From: Ian Rogers irogers@google.com
[ Upstream commit aba5daeb645181ee5a046bc00c231fd045882aaa ]
FD uses xyarray__entry that may return NULL if an index is out of bounds. If NULL is returned then a segv happens as FD unconditionally dereferences the pointer. This was happening in a case of with perf iostat as shown below. The fix is to make FD an "int*" rather than an int and handle the NULL case as either invalid input or a closed fd.
$ sudo gdb --args perf stat --iostat list ... Breakpoint 1, perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50 50 { (gdb) bt #0 perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50 #1 0x000055555585c188 in evsel__open_cpu (evsel=0x5555560951a0, cpus=0x555556093410, threads=0x555556086fb0, start_cpu=0, end_cpu=1) at util/evsel.c:1792 #2 0x000055555585cfb2 in evsel__open (evsel=0x5555560951a0, cpus=0x0, threads=0x555556086fb0) at util/evsel.c:2045 #3 0x000055555585d0db in evsel__open_per_thread (evsel=0x5555560951a0, threads=0x555556086fb0) at util/evsel.c:2065 #4 0x00005555558ece64 in create_perf_stat_counter (evsel=0x5555560951a0, config=0x555555c34700 <stat_config>, target=0x555555c2f1c0 <target>, cpu=0) at util/stat.c:590 #5 0x000055555578e927 in __run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0) at builtin-stat.c:833 #6 0x000055555578f3c6 in run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0) at builtin-stat.c:1048 #7 0x0000555555792ee5 in cmd_stat (argc=1, argv=0x7fffffffe4a0) at builtin-stat.c:2534 #8 0x0000555555835ed3 in run_builtin (p=0x555555c3f540 <commands+288>, argc=3, argv=0x7fffffffe4a0) at perf.c:313 #9 0x0000555555836154 in handle_internal_command (argc=3, argv=0x7fffffffe4a0) at perf.c:365 #10 0x000055555583629f in run_argv (argcp=0x7fffffffe2ec, argv=0x7fffffffe2e0) at perf.c:409 #11 0x0000555555836692 in main (argc=3, argv=0x7fffffffe4a0) at perf.c:539 ... (gdb) c Continuing. Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/). /bin/dmesg | grep -i perf may provide additional information.
Program received signal SIGSEGV, Segmentation fault. 0x00005555559b03ea in perf_evsel__close_fd_cpu (evsel=0x5555560951a0, cpu=1) at evsel.c:166 166 if (FD(evsel, cpu, thread) >= 0)
v3. fixes a bug in perf_evsel__run_ioctl where the sense of a branch was backward.
Signed-off-by: Ian Rogers irogers@google.com Acked-by: Jiri Olsa jolsa@redhat.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Link: http://lore.kernel.org/lkml/20210918054440.2350466-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/perf/evsel.c | 64 +++++++++++++++++++++++++++--------------- 1 file changed, 41 insertions(+), 23 deletions(-)
diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c index d8886720e83d..8441e3e1aaac 100644 --- a/tools/lib/perf/evsel.c +++ b/tools/lib/perf/evsel.c @@ -43,7 +43,7 @@ void perf_evsel__delete(struct perf_evsel *evsel) free(evsel); }
-#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y)) +#define FD(e, x, y) ((int *) xyarray__entry(e->fd, x, y)) #define MMAP(e, x, y) (e->mmap ? ((struct perf_mmap *) xyarray__entry(e->mmap, x, y)) : NULL)
int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads) @@ -54,7 +54,10 @@ int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads) int cpu, thread; for (cpu = 0; cpu < ncpus; cpu++) { for (thread = 0; thread < nthreads; thread++) { - FD(evsel, cpu, thread) = -1; + int *fd = FD(evsel, cpu, thread); + + if (fd) + *fd = -1; } } } @@ -80,7 +83,7 @@ sys_perf_event_open(struct perf_event_attr *attr, static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread, int *group_fd) { struct perf_evsel *leader = evsel->leader; - int fd; + int *fd;
