hwpmc: fix load/unload race and vm map LOR
- fix load/unload race by allocating the per-domain list structure at boot - fix long extant vm map LOR by replacing pmc_sx sx_slock with global_epoch to protect the liveness of elements of the pmc_ss_owners list Reported by: pho Approved by: sbruno
This commit is contained in:
Matt Macy
parent
0c58f85b8d
commit
0f00315cb3
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=333596
@ -63,20 +63,10 @@ __FBSDID("$FreeBSD$");
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#ifdef NUMA
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#define NDOMAINS vm_ndomains
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static int
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getdomain(int cpu)
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{
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struct pcpu *pc;
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pc = pcpu_find(cpu);
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return (pc->pc_domain);
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}
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#else
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#define NDOMAINS 1
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#define malloc_domain(size, type, domain, flags) malloc((size), (type), (flags))
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#define free_domain(addr, type) free(addr, type)
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#define getdomain(cpu) 0
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#endif
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/*
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@ -225,16 +215,6 @@ struct pmclog_buffer {
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uint16_t plb_domain;
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} __aligned(CACHE_LINE_SIZE);
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struct pmc_domain_buffer_header {
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struct mtx pdbh_mtx;
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TAILQ_HEAD(, pmclog_buffer) pdbh_head;
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struct pmclog_buffer *pdbh_plbs;
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int pdbh_ncpus;
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} __aligned(CACHE_LINE_SIZE);
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struct pmc_domain_buffer_header *pmc_dom_hdrs[MAXMEMDOM];
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/*
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* Prototypes
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*/
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@ -280,6 +260,7 @@ pmclog_get_buffer(struct pmc_owner *po)
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("[pmclog,%d] po=%p current buffer still valid", __LINE__, po));
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domain = PCPU_GET(domain);
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MPASS(pmc_dom_hdrs[domain]);
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mtx_lock_spin(&pmc_dom_hdrs[domain]->pdbh_mtx);
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if ((plb = TAILQ_FIRST(&pmc_dom_hdrs[domain]->pdbh_head)) != NULL)
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TAILQ_REMOVE(&pmc_dom_hdrs[domain]->pdbh_head, plb, plb_next);
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@ -1165,7 +1146,7 @@ pmclog_process_userlog(struct pmc_owner *po, struct pmc_op_writelog *wl)
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void
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pmclog_initialize()
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{
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int domain, cpu;
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int domain;
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struct pmclog_buffer *plb;
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if (pmclog_buffer_size <= 0 || pmclog_buffer_size > 16*1024) {
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@ -1180,24 +1161,12 @@ pmclog_initialize()
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"than zero.\n", pmc_nlogbuffers_pcpu);
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pmc_nlogbuffers_pcpu = PMC_NLOGBUFFERS_PCPU;
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}
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if (pmc_nlogbuffers_pcpu*pmclog_buffer_size > 32*1024) {
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(void) printf("hwpmc: memory allocated pcpu must be less than 32MB (is %dK).\n",
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pmc_nlogbuffers_pcpu*pmclog_buffer_size);
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pmc_nlogbuffers_pcpu = PMC_NLOGBUFFERS_PCPU;
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pmclog_buffer_size = PMC_LOG_BUFFER_SIZE;
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}
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for (domain = 0; domain < NDOMAINS; domain++) {
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pmc_dom_hdrs[domain] = malloc_domain(sizeof(struct pmc_domain_buffer_header), M_PMC, domain,
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M_WAITOK|M_ZERO);
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mtx_init(&pmc_dom_hdrs[domain]->pdbh_mtx, "pmc_bufferlist_mtx", "pmc-leaf", MTX_SPIN);
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TAILQ_INIT(&pmc_dom_hdrs[domain]->pdbh_head);
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}
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CPU_FOREACH(cpu) {
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domain = getdomain(cpu);
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KASSERT(pmc_dom_hdrs[domain] != NULL, ("no mem allocated for domain: %d", domain));
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pmc_dom_hdrs[domain]->pdbh_ncpus++;
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}
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for (domain = 0; domain < NDOMAINS; domain++) {
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int ncpus = pmc_dom_hdrs[domain]->pdbh_ncpus;
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int total = ncpus*pmc_nlogbuffers_pcpu;
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@ -1231,12 +1200,10 @@ pmclog_shutdown()
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mtx_destroy(&pmc_kthread_mtx);
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for (domain = 0; domain < NDOMAINS; domain++) {
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mtx_destroy(&pmc_dom_hdrs[domain]->pdbh_mtx);
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while ((plb = TAILQ_FIRST(&pmc_dom_hdrs[domain]->pdbh_head)) != NULL) {
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TAILQ_REMOVE(&pmc_dom_hdrs[domain]->pdbh_head, plb, plb_next);
