From: Clint George Date: Mon, 15 Dec 2025 08:47:37 +0000 (+0530) Subject: kselftest/coredump: use __builtin_trap() instead of null pointer X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=673a55cc49dafe47defb9ad76a73987fe89e5d70;p=thirdparty%2Fkernel%2Flinux.git kselftest/coredump: use __builtin_trap() instead of null pointer Use __builtin_trap() to truly crash the program instead of dereferencing null pointer which may be optimized by the compiler preventing the crash from occurring [] Testing: The diff between before and after of running the kselftest test of the module shows no regression on system with x86 architecture [] Error log: ~/Desktop/kernel-dev/linux-v1/tools/testing/selftests/coredump$ make LLVM=1 W=1 CC stackdump_test coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference] 59 | i = *(int *)NULL; | ^~~~~~~~~~~~ coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile' 1 warning generated. CC coredump_socket_test coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference] 59 | i = *(int *)NULL; | ^~~~~~~~~~~~ coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile' 1 warning generated. CC coredump_socket_protocol_test coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference] 59 | i = *(int *)NULL; | ^~~~~~~~~~~~ coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile' 1 warning generated. Link: https://lore.kernel.org/r/20251215084737.7504-1-clintbgeorge@gmail.com Signed-off-by: Clint George Signed-off-by: Shuah Khan --- diff --git a/tools/testing/selftests/coredump/coredump_test_helpers.c b/tools/testing/selftests/coredump/coredump_test_helpers.c index a6f6d5f2ae07a..5c8adee636414 100644 --- a/tools/testing/selftests/coredump/coredump_test_helpers.c +++ b/tools/testing/selftests/coredump/coredump_test_helpers.c @@ -56,7 +56,7 @@ void crashing_child(void) pthread_create(&thread, NULL, do_nothing, NULL); /* crash on purpose */ - i = *(int *)NULL; + __builtin_trap(); } int create_detached_tmpfs(void)