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perf tools: Add dso__data_get/put_fd() 

Using dso__data_fd() in multi-thread environment is not safe since
returned fd can be closed and/or reused anytime.

So convert it to the dso__data_get/put_fd() pair to protect the access
with lock.

The original dso__data_fd() is deprecated and kept only for testing.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1432137821-10853-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2015-05-21 01:03:41 +09:00 committed by Arnaldo Carvalho de Melo
parent e840238d7c
commit 4bb11d012a
4 changed files with 50 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
tools/perf/tests/dso-data.c
View File

@ -99,6 +99,17 @@ struct test_data_offset offsets[] = {
},
};
/* move it from util/dso.c for compatibility */
static int dso__data_fd(struct dso *dso, struct machine *machine)
{
int fd = dso__data_get_fd(dso, machine);
if (fd >= 0)
dso__data_put_fd(dso);
return fd;
}
int test__dso_data(void)
{
struct machine machine;

31
tools/perf/util/dso.c
View File

@ -473,25 +473,35 @@ static void try_to_open_dso(struct dso *dso, struct machine *machine)
}
/**
* dso__data_fd - Get dso's data file descriptor
* dso__data_get_fd - Get dso's data file descriptor
* @dso: dso object
* @machine: machine object
*
* External interface to find dso's file, open it and
* returns file descriptor.
* returns file descriptor. It should be paired with
* dso__data_put_fd() if it returns non-negative value.
*/
int dso__data_fd(struct dso *dso, struct machine *machine)
int dso__data_get_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 (pthread_mutex_lock(&dso__data_open_lock) < 0)
return -1;
try_to_open_dso(dso, machine);
pthread_mutex_unlock(&dso__data_open_lock);
if (dso->data.fd < 0)
pthread_mutex_unlock(&dso__data_open_lock);
return dso->data.fd;
}
void dso__data_put_fd(struct dso *dso __maybe_unused)
{
pthread_mutex_unlock(&dso__data_open_lock);
}
bool dso__data_status_seen(struct dso *dso, enum dso_data_status_seen by)
{
u32 flag = 1 << by;
@ -1199,12 +1209,15 @@ size_t dso__fprintf(struct dso *dso, enum map_type type, FILE *fp)
enum dso_type dso__type(struct dso *dso, struct machine *machine)
{
int fd;
enum dso_type type = DSO__TYPE_UNKNOWN;
fd = dso__data_fd(dso, machine);
if (fd < 0)
return DSO__TYPE_UNKNOWN;
fd = dso__data_get_fd(dso, machine);
if (fd >= 0) {
type = dso__type_fd(fd);
dso__data_put_fd(dso);
}
return dso__type_fd(fd);
return type;
}
int dso__strerror_load(struct dso *dso, char *buf, size_t buflen)

13
tools/perf/util/dso.h
View File

@ -240,7 +240,8 @@ int __kmod_path__parse(struct kmod_path *m, const char *path,
/*
* The dso__data_* external interface provides following functions:
* dso__data_fd
* dso__data_get_fd
* dso__data_put_fd
* dso__data_close
* dso__data_size
* dso__data_read_offset
@ -257,8 +258,11 @@ int __kmod_path__parse(struct kmod_path *m, const char *path,
* The current usage of the dso__data_* interface is as follows:
*
* Get DSO's fd:
* int fd = dso__data_fd(dso, machine);
* USE 'fd' SOMEHOW
* int fd = dso__data_get_fd(dso, machine);
* if (fd >= 0) {
* USE 'fd' SOMEHOW
* dso__data_put_fd(dso);
* }
*
* Read DSO's data:
* n = dso__data_read_offset(dso_0, &machine, 0, buf, BUFSIZE);
@ -277,7 +281,8 @@ int __kmod_path__parse(struct kmod_path *m, const char *path,
*
* TODO
*/
int dso__data_fd(struct dso *dso, struct machine *machine);
int dso__data_get_fd(struct dso *dso, struct machine *machine);
void dso__data_put_fd(struct dso *dso __maybe_unused);
void dso__data_close(struct dso *dso);
off_t dso__data_size(struct dso *dso, struct machine *machine);

11
tools/perf/util/unwind-libunwind.c
View File

@ -269,13 +269,14 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine,
u64 offset = dso->data.eh_frame_hdr_offset;
if (offset == 0) {
fd = dso__data_fd(dso, machine);
fd = dso__data_get_fd(dso, machine);
if (fd < 0)
return -EINVAL;
/* Check the .eh_frame section for unwinding info */
offset = elf_section_offset(fd, ".eh_frame_hdr");
dso->data.eh_frame_hdr_offset = offset;
dso__data_put_fd(dso);
}
if (offset)
@ -294,13 +295,14 @@ static int read_unwind_spec_debug_frame(struct dso *dso,
u64 ofs = dso->data.debug_frame_offset;
if (ofs == 0) {
fd = dso__data_fd(dso, machine);
fd = dso__data_get_fd(dso, machine);
if (fd < 0)
return -EINVAL;
/* Check the .debug_frame section for unwinding info */
ofs = elf_section_offset(fd, ".debug_frame");
dso->data.debug_frame_offset = ofs;
dso__data_put_fd(dso);
}
*offset = ofs;
@ -353,10 +355,13 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
#ifndef NO_LIBUNWIND_DEBUG_FRAME
/* Check the .debug_frame section for unwinding info */
if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) {
int fd = dso__data_fd(map->dso, ui->machine);
int fd = dso__data_get_fd(map->dso, ui->machine);
int is_exec = elf_is_exec(fd, map->dso->name);
unw_word_t base = is_exec ? 0 : map->start;
if (fd >= 0)
dso__data_put_fd(dso);
memset(&di, 0, sizeof(di));
if (dwarf_find_debug_frame(0, &di, ip, base, map->dso->name,
map->start, map->end))