Date: Tue, 21 Jul 2026 17:15:59 +0000 From: Mitchell Horne <mhorne@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Cc: Andre Silva <andasilv@amd.com> Subject: git: c185935b0d52 - main - hwpmc: Add EXTERROR diagnostics to the hwpmc syscall path Message-ID: <6a5fa94f.36e27.49d57a1f@gitrepo.freebsd.org>
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The branch main has been updated by mhorne: URL: https://cgit.FreeBSD.org/src/commit/?id=c185935b0d52f991d7e27fbac277ea8c9bb456a1 commit c185935b0d52f991d7e27fbac277ea8c9bb456a1 Author: Andre Silva <andasilv@amd.com> AuthorDate: 2026-06-12 15:38:57 +0000 Commit: Mitchell Horne <mhorne@FreeBSD.org> CommitDate: 2026-07-21 17:14:39 +0000 hwpmc: Add EXTERROR diagnostics to the hwpmc syscall path Annotate validation failures in the PMC syscall handlers (allocate, attach, read/write) with EXTERROR(), so pmc(3) callers see which precondition failed, not a bare errno. Register HWPMC_MOD in exterr_cat.h and the generated filenames.h. Signed-off-by: Andre Silva <andasilv@amd.com> Reviewed by: Ali Mashtizadeh <ali@mashtizadeh.com>, mhorne Sponsored by: AMD Pull Request: https://github.com/freebsd/freebsd-src/pull/2180 --- lib/libc/gen/exterr_cat_filenames.h | 1 + sys/dev/hwpmc/hwpmc_mod.c | 110 ++++++++++++++++++++++++++---------- sys/sys/exterr_cat.h | 1 + 3 files changed, 81 insertions(+), 31 deletions(-) diff --git a/lib/libc/gen/exterr_cat_filenames.h b/lib/libc/gen/exterr_cat_filenames.h index e098a94744f3..c93f84131ecf 100644 --- a/lib/libc/gen/exterr_cat_filenames.h +++ b/lib/libc/gen/exterr_cat_filenames.h @@ -4,6 +4,7 @@ */ [EXTERR_CAT_HWPMC_AMD] = "dev/hwpmc/hwpmc_amd.c", [EXTERR_CAT_HWPMC_IBS] = "dev/hwpmc/hwpmc_ibs.c", + [EXTERR_CAT_HWPMC_MOD] = "dev/hwpmc/hwpmc_mod.c", [EXTERR_CAT_VMM] = "dev/vmm/vmm_dev.c", [EXTERR_CAT_FUSE_DEVICE] = "fs/fuse/fuse_device.c", [EXTERR_CAT_FUSE_VFS] = "fs/fuse/fuse_vfsops.c", diff --git a/sys/dev/hwpmc/hwpmc_mod.c b/sys/dev/hwpmc/hwpmc_mod.c index efc2aefec2b9..32bb00d671fe 100644 --- a/sys/dev/hwpmc/hwpmc_mod.c +++ b/sys/dev/hwpmc/hwpmc_mod.c @@ -62,6 +62,9 @@ #include <sys/taskqueue.h> #include <sys/vnode.h> +#define EXTERR_CATEGORY EXTERR_CAT_HWPMC_MOD +#include <sys/exterrvar.h> + #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ #include <machine/atomic.h> @@ -3245,8 +3248,10 @@ pmc_start(struct pmc *pm) */ pmc_save_cpu_binding(&pb); cpu = PMC_TO_CPU(pm); - if (!pmc_cpu_is_active(cpu)) - return (ENXIO); + if (!pmc_cpu_is_active(cpu)) { + return (EXTERROR(ENXIO, "PMC CPU %ju is not active for start", + (uintmax_t)cpu)); + } pmc_select_cpu(cpu); /* @@ -3312,9 +3317,10 @@ pmc_stop(struct pmc *pm) cpu = PMC_TO_CPU(pm); KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); - if (!pmc_cpu_is_active(cpu)) - return (ENXIO); - + if (!pmc_cpu_is_active(cpu)) { + return (EXTERROR(ENXIO, "PMC CPU %ju is not active for stop", + (uintmax_t)cpu)); + } pmc_select_cpu(cpu); ri = PMC_TO_ROWINDEX(pm); @@ -3408,29 +3414,39 @@ pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) cpu = pa->pm_cpu; p = td->td_proc; - /* Requested mode must exist. */ if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && mode != PMC_MODE_TS && mode != PMC_MODE_TC)) - return (EINVAL); + return (EXTERROR(EINVAL, "Invalid PMC mode %ju", + (uintmax_t)mode)); /* Requested CPU must be valid. */ if (cpu != PMC_CPU_ANY && cpu >= pmc_cpu_max()) - return (EINVAL); + return (EXTERROR(EINVAL, "Invalid PMC CPU %ju", + (uintmax_t)cpu)); /* * Virtual PMCs should only ask for a default CPU. * System mode PMCs need to specify a non-default CPU. */ if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != