From: Mark Brown <broonie@kernel.org> mainline inclusion from mainline-v6.5-rc5 commit c9bb40b7f786662e33d71afe236442b0b61f0446 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8E73O CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ------------------------------------------------- When setting SME vector lengths we clear TIF_SME to reenable SME traps, doing a reallocation of the backing storage on next use. We do this using clear_thread_flag() which operates on the current thread, meaning that when setting the vector length via ptrace we may both not force traps for the target task and force a spurious flush of any SME state that the tracing task may have. Clear the flag in the target task. Fixes: e12310a0d30f ("arm64/sme: Implement ptrace support for streaming mode SVE registers") Reported-by: David Spickett <David.Spickett@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-tif-sme-v1-1-88312fd6fbf... Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com> --- arch/arm64/kernel/fpsimd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 4988c5245479c..bf056f0fbf587 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -841,7 +841,7 @@ int vec_set_vector_length(struct task_struct *task, enum vec_type type, */ task->thread.svcr &= ~(SVCR_SM_MASK | SVCR_ZA_MASK); - clear_thread_flag(TIF_SME); + clear_tsk_thread_flag(task, TIF_SME); free_sme = true; } } -- 2.25.1