Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH v2] signal: Skip the altstack update when not needed | Date | Mon, 13 Dec 2021 22:25:37 +0100 |
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On Fri, Dec 10 2021 at 14:55, Chang S. Bae wrote: > do_sigaltstack() acquires sigaltstack_lock() and is used for both > sys_sigaltstack() and restoring the sigaltstack in sys_sigreturn(). > Check for changes to the sigaltstack before taking the lock. If no > changes were made, return before acquiring the lock. > > This removes lock contention from the common-case sigreturn path. > > Reported-by: kernel test robot <oliver.sang@intel.com> > [1] https://lore.kernel.org/lkml/20211207012128.GA16074@xsang-OptiPlex-9020/ > Fixes: 3aac3ebea08f ("x86/signal: Implement sigaltstack size validation") > Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> > Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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