREATE: pmc_process_thread_add(td); pmc_process_threadcreate(td); break; case PMC_FN_THR_CREATE_LOG: pmc_process_threadcreate(td); break; case PMC_FN_THR_EXIT: KASSERT(td == curthread, ("[pmc,%d] td != curthread", __LINE__)); pmc_process_thread_delete(td); pmc_process_threadexit(td); break; case PMC_FN_THR_EXIT_LOG: pmc_process_threadexit(td); break; case PMC_FN_THR_USERRET: KASSERT(td == curthread, ("[pmc,%d] td != curthread", __LINE__)); pmc_process_thread_userret(td); break; default: #ifdef HWPMC_DEBUG KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); #endif break; } return (0); } /* * Allocate a 'struct pmc_owner' descriptor in the owner hash table. */ static struct pmc_owner * pmc_allocate_owner_descriptor(struct proc *p) { struct pmc_owner *po; struct pmc_ownerhash *poh; uint32_t hindex; hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); poh = &pmc_ownerhash[hindex]; /* Allocate space for N pointers and one descriptor struct. */ po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK | M_ZERO); po->po_owner = p; LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ TAILQ_INIT(&po->po_logbuffers); mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", p, p->p_pid, p->p_comm, po); return (po); } static void pmc_destroy_owner_descriptor(struct pmc_owner *po) { PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); mtx_destroy(&po->po_mtx); free(po, M_PMC); } /* * Allocate a thread descriptor from the free pool. * * NOTE: This *can* return NULL. */ static struct pmc_thread * pmc_thread_descriptor_pool_alloc(void) { struct pmc_thread *pt; mtx_lock_spin(&pmc_threadfreelist_mtx); if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { LIST_REMOVE(pt, pt_next); pmc_threadfreelist_entries--; } mtx_unlock_spin(&pmc_threadfreelist_mtx); return (pt); } /* * Add a thread descriptor to the free pool. We use this instead of free() * to maintain a cache of free entries. Additionally, we can safely call * this function when we cannot call free(), such as in a critical section. */ static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt) { if (pt == NULL) return; memset(pt, 0, THREADENTRY_SIZE); mtx_lock_spin(&pmc_threadfreelist_mtx); LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); pmc_threadfreelist_entries++; if (pmc_threadfreelist_entries > pmc_threadfreelist_max) taskqueue_enqueue(taskqueue_fast, &free_task); mtx_unlock_spin(&pmc_threadfreelist_mtx); } /* * An asynchronous task to manage the free list. */ static void pmc_thread_descriptor_pool_free_task(void *arg __unused, int pending __unused) { struct pmc_thread *pt; LIST_HEAD(, pmc_thread) tmplist; int delta; LIST_INIT(&tmplist); /* Determine what changes, if any, we need to make. */ mtx_lock_spin(&pmc_threadfreelist_mtx); delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; while (delta > 0 && (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { delta--; pmc_threadfreelist_entries--; LIST_REMOVE(pt, pt_next); LIST_INSERT_HEAD(&tmplist, pt, pt_next); } mtx_unlock_spin(&pmc_threadfreelist_mtx); /* If there are entries to free, free them. */ while (!LIST_EMPTY(&tmplist)) { pt = LIST_FIRST(&tmplist); LIST_REMOVE(pt, pt_next); free(pt, M_PMC); } } /* * Drain the thread free pool, freeing all allocations. */ static void pmc_thread_descriptor_pool_drain(void) { struct pmc_thread *pt, *next; LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { LIST_REMOVE(pt, pt_next); free(pt, M_PMC); } } /* * find the descriptor corresponding to thread 'td', adding or removing it * as specified by 'mode'. * * Note that this supports additional mode flags in addition to those * supported by pmc_find_process_descriptor(): * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. * This makes it safe to call while holding certain other locks. */ static struct pmc_thread * pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, uint32_t mode) { struct pmc_thread *pt = NULL, *ptnew = NULL; int wait_flag; KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); /* * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to * acquiring the lock. */ if ((mode & PMC_FLAG_ALLOCATE) != 0) { if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { wait_flag = M_WAITOK; if ((mode & PMC_FLAG_NOWAIT) != 0 || in_epoch(global_epoch_preempt)) wait_flag = M_NOWAIT; ptnew = malloc(THREADENTRY_SIZE, M_PMC, wait_flag | M_ZERO); } } mtx_lock_spin(pp->pp_tdslock); LIST_FOREACH(pt, &pp->pp_tds, pt_next) { if (pt->pt_td == td) break; } if ((mode & PMC_FLAG_REMOVE) != 0 && pt != NULL) LIST_REMOVE(pt, pt_next); if ((mode & PMC_FLAG_ALLOCATE) != 0 && pt == NULL && ptnew != NULL) { pt = ptnew; ptnew = NULL; pt->pt_td = td; LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); } mtx_unlock_spin(pp->pp_tdslock); if (ptnew != NULL) { free(ptnew, M_PMC); } return (pt); } /* * Try to add thread descriptors for each thread in a process. */ static void pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) { struct pmc_thread **tdlist; struct thread *curtd; int i, tdcnt, tdlistsz; KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", __LINE__)); tdcnt = 32; restart: tdlistsz = roundup2(tdcnt, 32); tdcnt = 0; tdlist = malloc(sizeof(struct pmc_thread *) * tdlistsz, M_TEMP, M_WAITOK); PROC_LOCK(p); FOREACH_THREAD_IN_PROC(p, curtd) tdcnt++; if (tdcnt >= tdlistsz) { PROC_UNLOCK(p); free(tdlist, M_TEMP); goto restart; } /* * Try to add each thread to the list without sleeping. If unable, * add to a queue to retry after dropping the process lock. */ tdcnt = 0; FOREACH_THREAD_IN_PROC(p, curtd) { tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, PMC_FLAG_ALLOCATE | PMC_FLAG_NOWAIT); if (tdlist[tdcnt] == NULL) { PROC_UNLOCK(p); for (i = 0; i <= tdcnt; i++) pmc_thread_descriptor_pool_free(tdlist[i]); free(tdlist, M_TEMP); goto restart; } tdcnt++; } PROC_UNLOCK(p); free(tdlist, M_TEMP); } /* * Find the descriptor corresponding to process 'p', adding or removing it * as specified by 'mode'. */ static struct pmc_process * pmc_find_process_descriptor(struct proc *p, uint32_t mode) { struct pmc_process *pp, *ppnew; struct pmc_processhash *pph; uint32_t hindex; hindex = PMC_HASH_PTR(p, pmc_processhashmask); pph = &pmc_processhash[hindex]; ppnew = NULL; /* * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we * cannot call malloc(9) once we hold a spin lock. */ if ((mode & PMC_FLAG_ALLOCATE) != 0) ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * sizeof(struct pmc_targetstate), M_PMC, M_WAITOK | M_ZERO); mtx_lock_spin(&pmc_processhash_mtx); LIST_FOREACH(pp, pph, pp_next) { if (pp->pp_proc == p) break; } if ((mode & PMC_FLAG_REMOVE) != 0 && pp != NULL) LIST_REMOVE(pp, pp_next); if ((mode & PMC_FLAG_ALLOCATE) != 0 && pp == NULL && ppnew != NULL) { ppnew->pp_proc = p; LIST_INIT(&ppnew->pp_tds); ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); LIST_INSERT_HEAD(pph, ppnew, pp_next); mtx_unlock_spin(&pmc_processhash_mtx); pp = ppnew; ppnew = NULL; /* Add thread descriptors for this process' current threads. */ pmc_add_thread_descriptors_from_proc(p, pp); } else mtx_unlock_spin(&pmc_processhash_mtx); if (ppnew != NULL) free(ppnew, M_PMC); return (pp); } /* * Remove a process descriptor from the process hash table. */ static void pmc_remove_process_descriptor(struct pmc_process *pp) { KASSERT(pp->pp_refcnt == 0, ("[pmc,%d] Removing process descriptor %p with count %d", __LINE__, pp, pp->pp_refcnt)); mtx_lock_spin(&pmc_processhash_mtx); LIST_REMOVE(pp, pp_next); mtx_unlock_spin(&pmc_processhash_mtx); } /* * Destroy a process descriptor. */ static void pmc_destroy_process_descriptor(struct pmc_process *pp) { struct pmc_thread *pmc_td; while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { LIST_REMOVE(pmc_td, pt_next); pmc_thread_descriptor_pool_free(pmc_td); } free(pp, M_PMC); } /* * Find an owner descriptor corresponding to proc 'p'. */ static struct pmc_owner * pmc_find_owner_descriptor(struct proc *p) { struct pmc_owner *po; struct pmc_ownerhash *poh; uint32_t hindex; hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); poh = &pmc_ownerhash[hindex]; po = NULL; LIST_FOREACH(po, poh, po_next) { if (po->po_owner == p) break; } PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); return (po); } /* * Allocate a pmc descriptor and initialize its fields. */ static struct pmc * pmc_allocate_pmc_descriptor(void) { struct pmc *pmc; pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK | M_ZERO); pmc->pm_runcount = counter_u64_alloc(M_WAITOK); pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state) * mp_ncpus, M_PMC, M_WAITOK | M_ZERO); PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); return (pmc); } /* * Destroy a pmc descriptor. */ static void pmc_destroy_pmc_descriptor(struct pmc *pm) { KASSERT(pm->pm_state == PMC_STATE_DELETED || pm->pm_state == PMC_STATE_FREE, ("[pmc,%d] destroying non-deleted PMC", __LINE__)); KASSERT(LIST_EMPTY(&pm->pm_targets), ("[pmc,%d] destroying pmc with targets", __LINE__)); KASSERT(pm->pm_owner == NULL, ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, ("[pmc,%d] pmc has non-zero run count %ju", __LINE__, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); counter_u64_free(pm->pm_runcount); free(pm->pm_pcpu_state, M_PMC); free(pm, M_PMC); } static void pmc_wait_for_pmc_idle(struct pmc *pm) { #ifdef INVARIANTS volatile int maxloop; maxloop = 100 * pmc_cpu_max(); #endif /* * Loop (with a forced context switch) till the PMC's runcount * comes down to zero. */ pmclog_flush(pm->pm_owner, 1); while (counter_u64_fetch(pm->pm_runcount) > 0) { pmclog_flush(pm->pm_owner, 1); #ifdef INVARIANTS maxloop--; KASSERT(maxloop > 0, ("[pmc,%d] (ri%d, rc%ju) waiting too long for " "pmc to be