From: Li Qiang Date: Fri, 19 Sep 2025 03:33:27 +0000 (+0800) Subject: arm64: add unlikely hint to MTE async fault check in el0_svc_common X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=df717b9564c8370e9198c9cd5d62e277a18563fb;p=thirdparty%2Flinux.git arm64: add unlikely hint to MTE async fault check in el0_svc_common Add unlikely() hint to the _TIF_MTE_ASYNC_FAULT flag check in el0_svc_common() since asynchronous MTE faults are expected to be rare occurrences during normal system call execution. This optimization helps the compiler to improve instruction caching and branch prediction for the common case where no asynchronous MTE faults are pending, while maintaining correct behavior for the exceptional case where such faults need to be handled prior to system call execution. Signed-off-by: Li Qiang Signed-off-by: Catalin Marinas --- diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index aba7ca6bca2d1..c062badd1a566 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -96,7 +96,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, * (Similarly for HVC and SMC elsewhere.) */ - if (flags & _TIF_MTE_ASYNC_FAULT) { + if (unlikely(flags & _TIF_MTE_ASYNC_FAULT)) { /* * Process the asynchronous tag check fault before the actual * syscall. do_notify_resume() will send a signal to userspace