| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAFpQJXWjx3uVG-6UNiJzmdc4FFw8kea2A5aJZquxVRXq8BR1VQ@mail.gmail.com>
Date: Thu, 27 Apr 2017 21:16:41 +0530
From: Ganapatrao Kulkarni <gpkulkarni@...il.com>
To: Mark Rutland <mark.rutland@....com>
Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@...ium.com>,
alexander.shishkin@...ux.intel.com,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <Will.Deacon@....com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
acme@...nel.org, peterz@...radead.org,
Ingo Molnar <mingo@...hat.com>, jnair@...iumnetworks.com,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH] perf evsel: Fix to perf-stat malloc corruption on arm64 platforms
On Thu, Apr 27, 2017 at 8:04 PM, Mark Rutland <mark.rutland@....com> wrote:
> On Wed, Apr 26, 2017 at 11:49:46PM +0530, Ganapatrao Kulkarni wrote:
>> On Wed, Apr 26, 2017 at 10:42 PM, Mark Rutland <mark.rutland@....com> wrote:
>> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
>> > index 13b5499..638aefa 100644
>> > --- a/tools/perf/builtin-stat.c
>> > +++ b/tools/perf/builtin-stat.c
>> > @@ -346,6 +346,28 @@ static void read_counters(void)
>> > }
>> > }
>> >
>> > +/*
>> > + * Close all evnt FDs we open in __run_perf_stat() and
>> > + * create_perf_stat_counter(), taking care to match the number of threads and CPUs.
>> > + *
>> > + * Note that perf_evlist__close(evsel_list) is not equivalent, as it doesn't
>> > + * take the target into account.
>> > + */
>> > +static void close_counters(void)
>> > +{
>> > + bool per_cpu = target__has_cpu(&target);
>> > + struct perf_evsel *evsel;
>> > +
>> > + evlist__for_each_entry(evsel_list, evsel) {
>> > + if (per_cpu)
>> > + perf_evsel__close_per_cpu(evsel,
>> > + perf_evsel__cpus(evsel));
>> > + else
>> > + perf_evsel__close_per_thread(evsel,
>> > + evsel_list->threads);
>> > + }
>> > +}
>> > +
>> > static void process_interval(void)
>> > {
>> > struct timespec ts, rs;
>> > @@ -686,7 +708,7 @@ static int __run_perf_stat(int argc, const char **argv)
>> > * group leaders.
>> > */
>> > read_counters();
>> > - perf_evlist__close(evsel_list);
>> > + close_counters();
>> >
>> > return WEXITSTATUS(status);
>> > }
>> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>> > index ac59710..726ceca 100644
>> > --- a/tools/perf/util/evsel.c
>> > +++ b/tools/perf/util/evsel.c
>> > @@ -1670,6 +1670,18 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>> > return err;
>> > }
>> >
>> > +int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
>> > + struct cpu_map *cpus)
>> > +{
>> > + return perf_evsel__open(evsel, cpus, NULL);
>> > +}
>> > +
>> > +int perf_evsel__open_per_thread(struct perf_evsel *evsel,
>> > + struct thread_map *threads)
>> > +{
>> > + return perf_evsel__open(evsel, NULL, threads);
>> > +}
>> > +
>> > void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
>> > {
>> > if (evsel->fd == NULL)
>> > @@ -1679,16 +1691,18 @@ void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
>> > perf_evsel__free_fd(evsel);
>> > }
>> >
>> > -int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
>> > - struct cpu_map *cpus)
>> > +void perf_evsel__close_per_cpu(struct perf_evsel *evsel,
>> > + struct cpu_map *cpus)
>> > {
>> > - return perf_evsel__open(evsel, cpus, NULL);
>> > + int ncpus = cpus ? cpus->nr : 1;
>> > + perf_evsel__close(evsel, ncpus, 1);
>> > }
>> >
>> > -int perf_evsel__open_per_thread(struct perf_evsel *evsel,
>> > - struct thread_map *threads)
>> > +void perf_evsel__close_per_thread(struct perf_evsel *evsel,
>> > + struct thread_map *threads)
>> > {
>> > - return perf_evsel__open(evsel, NULL, threads);
>> > + int nthreads = threads ? threads->nr : 1;
>> > + perf_evsel__close(evsel, 1, nthreads);
>> > }
>> >
>> > static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
>> > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
>> > index 06ef6f2..02bea43 100644
>> > --- a/tools/perf/util/evsel.h
>> > +++ b/tools/perf/util/evsel.h
>> > @@ -252,6 +252,10 @@ int perf_evsel__open_per_thread(struct perf_evsel *evsel,
>> > struct thread_map *threads);
>> > int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>> > struct thread_map *threads);
>> > +void perf_evsel__close_per_cpu(struct perf_evsel *evsel,
>> > + struct cpu_map *cpus);
>> > +void perf_evsel__close_per_thread(struct perf_evsel *evsel,
>> > + struct thread_map *threads);
>> > void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads);
>> >
>> > struct perf_sample;
>>
>> this diff looks to me doing same as mine.
