From: Ian Rogers irogers@google.com

mainline inclusion from mainline-v6.10-rc1 commit d9c5f5f94c2d356fdf3503f7fcaf254512bc032d category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9SXXQ CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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Sys events are eagerly loaded as each event has a compat option that may mean the event is or isn't associated with the PMU.

These shouldn't be counted as loaded_json_events as that is used for JSON events matching the CPUID that may or may not have been loaded. The mismatch causes issues on ARM64 that uses sys events.

Fixes: e6ff1eed3584362d ("perf pmu: Lazily add JSON events") Closes: https://lore.kernel.org/lkml/20240510024729.1075732-1-justin.he@arm.com/ Reported-by: Jia He justin.he@arm.com Signed-off-by: Ian Rogers irogers@google.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Ingo Molnar mingo@redhat.com Cc: James Clark james.clark@arm.com Cc: Jiri Olsa jolsa@kernel.org Cc: John Garry john.g.garry@oracle.com Cc: Kan Liang kan.liang@linux.intel.com Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Link: https://lore.kernel.org/r/20240511003601.2666907-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Junhao He hejunhao3@huawei.com --- tools/perf/util/pmu.c | 68 ++++++++++++++++++++++++++++++------------- tools/perf/util/pmu.h | 6 ++-- 2 files changed, 52 insertions(+), 22 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 86bfdf5db213..caf1067838f0 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -35,6 +35,18 @@ struct perf_pmu perf_pmu__fake = {

#define UNIT_MAX_LEN 31 /* max length for event unit name */

+enum event_source { + /* An event loaded from /sys/devices/<pmu>/events. */ + EVENT_SRC_SYSFS, + /* An event loaded from a CPUID matched json file. */ + EVENT_SRC_CPU_JSON, + /* + * An event loaded from a /sys/devices/<pmu>/identifier matched json + * file. + */ + EVENT_SRC_SYS_JSON, +}; + /** * struct perf_pmu_alias - An event either read from sysfs or builtin in * pmu-events.c, created by parsing the pmu-events json files. @@ -499,7 +511,7 @@ static int update_alias(const struct pmu_event *pe,

static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name, const char *desc, const char *val, FILE *val_fd, - const struct pmu_event *pe) + const struct pmu_event *pe, enum event_source src) { struct perf_pmu_alias *alias; int ret; @@ -551,25 +563,30 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name, } snprintf(alias->unit, sizeof(alias->unit), "%s", unit); } - if (!pe) { - /* Update an event from sysfs with json data. */ - struct update_alias_data data = { - .pmu = pmu, - .alias = alias, - }; - + switch (src) { + default: + case EVENT_SRC_SYSFS: alias->from_sysfs = true; if (pmu->events_table) { + /* Update an event from sysfs with json data. */ + struct update_alias_data data = { + .pmu = pmu, + .alias = alias, + }; if (pmu_events_table__find_event(pmu->events_table, pmu, name, update_alias, &data) == 0) - pmu->loaded_json_aliases++; + pmu->cpu_json_aliases++; } - } - - if (!pe) pmu->sysfs_aliases++; - else - pmu->loaded_json_aliases++; + break; + case EVENT_SRC_CPU_JSON: + pmu->cpu_json_aliases++; + break; + case EVENT_SRC_SYS_JSON: + pmu->sys_json_aliases++; + break; + + } list_add_tail(&alias->list, &pmu->aliases); return 0; } @@ -645,7 +662,8 @@ static int pmu_aliases_parse(struct perf_pmu *pmu) }

if (perf_pmu__new_alias(pmu, name, /*desc=*/ NULL, - /*val=*/ NULL, file, /*pe=*/ NULL) < 0) + /*val=*/ NULL, file, /*pe=*/ NULL, + EVENT_SRC_SYSFS) < 0) pr_debug("Cannot set up %s\n", name); fclose(file); } @@ -880,7 +898,8 @@ static int pmu_add_cpu_aliases_map_callback(const struct pmu_event *pe, { struct perf_pmu *pmu = vdata;

- perf_pmu__new_alias(pmu, pe->name, pe->desc, pe->event, /*val_fd=*/ NULL, pe); + perf_pmu__new_alias(pmu, pe->name, pe->desc, pe->event, /*val_fd=*/ NULL, + pe, EVENT_SRC_CPU_JSON); return 0; }

@@ -921,7 +940,8 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe, pe->desc, pe->event, /*val_fd=*/ NULL, - pe); + pe, + EVENT_SRC_SYS_JSON); }

return 0; @@ -1011,6 +1031,12 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char pmu->id = pmu_id(name); pmu->max_precise = pmu_max_precise(dirfd, pmu); pmu->events_table = perf_pmu__find_events_table(pmu); + /* + * Load the sys json events/aliases when loading the PMU as each event + * may have a different compat regular expression. We therefore can't + * know the number of sys json events/aliases without computing the + * regular expressions for them all. + */ pmu_add_sys_aliases(pmu); list_add_tail(&pmu->list, pmus);

@@ -1607,12 +1633,14 @@ size_t perf_pmu__num_events(struct perf_pmu *pmu) if (!pmu->sysfs_aliases_loaded) pmu_aliases_parse(pmu);

- nr = pmu->sysfs_aliases; + nr = pmu->sysfs_aliases + pmu->sys_json_aliases;;

if (pmu->cpu_aliases_added) - nr += pmu->loaded_json_aliases; + nr += pmu->cpu_json_aliases; else if (pmu->events_table) - nr += pmu_events_table__num_events(pmu->events_table, pmu) - pmu->loaded_json_aliases; + nr += pmu_events_table__num_events(pmu->events_table, pmu) - pmu->cpu_json_aliases; + else + assert(pmu->cpu_json_aliases == 0);

return pmu->selectable ? nr + 1 : nr; } diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h index 6a4e170c61d6..1e26294d8580 100644 --- a/tools/perf/util/pmu.h +++ b/tools/perf/util/pmu.h @@ -120,8 +120,10 @@ struct perf_pmu { const struct pmu_events_table *events_table; /** @sysfs_aliases: Number of sysfs aliases loaded. */ uint32_t sysfs_aliases; - /** @sysfs_aliases: Number of json event aliases loaded. */ - uint32_t loaded_json_aliases; + /** @cpu_json_aliases: Number of json event aliases loaded specific to the CPUID. */ + uint32_t cpu_json_aliases; + /** @sys_json_aliases: Number of json event aliases loaded matching the PMU's identifier. */ + uint32_t sys_json_aliases; /** @sysfs_aliases_loaded: Are sysfs aliases loaded from disk? */ bool sysfs_aliases_loaded; /**