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| author | Al Viro <[email protected]> | 2012-04-30 22:24:46 +0000 |
|---|---|---|
| committer | Al Viro <[email protected]> | 2012-06-01 17:01:51 +0000 |
| commit | 44fbbb3dc687c9709a6f2236197316e5c79ab1eb (patch) | |
| tree | d3c995b1cb7e3f9ac5af09b8d78f6c839a65f35a /tools/perf/util/trace-event-scripting.c | |
| parent | blackfin: check __get_user() return value (diff) | |
| download | kernel-44fbbb3dc687c9709a6f2236197316e5c79ab1eb.tar.gz kernel-44fbbb3dc687c9709a6f2236197316e5c79ab1eb.zip | |
x86: get rid of calling do_notify_resume() when returning to kernel mode
If we end up calling do_notify_resume() with !user_mode(refs), it
does nothing (do_signal() explicitly bails out and we can't get there
with TIF_NOTIFY_RESUME in such situations). Then we jump to
resume_userspace_sig, which rechecks the same thing and bails out
to resume_kernel, thus breaking the loop.
It's easier and cheaper to check *before* calling do_notify_resume()
and bail out to resume_kernel immediately. And kill the check in
do_signal()...
Note that on amd64 we can't get there with !user_mode() at all - asm
glue takes care of that.
Acked-and-reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Al Viro <[email protected]>
Diffstat (limited to 'tools/perf/util/trace-event-scripting.c')
0 files changed, 0 insertions, 0 deletions