From 3d1ba5cbfb622025690c218d8f20da92a9ecb383 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Wed, 9 Sep 2026 17:57:07 +0200 Subject: [PATCH] kselftest/arm64: Fix size of thread_data values for pthread_join() pthread_join() stores the thread's return value (a "void *", i.e. 8 bytes on 64 bit computers) into the address that is passed as second parameter. However, the entries of thread_data are only normal "int"s, i.e. only 4 bytes. The additional 4 bytes of the return value clobber whatever is adjacent on the stack, i.e. other members of the thread_data array (which will be re-written in the next iteration of the for-loop, so that nobody noticed this problem), or another other local variable on the stack for the last iteration. Use "intptr_t" to declare the thread_data array entries with the correct size. Fixes: 29f080881601c ("kselftest/arm64: check GCR_EL1 after context switch") Cc: stable@vger.kernel.org Signed-off-by: Thomas Huth Signed-off-by: Will Deacon --- tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c b/tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c index d23f154d3288..5d9dc8bcfbf5 100644 --- a/tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c +++ b/tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c @@ -69,7 +69,7 @@ void *execute_thread(void *x) int execute_test(pid_t pid) { pthread_t thread_id[MAX_THREADS]; - int thread_data[MAX_THREADS]; + intptr_t thread_data[MAX_THREADS]; for (int i = 0; i < MAX_THREADS; i++) pthread_create(&thread_id[i], NULL,