[PATCH v2 0/8] selftests/mm: Add compiler flags and fix found warnings

[PATCH v2 0/8] selftests/mm: Add compiler flags and fix found warnings

[Muhammad Usama Anjum]

Recently, I reviewed a patch on the mm/kselftest mailing list about a
test which had obvious type mismatch fix in it. It was strange why that
wasn't caught during development and when patch was accepted. This led
me to discover that those extra compiler options to catch these warnings
aren't being used. When I added them, I found tens of warnings in just
mm suite.

In this series, I'm adding these flags and fixing those warnings. In the
last try several months ago [1], I'd patches for individual tests. I've
made patches better by grouping the same type of fixes together. Hence
there is no changelog for individual patches.

The changes have been build tested on x86_64, arm64, powerpc64 and partially
on riscv64. The test run with and without this series has been done on
x86_64.

---
Changes since v1:
- Drop test harness patch which isn't needed anymore
- Revamp how patches are written per same kind of failure

Muhammad Usama Anjum (8):
  selftests/mm: Add -Wunreachable-code and fix warnings
  selftests/mm: protection_keys: Fix dead code
  selftests: kselftest.h: Add __unused macro
  selftests/mm: Add -Wunused family of flags
  selftests/mm: Remove unused parameters
  selftests/mm: Mark unused arguments with __unused
  selftests/mm: Mark unused arguments with __unused
  selftests/mm: Fix unused parameter warnings for different
    architectures

 tools/testing/selftests/kselftest.h           |  4 ++
 tools/testing/selftests/mm/Makefile           |  3 +-
 tools/testing/selftests/mm/compaction_test.c  |  2 +-
 tools/testing/selftests/mm/cow.c              | 22 +++++------
 tools/testing/selftests/mm/droppable.c        |  2 +-
 tools/testing/selftests/mm/gup_longterm.c     |  2 +-
 tools/testing/selftests/mm/hmm-tests.c        |  5 +--
 tools/testing/selftests/mm/hugepage-vmemmap.c |  2 +-
 tools/testing/selftests/mm/hugetlb-madvise.c  |  2 +-
 .../selftests/mm/hugetlb-soft-offline.c       |  2 +-
 .../selftests/mm/hugetlb_fault_after_madv.c   |  4 +-
 .../selftests/mm/hugetlb_madv_vs_map.c        |  6 +--
 tools/testing/selftests/mm/ksm_tests.c        | 17 ++++-----
 tools/testing/selftests/mm/madv_populate.c    |  2 +-
 tools/testing/selftests/mm/map_populate.c     |  2 +-
 tools/testing/selftests/mm/memfd_secret.c     |  6 +--
 .../testing/selftests/mm/mlock-random-test.c  |  2 +-
 tools/testing/selftests/mm/mlock2-tests.c     |  2 +-
 tools/testing/selftests/mm/mseal_test.c       |  8 +++-
 tools/testing/selftests/mm/on-fault-limit.c   |  2 +-
 tools/testing/selftests/mm/pfnmap.c           |  2 +-
 tools/testing/selftests/mm/pkey-arm64.h       |  5 ++-
 tools/testing/selftests/mm/pkey-powerpc.h     |  2 +-
 tools/testing/selftests/mm/pkey-x86.h         |  3 +-
 .../selftests/mm/pkey_sighandler_tests.c      | 35 ++++++++++++-----
 tools/testing/selftests/mm/protection_keys.c  | 22 +++++------
 tools/testing/selftests/mm/soft-dirty.c       |  6 +--
 .../selftests/mm/split_huge_page_test.c       |  8 ++--
 tools/testing/selftests/mm/uffd-common.c      | 15 ++++----
 tools/testing/selftests/mm/uffd-common.h      |  2 +-
 tools/testing/selftests/mm/uffd-stress.c      |  2 +-
 tools/testing/selftests/mm/uffd-unit-tests.c  | 38 +++++++++----------
 tools/testing/selftests/mm/uffd-wp-mremap.c   |  2 +-
 .../selftests/mm/virtual_address_range.c      |  2 +-
 34 files changed, 130 insertions(+), 111 deletions(-)

-- 
2.39.5

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

[Muhammad Usama Anjum]

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>
---
 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) {
-- 
2.39.5

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

[Sidhartha Kumar]

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) {

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

[Kevin Brodsky]

On 31/07/2025 18:01, Muhammad Usama Anjum wrote:
> [...]
>
> 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

Thanks for this, I had this fix locally but never got to post it!

>  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;

At that point the mount() call has succeeded so I think we do want to
keep the goto and just print the error message instead of calling
replace ksft_exit_fail_msg().

- Kevin

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

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

[Muhammad Usama Anjum]

On 8/18/25 1:10 PM, Kevin Brodsky wrote:
> On 31/07/2025 18:01, Muhammad Usama Anjum wrote:
>> [...]
>>
>> 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
> 
> Thanks for this, I had this fix locally but never got to post it!
> 
>>  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;
> 
> At that point the mount() call has succeeded so I think we do want to
> keep the goto and just print the error message instead of calling
> replace ksft_exit_fail_msg().
The cleanup tag does cleanup and then calls ksft_exit_fail_msg() without printing the
actual reason of failure. So current flow seems good where information about the error
is being printed.

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


-- 
---
Thanks,
Usama

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

[Kevin Brodsky]

On 21/08/2025 08:19, Muhammad Usama Anjum wrote:
>>> [...]
>>>
>>> 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;
>> At that point the mount() call has succeeded so I think we do want to
>> keep the goto and just print the error message instead of calling
>> replace ksft_exit_fail_msg().
> The cleanup tag does cleanup and then calls ksft_exit_fail_msg() without printing the
> actual reason of failure. So current flow seems good where information about the error
> is being printed.

My point is that with this patch, ksft_exit_fail_msg() still causes the
test to exit right away without the cleanup steps (i.e.
unmounting/removing the directory) being executed. Printing a specific
error message is good but we should also run the cleanup steps.

- Kevin

[PATCH v2 2/8] selftests/mm: protection_keys: Fix dead code

[Muhammad Usama Anjum]

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.

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",
-- 
2.39.5

Re: [PATCH v2 2/8] selftests/mm: protection_keys: Fix dead code

[Sidhartha Kumar]

On 7/31/25 12:01 PM, 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.
> 
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>

Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.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",

Re: [PATCH v2 2/8] selftests/mm: protection_keys: Fix dead code

[Kevin Brodsky]

+Dave Hansen

On 31/07/2025 18:01, 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.
>
> 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) {

Now that is a good catch! I had never realised this whole loop was dead
code...

The question is whether we really want it. This code looked exactly this
way when it was merged [1] so it has never been run. It looks
suspiciously like debug code.

Dave, should we just remove this?

- Kevin

[1]
https://lore.kernel.org/all/20160729163024.FC5A0C2D@viggo.jf.intel.com/T/#u

>  		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",

[PATCH v2 3/8] selftests: kselftest.h: Add __unused macro

[Muhammad Usama Anjum]

Add __unused macro instead of using the complete verbose unused compiler
attribute. The raw __attribute__((__unused__)) is quite long and makes
code too much verbose to the kernel developer's taste.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 tools/testing/selftests/kselftest.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index c3b6d2604b1e4..8d17036d88396 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -92,6 +92,10 @@
 #endif
 #define __printf(a, b)   __attribute__((format(printf, a, b)))
 
+#ifndef __unused
+#define __unused         __attribute__((__unused__))
+#endif
+
 /* counters */
 struct ksft_count {
 	unsigned int ksft_pass;
-- 
2.39.5

Re: [PATCH v2 3/8] selftests: kselftest.h: Add __unused macro

[John Hubbard]

On 7/31/25 9:01 AM, Muhammad Usama Anjum wrote:
...
> diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
> index c3b6d2604b1e4..8d17036d88396 100644
> --- a/tools/testing/selftests/kselftest.h
> +++ b/tools/testing/selftests/kselftest.h
> @@ -92,6 +92,10 @@
>  #endif
>  #define __printf(a, b)   __attribute__((format(printf, a, b)))
>  
> +#ifndef __unused
> +#define __unused         __attribute__((__unused__))
> +#endif