>
> Be careful when reading the diff above; the open functions have been
> moved, but have not changed.
>
> I've only changed the close path, whereas your proposal changed the open
> path. Those are not equivalent changes.
>
>> i think below diff should be more appropriate fix to this issue?
>>
>> when open allocates and uses dummy cpus, there is no point in holding
>> old unused one. instead it should free and link to dummy cpus which
>> is created with 1 CPU. same will be used by close.
>>
>> i did quick testing on both x86 and arm64. testing looks ok, may need
>> more testing!
>>
>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>> index ac59710..b1aab0a 100644
>> --- a/tools/perf/util/evsel.c
>> +++ b/tools/perf/util/evsel.c
>> @@ -1466,9 +1466,13 @@ int perf_evsel__open(struct perf_evsel *evsel,
>> struct cpu_map *cpus,
>> empty_cpu_map = cpu_map__dummy_new();
>> if (empty_cpu_map == NULL)
>> return -ENOMEM;
>> + } else {
>> + cpu_map__get(empty_cpu_map);
>> }
>>
>> cpus = empty_cpu_map;
>> + cpu_map__put(evsel->cpus);
>> + evsel->cpus = cpus;
>> }
>>
>> if (threads == NULL) {
>
> Unfortunately, I believe that might break the logic added in commit:
>
> 9f21b815be863218 ("perf evlist: Only open events on CPUs an evsel permits")
>
> ... since the evsel->cpus would now not represent the PMUs CPUs.
>
> As I'd mentioned in my prior reply, I think in order to use the cpu_maps
> consistently we need to do a bigger rework of the way cpu_maps are used,
> in order to separate the PMU CPUs from the requested event CPUs, etc.
> while taking all of these into account.
>
> Could you please give my diff a go?
i tried your diff, and testing looks ok.
below is the cleanly merged diff on top of latest commit
f832460 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 13b5499..4be2980 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -346,6 +346,28 @@ static void read_counters(void)
}
}
+/*
+ * Close all evnt FDs we open in __run_perf_stat() and
+ * create_perf_stat_counter(), taking care to match the number of
threads and CPUs.
+ *
+ * Note that perf_evlist__close(evsel_list) is not equivalent, as it doesn't
+ * take the target into account.
+ */
+static void close_counters(void)
+{
+ bool per_cpu = target__has_cpu(&target);
+ struct perf_evsel *evsel;
+
+ evlist__for_each_entry(evsel_list, evsel) {
+ if (per_cpu)
+ perf_evsel__close_per_cpu(evsel,
+ perf_evsel__cpus(evsel));
+ else
+ perf_evsel__close_per_thread(evsel,
+ evsel_list->threads);
+ }
+}
+
static void process_interval(void)
{
struct timespec ts, rs;
@@ -686,7 +708,7 @@ static int __run_perf_stat(int argc, const char **argv)
* group leaders.
*/
read_counters();
- perf_evlist__close(evsel_list);
+ close_counters();
return WEXITSTATUS(status);
}
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ac59710..ecd9778 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1691,6 +1691,20 @@ int perf_evsel__open_per_thread(struct perf_evsel *evsel,
return perf_evsel__open(evsel, NULL, threads);
}
+void perf_evsel__close_per_cpu(struct perf_evsel *evsel,
+ struct cpu_map *cpus)
+ {
+ int ncpus = cpus ? cpus->nr : 1;
+ perf_evsel__close(evsel, ncpus, 1);
+ }
+
+void perf_evsel__close_per_thread(struct perf_evsel *evsel,
+ struct thread_map *threads)
+ {
+ int nthreads = threads ? threads->nr : 1;
+ perf_evsel__close(evsel, 1, nthreads);
+ }
+
static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
const union perf_event *event,
struct perf_sample *sample)
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 06ef6f2..6779bd2 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -250,6 +250,10 @@ int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
struct cpu_map *cpus);
int perf_evsel__open_per_thread(struct perf_evsel *evsel,
struct thread_map *threads);
+void perf_evsel__close_per_cpu(struct perf_evsel *evsel,
+ struct cpu_map *cpus);
+void perf_evsel__close_per_thread(struct perf_evsel *evsel,
+ struct thread_map *threads);
int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads);
void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads);
>
> Thanks,
> Mark.
thanks
Ganapat
Powered by blists - more mailing lists