free", __LINE__, PMC_TO_ROWINDEX(pm), (uintmax_t)counter_u64_fetch(pm->pm_runcount))); #endif pmc_force_context_switch(); } } /* * This function does the following things: * * - detaches the PMC from hardware * - unlinks all target threads that were attached to it * - removes the PMC from its owner's list * - destroys the PMC private mutex * * Once this function completes, the given pmc pointer can be freed by * calling pmc_destroy_pmc_descriptor(). */ static void pmc_release_pmc_descriptor(struct pmc *pm) { struct pmc_binding pb; struct pmc_classdep *pcd; struct pmc_hw *phw __diagused; struct pmc_owner *po; struct pmc_process *pp; struct pmc_target *ptgt, *tmp; enum pmc_mode mode; u_int adjri, ri, cpu; sx_assert(&pmc_sx, SX_XLOCKED); KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); ri = PMC_TO_ROWINDEX(pm); pcd = pmc_ri_to_classdep(md, ri, &adjri); mode = PMC_TO_MODE(pm); PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, mode); /* * First, we take the PMC off hardware. */ cpu = 0; if (PMC_IS_SYSTEM_MODE(mode)) { /* * A system mode PMC runs on a specific CPU. Switch * to this CPU and turn hardware off. */ pmc_save_cpu_binding(&pb); cpu = PMC_TO_CPU(pm); pmc_select_cpu(cpu); /* switch off non-stalled CPUs */ pm->pm_pcpu_state[cpu].pps_cpustate = 0; if (pm->pm_state == PMC_STATE_RUNNING && pm->pm_pcpu_state[cpu].pps_stalled == 0) { phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; KASSERT(phw->phw_pmc == pm, ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", __LINE__, ri, phw->phw_pmc, pm)); PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); critical_enter(); (void)pcd->pcd_stop_pmc(cpu, adjri, pm); critical_exit(); } PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); critical_enter(); (void)pcd->pcd_config_pmc(cpu, adjri, NULL); critical_exit(); /* adjust the global and process count of SS mode PMCs */ if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { po = pm->pm_owner; po->po_sscount--; if (po->po_sscount == 0) { atomic_subtract_rel_int(&pmc_ss_count, 1); CK_LIST_REMOVE(po, po_ssnext); epoch_wait_preempt(global_epoch_preempt); } } pm->pm_state = PMC_STATE_DELETED; pmc_restore_cpu_binding(&pb); /* * We could have references to this PMC structure in the * per-cpu sample queues. Wait for the queue to drain. */ pmc_wait_for_pmc_idle(pm); } else if (PMC_IS_VIRTUAL_MODE(mode)) { /* * A virtual PMC could be running on multiple CPUs at a given * instant. * * By marking its state as DELETED, we ensure that this PMC is * never further scheduled on hardware. * * Then we wait till all CPUs are done with this PMC. */ pm->pm_state = PMC_STATE_DELETED; /* Wait for the PMCs runcount to come to zero. */ pmc_wait_for_pmc_idle(pm); /* * At this point the PMC is off all CPUs and cannot be freshly * scheduled onto a CPU. It is now safe to unlink all targets * from this PMC. If a process-record's refcount falls to zero, * we remove it from the hash table. The module-wide SX lock * protects us from races. */ LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { pp = ptgt->pt_process; pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); /* * If the target process record shows that no PMCs are * attached to it, reclaim its space. */ if (pp->pp_refcnt == 0) { pmc_remove_process_descriptor(pp); pmc_destroy_process_descriptor(pp); } } cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ } /* * Release any MD resources. */ (void)pcd->pcd_release_pmc(cpu, adjri, pm); /* * Update row disposition. */ if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) PMC_UNMARK_ROW_STANDALONE(ri); else PMC_UNMARK_ROW_THREAD(ri); /* Unlink from the owner's list. */ if (pm->pm_owner != NULL) { LIST_REMOVE(pm, pm_next); pm->pm_owner = NULL; } } /* * Register an owner and a pmc. */ static int pmc_register_owner(struct proc *p, struct pmc *pmc) { struct pmc_owner *po; sx_assert(&pmc_sx, SX_XLOCKED); if ((po = pmc_find_owner_descriptor(p)) == NULL) { if ((po = pmc_allocate_owner_descriptor(p)) == NULL) return (ENOMEM); } KASSERT(pmc->pm_owner == NULL, ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); pmc->pm_owner = po; LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); PROC_LOCK(p); p->p_flag |= P_HWPMC; PROC_UNLOCK(p); if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) pmclog_process_pmcallocate(pmc); PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", po, pmc); return (0); } /* * Return the current row disposition: * == 0 => FREE * > 0 => PROCESS MODE * < 0 => SYSTEM MODE */ int pmc_getrowdisp(int ri) { return (pmc_pmcdisp[ri]); } /* * Check if a PMC at row index 'ri' can be allocated to the current * process. * * Allocation can fail if: * - the current process is already being profiled by a PMC at index 'ri', * attached to it via OP_PMCATTACH. * - the current process has already allocated a PMC at index 'ri' * via OP_ALLOCATE. */ static bool pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) { struct pmc *pm; struct pmc_owner *po; struct pmc_process *pp; enum pmc_mode mode; PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); /* * We shouldn't have already allocated a process-mode PMC at * row index 'ri'. * * We shouldn't have allocated a system-wide PMC on the same * CPU and same RI. */ if ((po = pmc_find_owner_descriptor(p)) != NULL) { LIST_FOREACH(pm, &po->po_pmcs, pm_next) { if (PMC_TO_ROWINDEX(pm) == ri) { mode = PMC_TO_MODE(pm); if (PMC_IS_VIRTUAL_MODE(mode)) return (false); if (PMC_IS_SYSTEM_MODE(mode) && PMC_TO_CPU(pm) == cpu) return (false); } } } /* * We also shouldn't be the target of any PMC at this index * since otherwise a PMC_ATTACH to ourselves will fail. */ if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) if (pp->pp_pmcs[ri].pp_pmc != NULL) return (false); PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", p, p->p_pid, p->p_comm, ri); return (true); } /* * Check if a given PMC at row index 'ri' can be currently used in * mode 'mode'. */ static bool pmc_can_allocate_row(int ri, enum pmc_mode mode) { enum pmc_disp disp; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); if (PMC_IS_SYSTEM_MODE(mode)) disp = PMC_DISP_STANDALONE; else disp = PMC_DISP_THREAD; /* * check disposition for PMC row 'ri': * * Expected disposition Row-disposition Result * * STANDALONE STANDALONE or FREE proceed * STANDALONE THREAD fail * THREAD THREAD or FREE proceed * THREAD STANDALONE fail */ if (!PMC_ROW_DISP_IS_FREE(ri) && !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) return (false); /* * All OK */ PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); return (true); } /* * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. */ static struct pmc * pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) { struct pmc *pm; KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); LIST_FOREACH(pm, &po->po_pmcs, pm_next) { if (pm->pm_id == pmcid) return (pm); } return (NULL); } static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) { struct pmc *pm, *opm; struct pmc_owner *po; struct pmc_process *pp; PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) return (EINVAL); if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { /* * In case of PMC_F_DESCENDANTS child processes we will not find * the current process in the owners hash list. Find the owner * process first and from there lookup the po. */ pp = pmc_find_process_descriptor(curthread->td_proc, PMC_FLAG_NONE); if (pp == NULL) return (ESRCH); opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; if (opm == NULL) return (ESRCH); if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) return (ESRCH); po = opm->pm_owner; } if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) return (EINVAL); PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); *pmc = pm; return (0); } /* * Start a PMC. */ static int pmc_start(struct pmc *pm) { struct pmc_binding pb; struct pmc_classdep *pcd; struct pmc_owner *po; pmc_value_t v; enum pmc_mode mode; int adjri, error, cpu, ri; KASSERT(pm != NULL, ("[pmc,%d] null pm", __LINE__)); mode = PMC_TO_MODE(pm); ri = PMC_TO_ROWINDEX(pm); pcd = pmc_ri_to_classdep(md, ri, &adjri); error = 0; po = pm->pm_owner; PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); po = pm->pm_owner; /* * Disallow PMCSTART if a logfile is required but has not been * configured yet. */ if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) return (EDOOFUS); /* programming error */ /* * If this is a sampling mode PMC, log mapping information for * the kernel modules that are currently loaded. */ if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) pmc_log_kernel_mappings(pm); if (PMC_IS_VIRTUAL_MODE(mode)) { /* * If a PMCATTACH has never been done on this PMC, * attach it to its owner process. */ if (LIST_EMPTY(&pm->pm_targets)) { error = (pm->pm_flags & PMC_F_ATTACH_DONE) != 0 ? ESRCH : pmc_attach_process(po->po_owner, pm); } /* * If the PMC is attached to its owner, then force a context * switch to ensure that the MD state gets set correctly. */ if (error == 0) { pm->pm_state = PMC_STATE_RUNNING; if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) != 0) pmc_force_context_switch(); } return (error); } /* * A system-wide PMC. * * Add the owner to the global list if this is a system-wide * sampling PMC. */ if (mode == PMC_MODE_SS) { /* * Log mapping information for all existing processes in the * system. Subsequent mappings are logged as they happen; * see pmc_process_mmap(). */ if (po->po_logprocmaps == 0) { pmc_log_all_process_mappings(po); po->po_logprocmaps = 1; } po->po_sscount++; if (po->po_sscount == 1) { atomic_add_rel_int(&pmc_ss_count, 1); CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); PMCDBG1(PMC,OPS,1, "po=%p in global