The patch titled Subject: selftests/user_events: fix type cast for write_index packed member in perf_test has been added to the -mm mm-hotfixes-unstable branch. Its filename is selftests-user_events-fix-type-cast-for-write_index-packed-member-in-perf_test.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: Ankit Khushwaha ankitkhushwaha.linux@gmail.com Subject: selftests/user_events: fix type cast for write_index packed member in perf_test Date: Thu, 6 Nov 2025 15:25:32 +0530
Accessing 'reg.write_index' directly triggers a -Waddress-of-packed-member warning due to potential unaligned pointer access:
perf_test.c:239:38: warning: taking address of packed member 'write_index' of class or structure 'user_reg' may result in an unaligned pointer value [-Waddress-of-packed-member] 239 | ASSERT_NE(-1, write(self->data_fd, ®.write_index, | ^~~~~~~~~~~~~~~
Since write(2) works with any alignment. Casting '®.write_index' explicitly to 'void *' to suppress this warning.
Link: https://lkml.kernel.org/r/20251106095532.15185-1-ankitkhushwaha.linux@gmail.... Fixes: 42187bdc3ca4 ("selftests/user_events: Add perf self-test for empty arguments events") Signed-off-by: Ankit Khushwaha ankitkhushwaha.linux@gmail.com Cc: Beau Belgrave beaub@linux.microsoft.com Cc: "Masami Hiramatsu (Google)" mhiramat@kernel.org Cc: Steven Rostedt rostedt@goodmis.org Cc: sunliming sunliming@kylinos.cn Cc: Wei Yang richard.weiyang@gmail.com Cc: Shuah Khan shuah@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
tools/testing/selftests/user_events/perf_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/testing/selftests/user_events/perf_test.c~selftests-user_events-fix-type-cast-for-write_index-packed-member-in-perf_test +++ a/tools/testing/selftests/user_events/perf_test.c @@ -236,7 +236,7 @@ TEST_F(user, perf_empty_events) { ASSERT_EQ(1 << reg.enable_bit, self->check);
/* Ensure write shows up at correct offset */ - ASSERT_NE(-1, write(self->data_fd, ®.write_index, + ASSERT_NE(-1, write(self->data_fd, (void *)®.write_index, sizeof(reg.write_index))); val = (void *)(((char *)perf_page) + perf_page->data_offset); ASSERT_EQ(PERF_RECORD_SAMPLE, *val); _
Patches currently in -mm which might be from ankitkhushwaha.linux@gmail.com are
selftests-user_events-fix-type-cast-for-write_index-packed-member-in-perf_test.patch