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free(plb->plb_base, M_PMC);
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}
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free(pmc_dom_hdrs[domain]->pdbh_plbs, M_PMC);
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free(pmc_dom_hdrs[domain], M_PMC);
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}
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}
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@ -1564,12 +1564,14 @@ pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm)
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const struct pmc_process *pp;
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freepath = fullpath = NULL;
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epoch_exit(global_epoch);
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pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath);
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pid = td->td_proc->p_pid;
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epoch_enter(global_epoch);
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/* Inform owners of all system-wide sampling PMCs. */
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LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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if (po->po_flags & PMC_PO_OWNS_LOGFILE)
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pmclog_process_map_in(po, pid, pkm->pm_address, fullpath);
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@ -1606,10 +1608,12 @@ pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm)
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pid = td->td_proc->p_pid;
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LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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epoch_enter(global_epoch);
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CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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if (po->po_flags & PMC_PO_OWNS_LOGFILE)
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pmclog_process_map_out(po, pid, pkm->pm_address,
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pkm->pm_address + pkm->pm_size);
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epoch_exit(global_epoch);
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if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
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return;
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@ -1631,7 +1635,7 @@ pmc_log_kernel_mappings(struct pmc *pm)
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struct pmc_owner *po;
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struct pmckern_map_in *km, *kmbase;
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sx_assert(&pmc_sx, SX_LOCKED);
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MPASS(in_epoch() || sx_xlocked(&pmc_sx));
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KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
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("[pmc,%d] non-sampling PMC (%p) desires mapping information",
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__LINE__, (void *) pm));
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@ -1905,11 +1909,13 @@ pmc_hook_handler(struct thread *td, int function, void *arg)
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pk = (struct pmckern_procexec *) arg;
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epoch_enter(global_epoch);
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/* Inform owners of SS mode PMCs of the exec event. */
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LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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if (po->po_flags & PMC_PO_OWNS_LOGFILE)
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pmclog_process_procexec(po, PMC_ID_INVALID,
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p->p_pid, pk->pm_entryaddr, fullpath);
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epoch_exit(global_epoch);
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PROC_LOCK(p);
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is_using_hwpmcs = p->p_flag & P_HWPMC;
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@ -2033,12 +2039,12 @@ pmc_hook_handler(struct thread *td, int function, void *arg)
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break;
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case PMC_FN_MMAP:
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sx_assert(&pmc_sx, SX_LOCKED);
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MPASS(in_epoch() || sx_xlocked(&pmc_sx));
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pmc_process_mmap(td, (struct pmckern_map_in *) arg);
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break;
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case PMC_FN_MUNMAP:
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sx_assert(&pmc_sx, SX_LOCKED);
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MPASS(in_epoch() || sx_xlocked(&pmc_sx));
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pmc_process_munmap(td, (struct pmckern_map_out *) arg);
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break;
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@ -2360,7 +2366,8 @@ pmc_release_pmc_descriptor(struct pmc *pm)
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po->po_sscount--;
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if (po->po_sscount == 0) {
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atomic_subtract_rel_int(&pmc_ss_count, 1);
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LIST_REMOVE(po, po_ssnext);
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CK_LIST_REMOVE(po, po_ssnext);
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epoch_wait(global_epoch);
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}
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}
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@ -2727,7 +2734,7 @@ pmc_start(struct pmc *pm)
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if (mode == PMC_MODE_SS) {
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if (po->po_sscount == 0) {
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LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext);
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CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext);
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atomic_add_rel_int(&pmc_ss_count, 1);
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PMCDBG1(PMC,OPS,1, "po=%p in global list", po);
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}
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@ -2854,7 +2861,8 @@ pmc_stop(struct pmc *pm)
