6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ankit Khushwaha ankitkhushwaha.linux@gmail.com
commit 216158f063fe24fb003bd7da0cd92cd6e2c4d48b upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/testing/selftests/user_events/perf_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/user_events/perf_test.c b/tools/testing/selftests/user_events/perf_test.c index 5288e768b207..68625362add2 100644 --- a/tools/testing/selftests/user_events/perf_test.c +++ b/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);