Jiri Olsa d3296fb372 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		2020-04-08 11:33:46 +02:00
..
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
callchain.c	perf/core: Convert to SPDX license identifiers	2019-02-04 08:46:11 +01:00
core.c	perf/core: Disable page faults when getting phys address	2020-04-08 11:33:46 +02:00
hw_breakpoint.c	perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initialization	2019-09-06 08:24:01 +02:00
internal.h	perf: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
ring_buffer.c	perf: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
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