selftests/mm: add -Wunreachable-code and fix warnings

Patch series "selftests/mm: Add -Wunreachable-code and fix warnings".

Add -Wunreachable-code to selftests and remove dead code from generated
warnings.


This patch (of 2):

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(). So cleanup isn't done. Replace it
   with ksft_print_msg().
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

Link: https://lkml.kernel.org/r/20250912123025.1271051-1-usama.anjum@collabora.com
Link: https://lkml.kernel.org/r/20250912123025.1271051-2-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

4 files changed, 5 insertions, 5 deletions

diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 5a1dee50b898..eaf9312097f7 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 141bf63cbe05..15aadaf24a66 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 b5e076a564c9..302fef54049c 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 7731191cc8e9..743af3c05190 100644
--- a/tools/testing/selftests/mm/split_huge_page_test.c
+++ b/tools/testing/selftests/mm/split_huge_page_test.c
@@ -510,7 +510,7 @@ static void split_file_backed_thp(int order)
 
 	status = snprintf(testfile, INPUT_MAX, "%s/thp_file", tmpfs_loc);
 	if (status >= INPUT_MAX) {
-		ksft_exit_fail_msg("Fail to create file-backed THP split testing file\n");
+		ksft_print_msg("Fail to create file-backed THP split testing file\n");
 		goto cleanup;
 	}