Hi Muhammad,

In case you're interested in going slightly deeper on this:

Entertainingly, there are several kselftest dirs that also use this
attribute directly, and I quite enjoyed seeing that the *same* attribute
is now defined as:

    __maybe_unused
    __always_unused
    __unused         # from your patch here

$ git grep -n  '__attribute__((__unused__))'
bpf/prog_tests/sockmap_helpers.h:11:#define __always_unused     __attribute__((__unused__))
landlock/audit.h:28:#define __maybe_unused __attribute__((__unused__))
landlock/common.h:26:#define __maybe_unused __attribute__((__unused__))
mm/pkey-helpers.h:88:# define __maybe_unused __attribute__((__unused__))
mm/protection_keys.c:1307:      __attribute__((__unused__)) int peek_result;
net/ovpn/ovpn-cli.c:37:#define __always_unused __attribute__((__unused__))
perf_events/watermark_signal.c:20:#define __maybe_unused __attribute__((__unused__))



thanks,
-- 
John Hubbard

[PATCH v2 4/8] selftests/mm: Add -Wunused family of flags

[Muhammad Usama Anjum]

Add -Wunused family of flags and fix all the warnings coming because of
argc and argv. Remove them if they aren't being used entirely. Use
__unused compiler attribute with argc where argv is being used.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 tools/testing/selftests/mm/Makefile                | 2 +-
 tools/testing/selftests/mm/compaction_test.c       | 2 +-
 tools/testing/selftests/mm/cow.c                   | 2 +-
 tools/testing/selftests/mm/droppable.c             | 2 +-
 tools/testing/selftests/mm/gup_longterm.c          | 2 +-
 tools/testing/selftests/mm/hugepage-vmemmap.c      | 2 +-
 tools/testing/selftests/mm/hugetlb-madvise.c       | 2 +-
 tools/testing/selftests/mm/hugetlb-soft-offline.c  | 2 +-
 tools/testing/selftests/mm/madv_populate.c         | 2 +-
 tools/testing/selftests/mm/map_populate.c          | 2 +-
 tools/testing/selftests/mm/memfd_secret.c          | 2 +-
 tools/testing/selftests/mm/mlock-random-test.c     | 2 +-
 tools/testing/selftests/mm/mlock2-tests.c          | 2 +-
 tools/testing/selftests/mm/on-fault-limit.c        | 2 +-
 tools/testing/selftests/mm/pkey_sighandler_tests.c | 2 +-
 tools/testing/selftests/mm/soft-dirty.c            | 2 +-
 tools/testing/selftests/mm/uffd-wp-mremap.c        | 2 +-
 tools/testing/selftests/mm/virtual_address_range.c | 2 +-
 18 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 23d4bf6215465..d75f1effcb791 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -20,7 +20,6 @@ endif
 # thus tricking Make (and you!) into believing that All Is Well, in subsequent
 # make invocations:
 .DELETE_ON_ERROR:
-
 # Avoid accidental wrong builds, due to built-in rules working just a little
 # bit too well--but not quite as well as required for our situation here.
 #
@@ -35,6 +34,7 @@ MAKEFLAGS += --no-builtin-rules
 
 CFLAGS = -Wall -O2 -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
 CFLAGS += -Wunreachable-code
+CFLAGS += -Wunused  -Wunused-parameter -Wunused-function -Wunused-label -Wunused-variable -Wunused-value
 LDLIBS = -lrt -lpthread -lm
 
 # Some distributions (such as Ubuntu) configure GCC so that _FORTIFY_SOURCE is
diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c
index 9bc4591c7b169..4fa03679e9b07 100644
--- a/tools/testing/selftests/mm/compaction_test.c
+++ b/tools/testing/selftests/mm/compaction_test.c
@@ -203,7 +203,7 @@ int set_zero_hugepages(unsigned long *initial_nr_hugepages)
 	return ret;
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	struct rlimit lim;
 	struct map_list *list = NULL, *entry;
diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index d30625c18259b..eb1ccf067b633 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -1857,7 +1857,7 @@ static int tests_per_non_anon_test_case(void)
 	return tests;
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	struct thp_settings default_settings;
 
diff --git a/tools/testing/selftests/mm/droppable.c b/tools/testing/selftests/mm/droppable.c
index f3d9ecf96890a..90ea6377810c5 100644
--- a/tools/testing/selftests/mm/droppable.c
+++ b/tools/testing/selftests/mm/droppable.c
@@ -15,7 +15,7 @@
 
 #include "../kselftest.h"
 
-int main(int argc, char *argv[])
+int main(void)
 {
 	size_t alloc_size = 134217728;
 	size_t page_size = getpagesize();
diff --git a/tools/testing/selftests/mm/gup_longterm.c b/tools/testing/selftests/mm/gup_longterm.c
index 268dadb8ce438..7fe4f94400cb6 100644
--- a/tools/testing/selftests/mm/gup_longterm.c
+++ b/tools/testing/selftests/mm/gup_longterm.c
@@ -504,7 +504,7 @@ static int tests_per_test_case(void)
 	return 3 + nr_hugetlbsizes;
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	int i;
 
diff --git a/tools/testing/selftests/mm/hugepage-vmemmap.c b/tools/testing/selftests/mm/hugepage-vmemmap.c
index df366a4d1b92d..23e97e552057d 100644
--- a/tools/testing/selftests/mm/hugepage-vmemmap.c
+++ b/tools/testing/selftests/mm/hugepage-vmemmap.c
@@ -87,7 +87,7 @@ static int check_page_flags(unsigned long pfn)
 	return 0;
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	void *addr;
 	unsigned long pfn;
diff --git a/tools/testing/selftests/mm/hugetlb-madvise.c b/tools/testing/selftests/mm/hugetlb-madvise.c
index 1afe14b9dc0c3..27c8e46ae9b7d 100644
--- a/tools/testing/selftests/mm/hugetlb-madvise.c
+++ b/tools/testing/selftests/mm/hugetlb-madvise.c
@@ -55,7 +55,7 @@ void read_fault_pages(void *addr, unsigned long nr_pages)
 	}
 }
 
-int main(int argc, char **argv)
+int main(int __unused argc, char **argv)
 {
 	unsigned long free_hugepages;
 	void *addr, *addr2;
diff --git a/tools/testing/selftests/mm/hugetlb-soft-offline.c b/tools/testing/selftests/mm/hugetlb-soft-offline.c
index f086f0e04756f..cb087303f5ed3 100644
--- a/tools/testing/selftests/mm/hugetlb-soft-offline.c
+++ b/tools/testing/selftests/mm/hugetlb-soft-offline.c
@@ -216,7 +216,7 @@ static void test_soft_offline_common(int enable_soft_offline)
 			 enable_soft_offline);
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	ksft_print_header();
 	ksft_set_plan(2);
diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c
index b6fabd5c27ed6..178e0ae0cd4a1 100644
--- a/tools/testing/selftests/mm/madv_populate.c
+++ b/tools/testing/selftests/mm/madv_populate.c
@@ -281,7 +281,7 @@ static int system_has_softdirty(void)
 #endif
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	int nr_tests = 16;
 	int err;
diff --git a/tools/testing/selftests/mm/map_populate.c b/tools/testing/selftests/mm/map_populate.c
index 9df2636c829bf..2b240499f15c9 100644
--- a/tools/testing/selftests/mm/map_populate.c
+++ b/tools/testing/selftests/mm/map_populate.c
@@ -76,7 +76,7 @@ static int child_f(int sock, unsigned long *smap, int fd)
 	return ksft_cnt.ksft_pass;
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	int sock[2], child, ret;
 	FILE *ftmp;
diff --git a/tools/testing/selftests/mm/memfd_secret.c b/tools/testing/selftests/mm/memfd_secret.c
index 9a0597310a765..836383f63b630 100644
--- a/tools/testing/selftests/mm/memfd_secret.c
+++ b/tools/testing/selftests/mm/memfd_secret.c
@@ -299,7 +299,7 @@ static void prepare(void)
 
