/*- * Copyright (c) 2003-2005 Joseph Koshy * All rights reserved. * * 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 __FBSDID("$FreeBSD$"); #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 /* * 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 */ }; /* * 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)] >= (-mp_ncpus), ("[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; /* Module statistics */ struct pmc_op_getdriverstats pmc_stats; /* Machine/processor dependent operations */ 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 LIST_HEAD(, pmc_owner) pmc_ss_owners; /* * Prototypes */ #if 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_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 int 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_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 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 void pmc_force_context_switch(void); static void pmc_link_target_process(struct pmc *pm, struct pmc_process *pp); static void pmc_maybe_remove_owner(struct pmc_owner *po); static void pmc_process_csw_in(struct thread *td); static void pmc_process_csw_out(struct thread *td); 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_samples(int cpu); 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 void pmc_restore_cpu_binding(struct pmc_binding *pb); static void pmc_save_cpu_binding(struct pmc_binding *pb); static void pmc_select_cpu(int cpu); 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 void pmc_unlink_target_process(struct pmc *pmc, struct pmc_process *pp); /* * Kernel tunables and sysctl(8) interface. */ SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); #if 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_RW|CTLFLAG_TUN, 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); #endif /* * kern.hwpmc.hashrows -- determines the number of rows in the * of the hash table used to look up threads */ static int pmc_hashsize = PMC_HASH_SIZE; TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, &pmc_hashsize, 0, "rows in hash tables"); /* * kern.hwpmc.nsamples --- number of PC samples per CPU */ static int pmc_nsamples = PMC_NSAMPLES; TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, &pmc_nsamples, 0, "number of PC samples per CPU"); /* * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. */ static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, &pmc_mtxpool_size, 0, "size of spin mutex pool"); /* * 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. */ SYSCTL_DECL(_security_bsd); static int pmc_unprivileged_syspmcs = 0; TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, &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 = { 2, /* sy_narg */ pmc_syscall_handler /* sy_call */ }; static struct syscall_module_data pmc_syscall_mod = { load, NULL, &pmc_syscall_num, &pmc_sysent, { 0, NULL } }; static moduledata_t pmc_mod = { PMC_MODULE_NAME, syscall_module_handler, &pmc_syscall_mod }; DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); MODULE_VERSION(pmc, PMC_VERSION); #if 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) { char c, *p, *q; struct pmc_debugflags *tmpflags; int error, found, *newbits, tmp; size_t kwlen; MALLOC(tmpflags, struct pmc_debugflags *, sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); p = newstr; error = 0; for (; 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); 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); 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; unsigned int n; (void) arg1; (void) arg2; /* unused parameters */ n = sizeof(pmc_debugstr); MALLOC(newstr, char *, n, M_PMC, M_ZERO|M_WAITOK); (void) 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); if ((error = pmc_debugflags_parse(newstr, fence)) == 0) (void) strlcpy(pmc_debugstr, newstr, sizeof(pmc_debugstr)); } FREE(newstr, M_PMC); return error; } #endif /* * 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: * * - There is a 'global' SX lock "pmc_sx" that is used to protect * the its 'meta-data'. * * Calls into the module (via syscall() or by the kernel) 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. * * 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". These are 'leaf' mutexes, in that no other * lock is acquired with these locks held. * * - 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 an * tsleep() till the runcount comes to zero. * */ /* * save the cpu binding of the current kthread */ static void pmc_save_cpu_binding(struct pmc_binding *pb) { PMCDBG(CPU,BND,2, "%s", "save-cpu"); mtx_lock_spin(&sched_lock); pb->pb_bound = sched_is_bound(curthread); pb->pb_cpu = curthread->td_oncpu; mtx_unlock_spin(&sched_lock); PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); } /* * restore the cpu binding of the current thread */ static void pmc_restore_cpu_binding(struct pmc_binding *pb) { PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", curthread->td_oncpu, pb->pb_cpu); mtx_lock_spin(&sched_lock); if (pb->pb_bound) sched_bind(curthread, pb->pb_cpu); else sched_unbind(curthread); mtx_unlock_spin(&sched_lock); PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); } /* * move execution over the specified cpu and bind it there. */ static void pmc_select_cpu(int cpu) { KASSERT(cpu >= 0 && cpu < mp_ncpus, ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); /* never move to a disabled CPU */ KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " "disabled CPU %d", __LINE__, cpu)); PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); mtx_lock_spin(&sched_lock); sched_bind(curthread, cpu); mtx_unlock_spin(&sched_lock); KASSERT(curthread->td_oncpu == cpu, ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, cpu, curthread->td_oncpu)); PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); } /* * Force a context switch. * * We do this by tsleep'ing for 1 tick -- invoking mi_switch() is not * guaranteed to force a context switch. */ static void pmc_force_context_switch(void) { u_char curpri; mtx_lock_spin(&sched_lock); curpri = curthread->td_priority; mtx_unlock_spin(&sched_lock); (void) tsleep((void *) pmc_force_context_switch, curpri, "pmcctx", 1); } /* * 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) { struct thread *td; td = curthread; *fullpath = "unknown"; *freepath = NULL; vn_lock(v, LK_EXCLUSIVE | LK_RETRY, td); vn_fullpath(td, v, fullpath, freepath); VOP_UNLOCK(v, 0, td); } /* * remove an process owning PMCs */ void pmc_remove_owner(struct pmc_owner *po) { struct pmc *pm, *tmp; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG(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) { PMCDBG(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 */ } 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) { PMCDBG(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) { int ri; struct pmc_target *pt; 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); PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", pm, ri, pp); #if 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 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), M_PMC, M_ZERO|M_WAITOK); pt->pt_process = pp; LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); atomic_store_rel_ptr(&pp->pp_pmcs[ri].pp_pmc, 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++; } /* * 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; 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); PMCDBG(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; /* 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); psignal(p, SIGIO); PROC_UNLOCK(p); PMCDBG(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; char *fullpath, *freepath; struct pmc_process *pp; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG(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); if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) return ENOMEM; if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ return EEXIST; if (pp->pp_pmcs[ri].pp_pmc != NULL) return EBUSY; 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) { pmc_getfilename(p->p_textvp, &fullpath, &freepath); pmclog_process_pmcattach(pm, p->p_pid, fullpath); if (freepath) FREE(freepath, M_TEMP); } /* mark process as using HWPMCs */ PROC_LOCK(p); p->p_flag |= P_HWPMC; PROC_UNLOCK(p); return 0; } /* * 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); PMCDBG(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) (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); PMCDBG(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 targetting 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) FREE(pp, M_PMC); 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); PMCDBG(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; } /* * Thread context switch IN */ static void pmc_process_csw_in(struct thread *td) { int cpu; unsigned int ri; struct pmc *pm; struct proc *p; struct pmc_cpu *pc; struct pmc_hw *phw; struct pmc_process *pp; pmc_value_t newvalue; p = td->td_proc; 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 */ PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, p->p_pid, p->p_comm, pp); KASSERT(cpu >= 0 && cpu < mp_ncpus, ("[pmc,%d] wierd 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; /* increment PMC runcount */ atomic_add_rel_32(&pm->pm_runcount, 1); /* configure the HWPMC we are going to use. */ md->pmd_config_pmc(cpu, ri, 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-process value, while * counting mode PMCs use a per-pmc value that is * inherited across descendants. */ if (PMC_TO_MODE(pm) == PMC_MODE_TS) { mtx_pool_lock_spin(pmc_mtxpool, pm); newvalue = PMC_PCPU_SAVED(cpu,ri) = pp->pp_pmcs[ri].pp_pmcval; mtx_pool_unlock_spin(pmc_mtxpool, pm); } 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); } PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); md->pmd_write_pmc(cpu, ri, newvalue); md->pmd_start_pmc(cpu, ri); } /* * 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) { int cpu; enum pmc_mode mode; unsigned int ri; struct pmc *pm; struct proc *p; struct pmc_cpu *pc; struct pmc_process *pp; int64_t tmp; pmc_value_t newvalue; /* * 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); /* * save PMCs */ critical_enter(); cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, p->p_pid, p->p_comm, pp); KASSERT(cpu >= 0 && cpu < mp_ncpus, ("[pmc,%d wierd 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++) { pm = NULL; (void) (*md->pmd_get_config)(cpu, ri, &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)); /* Stop hardware if not already stopped */ if (pm->pm_stalled == 0) md->pmd_stop_pmc(cpu, ri); /* reduce this PMC's runcount */ atomic_subtract_rel_32(&pm->pm_runcount, 1); /* * If this PMC is associated with this process, * save the reading. */ if (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)); md->pmd_read_pmc(cpu, ri, &newvalue); tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, tmp); if (mode == PMC_MODE_TS) { /* * For sampling process-virtual PMCs, * we expect the count to be * decreasing as the 'value' * programmed into the PMC is the * number of events to be seen till * the next sampling interrupt. */ if (tmp < 0) tmp += pm->pm_sc.pm_reloadcount; mtx_pool_lock_spin(pmc_mtxpool, pm); pp->pp_pmcs[ri].pp_pmcval -= tmp; if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) pp->pp_pmcs[ri].pp_pmcval += pm->pm_sc.pm_reloadcount; mtx_pool_unlock_spin(pmc_mtxpool, pm); } else { /* * For counting process-virtual PMCs, * we expect the count to be * increasing monotonically, modulo a 64 * bit wraparound. */ KASSERT((int64_t) 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); } } /* mark hardware as free */ md->pmd_config_pmc(cpu, ri, NULL); } /* * perform any other architecture/cpu dependent thread * switch out functions. */ (void) (*md->pmd_switch_out)(pc, pp); critical_exit(); } /* * The 'hook' invoked from the kernel proper */ #if DEBUG const char *pmc_hooknames[] = { "", "EXIT", "EXEC", "FORK", "CSW-IN", "CSW-OUT", "SAMPLE" }; #endif static int pmc_hook_handler(struct thread *td, int function, void *arg) { PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, pmc_hooknames[function], arg); switch (function) { /* * Process exec() */ case PMC_FN_PROCESS_EXEC: { char *fullpath, *freepath; unsigned int ri; int is_using_hwpmcs; struct pmc *pm; struct proc *p; struct pmc_owner *po; struct pmc_process *pp; struct pmckern_procexec *pk; sx_assert(&pmc_sx, SX_XLOCKED); p = td->td_proc; pmc_getfilename(p->p_textvp, &fullpath, &freepath); pk = (struct pmckern_procexec *) arg; /* Inform owners of SS mode PMCs of the exec event. */ LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) if (po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_procexec(po, PMC_ID_INVALID, p->p_pid, pk->pm_entryaddr, fullpath); PROC_LOCK(p); is_using_hwpmcs = p->p_flag & P_HWPMC; PROC_UNLOCK(p); if (!is_using_hwpmcs) { if (freepath) FREE(freepath, M_TEMP); break; } /* * 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 this process is the target of a PMC, check if the new * credentials are compatible with the owner's permissions. */ if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) break; /* * Log the exec event to all monitoring owners. Skip * owners who have already recieved the event because * the have system sampling PMCs active. */ for (ri = 0; ri < md->pmd_npmc; ri++) if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { po = pm->pm_owner; if (po->po_sscount == 0 && po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_procexec(po, pm->pm_id, p->p_pid, pk->pm_entryaddr, fullpath); } if (freepath) FREE(freepath, M_TEMP); PMCDBG(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 */ break; /* * 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 priviledge. */ 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 < (int) md->pmd_npmc, ("[pmc,%d] Illegal ref count %d 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); FREE(pp, M_PMC); break; } } 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. */ atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); pmc_process_samples(PCPU_GET(cpuid)); break; default: #if 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) { uint32_t hindex; struct pmc_owner *po; struct pmc_ownerhash *poh; hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); poh = &pmc_ownerhash[hindex]; /* allocate space for N pointers and one descriptor struct */ MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), M_PMC, M_ZERO|M_WAITOK); po->po_sscount = po->po_error = po->po_flags = 0; po->po_file = NULL; po->po_owner = p; po->po_kthread = NULL; LIST_INIT(&po->po_pmcs); 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", MTX_SPIN); PMCDBG(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) { PMCDBG(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); } /* * 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) { uint32_t hindex; struct pmc_process *pp, *ppnew; struct pmc_processhash *pph; hindex = PMC_HASH_PTR(p, pmc_processhashmask); pph = &pmc_processhash[hindex]; ppnew = NULL; /* * Pre-allocate memory in the FIND_ALLOCATE case since we * cannot call malloc(9) once we hold a spin lock. */ if (mode & PMC_FLAG_ALLOCATE) { /* allocate additional space for 'n' pmc pointers */ MALLOC(ppnew, struct pmc_process *, sizeof(struct pmc_process) + md->pmd_npmc * sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); } mtx_lock_spin(&pmc_processhash_mtx); LIST_FOREACH(pp, pph, pp_next) if (pp->pp_proc == p) break; if ((mode & PMC_FLAG_REMOVE) && pp != NULL) LIST_REMOVE(pp, pp_next); if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && ppnew != NULL) { ppnew->pp_proc = p; LIST_INSERT_HEAD(pph, ppnew, pp_next); pp = ppnew; ppnew = NULL; } mtx_unlock_spin(&pmc_processhash_mtx); if (pp != NULL && 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); } /* * find an owner descriptor corresponding to proc 'p' */ static struct pmc_owner * pmc_find_owner_descriptor(struct proc *p) { uint32_t hindex; struct pmc_owner *po; struct pmc_ownerhash *poh; 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; PMCDBG(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; } /* * pmc_allocate_pmc_descriptor * * Allocate a pmc descriptor and initialize its * fields. */ static struct pmc * pmc_allocate_pmc_descriptor(void) { struct pmc *pmc; MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); if (pmc != NULL) { pmc->pm_owner = NULL; LIST_INIT(&pmc->pm_targets); } PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); return pmc; } /* * Destroy a pmc descriptor. */ static void pmc_destroy_pmc_descriptor(struct pmc *pm) { (void) pm; #if DEBUG 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(pm->pm_runcount == 