list", po); } } /* * Move to the CPU associated with this * PMC, and start the hardware. */ pmc_save_cpu_binding(&pb); cpu = PMC_TO_CPU(pm); if (!pmc_cpu_is_active(cpu)) return (ENXIO); pmc_select_cpu(cpu); /* * global PMCs are configured at allocation time * so write out the initial value and start the PMC. */ pm->pm_state = PMC_STATE_RUNNING; critical_enter(); v = PMC_IS_SAMPLING_MODE(mode) ? pm->pm_sc.pm_reloadcount : pm->pm_sc.pm_initial; if ((error = pcd->pcd_write_pmc(cpu, adjri, pm, v)) == 0) { /* If a sampling mode PMC, reset stalled state. */ if (PMC_IS_SAMPLING_MODE(mode)) pm->pm_pcpu_state[cpu].pps_stalled = 0; /* Indicate that we desire this to run. Start it. */ pm->pm_pcpu_state[cpu].pps_cpustate = 1; error = pcd->pcd_start_pmc(cpu, adjri, pm); } critical_exit(); pmc_restore_cpu_binding(&pb); return (error); } /* * Stop a PMC. */ static int pmc_stop(struct pmc *pm) { struct pmc_binding pb; struct pmc_classdep *pcd; struct pmc_owner *po; int adjri, cpu, error, ri; KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); pm->pm_state = PMC_STATE_STOPPED; /* * If the PMC is a virtual mode one, changing the state to non-RUNNING * is enough to ensure that the PMC never gets scheduled. * * If this PMC is current running on a CPU, then it will handled * correctly at the time its target process is context switched out. */ if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) return (0); /* * A system-mode PMC. Move to the CPU associated with this PMC, and * stop the hardware. We update the 'initial count' so that a * subsequent PMCSTART will resume counting from the current hardware * count. */ pmc_save_cpu_binding(&pb); cpu = PMC_TO_CPU(pm); KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); if (!pmc_cpu_is_active(cpu)) return (ENXIO); pmc_select_cpu(cpu); ri = PMC_TO_ROWINDEX(pm); pcd = pmc_ri_to_classdep(md, ri, &adjri); pm->pm_pcpu_state[cpu].pps_cpustate = 0; critical_enter(); if ((error = pcd->pcd_stop_pmc(cpu, adjri, pm)) == 0) { error = pcd->pcd_read_pmc(cpu, adjri, pm, &pm->pm_sc.pm_initial); } critical_exit(); pmc_restore_cpu_binding(&pb); /* Remove this owner from the global list of SS PMC owners. */ po = pm->pm_owner; if (PMC_TO_MODE(pm) == PMC_MODE_SS) { po->po_sscount--; if (po->po_sscount == 0) { atomic_subtract_rel_int(&pmc_ss_count, 1); CK_LIST_REMOVE(po, po_ssnext); epoch_wait_preempt(global_epoch_preempt); PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); } } return (error); } static struct pmc_classdep * pmc_class_to_classdep(enum pmc_class class) { int n; for (n = 0; n < md->pmd_nclass; n++) { if (md->pmd_classdep[n].pcd_class == class) return (&md->pmd_classdep[n]); } return (NULL); } #if defined(HWPMC_DEBUG) && defined(KTR) static const char *pmc_op_to_name[] = { #undef __PMC_OP #define __PMC_OP(N, D) #N , __PMC_OPS() NULL }; #endif /* * The syscall interface */ #define PMC_GET_SX_XLOCK(...) do { \ sx_xlock(&pmc_sx); \ if (pmc_hook == NULL) { \ sx_xunlock(&pmc_sx); \ return __VA_ARGS__; \ } \ } while (0) #define PMC_DOWNGRADE_SX() do { \ sx_downgrade(&pmc_sx); \ is_sx_downgraded = true; \ } while (0) /* * Main body of PMC_OP_PMCALLOCATE. */ static int pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) { struct proc *p; struct pmc *pmc; struct pmc_binding pb; struct pmc_classdep *pcd; struct pmc_hw *phw; enum pmc_mode mode; enum pmc_class class; uint32_t caps, flags; u_int cpu; int adjri, n; int error; class = pa->pm_class; caps = pa->pm_caps; flags = pa->pm_flags; mode = pa->pm_mode; cpu = pa->pm_cpu; p = td->td_proc; /* Requested mode must exist. */ if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && mode != PMC_MODE_TS && mode != PMC_MODE_TC)) return (EINVAL); /* Requested CPU must be valid. */ if (cpu != PMC_CPU_ANY && cpu >= pmc_cpu_max()) return (EINVAL); /* * Virtual PMCs should only ask for a default CPU. * System mode PMCs need to specify a non-default CPU. */ if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != PMC_CPU_ANY) || (PMC_IS_SYSTEM_MODE(mode) && cpu == PMC_CPU_ANY)) return (EINVAL); /* * Check that an inactive CPU is not being asked for. */ if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) return (ENXIO); /* * Refuse an allocation for a system-wide PMC if this process has been * jailed, or if this process lacks super-user credentials and the * sysctl tunable 'security.bsd.unprivileged_syspmcs' is zero. */ if (PMC_IS_SYSTEM_MODE(mode)) { if (jailed(td->td_ucred)) return (EPERM); if (!pmc_unprivileged_syspmcs) { error = priv_check(td, PRIV_PMC_SYSTEM); if (error != 0) return (error); } } /* * Look for valid values for 'pm_flags'. */ if ((flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN | PMC_F_EV_PMU)) != 0) return (EINVAL); /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN. */ if ((flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == PMC_F_USERCALLCHAIN) return (EINVAL); /* PMC_F_USERCALLCHAIN is only valid for sampling mode. */ if ((flags & PMC_F_USERCALLCHAIN) != 0 && mode != PMC_MODE_TS && mode != PMC_MODE_SS) return (EINVAL); /* Process logging options are not allowed for system PMCs. */ if (PMC_IS_SYSTEM_MODE(mode) && (flags & (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT)) != 0) return (EINVAL); /* * All sampling mode PMCs need to be able to interrupt the CPU. */ if (PMC_IS_SAMPLING_MODE(mode)) caps |= PMC_CAP_INTERRUPT; /* A valid class specifier should have been passed in. */ pcd = pmc_class_to_classdep(class); if (pcd == NULL) return (EINVAL); /* The requested PMC capabilities should be feasible. */ if ((pcd->pcd_caps & caps) != caps) return (EOPNOTSUPP); PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", pa->pm_ev, caps, mode, cpu); pmc = pmc_allocate_pmc_descriptor(); pmc->pm_id = PMC_ID_MAKE_ID(cpu, pa->pm_mode, class, PMC_ID_INVALID); pmc->pm_event = pa->pm_ev; pmc->pm_state = PMC_STATE_FREE; pmc->pm_caps = caps; pmc->pm_flags = flags; /* XXX set lower bound on sampling for process counters */ if (PMC_IS_SAMPLING_MODE(mode)) { /* * Don't permit requested sample rate to be less than * pmc_mincount. */ if (pa->pm_count < MAX(1, pmc_mincount)) log(LOG_WARNING, "pmcallocate: passed sample " "rate %ju - setting to %u\n", (uintmax_t)pa->pm_count, MAX(1, pmc_mincount)); pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), pa->pm_count); } else pmc->pm_sc.pm_initial = pa->pm_count; /* switch thread to CPU 'cpu' */ pmc_save_cpu_binding(&pb); #define PMC_IS_SHAREABLE_PMC(cpu, n) \ (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ PMC_PHW_FLAG_IS_SHAREABLE) #define PMC_IS_UNALLOCATED(cpu, n) \ (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) if (PMC_IS_SYSTEM_MODE(mode)) { pmc_select_cpu(cpu); for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { pcd = pmc_ri_to_classdep(md, n, &adjri); if (!pmc_can_allocate_row(n, mode) || !pmc_can_allocate_rowindex(p, n, cpu)) continue; if (!PMC_IS_UNALLOCATED(cpu, n) && !PMC_IS_SHAREABLE_PMC(cpu, n)) continue; if (pcd->pcd_allocate_pmc(cpu, adjri, pmc, pa) == 0) { /* Success. */ break; } } } else { /* Process virtual mode */ for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { pcd = pmc_ri_to_classdep(md, n, &adjri); if (!pmc_can_allocate_row(n, mode) || !pmc_can_allocate_rowindex(p, n, PMC_CPU_ANY)) continue; if (pcd->pcd_allocate_pmc(td->td_oncpu, adjri, pmc, pa) == 0) { /* Success. */ break; } } } #undef PMC_IS_UNALLOCATED #undef PMC_IS_SHAREABLE_PMC pmc_restore_cpu_binding(&pb); if (n == md->pmd_npmc) { pmc_destroy_pmc_descriptor(pmc); return (EINVAL); } /* Fill in the correct value in the ID field. */ pmc->pm_id = PMC_ID_MAKE_ID(cpu, mode, class, n); PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", pmc->pm_event, class, mode, n, pmc->pm_id); /* Process mode PMCs with logging enabled need log files. */ if ((pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) != 0) pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; /* All system mode sampling PMCs require a log file. */ if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; /* * Configure global pmc's immediately. */ if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { pmc_save_cpu_binding(&pb); pmc_select_cpu(cpu); phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; pcd = pmc_ri_to_classdep(md, n, &adjri); if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { (void)pcd->pcd_release_pmc(cpu, adjri, pmc); pmc_destroy_pmc_descriptor(pmc); pmc_restore_cpu_binding(&pb); return (EPERM); } pmc_restore_cpu_binding(&pb); } pmc->pm_state = PMC_STATE_ALLOCATED; pmc->pm_class = class; /* * Mark row disposition. */ if (PMC_IS_SYSTEM_MODE(mode)) PMC_MARK_ROW_STANDALONE(n); else PMC_MARK_ROW_THREAD(n); /* * Register this PMC with the current thread as its owner. */ error = pmc_register_owner(p, pmc); if (error != 0) { pmc_release_pmc_descriptor(pmc); pmc_destroy_pmc_descriptor(pmc); return (error); } /* * Return the allocated index. */ pa->pm_pmcid = pmc->pm_id; return (0); } /* * Main body of PMC_OP_PMCATTACH. */ static int pmc_do_op_pmcattach(struct thread *td, struct pmc_op_pmcattach a) { struct pmc *pm; struct proc *p; int error; sx_assert(&pmc_sx, SX_XLOCKED); if (a.pm_pid < 0) { return (EINVAL); } else if (a.pm_pid == 0) { a.pm_pid = td->td_proc->p_pid; } error = pmc_find_pmc(a.pm_pmc, &pm); if (error != 0) return (error); if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) return (EINVAL); /* PMCs may be (re)attached only when allocated or stopped */ if (pm->pm_state == PMC_STATE_RUNNING) { return (EBUSY); } else if (pm->pm_state != PMC_STATE_ALLOCATED && pm->pm_state != PMC_STATE_STOPPED) { return (EINVAL); } /* lookup pid */ if ((p = pfind(a.pm_pid)) == NULL) return (ESRCH); /* * Ignore processes that are working on