 #define NUM_TESTS 6
 
-int main(int argc, char *argv[])
+int main(void)
 {
 	int fd;
 
diff --git a/tools/testing/selftests/mm/mlock-random-test.c b/tools/testing/selftests/mm/mlock-random-test.c
index b8d7e966f44c6..4ff7a4cfc7331 100644
--- a/tools/testing/selftests/mm/mlock-random-test.c
+++ b/tools/testing/selftests/mm/mlock-random-test.c
@@ -236,7 +236,7 @@ static void test_mlock_outof_limit(char *p, int alloc_size)
 	ksft_test_result_pass("%s\n", __func__);
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	char *p = NULL;
 
diff --git a/tools/testing/selftests/mm/mlock2-tests.c b/tools/testing/selftests/mm/mlock2-tests.c
index 3e90ff37e336a..ce5fd5ce1f51f 100644
--- a/tools/testing/selftests/mm/mlock2-tests.c
+++ b/tools/testing/selftests/mm/mlock2-tests.c
@@ -425,7 +425,7 @@ static void test_mlockall(void)
 	munlockall();
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	int ret, size = 3 * getpagesize();
 	void *map;
diff --git a/tools/testing/selftests/mm/on-fault-limit.c b/tools/testing/selftests/mm/on-fault-limit.c
index 431c1277d83a1..ade160966c926 100644
--- a/tools/testing/selftests/mm/on-fault-limit.c
+++ b/tools/testing/selftests/mm/on-fault-limit.c
@@ -28,7 +28,7 @@ static void test_limit(void)
 	munlockall();
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	ksft_print_header();
 	ksft_set_plan(1);
diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
index 302fef54049c8..eb4ef8532c0bf 100644
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -528,7 +528,7 @@ static void (*pkey_tests[])(void) = {
 	test_pkru_sigreturn
 };
 
-int main(int argc, char *argv[])
+int main(void)
 {
 	int i;
 
diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c
index 8a3f2b4b21869..e62be4136f69e 100644
--- a/tools/testing/selftests/mm/soft-dirty.c
+++ b/tools/testing/selftests/mm/soft-dirty.c
@@ -194,7 +194,7 @@ static void test_mprotect_file(int pagemap_fd, int pagesize)
 	test_mprotect(pagemap_fd, pagesize, false);
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
 	int pagemap_fd;
 	int pagesize;
diff --git a/tools/testing/selftests/mm/uffd-wp-mremap.c b/tools/testing/selftests/mm/uffd-wp-mremap.c
index c2ba7d46c7b45..13ceb56289701 100644
--- a/tools/testing/selftests/mm/uffd-wp-mremap.c
+++ b/tools/testing/selftests/mm/uffd-wp-mremap.c
@@ -334,7 +334,7 @@ static const struct testcase testcases[] = {
 	},
 };
 
-int main(int argc, char **argv)
+int main(void)
 {
 	struct thp_settings settings;
 	int i, j, plan = 0;
diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/testing/selftests/mm/virtual_address_range.c
index 169dbd692bf5f..3c21d136962cb 100644
--- a/tools/testing/selftests/mm/virtual_address_range.c
+++ b/tools/testing/selftests/mm/virtual_address_range.c
@@ -189,7 +189,7 @@ static int validate_complete_va_space(void)
 	return 0;
 }
 
-int main(int argc, char *argv[])
+int main(void)
 {
 	char *ptr[NR_CHUNKS_LOW];
 	char **hptr;
-- 
2.39.5

Re: [PATCH v2 4/8] selftests/mm: Add -Wunused family of flags

[Kevin Brodsky]

On 31/07/2025 18:01, Muhammad Usama Anjum wrote:
> [...]
>
> diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
> index 23d4bf6215465..d75f1effcb791 100644
> --- a/tools/testing/selftests/mm/Makefile
> +++ b/tools/testing/selftests/mm/Makefile
> @@ -20,7 +20,6 @@ endif
>  # thus tricking Make (and you!) into believing that All Is Well, in subsequent
>  # make invocations:
>  .DELETE_ON_ERROR:
> -
>  # Avoid accidental wrong builds, due to built-in rules working just a little
>  # bit too well--but not quite as well as required for our situation here.
>  #
> @@ -35,6 +34,7 @@ MAKEFLAGS += --no-builtin-rules
>  
>  CFLAGS = -Wall -O2 -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
>  CFLAGS += -Wunreachable-code
> +CFLAGS += -Wunused  -Wunused-parameter -Wunused-function -Wunused-label -Wunused-variable -Wunused-value

-Wall implies all of these except -Wunused-parameter (at least according
to gcc(1)).

As to -Wunused-parameter I am frankly not convinced it's worth the
hassle. We're getting 90 lines changed in patch 6-8 just to mark
parameters as unused, in other words noise to keep the compiler happy.
It is not enabled by default in the kernel proper precisely because it
is so noisy when callbacks are involved.

Patch 5 is clearly an improvement, but I'd rather take it without
actually enabling -Wunused-parameter. The rest of this patch isn't that
useful either IMHO.

- Kevin

Re: [PATCH v2 4/8] selftests/mm: Add -Wunused family of flags

[Andrew Morton]

On Mon, 18 Aug 2025 10:16:35 +0200 Kevin Brodsky <kevin.brodsky@arm.com> wrote:

> >  # Avoid accidental wrong builds, due to built-in rules working just a little
> >  # bit too well--but not quite as well as required for our situation here.
> >  #
> > @@ -35,6 +34,7 @@ MAKEFLAGS += --no-builtin-rules
> >  
> >  CFLAGS = -Wall -O2 -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
> >  CFLAGS += -Wunreachable-code
> > +CFLAGS += -Wunused  -Wunused-parameter -Wunused-function -Wunused-label -Wunused-variable -Wunused-value
> 
> -Wall implies all of these except -Wunused-parameter (at least according
> to gcc(1)).
> 
> As to -Wunused-parameter I am frankly not convinced it's worth the
> hassle. We're getting 90 lines changed in patch 6-8 just to mark
> parameters as unused, in other words noise to keep the compiler happy.
> It is not enabled by default in the kernel proper precisely because it
> is so noisy when callbacks are involved.

Yeah, we rely upon unused parameters in a million places:

#else
static inline void some_stub_function(type1 arg2, type2 arg2)
{
}
#endif

Re: [PATCH v2 4/8] selftests/mm: Add -Wunused family of flags

[Muhammad Usama Anjum]

On 8/18/25 1:16 PM, Kevin Brodsky wrote:
> On 31/07/2025 18:01, Muhammad Usama Anjum wrote:
>> [...]
>>
>> diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
>> index 23d4bf6215465..d75f1effcb791 100644
>> --- a/tools/testing/selftests/mm/Makefile
>> +++ b/tools/testing/selftests/mm/Makefile
>> @@ -20,7 +20,6 @@ endif
>>  # thus tricking Make (and you!) into believing that All Is Well, in subsequent
>>  # make invocations:
>>  .DELETE_ON_ERROR:
>> -
>>  # Avoid accidental wrong builds, due to built-in rules working just a little
>>  # bit too well--but not quite as well as required for our situation here.
>>  #
>> @@ -35,6 +34,7 @@ MAKEFLAGS += --no-builtin-rules
>>  
>>  CFLAGS = -Wall -O2 -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
>>  CFLAGS += -Wunreachable-code
>> +CFLAGS += -Wunused  -Wunused-parameter -Wunused-function -Wunused-label -Wunused-variable -Wunused-value
> 
> -Wall implies all of these except -Wunused-parameter (at least according
> to gcc(1)).
I'll remove others in separate patch.

