Patch "perf pmu: "Compat" supports regular expression matching identifiers" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    perf pmu: "Compat" supports regular expression matching identifiers

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-pmu-compat-supports-regular-expression-matching.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7412db8257d232300a3fd93c28bc7b5291268542
Author: Jing Zhang <renyu.zj@xxxxxxxxxxxxxxxxx>
Date:   Wed Sep 27 13:59:45 2023 +0800

    perf pmu: "Compat" supports regular expression matching identifiers
    
    [ Upstream commit 2879ff36f5ed80deec5f9d82a7a4107f2347630e ]
    
    The jevent "Compat" is used for uncore PMU alias or metric definitions.
    
    The same PMU driver has different PMU identifiers due to different
    hardware versions and types, but they may have some common PMU event.
    Since a Compat value can only match one identifier, when adding the
    same event alias to PMUs with different identifiers, each identifier
    needs to be defined once, which is not streamlined enough.
    
    So let "Compat" support using regular expression to match identifiers
    for uncore PMU alias. For example, if the "Compat" value is set to
    "43401|43c01", it would be able to match PMU identifiers such as "43401"
    or "43c01", which correspond to CMN600_r0p0 or CMN700_r0p0.
    
    Signed-off-by: Jing Zhang <renyu.zj@xxxxxxxxxxxxxxxxx>
    Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
    Tested-by: Ian Rogers <irogers@xxxxxxxxxx>
    Cc: James Clark <james.clark@xxxxxxx>
    Cc: Will Deacon <will@xxxxxxxxxx>
    Cc: Leo Yan <leo.yan@xxxxxxxxxx>
    Cc: Mike Leach <mike.leach@xxxxxxxxxx>
    Cc: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
    Cc: Zhuo Song <zhuo.song@xxxxxxxxxxxxxxxxx>
    Cc: John Garry <john.g.garry@xxxxxxxxxx>
    Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
    Cc: linux-doc@xxxxxxxxxxxxxxx
    Link: https://lore.kernel.org/r/1695794391-34817-2-git-send-email-renyu.zj@xxxxxxxxxxxxxxxxx
    Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
    Stable-dep-of: d9c5f5f94c2d ("perf pmu: Count sys and cpuid JSON events separately")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 72b7a1d3225f6..64b605a6060e2 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -28,6 +28,7 @@
 #include "strbuf.h"
 #include "fncache.h"
 #include "util/evsel_config.h"
+#include <regex.h>
 
 struct perf_pmu perf_pmu__fake = {
 	.name = "fake",
@@ -874,6 +875,28 @@ static bool pmu_uncore_alias_match(const char *pmu_name, const char *name)
 	return res;
 }
 
+bool pmu_uncore_identifier_match(const char *compat, const char *id)
+{
+	regex_t re;
+	regmatch_t pmatch[1];
+	int match;
+
+	if (regcomp(&re, compat, REG_EXTENDED) != 0) {
+		/* Warn unable to generate match particular string. */
+		pr_info("Invalid regular expression %s\n", compat);
+		return false;
+	}
+
+	match = !regexec(&re, id, 1, pmatch, 0);
+	if (match) {
+		/* Ensure a full match. */
+		match = pmatch[0].rm_so == 0 && (size_t)pmatch[0].rm_eo == strlen(id);
+	}
+	regfree(&re);
+
+	return match;
+}
+
 static int pmu_add_cpu_aliases_map_callback(const struct pmu_event *pe,
 					const struct pmu_events_table *table __maybe_unused,
 					void *vdata)
@@ -914,8 +937,8 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe,
 	if (!pe->compat || !pe->pmu)
 		return 0;
 
-	if (!strcmp(pmu->id, pe->compat) &&
-	    pmu_uncore_alias_match(pe->pmu, pmu->name)) {
+	if (pmu_uncore_alias_match(pe->pmu, pmu->name) &&
+			pmu_uncore_identifier_match(pe->compat, pmu->id)) {
 		perf_pmu__new_alias(pmu,
 				pe->name,
 				pe->desc,
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 45079f26abf60..c4b4fabe16edc 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -240,6 +240,7 @@ void pmu_add_cpu_aliases_table(struct perf_pmu *pmu,
 char *perf_pmu__getcpuid(struct perf_pmu *pmu);
 const struct pmu_events_table *pmu_events_table__find(void);
 const struct pmu_metrics_table *pmu_metrics_table__find(void);
+bool pmu_uncore_identifier_match(const char *compat, const char *id);
 
 int perf_pmu__convert_scale(const char *scale, char **end, double *sval);