exiting. */ if ((p->p_flag & P_WEXIT) != 0) { PROC_UNLOCK(p); /* pfind() returns a locked process */ return (ESRCH); } /* * We are allowed to attach a PMC to a process if we can debug it. */ error = p_candebug(curthread, p); PROC_UNLOCK(p); if (error == 0) error = pmc_attach_process(p, pm); return (error); } /* * Main body of PMC_OP_PMCDETACH. */ static int pmc_do_op_pmcdetach(struct thread *td, struct pmc_op_pmcattach a) { struct pmc *pm; struct proc *p; int error; if (a.pm_pid < 0) { return (EINVAL); } else if (a.pm_pid == 0) a.pm_pid = td->td_proc->p_pid; error = pmc_find_pmc(a.pm_pmc, &pm); if (error != 0) return (error); if ((p = pfind(a.pm_pid)) == NULL) return (ESRCH); /* * Treat processes that are in the process of exiting as if they were * not present. */ if ((p->p_flag & P_WEXIT) != 0) { PROC_UNLOCK(p); return (ESRCH); } PROC_UNLOCK(p); /* pfind() returns a locked process */ if (error == 0) error = pmc_detach_process(p, pm); return (error); } /* * Main body of PMC_OP_PMCRELEASE. */ static int pmc_do_op_pmcrelease(pmc_id_t pmcid) { struct pmc_owner *po; struct pmc *pm; int error; /* * Find PMC pointer for the named PMC. * * Use pmc_release_pmc_descriptor() to switch off the * PMC, remove all its target threads, and remove the * PMC from its owner's list. * * Remove the owner record if this is the last PMC * owned. * * Free up space. */ error = pmc_find_pmc(pmcid, &pm); if (error != 0) return (error); po = pm->pm_owner; pmc_release_pmc_descriptor(pm); pmc_maybe_remove_owner(po); pmc_destroy_pmc_descriptor(pm); return (error); } /* * Main body of PMC_OP_PMCRW. */ static int pmc_do_op_pmcrw(const struct pmc_op_pmcrw *prw, pmc_value_t *valp) { struct pmc_binding pb; struct pmc_classdep *pcd; struct pmc *pm; u_int cpu, ri, adjri; int error; PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw->pm_pmcid, prw->pm_flags); /* Must have at least one flag set. */ if ((prw->pm_flags & (PMC_F_OLDVALUE | PMC_F_NEWVALUE)) == 0) return (EINVAL); /* Locate PMC descriptor. */ error = pmc_find_pmc(prw->pm_pmcid, &pm); if (error != 0) return (error); /* Can't read a PMC that hasn't been started. */ if (pm->pm_state != PMC_STATE_ALLOCATED && pm->pm_state != PMC_STATE_STOPPED && pm->pm_state != PMC_STATE_RUNNING) return (EINVAL); /* Writing a new value is allowed only for 'STOPPED' PMCs. */ if (pm->pm_state == PMC_STATE_RUNNING && (prw->pm_flags & PMC_F_NEWVALUE) != 0) return (EBUSY); if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { /* * If this PMC is attached to its owner (i.e., the process * requesting this operation) and is running, then attempt to * get an upto-date reading from hardware for a READ. Writes * are only allowed when the PMC is stopped, so only update the * saved value field. * * If the PMC is not running, or is not attached to its owner, * read/write to the savedvalue field. */ ri = PMC_TO_ROWINDEX(pm); pcd = pmc_ri_to_classdep(md, ri, &adjri); mtx_pool_lock_spin(pmc_mtxpool, pm); cpu = curthread->td_oncpu; if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) { if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && (pm->pm_state == PMC_STATE_RUNNING)) { error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, valp); } else { *valp = pm->pm_gv.pm_savedvalue; } } if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) pm->pm_gv.pm_savedvalue = prw->pm_value; mtx_pool_unlock_spin(pmc_mtxpool, pm); } else { /* System mode PMCs */ cpu = PMC_TO_CPU(pm); ri = PMC_TO_ROWINDEX(pm); pcd = pmc_ri_to_classdep(md, ri, &adjri); if (!pmc_cpu_is_active(cpu)) return (ENXIO); /* Move this thread to CPU 'cpu'. */ pmc_save_cpu_binding(&pb); pmc_select_cpu(cpu); critical_enter(); /* Save old value. */ if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, valp); /* Write out new value. */ if (error == 0 && (prw->pm_flags & PMC_F_NEWVALUE) != 0) error = (*pcd->pcd_write_pmc)(cpu, adjri, pm, prw->pm_value); critical_exit(); pmc_restore_cpu_binding(&pb); if (error != 0) return (error); } #ifdef HWPMC_DEBUG if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", ri, prw->pm_value, *valp); else PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, *valp); #endif return (error); } static int pmc_syscall_handler(struct thread *td, void *syscall_args) { struct pmc_syscall_args *c; void *pmclog_proc_handle; void *arg; int error, op; bool is_sx_downgraded; c = (struct pmc_syscall_args *)syscall_args; op = c->pmop_code; arg = c->pmop_data; /* PMC isn't set up yet */ if (pmc_hook == NULL) return (EINVAL); if (op == PMC_OP_CONFIGURELOG) { /* * We cannot create the logging process inside * pmclog_configure_log() because there is a LOR * between pmc_sx and process structure locks. * Instead, pre-create the process and ignite the loop * if everything is fine, otherwise direct the process * to exit. */ error = pmclog_proc_create(td, &pmclog_proc_handle); if (error != 0) goto done_syscall; } PMC_GET_SX_XLOCK(ENOSYS); is_sx_downgraded = false; PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, pmc_op_to_name[op], arg); error = 0; counter_u64_add(pmc_stats.pm_syscalls, 1); switch (op) { /* * Configure a log file. * * XXX This OP will be reworked. */ case PMC_OP_CONFIGURELOG: { struct proc *p; struct pmc *pm; struct pmc_owner *po; struct pmc_op_configurelog cl; if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { pmclog_proc_ignite(pmclog_proc_handle, NULL); break; } /* No flags currently implemented */ if (cl.pm_flags != 0) { pmclog_proc_ignite(pmclog_proc_handle, NULL); error = EINVAL; break; } /* mark this process as owning a log file */ p = td->td_proc; if ((po = pmc_find_owner_descriptor(p)) == NULL) if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { pmclog_proc_ignite(pmclog_proc_handle, NULL); error = ENOMEM; break; } /* * If a valid fd was passed in, try to configure that, * otherwise if 'fd' was less than zero and there was * a log file configured, flush its buffers and * de-configure it. */ if (cl.pm_logfd >= 0) { error = pmclog_configure_log(md, po, cl.pm_logfd); pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? po : NULL); } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { pmclog_proc_ignite(pmclog_proc_handle, NULL); error = pmclog_close(po); if (error == 0) { LIST_FOREACH(pm, &po->po_pmcs, pm_next) if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && pm->pm_state == PMC_STATE_RUNNING) pmc_stop(pm); error = pmclog_deconfigure_log(po); } } else { pmclog_proc_ignite(pmclog_proc_handle, NULL); error = EINVAL; } } break; /* * Flush a log file. */ case PMC_OP_FLUSHLOG: { struct pmc_owner *po; sx_assert(&pmc_sx, SX_XLOCKED); if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { error = EINVAL; break; } error = pmclog_flush(po, 0); } break; /* * Close a log file. */ case PMC_OP_CLOSELOG: { struct pmc_owner *po; sx_assert(&pmc_sx, SX_XLOCKED); if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { error = EINVAL; break; } error = pmclog_close(po); } break; /* * Retrieve hardware configuration. */ case PMC_OP_GETCPUINFO: /* CPU information */ { struct pmc_op_getcpuinfo gci; struct pmc_classinfo *pci; struct pmc_classdep *pcd; int cl; memset(&gci, 0, sizeof(gci)); gci.pm_cputype = md->pmd_cputype; gci.pm_ncpu = pmc_cpu_max(); gci.pm_npmc = md->pmd_npmc; gci.pm_nclass = md->pmd_nclass; pci = gci.pm_classes; pcd = md->pmd_classdep; for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { pci->pm_caps = pcd->pcd_caps; pci->pm_class = pcd->pcd_class; pci->pm_width = pcd->pcd_width; pci->pm_num = pcd->pcd_num; } error = copyout(&gci, arg, sizeof(gci)); } break; /* * Retrieve soft events list. */ case PMC_OP_GETDYNEVENTINFO: { enum pmc_class cl; enum pmc_event ev; struct pmc_op_getdyneventinfo *gei; struct pmc_dyn_event_descr dev; struct pmc_soft *ps; uint32_t nevent; sx_assert(&pmc_sx, SX_LOCKED); gei = (struct pmc_op_getdyneventinfo *) arg; if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) break; /* Only SOFT class is dynamic. */ if (cl != PMC_CLASS_SOFT) { error = EINVAL; break; } nevent = 0; for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { ps = pmc_soft_ev_acquire(ev); if (ps == NULL) continue; bcopy(&ps->ps_ev, &dev, sizeof(dev)); pmc_soft_ev_release(ps); error = copyout(&dev, &gei->pm_events[nevent], sizeof(struct pmc_dyn_event_descr)); if (error != 0) break; nevent++; } if (error != 0) break; error = copyout(&nevent, &gei->pm_nevent, sizeof(nevent)); } break; /* * Get module statistics */ case PMC_OP_GETDRIVERSTATS: { struct pmc_op_getdriverstats gms; #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) CFETCH(gms, pmc_stats, pm_intr_ignored); CFETCH(gms, pmc_stats, pm_intr_processed); CFETCH(gms, pmc_stats, pm_intr_bufferfull); CFETCH(gms, pmc_stats, pm_syscalls); CFETCH(gms, pmc_stats, pm_syscall_errors); CFETCH(gms, pmc_stats, pm_buffer_requests); CFETCH(gms, pmc_stats, pm_buffer_requests_failed); CFETCH(gms, pmc_stats, pm_log_sweeps); #undef CFETCH error = copyout(&gms, arg, sizeof(gms)); } break; /* * Retrieve module version number */ case PMC_OP_GETMODULEVERSION: { uint32_t cv, modv; /* retrieve the client's idea of the ABI version */ if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) break; /* don't service clients newer than our driver */ modv = PMC_VERSION; if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { error = EPROGMISMATCH; break; } error = copyout(&modv, arg, sizeof(int)); } break; /* * Retrieve the state of all the PMCs on a given * CPU. */ case PMC_OP_GETPMCINFO: { int ari; struct pmc *pm; size_t pmcinfo_size; uint32_t cpu, n, npmc; struct pmc_owner *po; struct pmc_binding pb; struct pmc_classdep *pcd; struct pmc_info *p, *pmcinfo; struct pmc_op_getpmcinfo *gpi; PMC_DOWNGRADE_SX(); gpi = (struct pmc_op_getpmcinfo *) arg; if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) break; if (cpu >= pmc_cpu_max()) { error = EINVAL; break; } if (!pmc_cpu_is_active(cpu)) { error = ENXIO; break; } /* switch to CPU 'cpu' */ pmc_save_cpu_binding(&pb); pmc_select_cpu(cpu); npmc = md->pmd_npmc; pmcinfo_size = npmc * sizeof(struct pmc_info); pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO); p = pmcinfo; for (n = 0; n < md->pmd_npmc; n++, p++) { pcd = pmc_ri_to_classdep(md, n, &ari); KASSERT(pcd != NULL, ("[pmc,%d] null pcd ri=%d", __LINE__, n)); if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) break; if (PMC_ROW_DISP_IS_STANDALONE(n)) p->pm_rowdisp = PMC_DISP_STANDALONE; else if (PMC_ROW_DISP_IS_THREAD(n)) p->pm_rowdisp = PMC_DISP_THREAD; else p->pm_rowdisp = PMC_DISP_FREE; p->pm_ownerpid = -1; if (pm == NULL) /* no PMC associated */ continue; po = pm->pm_owner; KASSERT(po->po_owner != NULL, ("[pmc,%d] pmc_owner had a null proc pointer", __LINE__)); p->pm_ownerpid = po->po_owner->p_pid; p->pm_mode = PMC_TO_MODE(pm); p->pm_event = pm->pm_event; p->pm_flags = pm->pm_flags; if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) p->pm_reloadcount = pm->pm_sc.pm_reloadcount; } pmc_restore_cpu_binding(&pb); /* now copy out the PMC info collected */ if (error == 0) error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); free(pmcinfo, M_PMC); } break; /* * Set the administrative state of a PMC. I.e. whether * the PMC is to be used or not. */ case PMC_OP_PMCADMIN: { int cpu, ri; enum pmc_state request; struct pmc_cpu *pc; struct pmc_hw *phw; struct pmc_op_pmcadmin pma; struct pmc_binding pb; sx_assert(&pmc_sx, SX_XLOCKED); KASSERT(td == curthread, ("[pmc,%d] td != curthread", __LINE__)); error = priv_check(td, PRIV_PMC_MANAGE); if (error) break; if ((error = copyin(arg, &pma, sizeof(pma))) != 0) break; cpu = pma.pm_cpu; if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { error = EINVAL; break; } if (!pmc_cpu_is_active(cpu)) { error = ENXIO; break; } request = pma.pm_state; if (request != PMC_STATE_DISABLED && request != PMC_STATE_FREE) { error = EINVAL; break; } ri = pma.pm_pmc; /* pmc id == row index */ if (ri < 0 || ri >= (int) md->pmd_npmc) { error = EINVAL; break; } /* * We can't disable a PMC with a row-index allocated * for process virtual PMCs. */ if (PMC_ROW_DISP_IS_THREAD(ri) && request == PMC_STATE_DISABLED) { error = EBUSY; break; } /* * otherwise, this PMC on this CPU is either free or * in system-wide mode. */ pmc_save_cpu_binding(&pb); pmc_select_cpu(cpu); pc = pmc_pcpu[cpu]; phw = pc->pc_hwpmcs[ri]; /* * XXX do we need some kind of 'forced' disable? */ if (phw->phw_pmc == NULL) { if (request == PMC_STATE_DISABLED && (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; PMC_MARK_ROW_STANDALONE(ri); } else if (request == PMC_STATE_FREE && (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; PMC_UNMARK_ROW_STANDALONE(ri); } /* other cases are a no-op */ } else error = EBUSY; pmc_restore_cpu_binding(&pb); } break; /* * Allocate a PMC. */ case PMC_OP_PMCALLOCATE: { struct pmc_op_pmcallocate pa; error = copyin(arg, &pa, sizeof(pa)); if (error != 0) break; error = pmc_do_op_pmcallocate(td, &pa); if (error != 0) break; error = copyout(&pa, arg, sizeof(pa)); } break; /* * Attach a PMC to a process. */ case PMC_OP_PMCATTACH: { struct pmc_op_pmcattach a; error = copyin(arg, &a, sizeof(a)); if (error != 0) break; error = pmc_do_op_pmcattach(td, a); } break; /* * Detach an attached PMC from a process. */ case PMC_OP_PMCDETACH: { struct pmc_op_pmcattach a; error = copyin(arg, &a, sizeof(a)); if (error != 0) break; error = pmc_do_op_pmcdetach(td, a); } break; /* * Retrieve the MSR number associated with the counter * 'pmc_id'. This allows processes to directly use RDPMC * instructions to read their PMCs, without the overhead of a * system call. */ case PMC_OP_PMCGETMSR: { int adjri, ri; struct pmc *pm; struct pmc_target *pt; struct pmc_op_getmsr gm; struct pmc_classdep *pcd; PMC_DOWNGRADE_SX(); if ((error = copyin(arg, &gm, sizeof(gm))) != 0) break; if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) break; /* * The allocated PMC has to be a process virtual PMC, * i.e., of type MODE_T[CS]. Global PMCs can only be * read using the PMCREAD operation since they may be * allocated on a different CPU than the one we could * be running on at the time of the RDPMC instruction. * * The GETMSR operation is not allowed for PMCs that * are inherited across processes. */ if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || (pm->pm_flags & PMC_F_DESCENDANTS)) { error = EINVAL; break; } /* * It only makes sense to use a RDPMC (or its * equivalent instruction on non-x86 architectures) on * a process that has allocated and attached a PMC to * itself. Conversely the PMC is only allowed to have * one process attached to it -- its owner. */ if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || LIST_NEXT(pt, pt_next) != NULL || pt->pt_process->pp_proc != pm->pm_owner->po_owner) { error = EINVAL; break; } ri = PMC_TO_ROWINDEX(pm); pcd = pmc_ri_to_classdep(md, ri, &adjri); /* PMC class has no 'GETMSR' support */ if (pcd->pcd_get_msr == NULL) { error = ENOSYS; break; } if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) break; if ((error = copyout(&gm, arg, sizeof(gm))) < 0) break; /* * Mark our process as using MSRs. Update machine * state using a forced context switch. */ pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; pmc_force_context_switch(); } break; /* * Release an allocated PMC. */ case PMC_OP_PMCRELEASE: { struct pmc_op_simple sp; error = copyin(arg, &sp, sizeof(sp)); if (error != 0) break; error = pmc_do_op_pmcrelease(sp.pm_pmcid); } break; /* * Read and/or write a PMC. */ case PMC_OP_PMCRW: { struct pmc_op_pmcrw prw; struct pmc_op_pmcrw *pprw; pmc_value_t oldvalue; PMC_DOWNGRADE_SX(); error = copyin(arg, &prw, sizeof(prw)); if (error != 0) break; error = pmc_do_op_pmcrw(&prw, &oldvalue); if (error != 0) break; /* Return old value if requested. */ if ((prw.pm_flags & PMC_F_OLDVALUE) != 0) { pprw = arg; error = copyout(&oldvalue, &pprw->pm_value, sizeof(prw.pm_value)); } } break; /* * Set the sampling rate for a sampling mode PMC and the * initial count for a counting mode PMC. */ case PMC_OP_PMCSETCOUNT: { struct pmc *pm; struct pmc_op_pmcsetcount sc; PMC_DOWNGRADE_SX(); if ((error = copyin(arg, &sc, sizeof(sc))) != 0) break; if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) break; if (pm->pm_state == PMC_STATE_RUNNING) { error = EBUSY; break; } if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { /* * Don't permit requested sample rate to be * less than pmc_mincount. */ if (sc.pm_count < MAX(1, pmc_mincount)) log(LOG_WARNING, "pmcsetcount: passed sample " "rate %ju - setting to %u\n", (uintmax_t)sc.pm_count, MAX(1, pmc_mincount)); pm->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), sc.pm_count); } else pm->pm_sc.pm_initial = sc.pm_count; } break; /* * Start a PMC. */ case PMC_OP_PMCSTART: { pmc_id_t pmcid; struct pmc *pm; struct pmc_op_simple sp; sx_assert(&pmc_sx, SX_XLOCKED); if ((error = copyin(arg, &sp, sizeof(sp))) != 0) break; pmcid = sp.pm_pmcid; if ((error = pmc_find_pmc(pmcid, &pm)) != 0) break; KASSERT(pmcid == pm->pm_id, ("[pmc,%d] pmcid %x != id %x", __LINE__, pm->pm_id, pmcid)); if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ break; else if (pm->pm_state != PMC_STATE_STOPPED && pm->pm_state != PMC_STATE_ALLOCATED) { error = EINVAL; break; } error = pmc_start(pm); } break; /* * Stop a PMC. */ case PMC_OP_PMCSTOP: { pmc_id_t pmcid; struct pmc *pm; struct pmc_op_simple sp; PMC_DOWNGRADE_SX(); if ((error = copyin(arg, &sp, sizeof(sp))) != 0) break; pmcid = sp.pm_pmcid; /* * Mark the PMC as inactive and invoke the MD stop * routines if needed. */ if ((error = pmc_find_pmc(pmcid, &pm)) != 0) break; KASSERT(pmcid == pm->pm_id, ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, pm->pm_id, pmcid)); if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ break; else if (pm->pm_state != PMC_STATE_RUNNING) { error = EINVAL; break; } error = pmc_stop(pm); } break; /* * Write a user supplied value to the log file. */ case PMC_OP_WRITELOG: { struct pmc_op_writelog wl; struct pmc_owner *po; PMC_DOWNGRADE_SX(); if ((error = copyin(arg, &wl, sizeof(wl))) != 0) break; if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { error = EINVAL; break; } if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { error = EINVAL; break; } error = pmclog_process_userlog(po, &wl); } break; default: error = EINVAL; break; } if (is_sx_downgraded) sx_sunlock(&pmc_sx); else sx_xunlock(&pmc_sx); done_syscall: if (error) counter_u64_add(pmc_stats.pm_syscall_errors, 1); return (error); } /* * Helper functions */ /* * Mark the thread as needing callchain capture and post an AST. The * actual callchain capture will be done in a context where it is safe * to take page faults. */ static void pmc_post_callchain_callback(void) { struct thread *td; td = curthread; /* * If there is multiple PMCs for the same interrupt ignore new post */ if ((td->td_pflags & TDP_CALLCHAIN) != 0) return; /* * Mark this thread as needing callchain capture. * `td->td_pflags' will be safe to touch because this thread * was in user space when it was interrupted. */ td->td_pflags |= TDP_CALLCHAIN; /* * Don't let this thread migrate between CPUs until callchain * capture completes. */ sched_pin(); return; } /* * Find a free slot in the per-cpu array of samples and capture the * current callchain there. If a sample was successfully added, a bit * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook * needs to be invoked from the clock handler. * * This