[PATCH] arm64/ptrace: Don't clear calling process' TIF_SME on OOM

Mark Brown broonie at kernel.org
Fri Sep 2 06:28:02 PDT 2022


If allocating memory for the target SVE state in za_set() fails we clear
TIF_SME for the ptracing task which is obviously not correct.  If we are
here we know that the target task already had neither TIF_SVE nor
TIF_SME set since we only need to allocate if either the target had not
used either SVE or SME and had no need to allocate state before or we
just changed the vector length with vec_set_vector_length() which clears
TIF_ for us on allocation failure so just remove the clear entirely.

Reported-by: Wang ShaoBo <bobo.shaobowang at huawei.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 arch/arm64/kernel/ptrace.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index eb7c08dfb834..041d2ae5c30a 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1084,7 +1084,6 @@ static int za_set(struct task_struct *target,
 	if (!target->thread.sve_state) {
 		sve_alloc(target, false);
 		if (!target->thread.sve_state) {
-			clear_thread_flag(TIF_SME);
 			ret = -ENOMEM;
 			goto out;
 		}
@@ -1094,7 +1093,6 @@ static int za_set(struct task_struct *target,
 	sme_alloc(target);
 	if (!target->thread.za_state) {
 		ret = -ENOMEM;
-		clear_tsk_thread_flag(target, TIF_SME);
 		goto out;
 	}
 
-- 
2.30.2




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