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Date:   Wed,  6 Dec 2023 17:16:37 -0800
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Subject: [PATCH v6 03/47] perf events x86: Use function to add missing lock
From:   Ian Rogers <irogers@google.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Nick Terrell <terrelln@fb.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Vincent Whitchurch <vincent.whitchurch@axis.com>,
        "Steinar H. Gunderson" <sesse@google.com>,
        Liam Howlett <liam.howlett@oracle.com>,
        Miguel Ojeda <ojeda@kernel.org>,
        Colin Ian King <colin.i.king@gmail.com>,
        Dmitrii Dolgov <9erthalion6@gmail.com>,
        Yang Jihong <yangjihong1@huawei.com>,
        Ming Wang <wangming01@loongson.cn>,
        James Clark <james.clark@arm.com>,
        K Prateek Nayak <kprateek.nayak@amd.com>,
        Sean Christopherson <seanjc@google.com>,
        Leo Yan <leo.yan@linaro.org>,
        Ravi Bangoria <ravi.bangoria@amd.com>,
        German Gomez <german.gomez@arm.com>,
        Changbin Du <changbin.du@huawei.com>,
        Paolo Bonzini <pbonzini@redhat.com>, Li Dong <lidong@vivo.com>,
        Sandipan Das <sandipan.das@amd.com>,
        liuwenyu <liuwenyu7@huawei.com>, linux-kernel@vger.kernel.org,
        linux-perf-users@vger.kernel.org,
        Guilherme Amadio <amadio@gentoo.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Switch from loop macro maps__for_each_entry to maps__for_each_map
function that takes a callback. The function holds the maps lock,
which should be held during iteration.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/arch/x86/util/event.c | 103 +++++++++++++++++--------------
 1 file changed, 58 insertions(+), 45 deletions(-)

diff --git a/tools/perf/arch/x86/util/event.c b/tools/perf/arch/x86/util/event.c
index 5741ffe47312..e65b7dbe27fb 100644
--- a/tools/perf/arch/x86/util/event.c
+++ b/tools/perf/arch/x86/util/event.c
@@ -14,66 +14,79 @@
 
 #if defined(__x86_64__)
 
-int perf_event__synthesize_extra_kmaps(struct perf_tool *tool,
-				       perf_event__handler_t process,
-				       struct machine *machine)
+struct perf_event__synthesize_extra_kmaps_cb_args {
+	struct perf_tool *tool;
+	perf_event__handler_t process;
+	struct machine *machine;
+	union perf_event *event;
+};
+
+static int perf_event__synthesize_extra_kmaps_cb(struct map *map, void *data)
 {
-	int rc = 0;
-	struct map_rb_node *pos;
-	struct maps *kmaps = machine__kernel_maps(machine);
-	union perf_event *event = zalloc(sizeof(event->mmap) +
-					 machine->id_hdr_size);
+	struct perf_event__synthesize_extra_kmaps_cb_args *args = data;
+	union perf_event *event = args->event;
+	struct kmap *kmap;
+	size_t size;
 
-	if (!event) {
-		pr_debug("Not enough memory synthesizing mmap event "
-			 "for extra kernel maps\n");
-		return -1;
-	}
+	if (!__map__is_extra_kernel_map(map))
+		return 0;
 
-	maps__for_each_entry(kmaps, pos) {
-		struct kmap *kmap;
-		size_t size;
-		struct map *map = pos->map;
+	kmap = map__kmap(map);
 
-		if (!__map__is_extra_kernel_map(map))
-			continue;
+	size = sizeof(event->mmap) - sizeof(event->mmap.filename) +
+		      PERF_ALIGN(strlen(kmap->name) + 1, sizeof(u64)) +
+		      args->machine->id_hdr_size;
 
-		kmap = map__kmap(map);
+	memset(event, 0, size);
 
-		size = sizeof(event->mmap) - sizeof(event->mmap.filename) +
-		       PERF_ALIGN(strlen(kmap->name) + 1, sizeof(u64)) +
-		       machine->id_hdr_size;
+	event->mmap.header.type = PERF_RECORD_MMAP;
 
-		memset(event, 0, size);
+	/*
+	 * kernel uses 0 for user space maps, see kernel/perf_event.c
+	 * __perf_event_mmap
+	 */
+	if (machine__is_host(args->machine))
+		event->header.misc = PERF_RECORD_MISC_KERNEL;
+	else
+		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
 
-		event->mmap.header.type = PERF_RECORD_MMAP;
+	event->mmap.header.size = size;
 
-		/*
-		 * kernel uses 0 for user space maps, see kernel/perf_event.c
-		 * __perf_event_mmap
-		 */
-		if (machine__is_host(machine))
-			event->header.misc = PERF_RECORD_MISC_KERNEL;
-		else
-			event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
+	event->mmap.start = map__start(map);
+	event->mmap.len   = map__size(map);
+	event->mmap.pgoff = map__pgoff(map);
+	event->mmap.pid   = args->machine->pid;
 
-		event->mmap.header.size = size;
+	strlcpy(event->mmap.filename, kmap->name, PATH_MAX);
 
-		event->mmap.start = map__start(map);
-		event->mmap.len   = map__size(map);
-		event->mmap.pgoff = map__pgoff(map);
-		event->mmap.pid   = machine->pid;
+	if (perf_tool__process_synth_event(args->tool, event, args->machine, args->process) != 0)
+		return -1;
 
-		strlcpy(event->mmap.filename, kmap->name, PATH_MAX);
+	return 0;
+}
 
-		if (perf_tool__process_synth_event(tool, event, machine,
-						   process) != 0) {
-			rc = -1;
-			break;
-		}
+int perf_event__synthesize_extra_kmaps(struct perf_tool *tool,
+				       perf_event__handler_t process,
+				       struct machine *machine)
+{
+	int rc;
+	struct maps *kmaps = machine__kernel_maps(machine);
+	struct perf_event__synthesize_extra_kmaps_cb_args args = {
+		.tool = tool,
+		.process = process,
+		.machine = machine,
+		.event = zalloc(sizeof(args.event->mmap) + machine->id_hdr_size),
+	};
+
+	if (!args.event) {
+		pr_debug("Not enough memory synthesizing mmap event "
+			 "for extra kernel maps\n");
+		return -1;
 	}
 
-	free(event);
+	rc = maps__for_each_map(kmaps, perf_event__synthesize_extra_kmaps_cb, &args);
+
+	free(args.event);
 	return rc;
 }
 
-- 
2.43.0.rc2.451.g8631bc7472-goog