> 
> As to -Wunused-parameter I am frankly not convinced it's worth the
> hassle. We're getting 90 lines changed in patch 6-8 just to mark
> parameters as unused, in other words noise to keep the compiler happy.
> It is not enabled by default in the kernel proper precisely because it
> is so noisy when callbacks are involved.
> 
> Patch 5 is clearly an improvement, but I'd rather take it without
> actually enabling -Wunused-parameter. The rest of this patch isn't that
> useful either IMHO.
Patch 5 removes genuinely unused parameters flagged by the compiler. If we
drop the -Wunused-parameter option, however, new unused parameters will
continue to creep in with future patches. The goal of enabling this warning
is to surface such issues early so developers can address them during
development, rather than later during review or debugging.

Long term, I’d like us to rely more on compiler and static analysis just like
kernel to catch these kinds of problems proactively, instead of waiting until
they’re reported or someone fixes them later. While it may feel like noise
initially, this is largely a one-time cleanup—once done, developers will
simply fix warnings as they arise, keeping the codebase cleaner going forward.

> 
> - Kevin


-- 
---
Thanks,
Usama

Re: [PATCH v2 4/8] selftests/mm: Add -Wunused family of flags

[Kevin Brodsky]

On 21/08/2025 08:28, Muhammad Usama Anjum wrote:
>> As to -Wunused-parameter I am frankly not convinced it's worth the
>> hassle. We're getting 90 lines changed in patch 6-8 just to mark
>> parameters as unused, in other words noise to keep the compiler happy.
>> It is not enabled by default in the kernel proper precisely because it
>> is so noisy when callbacks are involved.
>>
>> Patch 5 is clearly an improvement, but I'd rather take it without
>> actually enabling -Wunused-parameter. The rest of this patch isn't that
>> useful either IMHO.
> Patch 5 removes genuinely unused parameters flagged by the compiler. If we
> drop the -Wunused-parameter option, however, new unused parameters will
> continue to creep in with future patches. The goal of enabling this warning
> is to surface such issues early so developers can address them during
> development, rather than later during review or debugging.
>
> Long term, I’d like us to rely more on compiler and static analysis just like
> kernel to catch these kinds of problems proactively, instead of waiting until
> they’re reported or someone fixes them later. While it may feel like noise
> initially, this is largely a one-time cleanup—once done, developers will
> simply fix warnings as they arise, keeping the codebase cleaner going forward.

Agreed on the general principle, but I think the hassle is just too big
for what we're getting in return here (see also Andrew's reply). New
code may also introduce a bunch of unused parameters for legitimate
reasons and it's easy to imagine contributors ignoring such seemingly
harmless/irrelevant warnings instead of sprinkling __unused all over. My
feeling is that unused parameters are expected to be allowed in the
kernel and it isn't helpful to go against that expectation in just a
small subset of kselftests.

- Kevin

Re: [PATCH v2 4/8] selftests/mm: Add -Wunused family of flags

[Muhammad Usama Anjum]

On 8/21/25 3:43 PM, Kevin Brodsky wrote:
> On 21/08/2025 08:28, Muhammad Usama Anjum wrote:
>>> As to -Wunused-parameter I am frankly not convinced it's worth the
>>> hassle. We're getting 90 lines changed in patch 6-8 just to mark
>>> parameters as unused, in other words noise to keep the compiler happy.
>>> It is not enabled by default in the kernel proper precisely because it
>>> is so noisy when callbacks are involved.
>>>
>>> Patch 5 is clearly an improvement, but I'd rather take it without
>>> actually enabling -Wunused-parameter. The rest of this patch isn't that
>>> useful either IMHO.
>> Patch 5 removes genuinely unused parameters flagged by the compiler. If we
>> drop the -Wunused-parameter option, however, new unused parameters will
>> continue to creep in with future patches. The goal of enabling this warning
>> is to surface such issues early so developers can address them during
>> development, rather than later during review or debugging.
>>
>> Long term, I’d like us to rely more on compiler and static analysis just like
>> kernel to catch these kinds of problems proactively, instead of waiting until
>> they’re reported or someone fixes them later. While it may feel like noise
>> initially, this is largely a one-time cleanup—once done, developers will
>> simply fix warnings as they arise, keeping the codebase cleaner going forward.
> 
> Agreed on the general principle, but I think the hassle is just too big
> for what we're getting in return here (see also Andrew's reply). New
> code may also introduce a bunch of unused parameters for legitimate
> reasons and it's easy to imagine contributors ignoring such seemingly
> harmless/irrelevant warnings instead of sprinkling __unused all over.


> My
> feeling is that unused parameters are expected to be allowed in the
> kernel and it isn't helpful to go against that expectation in just a
> small subset of kselftests.
I thought kernel must be giving error for unused parameters as well (from
my memory). But just checked and it doesn't seem like it. I'm okay with
dropping -Wunused-parameters.

We need to drop patch 6/7 and in Patch 4 should have only:

-CFLAGS += -Wunused  -Wunused-parameter -Wunused-function -Wunused-label -Wunused-variable -Wunused-value
+CFLAGS += -Wunused

@Andrew, Should I resend the entire series or would you can make the change?

> 
> - Kevin


-- 
---
Thanks,
Usama

Re: [PATCH v2 4/8] selftests/mm: Add -Wunused family of flags

[Andrew Morton]

On Thu, 21 Aug 2025 17:31:21 +0500 Muhammad Usama Anjum <usama.anjum@collabora.com> wrote:

> > My
> > feeling is that unused parameters are expected to be allowed in the
> > kernel and it isn't helpful to go against that expectation in just a
> > small subset of kselftests.
> I thought kernel must be giving error for unused parameters as well (from
> my memory). But just checked and it doesn't seem like it. I'm okay with
> dropping -Wunused-parameters.
> 
> We need to drop patch 6/7 and in Patch 4 should have only:
> 
> -CFLAGS += -Wunused  -Wunused-parameter -Wunused-function -Wunused-label -Wunused-variable -Wunused-value
> +CFLAGS += -Wunused
> 
> @Andrew, Should I resend the entire series or would you can make the change?

I think a new series would be clearer, please.  It's unclear (to me)
whether Kevin's various comments have all been addressed.

[PATCH v2 5/8] selftests/mm: Remove unused parameters

[Muhammad Usama Anjum]

Cleanup code and remove the unused arguments

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 tools/testing/selftests/mm/ksm_tests.c          | 17 +++++++----------
 tools/testing/selftests/mm/soft-dirty.c         |  4 ++--
 .../testing/selftests/mm/split_huge_page_test.c |  4 ++--
 tools/testing/selftests/mm/uffd-common.c        |  4 ++--
 tools/testing/selftests/mm/uffd-common.h        |  2 +-
 tools/testing/selftests/mm/uffd-stress.c        |  2 +-
 tools/testing/selftests/mm/uffd-unit-tests.c    |  8 ++++----
 7 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c
index b77462b5c240b..f5dabb513ed7f 100644
--- a/tools/testing/selftests/mm/ksm_tests.c
+++ b/tools/testing/selftests/mm/ksm_tests.c
@@ -238,8 +238,7 @@ static int ksm_merge_pages(int merge_type, void *addr, size_t size,
 	return 0;
 }
 
-static int ksm_unmerge_pages(void *addr, size_t size,
-			     struct timespec start_time, int timeout)
+static int ksm_unmerge_pages(void *addr, size_t size)
 {
 	if (madvise(addr, size, MADV_UNMERGEABLE)) {
 		perror("madvise");
@@ -456,7 +455,7 @@ static int get_first_mem_node(void)
 	return get_next_mem_node(numa_max_node());
 }
 
-static int check_ksm_numa_merge(int merge_type, int mapping, int prot, int timeout,
+static int check_ksm_numa_merge(int merge_type, int timeout,
 				bool merge_across_nodes, size_t page_size)
 {
 	void *numa1_map_ptr, *numa2_map_ptr;
@@ -520,8 +519,7 @@ static int check_ksm_numa_merge(int merge_type, int mapping, int prot, int timeo
 	return KSFT_FAIL;
 }
 
