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| author | Stephane Eranian <eranian@google.com> | 2013-03-15 17:26:07 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-20 23:58:52 +0400 |
| commit | 87a42f27adef5e88b8907edbc168de1380e7129e (patch) | |
| tree | d448849712974ea959023897839e5f85efbcbe81 /lib/sha1.c | |
| parent | 5e44eef46e81bf6e159b44fa893cf7dd47a88f53 (diff) | |
| download | linux-87a42f27adef5e88b8907edbc168de1380e7129e.tar.xz | |
perf,x86: fix kernel crash with PEBS/BTS after suspend/resume
commit 1d9d8639c063caf6efc2447f5f26aa637f844ff6 upstream.
This patch fixes a kernel crash when using precise sampling (PEBS)
after a suspend/resume. Turns out the CPU notifier code is not invoked
on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
by the kernel and keeps it power-on/resume value of 0 causing any PEBS
measurement to crash when running on CPU0.
The workaround is to add a hook in the actual resume code to restore
the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
the DS_AREA will be restored twice but this is harmless.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/sha1.c')
0 files changed, 0 insertions, 0 deletions