0, ("[pmc,%d] pmc has non-zero run count %d", __LINE__, pm->pm_runcount)); #endif } static void pmc_wait_for_pmc_idle(struct pmc *pm) { #if DEBUG volatile int maxloop; maxloop = 100 * mp_ncpus; #endif /* * Loop (with a forced context switch) till the PMC's runcount * comes down to zero. */ while (atomic_load_acq_32(&pm->pm_runcount) > 0) { #if DEBUG maxloop--; KASSERT(maxloop > 0, ("[pmc,%d] (ri%d, rc%d) waiting too long for " "pmc to be free", __LINE__, PMC_TO_ROWINDEX(pm), 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 * - destroy's the PMC private mutex * * Once this function completes, the given pmc pointer can be safely * FREE'd by the caller. */ static void pmc_release_pmc_descriptor(struct pmc *pm) { u_int ri, cpu; enum pmc_mode mode; struct pmc_hw *phw; struct pmc_owner *po; struct pmc_process *pp; struct pmc_target *ptgt, *tmp; struct pmc_binding pb; sx_assert(&pmc_sx, SX_XLOCKED); KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); ri = PMC_TO_ROWINDEX(pm); mode = PMC_TO_MODE(pm); PMCDBG(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 */ if (pm->pm_state == PMC_STATE_RUNNING && pm->pm_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)); PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); critical_enter(); md->pmd_stop_pmc(cpu, ri); critical_exit(); } PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); critical_enter(); md->pmd_config_pmc(cpu, ri, 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); LIST_REMOVE(po, po_ssnext); } } 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' */ PMCDBG(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); FREE(pp, M_PMC); } } cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ } /* * Release any MD resources */ (void) md->pmd_release_pmc(cpu, ri, 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) { LIST_REMOVE(pm, pm_next); pm->pm_owner = NULL; } pmc_destroy_pmc_descriptor(pm); } /* * 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) pmclog_process_pmcallocate(pmc); PMCDBG(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 int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) { enum pmc_mode mode; struct pmc *pm; struct pmc_owner *po; struct pmc_process *pp; PMCDBG(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 EEXIST; if (PMC_IS_SYSTEM_MODE(mode) && (int) PMC_TO_CPU(pm) == cpu) return EEXIST; } } /* * 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) return EEXIST; PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", p, p->p_pid, p->p_comm, ri); return 0; } /* * Check if a given PMC at row index 'ri' can be currently used in * mode 'mode'. */ static int pmc_can_allocate_row(int ri, enum pmc_mode mode) { enum pmc_disp disp; sx_assert(&pmc_sx, SX_XLOCKED); PMCDBG(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 EBUSY; /* * All OK */ PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); return 0; } /* * 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; struct pmc_owner *po; PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) return ESRCH; if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) return EINVAL; PMCDBG(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) { int error, cpu, ri; enum pmc_mode mode; struct pmc_owner *po; struct pmc_binding pb; KASSERT(pm != NULL, ("[pmc,%d] null pm", __LINE__)); mode = PMC_TO_MODE(pm); ri = PMC_TO_ROWINDEX(pm); error = 0; PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); po = pm->pm_owner; 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) ? ESRCH : pmc_attach_process(po->po_owner, pm); /* * Disallow PMCSTART if a logfile is required but has not * been configured yet. */ if (error == 0 && (pm->pm_flags & PMC_F_NEEDS_LOGFILE) && (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) error = EDOOFUS; /* * 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) pmc_force_context_switch(); } return error; } /* * A system-wide PMC. */ if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) return EDOOFUS; /* programming error */ /* * Add the owner to the global list if this is a system-wide * sampling PMC. */ if (mode == PMC_MODE_SS) { if (po->po_sscount == 0) { LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); atomic_add_rel_int(&pmc_ss_count, 1); PMCDBG(PMC,OPS,1, "po=%p in global list", po); } po->po_sscount++; } /* * 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_disabled(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(); if ((error = md->pmd_write_pmc(cpu, ri, PMC_IS_SAMPLING_MODE(mode) ? pm->pm_sc.pm_reloadcount : pm->pm_sc.pm_initial)) == 0) error = md->pmd_start_pmc(cpu, ri); critical_exit(); pmc_restore_cpu_binding(&pb); return error; } /* * Stop a PMC. */ static int pmc_stop(struct pmc *pm) { int cpu, error, ri; struct pmc_owner *po; struct pmc_binding pb; KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); PMCDBG(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 < mp_ncpus, ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); if (pmc_cpu_is_disabled(cpu)) return ENXIO; pmc_select_cpu(cpu); ri = PMC_TO_ROWINDEX(pm); critical_enter(); if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); critical_exit(); pmc_restore_cpu_binding(&pb); po = pm->pm_owner; /* remove this owner from the global list of SS PMC owners */ if (PMC_TO_MODE(pm) == PMC_MODE_SS) { po->po_sscount--; if (po->po_sscount == 0) { atomic_subtract_rel_int(&pmc_ss_count, 1); LIST_REMOVE(po, po_ssnext); PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); } } return error; } #if DEBUG 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 = 1; \ } while (0) static