function is meant to be called from an NMI handler. It cannot * use any of the locking primitives supplied by the OS. */ static int pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf) { struct pmc_sample *ps; struct pmc_samplebuffer *psb; struct thread *td; int error, cpu, callchaindepth; bool inuserspace; error = 0; /* * Allocate space for a sample buffer. */ cpu = curcpu; psb = pmc_pcpu[cpu]->pc_sb[ring]; inuserspace = TRAPF_USERMODE(tf); ps = PMC_PROD_SAMPLE(psb); if (psb->ps_considx != psb->ps_prodidx && ps->ps_nsamples) { /* in use, reader hasn't caught up */ pm->pm_pcpu_state[cpu].pps_stalled = 1; counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, tf, inuserspace, (int)(psb->ps_prodidx & pmc_sample_mask), (int)(psb->ps_considx & pmc_sample_mask)); callchaindepth = 1; error = ENOMEM; goto done; } /* Fill in entry. */ PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, tf, inuserspace, (int)(psb->ps_prodidx & pmc_sample_mask), (int)(psb->ps_considx & pmc_sample_mask)); td = curthread; ps->ps_pmc = pm; ps->ps_td = td; ps->ps_pid = td->td_proc->p_pid; ps->ps_tid = td->td_tid; ps->ps_tsc = pmc_rdtsc(); ps->ps_ticks = ticks; ps->ps_cpu = cpu; ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? pmc_callchaindepth : 1; MPASS(ps->ps_pc != NULL); if (callchaindepth == 1) { ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); } else { /* * Kernel stack traversals can be done immediately, while we * defer to an AST for user space traversals. */ if (!inuserspace) { callchaindepth = pmc_save_kernel_callchain(ps->ps_pc, callchaindepth, tf); } else { pmc_post_callchain_callback(); callchaindepth = PMC_USER_CALLCHAIN_PENDING; } } ps->ps_nsamples = callchaindepth; /* mark entry as in-use */ if (ring == PMC_UR) { ps->ps_nsamples_actual = callchaindepth; ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; } KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ /* increment write pointer */ psb->ps_prodidx++; done: /* mark CPU as needing processing */ if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) DPCPU_SET(pmc_sampled, 1); return (error); } /* * Interrupt processing. * * This function may be called from an NMI handler. It cannot use any of the * locking primitives supplied by the OS. */ int pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) { struct thread *td; td = curthread; if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && (td->td_proc->p_flag & P_KPROC) == 0 && !TRAPF_USERMODE(tf)) { atomic_add_int(&td->td_pmcpend, 1); return (pmc_add_sample(PMC_UR, pm, tf)); } return (pmc_add_sample(ring, pm, tf)); } /* * Capture a user call chain. This function will be called from ast() * before control returns to userland and before the process gets * rescheduled. */ static void pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) { struct pmc *pm; struct pmc_sample *ps; struct pmc_samplebuffer *psb; struct thread *td; uint64_t considx, prodidx; int nsamples, nrecords, pass, iter; int start_ticks __diagused; psb = pmc_pcpu[cpu]->pc_sb[ring]; td = curthread; nrecords = INT_MAX; pass = 0; start_ticks = ticks; KASSERT(td->td_pflags & TDP_CALLCHAIN, ("[pmc,%d] Retrieving callchain for thread that doesn't want it", __LINE__)); restart: if (ring == PMC_UR) nrecords = atomic_readandclear_32(&td->td_pmcpend); for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; considx < prodidx && iter < pmc_nsamples; considx++, iter++) { ps = PMC_CONS_SAMPLE_OFF(psb, considx); /* * Iterate through all deferred callchain requests. Walk from * the current read pointer to the current write pointer. */ #ifdef INVARIANTS if (ps->ps_nsamples == PMC_SAMPLE_FREE) { continue; } #endif if (ps->ps_td != td || ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING || ps->ps_pmc->pm_state != PMC_STATE_RUNNING) continue; KASSERT(ps->ps_cpu == cpu, ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, ps->ps_cpu, PCPU_GET(cpuid))); pm = ps->ps_pmc; KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, ("[pmc,%d] Retrieving callchain for PMC that doesn't " "want it", __LINE__)); KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, ("[pmc,%d] runcount %ju", __LINE__, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); if (ring == PMC_UR) { nsamples = ps->ps_nsamples_actual; counter_u64_add(pmc_stats.pm_merges, 1); } else nsamples = 0; /* * Retrieve the callchain and mark the sample buffer * as 'processable' by the timer tick sweep code. */ if (__predict_true(nsamples < pmc_callchaindepth - 1)) nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, pmc_callchaindepth - nsamples - 1, tf); /* * We have to prevent hardclock from potentially overwriting * this sample between when we read the value and when we set * it. */ spinlock_enter(); /* * Verify that the sample hasn't been dropped in the meantime. */ if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { ps->ps_nsamples = nsamples; /* * If we couldn't get a sample, simply drop the * reference. */ if (nsamples == 0) counter_u64_add(pm->pm_runcount, -1); } spinlock_exit(); if (nrecords-- == 1) break; } if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { if (pass == 0) { pass = 1; goto restart; } /* only collect samples for this part once */ td->td_pmcpend = 0; } #ifdef INVARIANTS if ((ticks - start_ticks) > hz) log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); #endif /* mark CPU as needing processing */ DPCPU_SET(pmc_sampled, 1); } /* * Process saved PC samples. */ static void pmc_process_samples(int cpu, ring_type_t ring) { struct pmc *pm; struct thread *td; struct pmc_owner *po; struct pmc_sample *ps; struct pmc_classdep *pcd; struct pmc_samplebuffer *psb; uint64_t delta __diagused; int adjri, n; KASSERT(PCPU_GET(cpuid) == cpu, ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, PCPU_GET(cpuid), cpu)); psb = pmc_pcpu[cpu]->pc_sb[ring]; delta = psb->ps_prodidx - psb->ps_considx; MPASS(delta <= pmc_nsamples); MPASS(psb->ps_considx <= psb->ps_prodidx); for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { ps = PMC_CONS_SAMPLE(psb); if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) continue; /* skip non-running samples */ pm = ps->ps_pmc; if (pm->pm_state != PMC_STATE_RUNNING) goto entrydone; KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, pm, PMC_TO_MODE(pm))); po = pm->pm_owner; /* If there is a pending AST wait for completion */ if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { /* * If we've been waiting more than 1 tick to * collect a callchain for this record then * drop it and move on. */ if (ticks - ps->ps_ticks > 1) { /* * Track how often we hit this as it will * preferentially lose user samples * for long running system calls. */ counter_u64_add(pmc_stats.pm_overwrites, 1); goto entrydone; } /* Need a rescan at a later time. */ DPCPU_SET(pmc_sampled, 1); break; } PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, pm, ps->ps_nsamples, ps->ps_flags, (int)(psb->ps_prodidx & pmc_sample_mask), (int)(psb->ps_considx & pmc_sample_mask)); /* * If this is a process-mode PMC that is attached to * its owner, and if the PC is in user mode, update * profiling statistics like timer-based profiling * would have done. * * Otherwise, this is either a sampling-mode PMC that * is attached to a different process than its owner, * or a system-wide sampling PMC. Dispatch a log * entry to the PMC's owner process. */ if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { if (ps->ps_flags & PMC_CC_F_USERSPACE) { td = FIRST_THREAD_IN_PROC(po->po_owner); addupc_intr(td, ps->ps_pc[0], 1); } } else pmclog_process_callchain(pm, ps); entrydone: ps->ps_nsamples = 0; /* mark entry as free */ KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); counter_u64_add(pm->pm_runcount, -1); } counter_u64_add(pmc_stats.pm_log_sweeps, 1); /* Do not re-enable stalled PMCs if we failed to process any samples */ if (n == 0) return; /* * Restart any stalled sampling PMCs on this CPU. * * If the NMI handler sets the pm_stalled field of a PMC after * the check below, we'll end up processing the stalled PMC at * the next hardclock tick. */ for (n = 0; n < md->pmd_npmc; n++) { pcd = pmc_ri_to_classdep(md, n, &adjri); KASSERT(pcd != NULL, ("[pmc,%d] null pcd ri=%d", __LINE__, n)); (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); if (pm == NULL || /* !cfg'ed */ pm->pm_state != PMC_STATE_RUNNING || /* !active */ !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ continue; pm->pm_pcpu_state[cpu].pps_stalled = 0; (void)(*pcd->pcd_start_pmc)(cpu, adjri, pm); } } /* * Event handlers. */ /* * Handle a process exit. * * Remove this process from all hash tables. If this process * owned any PMCs, turn off those PMCs and deallocate them, * removing any associations with target processes. * * This function will be called by the last 'thread' of a * process. * * XXX This eventhandler gets called early in the exit process. * Consider using a 'hook' invocation from thread_exit() or equivalent * spot. Another negative is that kse_exit doesn't seem to call * exit1() [??]