Re: [PATCH v2 1/8] selftests/mm: Add -Wunreachable-code and fix warnings

On 7/31/25 12:01 PM, Muhammad Usama Anjum wrote:

Enable -Wunreachable-code flag to catch dead code and fix them.

1. Remove the dead code and write a comment instead:

hmm-tests.c:2033:3: warning: code will never be executed [-Wunreachable-code] perror("Should not reach this\n"); ^~~~~~

2. ksft_exit_fail_msg() calls exit(). Remove the dead code.

split_huge_page_test.c:301:3: warning: code will never be executed [-Wunreachable-code] goto cleanup; ^~~~~~~~~~~~

3. Remove duplicate inline.

pkey_sighandler_tests.c:44:15: warning: duplicate 'inline' declaration specifier [-Wduplicate-decl-specifier] static inline __always_inline

Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.com

Reviewed-by: Sidhartha Kumar sidhartha.kumar@oracle.com

---

tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/hmm-tests.c | 5 ++--- tools/testing/selftests/mm/pkey_sighandler_tests.c | 2 +- tools/testing/selftests/mm/split_huge_page_test.c | 4 +--- 4 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index d13b3cef2a2b2..23d4bf6215465 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -34,6 +34,7 @@ endif MAKEFLAGS += --no-builtin-rules CFLAGS = -Wall -O2 -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) $(TOOLS_INCLUDES) +CFLAGS += -Wunreachable-code LDLIBS = -lrt -lpthread -lm # Some distributions (such as Ubuntu) configure GCC so that _FORTIFY_SOURCE is diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c index 141bf63cbe05e..15aadaf24a667 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -2027,11 +2027,10 @@ TEST_F(hmm, hmm_cow_in_device) if (pid == -1) ASSERT_EQ(pid, 0); if (!pid) {

• /* Child process waitd for SIGTERM from the parent. */
  

• /* Child process waits for SIGTERM from the parent. */
  

  while (1) { }

• perror("Should not reach this\n");
  

• exit(0);
  

• /* Should not reach this */
  

  } /* Parent process writes to COW pages(s) and gets a
  • new copy in system. In case of device private pages,

diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c index b5e076a564c95..302fef54049c8 100644 --- a/tools/testing/selftests/mm/pkey_sighandler_tests.c +++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c @@ -41,7 +41,7 @@ static siginfo_t siginfo = {0};

• syscall will attempt to access the PLT in order to call a library function
• which is protected by MPK 0 which we don't have access to.

*/ -static inline __always_inline +static __always_inline long syscall_raw(long n, long a1, long a2, long a3, long a4, long a5, long a6) { unsigned long ret; diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index 05de1fc0005b7..a85b2e393e4e8 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -296,10 +296,8 @@ void split_file_backed_thp(int order) ksft_exit_fail_msg("Unable to create a tmpfs for testing\n"); status = snprintf(testfile, INPUT_MAX, "%s/thp_file", tmpfs_loc);

• if (status >= INPUT_MAX) {

• if (status >= INPUT_MAX) ksft_exit_fail_msg("Fail to create file-backed THP split testing file\n");

• goto cleanup;
  

• }

fd = open(testfile, O_CREAT|O_RDWR, 0664); if (fd == -1) {