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po->po_sscount--;
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if (po->po_sscount == 0) {
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atomic_subtract_rel_int(&pmc_ss_count, 1);
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LIST_REMOVE(po, po_ssnext);
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CK_LIST_REMOVE(po, po_ssnext);
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epoch_wait(global_epoch);
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PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po);
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}
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}
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@ -2900,6 +2908,9 @@ pmc_syscall_handler(struct thread *td, void *syscall_args)
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c = (struct pmc_syscall_args *)syscall_args;
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op = c->pmop_code;
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arg = c->pmop_data;
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/* PMC isn't set up yet */
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if (pmc_hook == NULL)
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return (EINVAL);
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if (op == PMC_OP_CONFIGURELOG) {
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/*
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* We cannot create the logging process inside
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@ -2916,7 +2927,6 @@ pmc_syscall_handler(struct thread *td, void *syscall_args)
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PMC_GET_SX_XLOCK(ENOSYS);
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is_sx_downgraded = 0;
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PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op,
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pmc_op_to_name[op], arg);
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@ -4482,9 +4492,11 @@ pmc_process_exit(void *arg __unused, struct proc *p)
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/*
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* Log a sysexit event to all SS PMC owners.
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*/
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LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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epoch_enter(global_epoch);
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CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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if (po->po_flags & PMC_PO_OWNS_LOGFILE)
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pmclog_process_sysexit(po, p->p_pid);
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epoch_exit(global_epoch);
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if (!is_using_hwpmcs)
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return;
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@ -4659,10 +4671,11 @@ pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc,
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* If there are system-wide sampling PMCs active, we need to
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* log all fork events to their owner's logs.
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*/
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LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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epoch_enter(global_epoch);
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CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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if (po->po_flags & PMC_PO_OWNS_LOGFILE)
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pmclog_process_procfork(po, p1->p_pid, newproc->p_pid);
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epoch_exit(global_epoch);
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if (!is_using_hwpmcs)
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return;
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@ -4728,21 +4741,19 @@ pmc_kld_load(void *arg __unused, linker_file_t lf)
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{
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struct pmc_owner *po;
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sx_slock(&pmc_sx);
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/*
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* Notify owners of system sampling PMCs about KLD operations.
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*/
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LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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epoch_enter(global_epoch);
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CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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if (po->po_flags & PMC_PO_OWNS_LOGFILE)
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pmclog_process_map_in(po, (pid_t) -1,
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(uintfptr_t) lf->address, lf->filename);
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epoch_exit(global_epoch);
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/*
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* TODO: Notify owners of (all) process-sampling PMCs too.
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*/
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sx_sunlock(&pmc_sx);
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}
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static void
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@ -4751,18 +4762,16 @@ pmc_kld_unload(void *arg __unused, const char *filename __unused,
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{
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struct pmc_owner *po;
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sx_slock(&pmc_sx);
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LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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epoch_enter(global_epoch);
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CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
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if (po->po_flags & PMC_PO_OWNS_LOGFILE)
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pmclog_process_map_out(po, (pid_t) -1,
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(uintfptr_t) address, (uintfptr_t) address + size);
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epoch_exit(global_epoch);
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/*
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* TODO: Notify owners of process-sampling PMCs.
