linux/kernel/events
Song Liu 003461559e perf/core: Fix mlock accounting in perf_mmap()
Decreasing sysctl_perf_event_mlock between two consecutive perf_mmap()s of
a perf ring buffer may lead to an integer underflow in locked memory
accounting. This may lead to the undesired behaviors, such as failures in
BPF map creation.

Address this by adjusting the accounting logic to take into account the
possibility that the amount of already locked memory may exceed the
current limit.

Fixes: c4b7547974 ("perf/core: Make the mlock accounting simple again")
Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/20200123181146.2238074-1-songliubraving@fb.com
2020-01-28 21:20:18 +01:00
..
callchain.c perf/core: Convert to SPDX license identifiers 2019-02-04 08:46:11 +01:00
core.c perf/core: Fix mlock accounting in perf_mmap() 2020-01-28 21:20:18 +01:00
hw_breakpoint.c perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initialization 2019-09-06 08:24:01 +02:00
internal.h perf/aux: Allow using AUX data in perf samples 2019-11-13 11:06:14 +01:00
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/aux: Allow using AUX data in perf samples 2019-11-13 11:06:14 +01:00
uprobes.c mm/mmap.c: use IS_ERR_VALUE to check return value of get_unmapped_area 2019-12-01 06:29:19 -08:00