. */ static void pmc_process_exit(void *arg __unused, struct proc *p) { struct pmc *pm; struct pmc_owner *po; struct pmc_process *pp; struct pmc_classdep *pcd; pmc_value_t newvalue, tmp; int ri, adjri, cpu; bool is_using_hwpmcs; PROC_LOCK(p); is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; PROC_UNLOCK(p); /* * Log a sysexit event to all SS PMC owners. */ PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) pmclog_process_sysexit(po, p->p_pid); } PMC_EPOCH_EXIT(); PMC_GET_SX_XLOCK(); PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, p->p_comm); if (!is_using_hwpmcs) goto out; /* * Since this code is invoked by the last thread in an exiting process, * we would have context switched IN at some prior point. However, with * PREEMPTION, kernel mode context switches may happen any time, so we * want to disable a context switch OUT till we get any PMCs targeting * this process off the hardware. * * We also need to atomically remove this process' entry from our * target process hash table, using PMC_FLAG_REMOVE. */ PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, p->p_comm); critical_enter(); /* no preemption */ cpu = curthread->td_oncpu; pp = pmc_find_process_descriptor(p, PMC_FLAG_REMOVE); if (pp == NULL) { critical_exit(); goto out; } PMCDBG2(PRC,EXT,2, "process-exit proc=%p pmc-process=%p", p, pp); /* * The exiting process could be the target of some PMCs which will be * running on currently executing CPU. * * We need to turn these PMCs off like we would do at context switch * OUT time. */ for (ri = 0; ri < md->pmd_npmc; ri++) { /* * Pick up the pmc pointer from hardware state similar to the * CSW_OUT code. */ pm = NULL; pcd = pmc_ri_to_classdep(md, ri, &adjri); (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); if (pm == NULL || !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) continue; PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p state=%d", ri, pp->pp_pmcs[ri].pp_pmc, pm, pm->pm_state); KASSERT(PMC_TO_ROWINDEX(pm) == ri, ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", __LINE__, PMC_TO_ROWINDEX(pm), ri)); KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, ("[pmc,%d] bad runcount ri %d rc %ju", __LINE__, ri, (uintmax_t)counter_u64_fetch(pm->pm_runcount))); /* * Change desired state, and then stop if not stalled. This * two-step dance should avoid race conditions where an * interrupt re-enables the PMC after this code has already * checked the pm_stalled flag. */ if (pm->pm_pcpu_state[cpu].pps_cpustate) { pm->pm_pcpu_state[cpu].pps_cpustate = 0; if (!pm->pm_pcpu_state[cpu].pps_stalled) { (void)pcd->pcd_stop_pmc(cpu, adjri, pm); if (PMC_TO_MODE(pm) == PMC_MODE_TC) { pcd->pcd_read_pmc(cpu, adjri, pm, &newvalue); tmp = newvalue - PMC_PCPU_SAVED(cpu, ri); mtx_pool_lock_spin(pmc_mtxpool, pm); pm->pm_gv.pm_savedvalue += tmp; pp->pp_pmcs[ri].pp_pmcval += tmp; mtx_pool_unlock_spin(pmc_mtxpool, pm); } } } KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, ("[pmc,%d] runcount is %d", __LINE__, ri)); counter_u64_add(pm->pm_runcount, -1); (void)pcd->pcd_config_pmc(cpu, adjri, NULL); } /* * Inform the MD layer of this pseudo "context switch out". */ (void)md->pmd_switch_out(pmc_pcpu[cpu], pp); critical_exit(); /* ok to be pre-empted now */ /* * Unlink this process from the PMCs that are targeting it. This will * send a signal to all PMC owner's whose PMCs are orphaned. * * Log PMC value at exit time if requested. */ for (ri = 0; ri < md->pmd_npmc; ri++) { if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) { pmclog_process_procexit(pm, pp); } pmc_unlink_target_process(pm, pp); } } free(pp, M_PMC); out: /* * If the process owned PMCs, free them up and free up memory. */ if ((po = pmc_find_owner_descriptor(p)) != NULL) { if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) pmclog_close(po); pmc_remove_owner(po); pmc_destroy_owner_descriptor(po); } sx_xunlock(&pmc_sx); } /* * Handle a process fork. * * If the parent process 'p1' is under HWPMC monitoring, then copy * over any attached PMCs that have 'do_descendants' semantics. */ static void pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, int flags __unused) { struct pmc *pm; struct pmc_owner *po; struct pmc_process *ppnew, *ppold; unsigned int ri; bool is_using_hwpmcs, do_descendants; PROC_LOCK(p1); is_using_hwpmcs = (p1->p_flag & P_HWPMC) != 0; PROC_UNLOCK(p1); /* * If there are system-wide sampling PMCs active, we need to * log all fork events to their owner's logs. */ PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if (po->po_flags & PMC_PO_OWNS_LOGFILE) { pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); pmclog_process_proccreate(po, newproc, 1); } } PMC_EPOCH_EXIT(); if (!is_using_hwpmcs) return; PMC_GET_SX_XLOCK(); PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, p1->p_pid, p1->p_comm, newproc); /* * If the parent process (curthread->td_proc) is a * target of any PMCs, look for PMCs that are to be * inherited, and link these into the new process * descriptor. */ ppold = pmc_find_process_descriptor(curthread->td_proc, PMC_FLAG_NONE); if (ppold == NULL) goto done; /* nothing to do */ do_descendants = false; for (ri = 0; ri < md->pmd_npmc; ri++) { if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { do_descendants = true; break; } } if (!do_descendants) /* nothing to do */ goto done; /* * Now mark the new process as being tracked by this driver. */ PROC_LOCK(newproc); newproc->p_flag |= P_HWPMC; PROC_UNLOCK(newproc); /* Allocate a descriptor for the new process. */ ppnew = pmc_find_process_descriptor(newproc, PMC_FLAG_ALLOCATE); if (ppnew == NULL) goto done; /* * Run through all PMCs that were targeting the old process * and which specified F_DESCENDANTS and attach them to the * new process. * * Log the fork event to all owners of PMCs attached to this * process, if not already logged. */ for (ri = 0; ri < md->pmd_npmc; ri++) { if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { pmc_link_target_process(pm, ppnew); po = pm->pm_owner; if (po->po_sscount == 0 && (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); } } } done: sx_xunlock(&pmc_sx); } static void pmc_process_threadcreate(struct thread *td) { struct pmc_owner *po; PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) pmclog_process_threadcreate(po, td, 1); } PMC_EPOCH_EXIT(); } static void pmc_process_threadexit(struct thread *td) { struct pmc_owner *po; PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) pmclog_process_threadexit(po, td); } PMC_EPOCH_EXIT(); } static void pmc_process_proccreate(struct proc *p) { struct pmc_owner *po; PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) pmclog_process_proccreate(po, p, 1 /* sync */); } PMC_EPOCH_EXIT(); } static void pmc_process_allproc(struct pmc *pm) { struct pmc_owner *po; struct thread *td; struct proc *p; po = pm->pm_owner; if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) return; sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { pmclog_process_proccreate(po, p, 0 /* sync */); PROC_LOCK(p); FOREACH_THREAD_IN_PROC(p, td) pmclog_process_threadcreate(po, td, 0 /* sync */); PROC_UNLOCK(p); } sx_sunlock(&allproc_lock); pmclog_flush(po, 0); } static void pmc_kld_load(void *arg __unused, linker_file_t lf) { struct pmc_owner *po; /* * Notify owners of system sampling PMCs about KLD operations. */ PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if (po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_map_in(po, (pid_t) -1, (uintfptr_t) lf->address, lf->pathname); } PMC_EPOCH_EXIT(); /* * TODO: Notify owners of (all) process-sampling PMCs too. */ } static void pmc_kld_unload(void *arg __unused, const char *filename __unused, caddr_t address, size_t size) { struct pmc_owner *po; PMC_EPOCH_ENTER(); CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { pmclog_process_map_out(po, (pid_t)-1, (uintfptr_t)address, (uintfptr_t)address + size); } } PMC_EPOCH_EXIT(); /* * TODO: Notify owners of process-sampling PMCs. */ } /* * initialization */ static const char * pmc_name_of_pmcclass(enum pmc_class class) { switch (class) { #undef __PMC_CLASS #define __PMC_CLASS(S,V,D) \ case PMC_CLASS_##S: \ return #S; __PMC_CLASSES(); default: return (""); } } /* * Base class initializer: allocate structure and set default classes. */ struct pmc_mdep * pmc_mdep_alloc(int nclasses) { struct pmc_mdep *md; int n; /* SOFT + md classes */ n = 1 + nclasses; md = malloc(sizeof(struct pmc_mdep) + n * sizeof(struct pmc_classdep), M_PMC, M_WAITOK | M_ZERO); md->pmd_nclass = n; /* Default methods */ md->pmd_switch_in = generic_switch_in; md->pmd_switch_out = generic_switch_out; /* Add base class. */ pmc_soft_initialize(md); return (md); } void pmc_mdep_free(struct pmc_mdep *md) { pmc_soft_finalize(md); free(md, M_PMC); } static int generic_switch_in(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) { return (0); } static int generic_switch_out(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) { return (0); } static struct pmc_mdep * pmc_generic_cpu_initialize(void) { struct pmc_mdep *md; md = pmc_mdep_alloc(0); md->pmd_cputype = PMC_CPU_GENERIC; return (md); } static void pmc_generic_cpu_finalize(struct pmc_mdep *md __unused) { } static int pmc_initialize(void) { struct pcpu *pc; struct pmc_binding pb; struct pmc_classdep *pcd; struct pmc_sample *ps; struct pmc_samplebuffer *sb; int c, cpu, error, n, ri; u_int maxcpu, domain; md = NULL; error = 0; pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); #ifdef HWPMC_DEBUG /* parse debug flags first */ if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, sizeof(pmc_debugstr))) { pmc_debugflags_parse(pmc_debugstr, pmc_debugstr + strlen(pmc_debugstr)); } #endif PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); /* check kernel version */ if (pmc_kernel_version != PMC_VERSION) { if (pmc_kernel_version == 0) printf("hwpmc: this kernel has not been compiled with " "'options HWPMC_HOOKS'.\n"); else printf("hwpmc: kernel version (0x%x) does not match " "module version (0x%x).\n", pmc_kernel_version, PMC_VERSION); return (EPROGMISMATCH); } /* * check sysctl parameters */ if (pmc_hashsize <= 0) { printf("hwpmc: tunable \"hashsize\"=%d must be " "greater than zero.\n", pmc_hashsize); pmc_hashsize = PMC_HASH_SIZE; } if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { printf("hwpmc: tunable \"nsamples\"=%d out of " "range.