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*/
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sx_sunlock(&pmc_sx);
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}
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/*
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@ -5064,6 +5073,7 @@ pmc_initialize(void)
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/* set hook functions */
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pmc_intr = md->pmd_intr;
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wmb();
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pmc_hook = pmc_hook_handler;
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if (error == 0) {
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@ -5282,6 +5292,3 @@ load (struct module *module __unused, int cmd, void *arg __unused)
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return error;
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}
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/* memory pool */
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MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module");
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@ -48,6 +48,10 @@ __FBSDID("$FreeBSD$");
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#include <sys/sysctl.h>
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#include <sys/systm.h>
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#include <vm/vm.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_kern.h>
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#ifdef HWPMC_HOOKS
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FEATURE(hwpmc_hooks, "Kernel support for HW PMC");
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#define PMC_KERNEL_VERSION PMC_VERSION
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@ -58,6 +62,9 @@ FEATURE(hwpmc_hooks, "Kernel support for HW PMC");
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MALLOC_DECLARE(M_PMCHOOKS);
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MALLOC_DEFINE(M_PMCHOOKS, "pmchooks", "Memory space for PMC hooks");
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/* memory pool */
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MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module");
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const int pmc_kernel_version = PMC_KERNEL_VERSION;
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/* Hook variable. */
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@ -84,12 +91,18 @@ volatile int pmc_ss_count;
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* somewhat more expensive than a simple 'if' check and indirect call.
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*/
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struct sx pmc_sx;
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SX_SYSINIT(pmcsx, &pmc_sx, "pmc-sx");
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/*
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* PMC Soft per cpu trapframe.
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*/
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struct trapframe pmc_tf[MAXCPU];
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/*
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* Per domain list of buffer headers
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*/
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__read_mostly struct pmc_domain_buffer_header *pmc_dom_hdrs[MAXMEMDOM];
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/*
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* PMC Soft use a global table to store registered events.
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*/
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@ -100,20 +113,12 @@ static int pmc_softevents = 16;
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SYSCTL_INT(_kern_hwpmc, OID_AUTO, softevents, CTLFLAG_RDTUN,
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&pmc_softevents, 0, "maximum number of soft events");
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struct mtx pmc_softs_mtx;
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int pmc_softs_count;
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struct pmc_soft **pmc_softs;
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struct mtx pmc_softs_mtx;
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MTX_SYSINIT(pmc_soft_mtx, &pmc_softs_mtx, "pmc-softs", MTX_SPIN);
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static void
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pmc_init_sx(void)
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{
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sx_init_flags(&pmc_sx, "pmc-sx", SX_NOWITNESS);
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}
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SYSINIT(pmcsx, SI_SUB_LOCK, SI_ORDER_MIDDLE, pmc_init_sx, NULL);
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/*
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* Helper functions.
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*/
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@ -325,12 +330,30 @@ pmc_soft_ev_release(struct pmc_soft *ps)
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mtx_unlock_spin(&pmc_softs_mtx);
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}
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#ifdef NUMA
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#define NDOMAINS vm_ndomains
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static int
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getdomain(int cpu)
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{
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struct pcpu *pc;
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pc = pcpu_find(cpu);
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return (pc->pc_domain);
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}
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#else
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#define NDOMAINS 1
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#define malloc_domain(size, type, domain, flags) malloc((size), (type), (flags))
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#define getdomain(cpu) 0
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#endif
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/*
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* Initialise hwpmc.
