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perf cgroup: Convert cgroup_sel.refcnt from atomic_t to refcount_t

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The refcount_t type and corresponding API should be used instead of
atomic_t when the variable is used as a reference counter.

This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Kook <keescook@chromium.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: alsa-devel@alsa-project.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1487691303-31858-2-git-send-email-elena.reshetova@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Elena Reshetova 2017-02-21 17:34:55 +02:00 committed by Arnaldo Carvalho de Melo
parent 73a9bf95ed
commit 79c5fe6db8
2 changed files with 5 additions and 5 deletions
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6
tools/perf/util/cgroup.c
View File

@ -127,19 +127,19 @@ static int add_cgroup(struct perf_evlist *evlist, char *str)
goto found; goto found;
n++; n++;
} }
if (atomic_read(&cgrp->refcnt) == 0) if (refcount_read(&cgrp->refcnt) == 0)
free(cgrp); free(cgrp);
return -1; return -1;
found: found:
atomic_inc(&cgrp->refcnt); refcount_inc(&cgrp->refcnt);
counter->cgrp = cgrp; counter->cgrp = cgrp;
return 0; return 0;
} }
void close_cgroup(struct cgroup_sel *cgrp) void close_cgroup(struct cgroup_sel *cgrp)
{ {
if (cgrp && atomic_dec_and_test(&cgrp->refcnt)) { if (cgrp && refcount_dec_and_test(&cgrp->refcnt)) {
close(cgrp->fd); close(cgrp->fd);
zfree(&cgrp->name); zfree(&cgrp->name);
free(cgrp); free(cgrp);

4
tools/perf/util/cgroup.h
View File

@ -1,14 +1,14 @@
#ifndef __CGROUP_H__ #ifndef __CGROUP_H__
#define __CGROUP_H__ #define __CGROUP_H__
#include <linux/atomic.h> #include <linux/refcount.h>
struct option; struct option;
struct cgroup_sel { struct cgroup_sel {
char *name; char *name;
int fd; int fd;
atomic_t refcnt; refcount_t refcnt;
}; };