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| author | Jiri Olsa <jolsa@kernel.org> | 2020-04-07 16:14:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-04-08 11:33:46 +0200 |
| commit | d3296fb372bf7497b0e5d0478c4e7a677ec6f6e9 (patch) | |
| tree | 7cecee8c57730cc38b87cd610595721a955ab666 /crypto | |
| parent | 2b3b76b5ec67568da4bb475d3ce8a92ef494b5de (diff) | |
| download | linux-d3296fb372bf7497b0e5d0478c4e7a677ec6f6e9.tar.gz linux-d3296fb372bf7497b0e5d0478c4e7a677ec6f6e9.tar.bz2 linux-d3296fb372bf7497b0e5d0478c4e7a677ec6f6e9.zip | |
perf/core: Disable page faults when getting phys address
We hit following warning when running tests on kernel
compiled with CONFIG_DEBUG_ATOMIC_SLEEP=y:
WARNING: CPU: 19 PID: 4472 at mm/gup.c:2381 __get_user_pages_fast+0x1a4/0x200
CPU: 19 PID: 4472 Comm: dummy Not tainted 5.6.0-rc6+ #3
RIP: 0010:__get_user_pages_fast+0x1a4/0x200
...
Call Trace:
perf_prepare_sample+0xff1/0x1d90
perf_event_output_forward+0xe8/0x210
__perf_event_overflow+0x11a/0x310
__intel_pmu_pebs_event+0x657/0x850
intel_pmu_drain_pebs_nhm+0x7de/0x11d0
handle_pmi_common+0x1b2/0x650
intel_pmu_handle_irq+0x17b/0x370
perf_event_nmi_handler+0x40/0x60
nmi_handle+0x192/0x590
default_do_nmi+0x6d/0x150
do_nmi+0x2f9/0x3c0
nmi+0x8e/0xd7
While __get_user_pages_fast() is IRQ-safe, it calls access_ok(),
which warns on:
WARN_ON_ONCE(!in_task() && !pagefault_disabled())
Peter suggested disabling page faults around __get_user_pages_fast(),
which gets rid of the warning in access_ok() call.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200407141427.3184722-1-jolsa@kernel.org
Diffstat (limited to 'crypto')
0 files changed, 0 insertions, 0 deletions