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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-04-30 18:24:46 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-06-01 13:01:51 -0400 |
| commit | 44fbbb3dc687c9709a6f2236197316e5c79ab1eb (patch) | |
| tree | d3c995b1cb7e3f9ac5af09b8d78f6c839a65f35a /fs/compat.c | |
| parent | 29bf5dd895219e5111099908040aecfc1509f9bb (diff) | |
| download | lwn-44fbbb3dc687c9709a6f2236197316e5c79ab1eb.tar.gz lwn-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 <tglx@linutronix.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/compat.c')
0 files changed, 0 insertions, 0 deletions