Ingo Molnar 528871b456 perf/core: Fix impossible ring-buffer sizes warning ...

The following commit:

  9dff0aa95a ("perf/core: Don't WARN() for impossible ring-buffer sizes")

results in perf recording failures with larger mmap areas:

  root@skl:/tmp# perf record -g -a
  failed to mmap with 12 (Cannot allocate memory)

The root cause is that the following condition is buggy:

	if (order_base_2(size) >= MAX_ORDER)
		goto fail;

The problem is that @size is in bytes and MAX_ORDER is in pages,
so the right test is:

	if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
		goto fail;

Fix it.

Reported-by: "Jin, Yao" <[email protected]>
Bisected-by: Borislav Petkov <[email protected]>
Analyzed-by: Peter Zijlstra <[email protected]>
Cc: Julien Thierry <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: <[email protected]>
Fixes: 9dff0aa95a ("perf/core: Don't WARN() for impossible ring-buffer sizes")
Signed-off-by: Ingo Molnar <[email protected]>

2019-02-13 08:05:02 +01:00

..

callchain.c

treewide: convert ISO_8859-1 text comments to utf-8

2018-08-23 18:48:43 -07:00

core.c

perf/x86: Add check_period PMU callback

2019-02-11 11:46:43 +01:00

hw_breakpoint.c

perf: Fix typos in comments

2018-12-03 11:22:32 +01:00

internal.h

perf: Make perf_callchain function static

2018-01-08 12:33:01 -03:00

Makefile

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

ring_buffer.c

perf/core: Fix impossible ring-buffer sizes warning

2019-02-13 08:05:02 +01:00

uprobes.c

mm/mmu_notifier: use structure for invalidate_range_start/end calls v2

2018-12-28 12:11:50 -08:00