-static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot,
-				int timeout, size_t map_size)
+static int ksm_merge_hugepages_time(int merge_type, int timeout, size_t map_size)
 {
 	void *map_ptr, *map_ptr_orig;
 	struct timespec start_time, end_time;
@@ -656,7 +654,7 @@ static int ksm_unmerge_time(int merge_type, int mapping, int prot, int timeout,
 		perror("clock_gettime");
 		goto err_out;
 	}
-	if (ksm_unmerge_pages(map_ptr, map_size, start_time, timeout))
+	if (ksm_unmerge_pages(map_ptr, map_size))
 		goto err_out;
 	if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
 		perror("clock_gettime");
@@ -884,8 +882,8 @@ int main(int argc, char *argv[])
 						page_size);
 		break;
 	case CHECK_KSM_NUMA_MERGE:
-		ret = check_ksm_numa_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
-					ksm_scan_limit_sec, merge_across_nodes, page_size);
+		ret = check_ksm_numa_merge(merge_type, ksm_scan_limit_sec, merge_across_nodes,
+					   page_size);
 		break;
 	case KSM_MERGE_TIME:
 		if (size_MB == 0) {
@@ -900,8 +898,7 @@ int main(int argc, char *argv[])
 			printf("Option '-s' is required.\n");
 			return KSFT_FAIL;
 		}
-		ret = ksm_merge_hugepages_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
-				ksm_scan_limit_sec, size_MB);
+		ret = ksm_merge_hugepages_time(merge_type, ksm_scan_limit_sec, size_MB);
 		break;
 	case KSM_UNMERGE_TIME:
 		if (size_MB == 0) {
diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c
index e62be4136f69e..751fbc52857ea 100644
--- a/tools/testing/selftests/mm/soft-dirty.c
+++ b/tools/testing/selftests/mm/soft-dirty.c
@@ -76,7 +76,7 @@ static void test_vma_reuse(int pagemap_fd, int pagesize)
 	munmap(map2, pagesize);
 }
 
-static void test_hugepage(int pagemap_fd, int pagesize)
+static void test_hugepage(int pagemap_fd)
 {
 	char *map;
 	int i, ret;
@@ -210,7 +210,7 @@ int main(void)
 
 	test_simple(pagemap_fd, pagesize);
 	test_vma_reuse(pagemap_fd, pagesize);
-	test_hugepage(pagemap_fd, pagesize);
+	test_hugepage(pagemap_fd);
 	test_mprotect_anon(pagemap_fd, pagesize);
 	test_mprotect_file(pagemap_fd, pagesize);
 
diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c
index a85b2e393e4e8..2c56ab2d220f7 100644
--- a/tools/testing/selftests/mm/split_huge_page_test.c
+++ b/tools/testing/selftests/mm/split_huge_page_test.c
@@ -106,7 +106,7 @@ static char *allocate_zero_filled_hugepage(size_t len)
 	return result;
 }
 
-static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hpages, size_t len)
+static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, size_t len)
 {
 	unsigned long rss_anon_before, rss_anon_after;
 	size_t i;
@@ -142,7 +142,7 @@ void split_pmd_zero_pages(void)
 	size_t len = nr_hpages * pmd_pagesize;
 
 	one_page = allocate_zero_filled_hugepage(len);
-	verify_rss_anon_split_huge_page_all_zeroes(one_page, nr_hpages, len);
+	verify_rss_anon_split_huge_page_all_zeroes(one_page, len);
 	ksft_test_result_pass("Split zero filled huge pages successful\n");
 	free(one_page);
 }
diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index a37088a23ffef..815c22114b57e 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -416,7 +416,7 @@ static void continue_range(int ufd, __u64 start, __u64 len, bool wp)
 		    ret, (int64_t) req.mapped);
 }
 
-int uffd_read_msg(int ufd, struct uffd_msg *msg)
+int uffd_read_msg(struct uffd_msg *msg)
 {
 	int ret = read(uffd, msg, sizeof(*msg));
 
@@ -537,7 +537,7 @@ void *uffd_poll_thread(void *arg)
 		}
 		if (!(pollfd[0].revents & POLLIN))
 			err("pollfd[0].revents %d", pollfd[0].revents);
-		if (uffd_read_msg(uffd, &msg))
+		if (uffd_read_msg(&msg))
 			continue;
 		switch (msg.event) {
 		default:
diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
index 7700cbfa39756..2e7066d69103d 100644
--- a/tools/testing/selftests/mm/uffd-common.h
+++ b/tools/testing/selftests/mm/uffd-common.h
@@ -117,7 +117,7 @@ void uffd_stats_report(struct uffd_args *args, int n_cpus);
 int uffd_test_ctx_init(uint64_t features, const char **errmsg);
 void uffd_test_ctx_clear(void);
 int userfaultfd_open(uint64_t *features);
-int uffd_read_msg(int ufd, struct uffd_msg *msg);
+int uffd_read_msg(struct uffd_msg *msg);
 void wp_range(int ufd, __u64 start, __u64 len, bool wp);
 void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args);
 int __copy_page(int ufd, unsigned long offset, bool retry, bool wp);
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index 40af7f67c4074..4a615ab0c0506 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -137,7 +137,7 @@ static void *uffd_read_thread(void *arg)
 	/* from here cancellation is ok */
 
 	for (;;) {
-		if (uffd_read_msg(uffd, &msg))
+		if (uffd_read_msg(&msg))
 			continue;
 		uffd_handle_page_fault(&msg, args);
 	}
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index 50501b38e34e7..df7b82bbebaad 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -248,7 +248,7 @@ static void *fork_event_consumer(void *data)
 	ready_for_fork = true;
 
 	/* Read until a full msg received */
-	while (uffd_read_msg(args->parent_uffd, &msg));
+	while (uffd_read_msg(&msg));
 
 	if (msg.event != UFFD_EVENT_FORK)
 		err("wrong message: %u\n", msg.event);
@@ -1352,11 +1352,11 @@ static void *uffd_mmap_changing_thread(void *opaque)
 	return NULL;
 }
 
-static void uffd_consume_message(int fd)
+static void uffd_consume_message(void)
 {
 	struct uffd_msg msg = { 0 };
 
-	while (uffd_read_msg(fd, &msg));
+	while (uffd_read_msg(&msg));
 }
 
 static void uffd_mmap_changing_test(uffd_test_args_t *targs)
@@ -1407,7 +1407,7 @@ static void uffd_mmap_changing_test(uffd_test_args_t *targs)
 	 * All succeeded above!  Recycle everything.  Start by reading the
 	 * event so as to kick the thread roll again..
 	 */
-	uffd_consume_message(uffd);
+	uffd_consume_message();
 
 	ret = pthread_join(tid, NULL);
 	assert(ret == 0);
-- 
2.39.5

[PATCH v2 6/8] selftests/mm: Mark unused arguments with __unused

[Muhammad Usama Anjum]

Mark the arguments which cannot be removed with __unused attribute.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 tools/testing/selftests/mm/cow.c             | 20 ++++++-------
 tools/testing/selftests/mm/memfd_secret.c    |  4 +--
 tools/testing/selftests/mm/pfnmap.c          |  2 +-
 tools/testing/selftests/mm/uffd-common.c     | 11 +++----
 tools/testing/selftests/mm/uffd-unit-tests.c | 30 ++++++++++----------
 5 files changed, 34 insertions(+), 33 deletions(-)

diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index eb1ccf067b633..6f6c4e85240c7 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -253,12 +253,12 @@ static void do_test_cow_in_parent(char *mem, size_t size, bool do_mprotect,
 	close_comm_pipes(&comm_pipes);
 }
 
-static void test_cow_in_parent(char *mem, size_t size, bool is_hugetlb)
+static void test_cow_in_parent(char *mem, size_t size, bool __unused is_hugetlb)
 {
 	do_test_cow_in_parent(mem, size, false, child_memcmp_fn, false);
 }
 
-static void test_cow_in_parent_mprotect(char *mem, size_t size, bool is_hugetlb)
+static void test_cow_in_parent_mprotect(char *mem, size_t size, bool __unused is_hugetlb)
 {
 	do_test_cow_in_parent(mem, size, true, child_memcmp_fn, false);
 }
@@ -734,36 +734,36 @@ static void do_test_ro_pin(char *mem, size_t size, enum ro_pin_test test,
 	free(tmp);
 }
 
