This series is trimmed down version of previous more generic series[1]. In this new series, only -wunreachable-code flag is being added and dead code is being removed from generated warnings.
[1] https://lore.kernel.org/all/20250822082145.4145617-1-usama.anjum@collabora.c...
Muhammad Usama Anjum (2): selftests/mm: Add -Wunreachable-code and fix warnings selftests/mm: protection_keys: Fix dead code
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/protection_keys.c | 4 +--- tools/testing/selftests/mm/split_huge_page_test.c | 2 +- 5 files changed, 6 insertions(+), 8 deletions(-)
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
Reviewed-by: Sidhartha Kumar sidhartha.kumar@oracle.com Reviewed-by: Kevin Brodsky kevin.brodsky@arm.com Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.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 | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index 5a1dee50b8987..eaf9312097f7b 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 1325de70f44fc..25045536f4707 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/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, 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 7731191cc8e9b..743af3c051905 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; }
On 12.09.25 14:30, Muhammad Usama Anjum wrote:
Enable -Wunreachable-code flag to catch dead code and fix them.
- 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"); ^~~~~~
- 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; ^~~~~~~~~~~~
- Remove duplicate inline.
pkey_sighandler_tests.c:44:15: warning: duplicate 'inline' declaration specifier [-Wduplicate-decl-specifier] static inline __always_inline
Reviewed-by: Sidhartha Kumar sidhartha.kumar@oracle.com Reviewed-by: Kevin Brodsky kevin.brodsky@arm.com Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.com
Acked-by: David Hildenbrand david@redhat.com
On 12 Sep 2025, at 8:30, Muhammad Usama Anjum wrote:
Enable -Wunreachable-code flag to catch dead code and fix them.
- 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"); ^~~~~~
- 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; ^~~~~~~~~~~~
- Remove duplicate inline.
pkey_sighandler_tests.c:44:15: warning: duplicate 'inline' declaration specifier [-Wduplicate-decl-specifier] static inline __always_inline
Reviewed-by: Sidhartha Kumar sidhartha.kumar@oracle.com Reviewed-by: Kevin Brodsky kevin.brodsky@arm.com Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.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 | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-)
LGTM. Reviewed-by: Zi Yan ziy@nvidia.com
Best Regards, Yan, Zi
The while loop doesn't execute and following warning gets generated:
protection_keys.c:561:15: warning: code will never be executed [-Wunreachable-code] int rpkey = alloc_random_pkey();
Let's enable the while loop such that it gets executed nr_iterations times. Simplify the code a bit as well.
Reviewed-by: Sidhartha Kumar sidhartha.kumar@oracle.com Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.com --- tools/testing/selftests/mm/protection_keys.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c index 23ebec367015f..6281d4c61b50e 100644 --- a/tools/testing/selftests/mm/protection_keys.c +++ b/tools/testing/selftests/mm/protection_keys.c @@ -557,13 +557,11 @@ int mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot, int nr_iterations = random() % 100; int ret;
- while (0) { + while (nr_iterations-- >= 0) { int rpkey = alloc_random_pkey(); ret = sys_mprotect_pkey(ptr, size, orig_prot, pkey); dprintf1("sys_mprotect_pkey(%p, %zx, prot=0x%lx, pkey=%ld) ret: %d\n", ptr, size, orig_prot, pkey, ret); - if (nr_iterations-- < 0) - break;
dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx" " shadow: 0x%016llx\n",
On 12 Sep 2025, at 8:30, Muhammad Usama Anjum wrote:
The while loop doesn't execute and following warning gets generated:
protection_keys.c:561:15: warning: code will never be executed [-Wunreachable-code] int rpkey = alloc_random_pkey();
Let's enable the while loop such that it gets executed nr_iterations times. Simplify the code a bit as well.
Reviewed-by: Sidhartha Kumar sidhartha.kumar@oracle.com Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.com
tools/testing/selftests/mm/protection_keys.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
LGTM. Reviewed-by: Zi Yan ziy@nvidia.com
Best Regards, Yan, Zi
linux-kselftest-mirror@lists.linaro.org
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David Hildenbrand -
Muhammad Usama Anjum -
Zi Yan