\n", pmc_nsamples); pmc_nsamples = PMC_NSAMPLES; } pmc_sample_mask = pmc_nsamples - 1; if (pmc_callchaindepth <= 0 || pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { printf("hwpmc: tunable \"callchaindepth\"=%d out of " "range - using %d.\n", pmc_callchaindepth, PMC_CALLCHAIN_DEPTH_MAX); pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; } md = pmc_md_initialize(); if (md == NULL) { /* Default to generic CPU. */ md = pmc_generic_cpu_initialize(); if (md == NULL) return (ENOSYS); } /* * Refresh classes base ri. Optional classes may come in different * order. */ for (ri = c = 0; c < md->pmd_nclass; c++) { pcd = &md->pmd_classdep[c]; pcd->pcd_ri = ri; ri += pcd->pcd_num; } KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, ("[pmc,%d] no classes or pmcs", __LINE__)); /* Compute the map from row-indices to classdep pointers. */ pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * md->pmd_npmc, M_PMC, M_WAITOK | M_ZERO); for (n = 0; n < md->pmd_npmc; n++) pmc_rowindex_to_classdep[n] = NULL; for (ri = c = 0; c < md->pmd_nclass; c++) { pcd = &md->pmd_classdep[c]; for (n = 0; n < pcd->pcd_num; n++, ri++) pmc_rowindex_to_classdep[ri] = pcd; } KASSERT(ri == md->pmd_npmc, ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, ri, md->pmd_npmc)); maxcpu = pmc_cpu_max(); /* allocate space for the per-cpu array */ pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, M_WAITOK | M_ZERO); /* per-cpu 'saved values' for managing process-mode PMCs */ pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, M_PMC, M_WAITOK); /* Perform CPU-dependent initialization. */ pmc_save_cpu_binding(&pb); error = 0; for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { if (!pmc_cpu_is_active(cpu)) continue; pmc_select_cpu(cpu); pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, M_WAITOK | M_ZERO); for (n = 0; error == 0 && n < md->pmd_nclass; n++) if (md->pmd_classdep[n].pcd_num > 0) error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); } pmc_restore_cpu_binding(&pb); if (error != 0) return (error); /* allocate space for the sample array */ for (cpu = 0; cpu < maxcpu; cpu++) { if (!pmc_cpu_is_active(cpu)) continue; pc = pcpu_find(cpu); domain = pc->pc_domain; sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + pmc_nsamples * sizeof(struct pmc_sample), M_PMC, DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); KASSERT(pmc_pcpu[cpu] != NULL, ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); sb->ps_callchains = malloc_domainset(pmc_callchaindepth * pmc_nsamples * sizeof(uintptr_t), M_PMC, DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) ps->ps_pc = sb->ps_callchains + (n * pmc_callchaindepth); pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + pmc_nsamples * sizeof(struct pmc_sample), M_PMC, DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); sb->ps_callchains = malloc_domainset(pmc_callchaindepth * pmc_nsamples * sizeof(uintptr_t), M_PMC, DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) ps->ps_pc = sb->ps_callchains + (n * pmc_callchaindepth); pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + pmc_nsamples * sizeof(struct pmc_sample), M_PMC, DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); sb->ps_callchains = malloc_domainset(pmc_callchaindepth * pmc_nsamples * sizeof(uintptr_t), M_PMC, DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; } /* allocate space for the row disposition array */ pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, M_PMC, M_WAITOK | M_ZERO); /* mark all PMCs as available */ for (n = 0; n < md->pmd_npmc; n++) PMC_MARK_ROW_FREE(n); /* allocate thread hash tables */ pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, &pmc_ownerhashmask); pmc_processhash = hashinit(pmc_hashsize, M_PMC, &pmc_processhashmask); mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", MTX_SPIN); CK_LIST_INIT(&pmc_ss_owners); pmc_ss_count = 0; /* allocate a pool of spin mutexes */ pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, MTX_SPIN); PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, pmc_processhash, pmc_processhashmask); /* Initialize a spin mutex for the thread free list. */ mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", MTX_SPIN); /* Initialize the task to prune the thread free list. */ TASK_INIT(&free_task, 0, pmc_thread_descriptor_pool_free_task, NULL); /* register process {exit,fork,exec} handlers */ pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); /* register kld event handlers */ pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, NULL, EVENTHANDLER_PRI_ANY); pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, NULL, EVENTHANDLER_PRI_ANY); /* initialize logging */ pmclog_initialize(); /* set hook functions */ pmc_intr = md->pmd_intr; wmb(); pmc_hook = pmc_hook_handler; if (error == 0) { printf(PMC_MODULE_NAME ":"); for (n = 0; n < md->pmd_nclass; n++) { if (md->pmd_classdep[n].pcd_num == 0) continue; pcd = &md->pmd_classdep[n]; printf(" %s/%d/%d/0x%b", pmc_name_of_pmcclass(pcd->pcd_class), pcd->pcd_num, pcd->pcd_width, pcd->pcd_caps, "\20" "\1INT\2USR\3SYS\4EDG\5THR" "\6REA\7WRI\10INV\11QUA\12PRC" "\13TAG\14CSC"); } printf("\n"); } return (error); } /* prepare to be unloaded */ static void pmc_cleanup(void) { struct pmc_binding pb; struct pmc_owner *po, *tmp; struct pmc_ownerhash *ph; struct pmc_processhash *prh __pmcdbg_used; u_int maxcpu; int cpu, c; PMCDBG0(MOD,INI,0, "cleanup"); /* switch off sampling */ CPU_FOREACH(cpu) DPCPU_ID_SET(cpu, pmc_sampled, 0); pmc_intr = NULL; sx_xlock(&pmc_sx); if (pmc_hook == NULL) { /* being unloaded already */ sx_xunlock(&pmc_sx); return; } pmc_hook = NULL; /* prevent new threads from entering module */ /* deregister event handlers */ EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); /* send SIGBUS to all owner threads, free up allocations */ if (pmc_ownerhash != NULL) { for (ph = pmc_ownerhash; ph <= &pmc_ownerhash[pmc_ownerhashmask]; ph++) { LIST_FOREACH_SAFE(po, ph, po_next, tmp) { pmc_remove_owner(po); PMCDBG3(MOD,INI,2, "cleanup signal proc=%p (%d, %s)", po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); PROC_LOCK(po->po_owner); kern_psignal(po->po_owner, SIGBUS); PROC_UNLOCK(po->po_owner); pmc_destroy_owner_descriptor(po); } } } /* reclaim allocated data structures */ taskqueue_drain(taskqueue_fast, &free_task); mtx_destroy(&pmc_threadfreelist_mtx); pmc_thread_descriptor_pool_drain(); if (pmc_mtxpool != NULL) mtx_pool_destroy(&pmc_mtxpool); mtx_destroy(&pmc_processhash_mtx); if (pmc_processhash != NULL) { #ifdef HWPMC_DEBUG struct pmc_process *pp; PMCDBG0(MOD,INI,3, "destroy process hash"); for (prh = pmc_processhash; prh <= &pmc_processhash[pmc_processhashmask]; prh++) LIST_FOREACH(pp, prh, pp_next) PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); #endif hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); pmc_processhash = NULL; } if (pmc_ownerhash != NULL) { PMCDBG0(MOD,INI,3, "destroy owner hash"); hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); pmc_ownerhash = NULL; } KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), ("[pmc,%d] Global SS owner list not empty", __LINE__)); KASSERT(pmc_ss_count == 0, ("[pmc,%d] Global SS count not empty", __LINE__)); /* do processor and pmc-class dependent cleanup */ maxcpu = pmc_cpu_max(); PMCDBG0(MOD,INI,3, "md cleanup"); if (md) { pmc_save_cpu_binding(&pb); for (cpu = 0; cpu < maxcpu; cpu++) { PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", cpu, pmc_pcpu[cpu]); if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) continue; pmc_select_cpu(cpu); for (c = 0; c < md->pmd_nclass; c++) { if (md->pmd_classdep[c].pcd_num > 0) { md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); } } } if (md->pmd_cputype == PMC_CPU_GENERIC) pmc_generic_cpu_finalize(md); else pmc_md_finalize(md); pmc_mdep_free(md); md = NULL; pmc_restore_cpu_binding(&pb); } /* Free per-cpu descriptors. */ for (cpu = 0; cpu < maxcpu; cpu++) { if (!pmc_cpu_is_active(cpu)) continue; KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, cpu)); KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, cpu)); KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, cpu)); free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); free(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); free(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); free(pmc_pcpu[cpu], M_PMC); } free(pmc_pcpu, M_PMC); pmc_pcpu = NULL; free(pmc_pcpu_saved, M_PMC); pmc_pcpu_saved = NULL; if (pmc_pmcdisp != NULL) { free(pmc_pmcdisp, M_PMC); pmc_pmcdisp = NULL; } if (pmc_rowindex_to_classdep != NULL) { free(pmc_rowindex_to_classdep, M_PMC); pmc_rowindex_to_classdep = NULL; } pmclog_shutdown(); counter_u64_free(pmc_stats.pm_intr_ignored); counter_u64_free(pmc_stats.pm_intr_processed); counter_u64_free(pmc_stats.pm_intr_bufferfull); counter_u64_free(pmc_stats.pm_syscalls); counter_u64_free(pmc_stats.pm_syscall_errors); counter_u64_free(pmc_stats.pm_buffer_requests); counter_u64_free(pmc_stats.pm_buffer_requests_failed); counter_u64_free(pmc_stats.pm_log_sweeps); counter_u64_free(pmc_stats.pm_merges); counter_u64_free(pmc_stats.pm_overwrites); sx_xunlock(&pmc_sx); /* we are done */ } /* * The function called at load/unload. */ static int load(struct module *module __unused, int cmd, void *arg __unused) { int error; error = 0; switch (cmd) { case MOD_LOAD: /* initialize the subsystem */ error = pmc_initialize(); if (error != 0) break; PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", pmc_syscall_num, pmc_cpu_max()); break; case MOD_UNLOAD: case MOD_SHUTDOWN: pmc_cleanup(); PMCDBG0(MOD,INI,1, "unloaded"); break; default: error = EINVAL; break; } return (error); }