if (evsel == leader) { *group_fd = -1; @@ -95,10 +98,10 @@ static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread, int *grou return -ENOTCONN;
fd = FD(leader, cpu, thread); - if (fd == -1) + if (fd == NULL || *fd == -1) return -EBADF;
- *group_fd = fd; + *group_fd = *fd;
return 0; } @@ -138,7 +141,11 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
for (cpu = 0; cpu < cpus->nr; cpu++) { for (thread = 0; thread < threads->nr; thread++) { - int fd, group_fd; + int fd, group_fd, *evsel_fd; + + evsel_fd = FD(evsel, cpu, thread); + if (evsel_fd == NULL) + return -EINVAL;
err = get_group_fd(evsel, cpu, thread, &group_fd); if (err < 0) @@ -151,7 +158,7 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, if (fd < 0) return -errno;
- FD(evsel, cpu, thread) = fd; + *evsel_fd = fd; } }
@@ -163,9 +170,12 @@ static void perf_evsel__close_fd_cpu(struct perf_evsel *evsel, int cpu) int thread;
for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) { - if (FD(evsel, cpu, thread) >= 0) - close(FD(evsel, cpu, thread)); - FD(evsel, cpu, thread) = -1; + int *fd = FD(evsel, cpu, thread); + + if (fd && *fd >= 0) { + close(*fd); + *fd = -1; + } } }
@@ -209,13 +219,12 @@ void perf_evsel__munmap(struct perf_evsel *evsel)
for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++) { for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) { - int fd = FD(evsel, cpu, thread); - struct perf_mmap *map = MMAP(evsel, cpu, thread); + int *fd = FD(evsel, cpu, thread);
- if (fd < 0) + if (fd == NULL || *fd < 0) continue;
- perf_mmap__munmap(map); + perf_mmap__munmap(MMAP(evsel, cpu, thread)); } }
@@ -239,15 +248,16 @@ int perf_evsel__mmap(struct perf_evsel *evsel, int pages)
for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++) { for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) { - int fd = FD(evsel, cpu, thread); - struct perf_mmap *map = MMAP(evsel, cpu, thread); + int *fd = FD(evsel, cpu, thread); + struct perf_mmap *map;
- if (fd < 0) + if (fd == NULL || *fd < 0) continue;
+ map = MMAP(evsel, cpu, thread); perf_mmap__init(map, NULL, false, NULL);
- ret = perf_mmap__mmap(map, &mp, fd, cpu); + ret = perf_mmap__mmap(map, &mp, *fd, cpu); if (ret) { perf_evsel__munmap(evsel); return ret; @@ -260,7 +270,9 @@ int perf_evsel__mmap(struct perf_evsel *evsel, int pages)
void *perf_evsel__mmap_base(struct perf_evsel *evsel, int cpu, int thread) { - if (FD(evsel, cpu, thread) < 0 || MMAP(evsel, cpu, thread) == NULL) + int *fd = FD(evsel, cpu, thread); + + if (fd == NULL || *fd < 0 || MMAP(evsel, cpu, thread) == NULL) return NULL;
return MMAP(evsel, cpu, thread)->base; @@ -295,17 +307,18 @@ int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread, struct perf_counts_values *count) { size_t size = perf_evsel__read_size(evsel); + int *fd = FD(evsel, cpu, thread);
memset(count, 0, sizeof(*count));
- if (FD(evsel, cpu, thread) < 0) + if (fd == NULL || *fd < 0) return -EINVAL;
if (MMAP(evsel, cpu, thread) && !perf_mmap__read_self(MMAP(evsel, cpu, thread), count)) return 0;
- if (readn(FD(evsel, cpu, thread), count->values, size) <= 0) + if (readn(*fd, count->values, size) <= 0) return -errno;
return 0; @@ -318,8 +331,13 @@ static int perf_evsel__run_ioctl(struct perf_evsel *evsel, int thread;
for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) { - int fd = FD(evsel, cpu, thread), - err = ioctl(fd, ioc, arg); + int err; + int *fd = FD(evsel, cpu, thread); + + if (fd == NULL || *fd < 0) + return -1; + + err = ioctl(*fd, ioc, arg);
if (err) return err;