+ selftests-mm-add-wunreachable-code-and-fix-warnings.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: selftests/mm: add -Wunreachable-code and fix warnings
has been added to the -mm mm-new branch.  Its filename is
     selftests-mm-add-wunreachable-code-and-fix-warnings.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-add-wunreachable-code-and-fix-warnings.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

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------------------------------------------------------
From: Muhammad Usama Anjum <usama.anjum@collabora.com>
Subject: selftests/mm: add -Wunreachable-code and fix warnings
Date: Fri, 12 Sep 2025 17:30:21 +0500

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>
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>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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  |    2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

--- a/tools/testing/selftests/mm/hmm-tests.c~selftests-mm-add-wunreachable-code-and-fix-warnings
+++ a/tools/testing/selftests/mm/hmm-tests.c
@@ -2030,11 +2030,10 @@ 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,
--- a/tools/testing/selftests/mm/Makefile~selftests-mm-add-wunreachable-code-and-fix-warnings
+++ a/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
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c~selftests-mm-add-wunreachable-code-and-fix-warnings
+++ a/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;
--- a/tools/testing/selftests/mm/split_huge_page_test.c~selftests-mm-add-wunreachable-code-and-fix-warnings
+++ a/tools/testing/selftests/mm/split_huge_page_test.c
@@ -510,7 +510,7 @@ static void split_file_backed_thp(int or
 
 	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;
 	}
 
_

Patches currently in -mm which might be from usama.anjum@collabora.com are

selftests-mm-centralize-the-__always_unused-macro.patch
selftests-mm-add-wunreachable-code-and-fix-warnings.patch
selftests-mm-protection_keys-fix-dead-code.patch