-static void test_ro_pin_on_shared(char *mem, size_t size, bool is_hugetlb)
+static void test_ro_pin_on_shared(char *mem, size_t size, bool __unused is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_SHARED, false);
 }
 
-static void test_ro_fast_pin_on_shared(char *mem, size_t size, bool is_hugetlb)
+static void test_ro_fast_pin_on_shared(char *mem, size_t size, bool __unused is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_SHARED, true);
 }
 
 static void test_ro_pin_on_ro_previously_shared(char *mem, size_t size,
-		bool is_hugetlb)
+		bool __unused is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_PREVIOUSLY_SHARED, false);
 }
 
 static void test_ro_fast_pin_on_ro_previously_shared(char *mem, size_t size,
-		bool is_hugetlb)
+		bool __unused is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_PREVIOUSLY_SHARED, true);
 }
 
 static void test_ro_pin_on_ro_exclusive(char *mem, size_t size,
-		bool is_hugetlb)
+		bool __unused is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_RO_EXCLUSIVE, false);
 }
 
 static void test_ro_fast_pin_on_ro_exclusive(char *mem, size_t size,
-		bool is_hugetlb)
+		bool __unused is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_RO_EXCLUSIVE, true);
 }
@@ -1522,12 +1522,12 @@ static void test_cow(char *mem, const char *smem, size_t size)
 	free(old);
 }
 
-static void test_ro_pin(char *mem, const char *smem, size_t size)
+static void test_ro_pin(char *mem, const char __unused *smem, size_t size)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST, false);
 }
 
-static void test_ro_fast_pin(char *mem, const char *smem, size_t size)
+static void test_ro_fast_pin(char *mem, const char __unused *smem, size_t size)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST, true);
 }
diff --git a/tools/testing/selftests/mm/memfd_secret.c b/tools/testing/selftests/mm/memfd_secret.c
index 836383f63b630..7117cc0f56dbb 100644
--- a/tools/testing/selftests/mm/memfd_secret.c
+++ b/tools/testing/selftests/mm/memfd_secret.c
@@ -123,7 +123,7 @@ static void test_vmsplice(int fd, const char *desc)
 	close(pipefd[1]);
 }
 
-static void try_process_vm_read(int fd, int pipefd[2])
+static void try_process_vm_read(int __unused fd, int pipefd[2])
 {
 	struct iovec liov, riov;
 	char buf[64];
@@ -147,7 +147,7 @@ static void try_process_vm_read(int fd, int pipefd[2])
 	exit(KSFT_FAIL);
 }
 
-static void try_ptrace(int fd, int pipefd[2])
+static void try_ptrace(int __unused fd, int pipefd[2])
 {
 	pid_t ppid = getppid();
 	int status;
diff --git a/tools/testing/selftests/mm/pfnmap.c b/tools/testing/selftests/mm/pfnmap.c
index 866ac023baf5c..54c9af20d312e 100644
--- a/tools/testing/selftests/mm/pfnmap.c
+++ b/tools/testing/selftests/mm/pfnmap.c
@@ -26,7 +26,7 @@
 
 static sigjmp_buf sigjmp_buf_env;
 
-static void signal_handler(int sig)
+static void signal_handler(int __unused sig)
 {
 	siglongjmp(sigjmp_buf_env, -EFAULT);
 }
diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index 815c22114b57e..e309ec886fa72 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -46,7 +46,7 @@ static void anon_release_pages(char *rel_area)
 		err("madvise(MADV_DONTNEED) failed");
 }
 
-static int anon_allocate_area(void **alloc_area, bool is_src)
+static int anon_allocate_area(void **alloc_area, bool __unused is_src)
 {
 	*alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
 			   MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
@@ -57,7 +57,8 @@ static int anon_allocate_area(void **alloc_area, bool is_src)
 	return 0;
 }
 
-static void noop_alias_mapping(__u64 *start, size_t len, unsigned long offset)
+static void noop_alias_mapping(__u64 __unused *start, size_t __unused len,
+			       unsigned long __unused offset)
 {
 }
 
@@ -108,7 +109,7 @@ static int hugetlb_allocate_area(void **alloc_area, bool is_src)
 	return 0;
 }
 
-static void hugetlb_alias_mapping(__u64 *start, size_t len, unsigned long offset)
+static void hugetlb_alias_mapping(__u64 *start, size_t __unused len, unsigned long offset)
 {
 	if (!map_shared)
 		return;
@@ -167,12 +168,12 @@ static int shmem_allocate_area(void **alloc_area, bool is_src)
 	return 0;
 }
 
-static void shmem_alias_mapping(__u64 *start, size_t len, unsigned long offset)
+static void shmem_alias_mapping(__u64 *start, size_t __unused len, unsigned long offset)
 {
 	*start = (unsigned long)area_dst_alias + offset;
 }
 
-static void shmem_check_pmd_mapping(void *p, int expect_nr_hpages)
+static void shmem_check_pmd_mapping(void __unused *p, int expect_nr_hpages)
 {
 	if (!check_huge_shmem(area_dst_alias, expect_nr_hpages,
 			      read_pmd_pagesize()))
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index df7b82bbebaad..ee9b407e893e1 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -361,7 +361,7 @@ static int pagemap_test_fork(int uffd, bool with_event, bool test_pin)
 	return result;
 }
 
-static void uffd_wp_unpopulated_test(uffd_test_args_t *args)
+static void uffd_wp_unpopulated_test(uffd_test_args_t __unused *args)
 {
 	uint64_t value;
 	int pagemap_fd;
@@ -487,7 +487,7 @@ static void uffd_wp_fork_with_event_test(uffd_test_args_t *args)
 	uffd_wp_fork_test_common(args, true);
 }
 
-static void uffd_wp_fork_pin_test_common(uffd_test_args_t *args,
+static void uffd_wp_fork_pin_test_common(uffd_test_args_t __unused *args,
 					 bool with_event)
 {
 	int pagemap_fd;
@@ -631,24 +631,24 @@ static void uffd_minor_test_common(bool test_collapse, bool test_wp)
 		uffd_test_pass();
 }
 
-void uffd_minor_test(uffd_test_args_t *args)
+void uffd_minor_test(uffd_test_args_t __unused *args)
 {
 	uffd_minor_test_common(false, false);
 }
 
-void uffd_minor_wp_test(uffd_test_args_t *args)
+void uffd_minor_wp_test(uffd_test_args_t __unused *args)
 {
 	uffd_minor_test_common(false, true);
 }
 
-void uffd_minor_collapse_test(uffd_test_args_t *args)
+void uffd_minor_collapse_test(uffd_test_args_t __unused *args)
 {
 	uffd_minor_test_common(true, false);
 }
 
 static sigjmp_buf jbuf, *sigbuf;
 
-static void sighndl(int sig, siginfo_t *siginfo, void *ptr)
+static void sighndl(int sig, siginfo_t __unused *siginfo, void __unused *ptr)
 {
 	if (sig == SIGBUS) {
 		if (sigbuf)
@@ -824,12 +824,12 @@ static void uffd_sigbus_test_common(bool wp)
 		uffd_test_pass();
 }
 
-static void uffd_sigbus_test(uffd_test_args_t *args)
+static void uffd_sigbus_test(uffd_test_args_t __unused *args)
 {
 	uffd_sigbus_test_common(false);
 }
 
-static void uffd_sigbus_wp_test(uffd_test_args_t *args)
+static void uffd_sigbus_wp_test(uffd_test_args_t __unused *args)
 {
 	uffd_sigbus_test_common(true);
 }
@@ -877,12 +877,12 @@ static void uffd_events_test_common(bool wp)
 		uffd_test_pass();
 }
 
-static void uffd_events_test(uffd_test_args_t *args)
+static void uffd_events_test(uffd_test_args_t __unused *args)
 {
 	uffd_events_test_common(false);
 }
 