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*/
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static void
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init_hwpmc(void *dummy __unused)
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{
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int domain, cpu;
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if (pmc_softevents <= 0 ||
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pmc_softevents > PMC_EV_DYN_COUNT) {
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(void) printf("hwpmc: tunable \"softevents\"=%d out of "
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@ -339,6 +362,19 @@ init_hwpmc(void *dummy __unused)
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}
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pmc_softs = malloc(pmc_softevents * sizeof(struct pmc_soft *), M_PMCHOOKS, M_NOWAIT|M_ZERO);
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KASSERT(pmc_softs != NULL, ("cannot allocate soft events table"));
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for (domain = 0; domain < NDOMAINS; domain++) {
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pmc_dom_hdrs[domain] = malloc_domain(sizeof(struct pmc_domain_buffer_header), M_PMC, domain,
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M_WAITOK|M_ZERO);
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mtx_init(&pmc_dom_hdrs[domain]->pdbh_mtx, "pmc_bufferlist_mtx", "pmc-leaf", MTX_SPIN);
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TAILQ_INIT(&pmc_dom_hdrs[domain]->pdbh_head);
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}
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CPU_FOREACH(cpu) {
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domain = getdomain(cpu);
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KASSERT(pmc_dom_hdrs[domain] != NULL, ("no mem allocated for domain: %d", domain));
|
||||
pmc_dom_hdrs[domain]->pdbh_ncpus++;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
SYSINIT(hwpmc, SI_SUB_KDTRACE, SI_ORDER_FIRST, init_hwpmc, NULL);
|
||||
|
||||
@ -40,6 +40,8 @@
|
||||
#include <sys/counter.h>
|
||||
#include <machine/pmc_mdep.h>
|
||||
#include <machine/profile.h>
|
||||
#include <sys/epoch.h>
|
||||
#include <ck_queue.h>
|
||||
|
||||
#define PMC_MODULE_NAME "hwpmc"
|
||||
#define PMC_NAME_MAX 64 /* HW counter name size */
|
||||
@ -826,7 +828,7 @@ struct pmc_process {
|
||||
|
||||
struct pmc_owner {
|
||||
LIST_ENTRY(pmc_owner) po_next; /* hash chain */
|
||||
LIST_ENTRY(pmc_owner) po_ssnext; /* list of SS PMC owners */
|
||||
CK_LIST_ENTRY(pmc_owner) po_ssnext; /* list of SS PMC owners */
|
||||
LIST_HEAD(, pmc) po_pmcs; /* owned PMC list */
|
||||
TAILQ_HEAD(, pmclog_buffer) po_logbuffers; /* (o) logbuffer list */
|
||||
struct mtx po_mtx; /* spin lock for (o) */
|
||||
|
||||
@ -157,6 +157,15 @@ struct pmc_soft {
|
||||
struct pmc_dyn_event_descr ps_ev;
|
||||
};
|
||||
|
||||
struct pmclog_buffer;
|
||||
|
||||
struct pmc_domain_buffer_header {
|
||||
struct mtx pdbh_mtx;
|
||||
TAILQ_HEAD(, pmclog_buffer) pdbh_head;
|
||||
struct pmclog_buffer *pdbh_plbs;
|
||||
int pdbh_ncpus;
|
||||
} __aligned(CACHE_LINE_SIZE);
|
||||
|
||||
/* hook */
|
||||
extern int (*pmc_hook)(struct thread *_td, int _function, void *_arg);
|
||||
extern int (*pmc_intr)(int _cpu, struct trapframe *_frame);
|
||||
@ -176,16 +185,19 @@ extern const int pmc_kernel_version;
|
||||
/* PMC soft per cpu trapframe */
|
||||
extern struct trapframe pmc_tf[MAXCPU];
|
||||
|
||||
/* per domain buffer header list */
|
||||
extern struct pmc_domain_buffer_header *pmc_dom_hdrs[MAXMEMDOM];
|
||||
|
||||
/* Quick check if preparatory work is necessary */
|
||||
#define PMC_HOOK_INSTALLED(cmd) __predict_false(pmc_hook != NULL)
|
||||
|
||||
/* Hook invocation; for use within the kernel */
|
||||
#define PMC_CALL_HOOK(t, cmd, arg) \
|
||||
do { \
|
||||
sx_slock(&pmc_sx); \
|
||||
epoch_enter(global_epoch); \
|
||||
if (pmc_hook != NULL) \
|
||||
(pmc_hook)((t), (cmd), (arg)); \
|
||||
sx_sunlock(&pmc_sx); \
|
||||
epoch_exit(global_epoch); \
|
||||
} while (0)
|
||||
|
||||
/* Hook invocation that needs an exclusive lock */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user