PMC_CPU_ANY) || - (PMC_IS_SYSTEM_MODE(mode) && cpu == PMC_CPU_ANY)) - return (EINVAL); + (PMC_IS_SYSTEM_MODE(mode) && cpu == PMC_CPU_ANY)) { + if (PMC_IS_VIRTUAL_MODE(mode)) { + return (EXTERROR(EINVAL, + "PMC mode %ju requires the default CPU", + (uintmax_t)mode)); + } + return (EXTERROR(EINVAL, + "PMC mode %ju requires an explicit CPU", + (uintmax_t)mode)); + } /* * Check that an inactive CPU is not being asked for. */ if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) - return (ENXIO); + return (EXTERROR(ENXIO, "PMC CPU %ju is not active", + (uintmax_t)cpu)); /* * Refuse an allocation for a system-wide PMC if this process has been @@ -3453,22 +3469,26 @@ pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) if ((flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN | PMC_F_EV_PMU)) != 0) - return (EINVAL); + return (EXTERROR(EINVAL, "Invalid PMC flags %#jx", + (uintmax_t)flags)); /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN. */ if ((flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == PMC_F_USERCALLCHAIN) - return (EINVAL); + return (EXTERROR(EINVAL, + "PMC_F_USERCALLCHAIN requires PMC_F_CALLCHAIN")); /* PMC_F_USERCALLCHAIN is only valid for sampling mode. */ if ((flags & PMC_F_USERCALLCHAIN) != 0 && mode != PMC_MODE_TS && mode != PMC_MODE_SS) - return (EINVAL); + return (EXTERROR(EINVAL, + "PMC_F_USERCALLCHAIN requires sampling mode")); /* Process logging options are not allowed for system PMCs. */ if (PMC_IS_SYSTEM_MODE(mode) && (flags & (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT)) != 0) - return (EINVAL); + return (EXTERROR(EINVAL, + "Process logging flags are not valid for system PMCs")); /* * All sampling mode PMCs need to be able to interrupt the CPU. @@ -3479,11 +3499,14 @@ pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) /* A valid class specifier should have been passed in. */ pcd = pmc_class_to_classdep(class); if (pcd == NULL) - return (EINVAL); + return (EXTERROR(EINVAL, "Invalid PMC class %ju", + (uintmax_t)class)); /* The requested PMC capabilities should be feasible. */ if ((pcd->pcd_caps & caps) != caps) - return (EOPNOTSUPP); + return (EXTERROR(EOPNOTSUPP, + "Requested PMC capabilities %#jx are not supported", + (uintmax_t)caps)); PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", pa->pm_ev, caps, mode, cpu); @@ -3561,7 +3584,11 @@ pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) if (n == md->pmd_npmc) { pmc_destroy_pmc_descriptor(pmc); - return (EINVAL); + /* Preserve a more specific error from the class allocator. */ + if ((td->td_pflags2 & TDP2_EXTERR) != 0) + return (EINVAL); + return (EXTERROR(EINVAL, + "No PMC row accepted the allocation request")); } /* Fill in the correct value in the ID field. */ @@ -3588,12 +3615,21 @@ pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; pcd = pmc_ri_to_classdep(md, n, &adjri); - if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || - (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { + if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { (void)pcd->pcd_release_pmc(cpu, adjri, pmc); pmc_destroy_pmc_descriptor(pmc); pmc_restore_cpu_binding(&pb); - return (EPERM); + return (EXTERROR(EPERM, + "PMC row %ju on CPU %ju is not enabled", + (uintmax_t)n, (uintmax_t)cpu)); + } + if ((error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { + (void)pcd->pcd_release_pmc(cpu, adjri, pmc); + pmc_destroy_pmc_descriptor(pmc); + pmc_restore_cpu_binding(&pb); + return (EXTERROR(EPERM, + "PMC configuration failed for row %ju on CPU %ju", + (uintmax_t)n, (uintmax_t)cpu)); } pmc_restore_cpu_binding(&pb); @@ -3617,7 +3653,7 @@ pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) if (error != 0) { pmc_release_pmc_descriptor(pmc); pmc_destroy_pmc_descriptor(pmc); - return (error); + return (EXTERROR(error, "Failed to register PMC owner")); } /* @@ -3640,7 +3676,8 @@ pmc_do_op_pmcattach(struct thread *td, struct pmc_op_pmcattach a) sx_assert(&pmc_sx, SX_XLOCKED); if (a.pm_pid < 0) { - return (EINVAL); + return (EXTERROR(EINVAL, "Invalid PMC attach pid %jd", + (intmax_t)a.pm_pid)); } else if (a.pm_pid == 0) { a.pm_pid = td->td_proc->p_pid; } @@ -3650,14 +3687,18 @@ pmc_do_op_pmcattach(struct thread *td, struct pmc_op_pmcattach a) return (error); if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) - return (EINVAL); + return (EXTERROR(EINVAL, + "Cannot attach a system-mode PMC to a process")); /* PMCs may be (re)attached only when allocated or stopped */ if (pm->pm_state == PMC_STATE_RUNNING) { - return (EBUSY); + return (EXTERROR(EBUSY, + "PMC must be stopped before attach")); } else if (pm->pm_state != PMC_STATE_ALLOCATED && pm->pm_state != PMC_STATE_STOPPED) { - return (EINVAL); + return (EXTERROR(EINVAL, + "PMC state %ju does not allow attach", + (uintmax_t)pm->pm_state)); } /* lookup pid */ @@ -3696,7 +3737,8 @@ pmc_do_op_pmcdetach(struct thread *td, struct pmc_op_pmcattach a) int error; if (a.pm_pid < 0) { - return (EINVAL); + return (EXTERROR(EINVAL, "Invalid PMC detach pid %jd", + (intmax_t)a.pm_pid)); } else if (a.pm_pid == 0) a.pm_pid = td->td_proc->p_pid; @@ -3774,7 +3816,8 @@ pmc_do_op_pmcrw(const struct pmc_op_pmcrw *prw, pmc_value_t *valp) /* Must have at least one flag set. */ if ((prw->pm_flags & (PMC_F_OLDVALUE | PMC_F_NEWVALUE)) == 0) - return (EINVAL); + return (EXTERROR(EINVAL, + "PMCRW requires PMC_F_OLDVALUE and/or PMC_F_NEWVALUE")); /* Locate PMC descriptor. */ error = pmc_find_pmc(prw->pm_pmcid, &pm); @@ -3785,12 +3828,15 @@ pmc_do_op_pmcrw(const struct pmc_op_pmcrw *prw, pmc_value_t *valp) if (pm->pm_state != PMC_STATE_ALLOCATED && pm->pm_state != PMC_STATE_STOPPED && pm->pm_state != PMC_STATE_RUNNING) - return (EINVAL); + return (EXTERROR(EINVAL, + "PMC state %ju does not allow read/write", + (uintmax_t)pm->pm_state)); /* Writing a new value is allowed only for 'STOPPED' PMCs. */ if (pm->pm_state == PMC_STATE_RUNNING && (prw->pm_flags & PMC_F_NEWVALUE) != 0) - return (EBUSY); + return (EXTERROR(EBUSY, + "Cannot write a PMC while it is running")); if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { /* @@ -3830,7 +3876,9 @@ pmc_do_op_pmcrw(const struct pmc_op_pmcrw *prw, pmc_value_t *valp) pcd = pmc_ri_to_classdep(md, ri, &adjri); if (!pmc_cpu_is_active(cpu)) - return (ENXIO); + return (EXTERROR(ENXIO, + "PMC CPU %ju is not active for read/write", + (uintmax_t)cpu)); /* Move this thread to CPU 'cpu'. */ pmc_save_cpu_binding(&pb); diff --git a/sys/sys/exterr_cat.h b/sys/sys/exterr_cat.h index e63d118d7eb7..637cecdcbcd0 100644 --- a/sys/sys/exterr_cat.h +++ b/sys/sys/exterr_cat.h @@ -43,5 +43,6 @@ #define EXTERR_CAT_HWPMC_IBS 18 #define EXTERR_CAT_LINKER 19 #define EXTERR_CAT_HWPMC_AMD 20 +#define EXTERR_CAT_HWPMC_MOD 21 #endifhome | help
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