mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-19 10:44:14 +08:00
perf/core: Don't WARN() for impossible ring-buffer sizes
The perf tool uses /proc/sys/kernel/perf_event_mlock_kb to determine how large its ringbuffer mmap should be. This can be configured to arbitrary values, which can be larger than the maximum possible allocation from kmalloc. When this is configured to a suitably large value (e.g. thanks to the perf fuzzer), attempting to use perf record triggers a WARN_ON_ONCE() in __alloc_pages_nodemask(): WARNING: CPU: 2 PID: 5666 at mm/page_alloc.c:4511 __alloc_pages_nodemask+0x3f8/0xbc8 Let's avoid this by checking that the requested allocation is possible before calling kzalloc. Reported-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20190110142745.25495-1-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
parent
602cae04c4
commit
9dff0aa95a
@ -734,6 +734,9 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
|
||||
size = sizeof(struct ring_buffer);
|
||||
size += nr_pages * sizeof(void *);
|
||||
|
||||
if (order_base_2(size) >= MAX_ORDER)
|
||||
goto fail;
|
||||
|
||||
rb = kzalloc(size, GFP_KERNEL);
|
||||
if (!rb)
|
||||
goto fail;
|
||||
|
Loading…
Reference in New Issue
Block a user