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perf tools: Protect dso cache fd with a mutex 

When dso cache is accessed in multi-thread environment, it's possible to
close other dso->data.fd during operation due to open file limit.
Protect the file descriptors using a separate mutex.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1431909055-21442-28-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2015-05-18 09:30:42 +09:00 committed by Arnaldo Carvalho de Melo
parent 8e67b7258e
commit 33bdedcea2
1 changed files with 72 additions and 26 deletions
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98
tools/perf/util/dso.c
View File

@ -265,6 +265,7 @@ int __kmod_path__parse(struct kmod_path *m, const char *path,
*/
static LIST_HEAD(dso__data_open);
static long dso__data_open_cnt;
static pthread_mutex_t dso__data_open_lock = PTHREAD_MUTEX_INITIALIZER;
static void dso__list_add(struct dso *dso)
{
@ -434,7 +435,9 @@ static void check_data_close(void)
*/
void dso__data_close(struct dso *dso)
{
pthread_mutex_lock(&dso__data_open_lock);
close_dso(dso);
pthread_mutex_unlock(&dso__data_open_lock);
}
/**
@ -457,6 +460,8 @@ int dso__data_fd(struct dso *dso, struct machine *machine)
if (dso->data.status == DSO_DATA_STATUS_ERROR)
return -1;
pthread_mutex_lock(&dso__data_open_lock);
if (dso->data.fd >= 0)
goto out;
@ -479,6 +484,7 @@ out:
else
dso->data.status = DSO_DATA_STATUS_ERROR;
pthread_mutex_unlock(&dso__data_open_lock);
return dso->data.fd;
}
@ -583,7 +589,8 @@ dso_cache__memcpy(struct dso_cache *cache, u64 offset,
}
static ssize_t
dso_cache__read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
dso_cache__read(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
struct dso_cache *cache;
struct dso_cache *old;
@ -592,11 +599,24 @@ dso_cache__read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
do {
u64 cache_offset;
ret = -ENOMEM;
cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
if (!cache)
break;
return -ENOMEM;
pthread_mutex_lock(&dso__data_open_lock);
/*
* dso->data.fd might be closed if other thread opened another
* file (dso) due to open file limit (RLIMIT_NOFILE).
*/
if (dso->data.fd < 0) {
dso->data.fd = open_dso(dso, machine);
if (dso->data.fd < 0) {
ret = -errno;
dso->data.status = DSO_DATA_STATUS_ERROR;
break;
}
}
cache_offset = offset & DSO__DATA_CACHE_MASK;
@ -606,6 +626,11 @@ dso_cache__read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
cache->offset = cache_offset;
cache->size = ret;
} while (0);
pthread_mutex_unlock(&dso__data_open_lock);
if (ret > 0) {
old = dso_cache__insert(dso, cache);
if (old) {
/* we lose the race */
@ -614,8 +639,7 @@ dso_cache__read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
}
ret = dso_cache__memcpy(cache, offset, data, size);
} while (0);
}
if (ret <= 0)
free(cache);
@ -623,8 +647,8 @@ dso_cache__read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
return ret;
}
static ssize_t dso_cache_read(struct dso *dso, u64 offset,
u8 *data, ssize_t size)
static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
struct dso_cache *cache;
@ -632,7 +656,7 @@ static ssize_t dso_cache_read(struct dso *dso, u64 offset,
if (cache)
return dso_cache__memcpy(cache, offset, data, size);
else
return dso_cache__read(dso, offset, data, size);
return dso_cache__read(dso, machine, offset, data, size);
}
/*
@ -640,7 +664,8 @@ static ssize_t dso_cache_read(struct dso *dso, u64 offset,
* in the rb_tree. Any read to already cached data is served
* by cached data.
*/
static ssize_t cached_read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
static ssize_t cached_read(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
ssize_t r = 0;
u8 *p = data;
@ -648,7 +673,7 @@ static ssize_t cached_read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
do {
ssize_t ret;
ret = dso_cache_read(dso, offset, p, size);
ret = dso_cache_read(dso, machine, offset, p, size);
if (ret < 0)
return ret;
@ -668,21 +693,42 @@ static ssize_t cached_read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
return r;
}
static int data_file_size(struct dso *dso)
static int data_file_size(struct dso *dso, struct machine *machine)
{
int ret = 0;
struct stat st;
char sbuf[STRERR_BUFSIZE];
if (!dso->data.file_size) {
if (fstat(dso->data.fd, &st)) {
pr_err("dso mmap failed, fstat: %s\n",
strerror_r(errno, sbuf, sizeof(sbuf)));
return -1;
if (dso->data.file_size)
return 0;
pthread_mutex_lock(&dso__data_open_lock);
/*
* dso->data.fd might be closed if other thread opened another
* file (dso) due to open file limit (RLIMIT_NOFILE).
*/
if (dso->data.fd < 0) {
dso->data.fd = open_dso(dso, machine);
if (dso->data.fd < 0) {
ret = -errno;
dso->data.status = DSO_DATA_STATUS_ERROR;
goto out;
}
dso->data.file_size = st.st_size;
}
return 0;
if (fstat(dso->data.fd, &st) < 0) {
ret = -errno;
pr_err("dso cache fstat failed: %s\n",
strerror_r(errno, sbuf, sizeof(sbuf)));
dso->data.status = DSO_DATA_STATUS_ERROR;
goto out;
}
dso->data.file_size = st.st_size;
out:
pthread_mutex_unlock(&dso__data_open_lock);
return ret;
}
/**
@ -700,17 +746,17 @@ off_t dso__data_size(struct dso *dso, struct machine *machine)
if (fd < 0)
return fd;
if (data_file_size(dso))
if (data_file_size(dso, machine))
return -1;
/* For now just estimate dso data size is close to file size */
return dso->data.file_size;
}
static ssize_t data_read_offset(struct dso *dso, u64 offset,
u8 *data, ssize_t size)
static ssize_t data_read_offset(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
if (data_file_size(dso))
if (data_file_size(dso, machine))
return -1;
/* Check the offset sanity. */
@ -720,7 +766,7 @@ static ssize_t data_read_offset(struct dso *dso, u64 offset,
if (offset + size < offset)
return -1;
return cached_read(dso, offset, data, size);
return cached_read(dso, machine, offset, data, size);
}
/**
@ -737,10 +783,10 @@ static ssize_t data_read_offset(struct dso *dso, u64 offset,
ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
if (dso__data_fd(dso, machine) < 0)
if (dso->data.status == DSO_DATA_STATUS_ERROR)
return -1;
return data_read_offset(dso, offset, data, size);
return data_read_offset(dso, machine, offset, data, size);
}
/**