int pmc_syscall_handler(struct thread *td, void *syscall_args) { int error, is_sx_downgraded, op; struct pmc_syscall_args *c; void *arg; PMC_GET_SX_XLOCK(ENOSYS); DROP_GIANT(); is_sx_downgraded = 0; c = (struct pmc_syscall_args *) syscall_args; op = c->pmop_code; arg = c->pmop_data; PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, pmc_op_to_name[op], arg); error = 0; atomic_add_int(&pmc_stats.pm_syscalls, 1); switch(op) { /* * Configure a log file. * * XXX This OP will be reworked. */ case PMC_OP_CONFIGURELOG: { struct pmc_owner *po; struct pmc_op_configurelog cl; struct proc *p; sx_assert(&pmc_sx, SX_XLOCKED); if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 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) { 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(po, cl.pm_logfd); else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { pmclog_process_closelog(po); error = pmclog_flush(po); if (error == 0) error = pmclog_deconfigure_log(po); } else 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); } break; /* * Retrieve hardware configuration. */ case PMC_OP_GETCPUINFO: /* CPU information */ { struct pmc_op_getcpuinfo gci; gci.pm_cputype = md->pmd_cputype; gci.pm_ncpu = mp_ncpus; gci.pm_npmc = md->pmd_npmc; gci.pm_nclass = md->pmd_nclass; bcopy(md->pmd_classes, &gci.pm_classes, sizeof(gci.pm_classes)); error = copyout(&gci, arg, sizeof(gci)); } break; /* * Get module statistics */ case PMC_OP_GETDRIVERSTATS: { struct pmc_op_getdriverstats gms; bcopy(&pmc_stats, &gms, sizeof(gms)); 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: { uint32_t cpu, n, npmc; size_t pmcinfo_size; struct pmc *pm; struct pmc_info *p, *pmcinfo; struct pmc_op_getpmcinfo *gpi; struct pmc_owner *po; struct pmc_binding pb; PMC_DOWNGRADE_SX(); gpi = (struct pmc_op_getpmcinfo *) arg; if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) break; if (cpu >= (unsigned int) mp_ncpus) { error = EINVAL; break; } if (pmc_cpu_is_disabled(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); MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, M_WAITOK); p = pmcinfo; for (n = 0; n < md->pmd_npmc; n++, p++) { if ((error = md->pmd_describe(cpu, n, 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__)); if (suser(td) || jailed(td->td_ucred)) { error = EPERM; break; } if ((error = copyin(arg, &pma, sizeof(pma))) != 0) break; cpu = pma.pm_cpu; if (cpu < 0 || cpu >= mp_ncpus) { error = EINVAL; break; } if (pmc_cpu_is_disabled(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: { uint32_t caps; u_int cpu; int n; enum pmc_mode mode; struct pmc *pmc; struct pmc_hw *phw; struct pmc_op_pmcallocate pa; struct pmc_binding pb; if ((error = copyin(arg, &pa, sizeof(pa))) != 0) break; caps = pa.pm_caps; mode = pa.pm_mode; cpu = pa.pm_cpu; if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && mode != PMC_MODE_TS && mode != PMC_MODE_TC) || (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { error = EINVAL; break; } /* * 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 != (u_int) PMC_CPU_ANY) || (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { error = EINVAL; break; } /* * Check that a disabled CPU is not being asked for. */ if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { error = ENXIO; break; } /* * 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(curthread->td_ucred)) error = EPERM; else if (suser(curthread) && (pmc_unprivileged_syspmcs == 0)) error = EPERM; } if (error) break; /* * Look for valid values for 'pm_flags' */ if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT)) != 0) { error = EINVAL; break; } /* process logging options are not allowed for system PMCs */ if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { error = EINVAL; break; } /* * All sampling mode PMCs need to be able to interrupt the * CPU. */ if (PMC_IS_SAMPLING_MODE(mode)) caps |= PMC_CAP_INTERRUPT; PMCDBG(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,pa.pm_class, PMC_ID_INVALID); pmc->pm_event = pa.pm_ev; pmc->pm_state = PMC_STATE_FREE; pmc->pm_caps = caps; pmc->pm_flags = pa.pm_flags; /* 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 = 0; n < (int) md->pmd_npmc; n++) if (pmc_can_allocate_row(n, mode) == 0 && pmc_can_allocate_rowindex( curthread->td_proc, n, cpu) == 0 && (PMC_IS_UNALLOCATED(cpu, n) || PMC_IS_SHAREABLE_PMC(cpu, n)) && md->pmd_allocate_pmc(cpu, n, pmc, &pa) == 0) break; } else { /* Process virtual mode */ for (n = 0; n < (int) md->pmd_npmc; n++) { if (pmc_can_allocate_row(n, mode) == 0 && pmc_can_allocate_rowindex( curthread->td_proc, n, PMC_CPU_ANY) == 0 && md->pmd_allocate_pmc(curthread->td_oncpu, n, pmc, &pa) == 0) break; } } #undef PMC_IS_UNALLOCATED #undef PMC_IS_SHAREABLE_PMC pmc_restore_cpu_binding(&pb); if (n == (int) md->pmd_npmc) { pmc_destroy_pmc_descriptor(pmc); FREE(pmc, M_PMC); pmc = NULL; error = EINVAL; break; } /* Fill in the correct value in the ID field */ pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", pmc->pm_event, pa.pm_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)) 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]; if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { (void) md->pmd_release_pmc(cpu, n, pmc); pmc_destroy_pmc_descriptor(pmc); FREE(pmc, M_PMC); pmc = NULL; pmc_restore_cpu_binding(&pb); error = EPERM; break; } pmc_restore_cpu_binding(&pb); } pmc->pm_state = PMC_STATE_ALLOCATED; /* * 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. */ if ((error = pmc_register_owner(curthread->td_proc, pmc)) != 0) { pmc_release_pmc_descriptor(pmc); FREE(pmc, M_PMC); pmc = NULL; break; } /* * Return the allocated index. */ pa.pm_pmcid = pmc->pm_id; error = copyout(&pa, arg, sizeof(pa)); } break; /* * Attach a PMC to a process. */ case PMC_OP_PMCATTACH: { struct pmc *pm; struct proc *p; struct pmc_op_pmcattach a; sx_assert(&pmc_sx, SX_XLOCKED); if ((error = copyin(arg, &a, sizeof(a))) != 0) break; if (a.pm_pid < 0) { error = EINVAL; break; } else if (a.pm_pid == 0) a.pm_pid = td->td_proc->p_pid; if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) break; if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { error = EINVAL; break; } /* PMCs may be (re)attached only when allocated or stopped */ if (pm->pm_state == PMC_STATE_RUNNING) { error = EBUSY; break; } else if (pm->pm_state != PMC_STATE_ALLOCATED && pm->pm_state != PMC_STATE_STOPPED) { error = EINVAL; break; } /* lookup pid */ if ((p = pfind(a.pm_pid)) == NULL) { error = ESRCH; break; } /* * Ignore processes that are working on exiting. */ if (p->p_flag & P_WEXIT) { error = ESRCH; PROC_UNLOCK(p); /* pfind() returns a locked process */ break; } /* * 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); } break; /* * Detach an attached PMC from a process. */ case PMC_OP_PMCDETACH: { struct pmc *pm; struct proc *p; struct pmc_op_pmcattach a; if ((error = copyin(arg, &a, sizeof(a))) != 0) break; if (a.pm_pid < 0) { error = EINVAL; break; } else if (a.pm_pid == 0) a.pm_pid = td->td_proc->p_pid; if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) break; if ((p = pfind(a.pm_pid)) == NULL) { error = ESRCH; break; } /* * Treat processes that are in the process of exiting * as if they were not present. */ if (p->p_flag & P_WEXIT) error = ESRCH; PROC_UNLOCK(p); /* pfind() returns a locked process */ if (error == 0) error = pmc_detach_process(p, pm); } 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 ri; struct pmc *pm; struct pmc_target *pt; struct pmc_op_getmsr gm; PMC_DOWNGRADE_SX(); /* CPU has no 'GETMSR' support */ if (md->pmd_get_msr == NULL) { error = ENOSYS; break; } 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); if ((error = (*md->pmd_get_msr)(ri, &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: { pmc_id_t pmcid; struct pmc *pm; struct pmc_owner *po; struct pmc_op_simple sp; /* * 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. */ if ((error = copyin(arg, &sp, sizeof(sp))) != 0) break; pmcid = sp.pm_pmcid; if ((error = pmc_find_pmc(pmcid, &pm)) != 0) break; po = pm->pm_owner; pmc_release_pmc_descriptor(pm); pmc_maybe_remove_owner(po); FREE(pm, M_PMC); } break; /* * Read and/or write a PMC. */ case PMC_OP_PMCRW: { uint32_t cpu, ri; struct pmc *pm; struct pmc_op_pmcrw *pprw; struct pmc_op_pmcrw prw; struct pmc_binding pb; pmc_value_t oldvalue; PMC_DOWNGRADE_SX(); if ((error = copyin(arg, &prw, sizeof(prw))) != 0) break; ri = 0; PMCDBG(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) { error = EINVAL; break; } /* locate pmc descriptor */ if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) break; /* 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) { error = EINVAL; break; } /* writing a new value is allowed only for 'STOPPED' pmcs */ if (pm->pm_state == PMC_STATE_RUNNING && (prw.pm_flags & PMC_F_NEWVALUE)) { error = EBUSY; break; } 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); mtx_pool_lock_spin(pmc_mtxpool, pm); cpu = curthread->td_oncpu; if (prw.pm_flags & PMC_F_OLDVALUE) { if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && (pm->pm_state == PMC_STATE_RUNNING)) error = (*md->pmd_read_pmc)(cpu, ri, &oldvalue); else oldvalue = pm->pm_gv.pm_savedvalue; } if (prw.pm_flags & PMC_F_NEWVALUE) 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); if (pmc_cpu_is_disabled(cpu)) { error = ENXIO; break; } /* 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) if ((error = (*md->pmd_read_pmc)(cpu, ri, &oldvalue))) goto error; /* write out new value */ if (prw.pm_flags & PMC_F_NEWVALUE) error = (*md->pmd_write_pmc)(cpu, ri, prw.pm_value); error: critical_exit(); pmc_restore_cpu_binding(&pb); if (error) break; } pprw = (struct pmc_op_pmcrw *) arg; #if DEBUG if (prw.pm_flags & PMC_F_NEWVALUE) PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", ri, prw.pm_value, oldvalue); else PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); #endif /* return old value if requested */ if (prw.pm_flags & PMC_F_OLDVALUE) if ((error = copyout(&oldvalue, &pprw->pm_value, sizeof(prw.pm_value)))) break; } 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))) pm->pm_sc.pm_reloadcount = 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); if (error) atomic_add_int(&pmc_stats.pm_syscall_errors, 1); PICKUP_GIANT(); return error; } /* * Helper functions */ /* * Interrupt processing. * * Find a free slot in the per-cpu array of PC samples and write the * current (PMC,PID,PC) triple to it. If an event 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. */ int pmc_process_interrupt(int cpu, struct pmc *pm, uintfptr_t pc, int usermode) { int error, ri; struct thread *td; struct pmc_sample *ps; struct pmc_samplebuffer *psb; error = 0; ri = PMC_TO_ROWINDEX(pm); psb = pmc_pcpu[cpu]->pc_sb; ps = psb->ps_write; if (ps->ps_pc) { /* in use, reader hasn't caught up */ pm->pm_stalled = 1; atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, (uint64_t) pc, usermode, (int) (psb->ps_write - psb->ps_samples), (int) (psb->ps_read - psb->ps_samples)); error = ENOMEM; goto done; } /* fill in entry */ PMCDBG(SAM,INT,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, (uint64_t) pc, usermode, (int) (psb->ps_write - psb->ps_samples), (int) (psb->ps_read - psb->ps_samples)); atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ ps->ps_pmc = pm; if ((td = curthread) && td->td_proc) ps->ps_pid = td->td_proc->p_pid; else ps->ps_pid = -1; ps->ps_usermode = usermode; ps->ps_pc = pc; /* mark entry as in use */ /* increment write pointer, modulo ring buffer size */ ps++; if (ps == psb->ps_fence) psb->ps_write = psb->ps_samples; else psb->ps_write = ps; done: /* mark CPU as needing processing */ atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); return error; } /* * Process saved PC samples. */ static void pmc_process_samples(int cpu) { int n, ri; struct pmc *pm; struct thread *td; struct pmc_owner *po; struct pmc_sample *ps; struct pmc_samplebuffer *psb; 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; for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ ps = psb->ps_read; if (ps->ps_pc == (uintfptr_t) 0) /* no data */ break; pm = ps->ps_pmc; po = pm->pm_owner; KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, pm, PMC_TO_MODE(pm))); /* Ignore PMCs that have been switched off */ if (pm->pm_state != PMC_STATE_RUNNING) goto entrydone; PMCDBG(SAM,OPS,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, (uint64_t) ps->ps_pc, ps->ps_usermode, (int) (psb->ps_write - psb->ps_samples), (int) (psb->ps_read - psb->ps_samples)); /* * 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. */ if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { if (ps->ps_usermode) { td = FIRST_THREAD_IN_PROC(po->po_owner); addupc_intr(td, ps->ps_pc, 1); } goto entrydone; } /* * 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. */ pmclog_process_pcsample(pm, ps); entrydone: ps->ps_pc = (uintfptr_t) 0; /* mark entry as free */ atomic_subtract_rel_32(&pm->pm_runcount, 1); /* increment read pointer, modulo sample size */ if (++ps == psb->ps_fence) psb->ps_read = psb->ps_samples; else psb->ps_read = ps; } atomic_add_int(&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++) { (void) (*md->pmd_get_config)(cpu,n,&pm); if (pm == NULL || /* !cfg'ed */ pm->pm_state != PMC_STATE_RUNNING || /* !active */ !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ pm->pm_stalled == 0) /* !stalled */ continue; pm->pm_stalled = 0; ri = PMC_TO_ROWINDEX(pm); (*md->pmd_start_pmc)(cpu, ri); } } /* * 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) { int is_using_hwpmcs; int cpu; unsigned int ri; struct pmc *pm; struct pmc_process *pp; struct pmc_owner *po; pmc_value_t newvalue, tmp; PROC_LOCK(p); is_using_hwpmcs = p->p_flag & P_HWPMC; PROC_UNLOCK(p); /* * Log a sysexit event to all SS PMC owners. */ LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) if (po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_sysexit(po, p->p_pid); if (!is_using_hwpmcs) return; PMC_GET_SX_XLOCK(); PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, p->p_comm); /* * 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 targetting this * process off the hardware. * * We also need to atomically remove this process' * entry from our target process hash table, using * PMC_FLAG_REMOVE. */ PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, p->p_comm); critical_enter(); /* no preemption */ cpu = curthread->td_oncpu; if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_REMOVE)) != NULL) { PMCDBG(PRC,EXT,2, "process-exit proc=%p pmc-process=%p", p, pp); /* * The exiting process could 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; (void) (*md->pmd_get_config)(cpu, ri, &pm); PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); if (pm == NULL || !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) continue; PMCDBG(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)); (void) md->pmd_stop_pmc(cpu, ri); KASSERT(pm->pm_runcount > 0, ("[pmc,%d] bad runcount ri %d rc %d", __LINE__, ri, pm->pm_runcount)); /* Stop hardware only if it is actually running */ if (pm->pm_state == PMC_STATE_RUNNING && pm->pm_stalled == 0) { md->pmd_read_pmc(cpu, ri, &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); } atomic_subtract_rel_32(&pm->pm_runcount,1); KASSERT((int) pm->pm_runcount >= 0, ("[pmc,%d] runcount is %d", __LINE__, ri)); (void) md->pmd_config_pmc(cpu, ri, 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 * targetting 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 && PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) pmclog_process_procexit(pm, pp); pmc_unlink_target_process(pm, pp); } FREE(pp, M_PMC); } else critical_exit(); /* pp == NULL */ /* * If the process owned PMCs, free them up and free up * memory. */ if ((po = pmc_find_owner_descriptor(p)) != NULL) { 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) { int is_using_hwpmcs; unsigned int ri; uint32_t do_descendants; struct pmc *pm; struct pmc_owner *po; struct pmc_process *ppnew, *ppold; (void) flags; /* unused parameter */ PROC_LOCK(p1); is_using_hwpmcs = p1->p_flag & P_HWPMC; PROC_UNLOCK(p1); /* * If there are system-wide sampling PMCs active, we need to * log all fork events to their owner's logs. */ 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); if (!is_using_hwpmcs) return; PMC_GET_SX_XLOCK(); PMCDBG(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. */ if ((ppold = pmc_find_process_descriptor(curthread->td_proc, PMC_FLAG_NONE)) == NULL) goto done; /* nothing to do */ do_descendants = 0; for (ri = 0; ri < md->pmd_npmc; ri++) if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; if (do_descendants == 0) /* nothing to do */ goto done; /* allocate a descriptor for the new process */ if ((ppnew = pmc_find_process_descriptor(newproc, PMC_FLAG_ALLOCATE)) == 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)) { pmc_link_target_process(pm, ppnew); po = pm->pm_owner; if (po->po_sscount == 0 && po->po_flags & PMC_PO_OWNS_LOGFILE) pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); } /* * Now mark the new process as being tracked by this driver. */ PROC_LOCK(newproc); newproc->p_flag |= P_HWPMC; PROC_UNLOCK(newproc); done: sx_xunlock(&pmc_sx); } /* * initialization */ static const char *pmc_name_of_pmcclass[] = { #undef __PMC_CLASS #define __PMC_CLASS(N) #N , __PMC_CLASSES() }; static int pmc_initialize(void) { int cpu, error, n; struct pmc_binding pb; struct pmc_samplebuffer *sb; md = NULL; error = 0; #if 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 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); /* * check sysctl parameters */ if (pmc_hashsize <= 0) { (void) 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) { (void) printf("hwpmc: tunable nsamples=%d out of range.\n", pmc_nsamples); pmc_nsamples = PMC_NSAMPLES; } md = pmc_md_initialize(); if (md == NULL || md->pmd_init == NULL) return ENOSYS; /* allocate space for the per-cpu array */ MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), M_PMC, M_WAITOK|M_ZERO); /* per-cpu 'saved values' for managing process-mode PMCs */ MALLOC(pmc_pcpu_saved, pmc_value_t *, sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); /* perform cpu dependent initialization */ pmc_save_cpu_binding(&pb); for (cpu = 0; cpu < mp_ncpus; cpu++) { if (pmc_cpu_is_disabled(cpu)) continue; pmc_select_cpu(cpu); if ((error = md->pmd_init(cpu)) != 0) break; } pmc_restore_cpu_binding(&pb); if (error != 0) return error; /* allocate space for the sample array */ for (cpu = 0; cpu < mp_ncpus; cpu++) { if (pmc_cpu_is_disabled(cpu)) continue; MALLOC(sb, struct pmc_samplebuffer *, sizeof(struct pmc_samplebuffer) + pmc_nsamples * sizeof(struct pmc_sample), M_PMC, M_WAITOK|M_ZERO); sb->ps_read = sb->ps_write = sb->ps_samples; sb->ps_fence = sb->ps_samples + pmc_nsamples ; KASSERT(pmc_pcpu[cpu] != NULL, ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); pmc_pcpu[cpu]->pc_sb = sb; } /* allocate space for the row disposition array */ pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); KASSERT(pmc_pmcdisp != NULL, ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); /* mark all PMCs as available */ for (n = 0; n < (int) 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", MTX_SPIN); LIST_INIT(&pmc_ss_owners); pmc_ss_count = 0; /* allocate a pool of spin mutexes */ pmc_mtxpool = mtx_pool_create("pmc", pmc_mtxpool_size, MTX_SPIN); PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, pmc_processhash, pmc_processhashmask); /* 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); /* initialize logging */ pmclog_initialize(); /* set hook functions */ pmc_intr = md->pmd_intr; pmc_hook = pmc_hook_handler; if (error == 0) { printf(PMC_MODULE_NAME ":"); for (n = 0; n < (int) md->pmd_nclass; n++) printf(" %s(%d)", pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], md->pmd_nclasspmcs[n]); printf("\n"); } return error; } /* prepare to be unloaded */ static void pmc_cleanup(void) { int cpu; struct pmc_ownerhash *ph; struct pmc_owner *po, *tmp; struct pmc_binding pb; #if DEBUG struct pmc_processhash *prh; #endif PMCDBG(MOD,INI,0, "%s", "cleanup"); /* switch off sampling */ atomic_store_rel_int(&pmc_cpumask, 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); /* send SIGBUS to all owner threads, free up allocations */ if (pmc_ownerhash) for (ph = pmc_ownerhash; ph <= &pmc_ownerhash[pmc_ownerhashmask]; ph++) { LIST_FOREACH_SAFE(po, ph, po_next, tmp) { pmc_remove_owner(po); /* send SIGBUS to owner processes */ PMCDBG(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); psignal(po->po_owner, SIGBUS); PROC_UNLOCK(po->po_owner); pmc_destroy_owner_descriptor(po); } } /* reclaim allocated data structures */ if (pmc_mtxpool) mtx_pool_destroy(&pmc_mtxpool); mtx_destroy(&pmc_processhash_mtx); if (pmc_processhash) { #if DEBUG struct pmc_process *pp; PMCDBG(MOD,INI,3, "%s", "destroy process hash"); for (prh = pmc_processhash; prh <= &pmc_processhash[pmc_processhashmask]; prh++) LIST_FOREACH(pp, prh, pp_next) PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); #endif hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); pmc_processhash = NULL; } if (pmc_ownerhash) { PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); pmc_ownerhash = NULL; } KASSERT(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 dependent cleanup */ PMCDBG(MOD,INI,3, "%s", "md cleanup"); if (md) { pmc_save_cpu_binding(&pb); for (cpu = 0; cpu < mp_ncpus; cpu++) { PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", cpu, pmc_pcpu[cpu]); if (pmc_cpu_is_disabled(cpu)) continue; pmc_select_cpu(cpu); if (pmc_pcpu[cpu]) (void) md->pmd_cleanup(cpu); } FREE(md, M_PMC); md = NULL; pmc_restore_cpu_binding(&pb); } /* deallocate per-cpu structures */ FREE(pmc_pcpu, M_PMC); pmc_pcpu = NULL; FREE(pmc_pcpu_saved, M_PMC); pmc_pcpu_saved = NULL; if (pmc_pmcdisp) { FREE(pmc_pmcdisp, M_PMC); pmc_pmcdisp = NULL; } pmclog_shutdown(); 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; PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", pmc_syscall_num, mp_ncpus); break; case MOD_UNLOAD : case MOD_SHUTDOWN: pmc_cleanup(); PMCDBG(MOD,INI,1, "%s", "unloaded"); break; default : error = EINVAL; /* XXX should panic(9) */ break; } return error; } /* memory pool */ MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module");