-static void uffd_events_wp_test(uffd_test_args_t *args)
+static void uffd_events_wp_test(uffd_test_args_t __unused *args)
 {
 	uffd_events_test_common(true);
 }
@@ -950,7 +950,7 @@ uffd_register_detect_zeropage(int uffd, void *addr, uint64_t len)
 }
 
 /* exercise UFFDIO_ZEROPAGE */
-static void uffd_zeropage_test(uffd_test_args_t *args)
+static void uffd_zeropage_test(uffd_test_args_t __unused *args)
 {
 	bool has_zeropage;
 	int i;
@@ -1006,7 +1006,7 @@ static void do_uffdio_poison(int uffd, unsigned long offset)
 }
 
 static void uffd_poison_handle_fault(
-	struct uffd_msg *msg, struct uffd_args *args)
+	struct uffd_msg *msg, struct uffd_args __unused *args)
 {
 	unsigned long offset;
 
@@ -1030,7 +1030,7 @@ static void uffd_poison_handle_fault(
 /* Make sure to cover odd/even, and minimum duplications */
 #define  UFFD_POISON_TEST_NPAGES  4
 
-static void uffd_poison_test(uffd_test_args_t *targs)
+static void uffd_poison_test(uffd_test_args_t __unused *targs)
 {
 	pthread_t uffd_mon;
 	char c;
@@ -1126,7 +1126,7 @@ static void uffd_move_pmd_handle_fault(struct uffd_msg *msg,
 }
 
 static void
-uffd_move_test_common(uffd_test_args_t *targs, unsigned long chunk_size,
+uffd_move_test_common(uffd_test_args_t __unused *targs, unsigned long chunk_size,
 		      void (*handle_fault)(struct uffd_msg *msg, struct uffd_args *args))
 {
 	unsigned long nr;
@@ -1359,7 +1359,7 @@ static void uffd_consume_message(void)
 	while (uffd_read_msg(&msg));
 }
 
-static void uffd_mmap_changing_test(uffd_test_args_t *targs)
+static void uffd_mmap_changing_test(uffd_test_args_t __unused *targs)
 {
 	/*
 	 * This stores the real PID (which can be different from how tid is
-- 
2.39.5

[PATCH v2 7/8] selftests/mm: Mark unused arguments with __unused

[Muhammad Usama Anjum]

Mark the arguments which cannot be removed with __unused attribute.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 .../selftests/mm/hugetlb_fault_after_madv.c    |  4 ++--
 .../testing/selftests/mm/hugetlb_madv_vs_map.c |  6 +++---
 tools/testing/selftests/mm/pkey-arm64.h        |  5 +++--
 tools/testing/selftests/mm/pkey-powerpc.h      |  2 +-
 tools/testing/selftests/mm/pkey-x86.h          |  3 ++-
 .../selftests/mm/pkey_sighandler_tests.c       | 10 +++++-----
 tools/testing/selftests/mm/protection_keys.c   | 18 +++++++++---------
 7 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/tools/testing/selftests/mm/hugetlb_fault_after_madv.c b/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
index e2640529dbb29..72706c64fe57c 100644
--- a/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
+++ b/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
@@ -28,7 +28,7 @@ static void signal_handler(int signal)
 }
 
 /* Touch the memory while it is being madvised() */
-void *touch(void *unused)
+void *touch(void __unused *unused)
 {
 	char *ptr = (char *)huge_ptr;
 
@@ -41,7 +41,7 @@ void *touch(void *unused)
 	return NULL;
 }
 
-void *madv(void *unused)
+void *madv(void __unused *unused)
 {
 	usleep(rand() % 10);
 
diff --git a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
index 8f122a0f08281..64a1455940394 100644
--- a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
+++ b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
@@ -33,7 +33,7 @@ size_t mmap_size;
 char *huge_ptr;
 
 /* Touch the memory while it is being madvised() */
-void *touch(void *unused)
+void *touch(void __unused *unused)
 {
 	for (int i = 0; i < INLOOP_ITER; i++)
 		huge_ptr[0] = '.';
@@ -41,7 +41,7 @@ void *touch(void *unused)
 	return NULL;
 }
 
-void *madv(void *unused)
+void *madv(void __unused *unused)
 {
 	for (int i = 0; i < INLOOP_ITER; i++)
 		madvise(huge_ptr, mmap_size, MADV_DONTNEED);
@@ -54,7 +54,7 @@ void *madv(void *unused)
  * The other hugepage should be flipping from used <-> reserved, because
  * of madvise(DONTNEED).
  */
-void *map_extra(void *unused)
+void *map_extra(void __unused *unused)
 {
 	void *ptr;
 
diff --git a/tools/testing/selftests/mm/pkey-arm64.h b/tools/testing/selftests/mm/pkey-arm64.h
index 8e9685e03c441..a9cacf3732f60 100644
--- a/tools/testing/selftests/mm/pkey-arm64.h
+++ b/tools/testing/selftests/mm/pkey-arm64.h
@@ -81,11 +81,12 @@ static inline int get_arch_reserved_keys(void)
 	return NR_RESERVED_PKEYS;
 }
 
-static inline void expect_fault_on_read_execonly_key(void *p1, int pkey)
+static inline void expect_fault_on_read_execonly_key(void __unused *p1, int __unused pkey)
 {
 }
 
-static inline void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
+static inline void *malloc_pkey_with_mprotect_subpage(long __unused size, int __unused prot,
+						      u16 __unused pkey)
 {
 	return PTR_ERR_ENOTSUP;
 }
diff --git a/tools/testing/selftests/mm/pkey-powerpc.h b/tools/testing/selftests/mm/pkey-powerpc.h
index 17bf2d1b0192e..8a367c32a9dd6 100644
--- a/tools/testing/selftests/mm/pkey-powerpc.h
+++ b/tools/testing/selftests/mm/pkey-powerpc.h
@@ -93,7 +93,7 @@ static inline int get_arch_reserved_keys(void)
 			return NR_RESERVED_PKEYS_64K_3KEYS;
 }
 
-static inline void expect_fault_on_read_execonly_key(void *p1, int pkey)
+static inline void expect_fault_on_read_execonly_key(void __unused *p1, int __unused pkey)
 {
 	/*
 	 * powerpc does not allow userspace to change permissions of exec-only
diff --git a/tools/testing/selftests/mm/pkey-x86.h b/tools/testing/selftests/mm/pkey-x86.h
index f7ecd335df1e6..27688c04abd35 100644
--- a/tools/testing/selftests/mm/pkey-x86.h
+++ b/tools/testing/selftests/mm/pkey-x86.h
@@ -157,7 +157,8 @@ static inline void expect_fault_on_read_execonly_key(void *p1, int pkey)
 	expected_pkey_fault(pkey);
 }
 
-static inline void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
+static inline void *malloc_pkey_with_mprotect_subpage(long __unused size, int __unused prot,
+						      u16 __unused pkey)
 {
 	return PTR_ERR_ENOTSUP;
 }
diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
index eb4ef8532c0bf..638477494ff3a 100644
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -110,7 +110,7 @@ static inline u64 pkey_reg_restrictive_default(void)
 	return set_pkey_bits(PKEY_REG_ALLOW_NONE, 0, PKEY_DISABLE_ACCESS);
 }
 
-static void sigsegv_handler(int signo, siginfo_t *info, void *ucontext)
+static void sigsegv_handler(int __unused signo, siginfo_t *info, void __unused *ucontext)
 {
 	pthread_mutex_lock(&mutex);
 
@@ -122,7 +122,7 @@ static void sigsegv_handler(int signo, siginfo_t *info, void *ucontext)
 	syscall_raw(SYS_exit, 0, 0, 0, 0, 0, 0);
 }
 
-static void sigusr1_handler(int signo, siginfo_t *info, void *ucontext)
+static void sigusr1_handler(int __unused signo, siginfo_t *info, void __unused *ucontext)
 {
 	pthread_mutex_lock(&mutex);
 
@@ -132,7 +132,7 @@ static void sigusr1_handler(int signo, siginfo_t *info, void *ucontext)
 	pthread_mutex_unlock(&mutex);
 }
 
-static void sigusr2_handler(int signo, siginfo_t *info, void *ucontext)
+static void sigusr2_handler(int __unused signo, siginfo_t __unused *info, void __unused *ucontext)
 {
 	/*
 	 * pkru should be the init_pkru value which enabled MPK 0 so
@@ -155,7 +155,7 @@ static void raise_sigusr2(void)
 	 */
 }
 
-static void *thread_segv_with_pkey0_disabled(void *ptr)
+static void *thread_segv_with_pkey0_disabled(void __unused *ptr)
 {
 	/* Disable MPK 0 (and all others too) */
 	__write_pkey_reg(pkey_reg_restrictive_default());
@@ -165,7 +165,7 @@ static void *thread_segv_with_pkey0_disabled(void *ptr)
 	return NULL;
 }
 
-static void *thread_segv_pkuerr_stack(void *ptr)
+static void *thread_segv_pkuerr_stack(void __unused *ptr)
 {
 	/* Disable MPK 0 (and all others too) */
 	__write_pkey_reg(pkey_reg_restrictive_default());
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 6281d4c61b50e..65bc9ba59f72b 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -309,7 +309,7 @@ static char *si_code_str(int si_code)
 
 static int pkey_faults;
 static int last_si_pkey = -1;
-static void signal_handler(int signum, siginfo_t *si, void *vucontext)
+static void signal_handler(int __unused signum, siginfo_t *si, void *vucontext)
 {
 	ucontext_t *uctxt = vucontext;
 	int trapno;
@@ -889,7 +889,7 @@ static void close_test_fds(void)
 	nr_test_fds = 0;
 }
 
-static void test_pkey_alloc_free_attach_pkey0(int *ptr, u16 pkey)
+static void test_pkey_alloc_free_attach_pkey0(int *ptr, u16 __unused pkey)
 {
 	int i, err;
 	int max_nr_pkey_allocs;
@@ -1106,7 +1106,7 @@ static void test_pkey_syscalls_on_non_allocated_pkey(int *ptr, u16 pkey)
 }
 
 /* Assumes that all pkeys other than 'pkey' are unallocated */
-static void test_pkey_syscalls_bad_args(int *ptr, u16 pkey)
+static void test_pkey_syscalls_bad_args(int *ptr, u16 __unused pkey)
 {
 	int err;
 	int bad_pkey = NR_PKEYS+99;
@@ -1132,7 +1132,7 @@ static void become_child(void)
 }
 
 /* Assumes that all pkeys other than 'pkey' are unallocated */
-static void test_pkey_alloc_exhaust(int *ptr, u16 pkey)
+static void test_pkey_alloc_exhaust(int __unused *ptr, u16 __unused pkey)
 {
 	int err;
 	int allocated_pkeys[NR_PKEYS] = {0};
@@ -1238,7 +1238,7 @@ static void arch_force_pkey_reg_init(void)
  * a long-running test that continually checks the pkey
  * register.
  */
-static void test_pkey_init_state(int *ptr, u16 pkey)
+static void test_pkey_init_state(int __unused *ptr, u16 __unused pkey)
 {
 	int err;
 	int allocated_pkeys[NR_PKEYS] = {0};
@@ -1397,7 +1397,7 @@ static void *get_pointer_to_instructions(void)
 	return p1;
 }
 
-static void test_executing_on_unreadable_memory(int *ptr, u16 pkey)
+static void test_executing_on_unreadable_memory(int __unused *ptr, u16 pkey)
 {
 	void *p1;
 	int scratch;
@@ -1429,7 +1429,7 @@ static void test_executing_on_unreadable_memory(int *ptr, u16 pkey)
 	pkey_assert(!ret);
 }
 
-static void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey)
+static void test_implicit_mprotect_exec_only_memory(int __unused *ptr, u16 __unused pkey)
 {
 	void *p1;
 	int scratch;
@@ -1478,7 +1478,7 @@ static void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey)
 }
 
 #if defined(__i386__) || defined(__x86_64__)
-static void test_ptrace_modifies_pkru(int *ptr, u16 pkey)
+static void test_ptrace_modifies_pkru(int __unused *ptr, u16 __unused pkey)
 {
 	u32 new_pkru;
 	pid_t child;
@@ -1601,7 +1601,7 @@ static void test_ptrace_modifies_pkru(int *ptr, u16 pkey)
 #endif
 
 #if defined(__aarch64__)
-static void test_ptrace_modifies_pkru(int *ptr, u16 pkey)
+static void test_ptrace_modifies_pkru(int __unused *ptr, u16 __unused pkey)
 {
 	pid_t child;
 	int status, ret;
-- 
2.39.5

[PATCH v2 8/8] selftests/mm: Fix unused parameter warnings for different architectures

[Muhammad Usama Anjum]

There are functions which have unused arguments for different
architectures. Separate the code for each architecture and move #ifdef
arch outside these functions.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 tools/testing/selftests/mm/mseal_test.c       |  8 +++++--
 .../selftests/mm/pkey_sighandler_tests.c      | 21 ++++++++++++++++---
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c
index 34c042da4de27..af49f72e1f465 100644
--- a/tools/testing/selftests/mm/mseal_test.c
+++ b/tools/testing/selftests/mm/mseal_test.c
@@ -131,17 +131,21 @@ static unsigned int __read_pkey_reg(void)
 	return pkey_reg;
 }
 
+#if defined(__i386__) || defined(__x86_64__) /* arch */
 static void __write_pkey_reg(u64 pkey_reg)
 {
-#if defined(__i386__) || defined(__x86_64__) /* arch */
 	unsigned int eax = pkey_reg;
 	unsigned int ecx = 0;
 	unsigned int edx = 0;
 
 	asm volatile(".byte 0x0f,0x01,0xef\n\t"
 			: : "a" (eax), "c" (ecx), "d" (edx));
-#endif
 }
+#else
+static void __write_pkey_reg(u64 __unused pkey_reg)
+{
+}
+#endif
 
 static unsigned long pkey_bit_position(int pkey)
 {
diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
index 638477494ff3a..68f106d0876a7 100644
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -41,11 +41,12 @@ 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.
  */
+#ifdef __x86_64__
 static __always_inline
 long syscall_raw(long n, long a1, long a2, long a3, long a4, long a5, long a6)
 {
 	unsigned long ret;
-#ifdef __x86_64__
+
 	register long r10 asm("r10") = a4;
 	register long r8 asm("r8") = a5;
 	register long r9 asm("r9") = a6;
@@ -53,12 +54,26 @@ long syscall_raw(long n, long a1, long a2, long a3, long a4, long a5, long a6)
 		      : "=a"(ret)
 		      : "a"(n), "D"(a1), "S"(a2), "d"(a3), "r"(r10), "r"(r8), "r"(r9)
 		      : "rcx", "r11", "memory");
+	return ret;
+}
 #elif defined __i386__
+static __always_inline
+long syscall_raw(long n, long a1, long a2, long a3, long a4, long a5, long __unused a6)
+{
+	unsigned long ret;
+
 	asm volatile ("int $0x80"
 		      : "=a"(ret)
 		      : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5)
 		      : "memory");
+	return ret;
+}
 #elif defined __aarch64__
+static __always_inline
+long syscall_raw(long n, long a1, long a2, long a3, long a4, long a5, long a6)
+{
+	unsigned long ret;
+
 	register long x0 asm("x0") = a1;
 	register long x1 asm("x1") = a2;
 	register long x2 asm("x2") = a3;
@@ -71,11 +86,11 @@ long syscall_raw(long n, long a1, long a2, long a3, long a4, long a5, long a6)
 		      : "r"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x4), "r"(x5), "r"(x8)
 		      : "memory");
 	ret = x0;
+	return ret;
+}
 #else
 # error syscall_raw() not implemented
 #endif
-	return ret;
-}
 
 static inline long clone_raw(unsigned long flags, void *stack,
 			     int *parent_tid, int *child_tid)
-- 
2.39.5