Re: [PATCH v3 2/9] syscalls: fanotify: Add macro to require specific events

[Matthew Bobrowski <repnop@google.com>]

On Fri, Oct 29, 2021 at 06:17:25PM -0300, Gabriel Krisman Bertazi wrote:
> Add a helper for tests to fail if an event is not available in the
> kernel.  Since some events only work with REPORT_FID or a specific
> class, update the verifier to allow those to be specified.
> 
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

Made a single comment, otherwise this looks OK to me.

Reviewed-by: Matthew Bobrowski <repnop@google.com>

> ---
> Changes since v1:
>   - Use SAFE_FANOTIFY_INIT instead of open coding. (Amir)
>   - Use FAN_CLASS_NOTIF for fanotify12 testcase. (Amir)
> ---
>  testcases/kernel/syscalls/fanotify/fanotify.h   | 17 ++++++++++++++---
>  testcases/kernel/syscalls/fanotify/fanotify03.c |  4 ++--
>  testcases/kernel/syscalls/fanotify/fanotify10.c |  3 ++-
>  testcases/kernel/syscalls/fanotify/fanotify12.c |  3 ++-
>  4 files changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify.h b/testcases/kernel/syscalls/fanotify/fanotify.h
> index c67db3117e29..820073709571 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify.h
> +++ b/testcases/kernel/syscalls/fanotify/fanotify.h
> @@ -266,14 +266,16 @@ static inline void require_fanotify_access_permissions_supported_by_kernel(void)
>  	SAFE_CLOSE(fd);
>  }
>  
> -static inline int fanotify_events_supported_by_kernel(uint64_t mask)
> +static inline int fanotify_events_supported_by_kernel(uint64_t mask,
> +						      unsigned int init_flags,
> +						      unsigned int mark_flags)
>  {
>  	int fd;
>  	int rval = 0;
>  
> -	fd = SAFE_FANOTIFY_INIT(FAN_CLASS_CONTENT, O_RDONLY);
> +	fd = SAFE_FANOTIFY_INIT(init_flags, O_RDONLY);
>  
> -	if (fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, ".") < 0) {
> +	if (fanotify_mark(fd, FAN_MARK_ADD | mark_flags, mask, AT_FDCWD, ".") < 0) {
>  		if (errno == EINVAL) {
>  			rval = -1;
>  		} else {
> @@ -378,4 +380,13 @@ static inline int fanotify_mark_supported_by_kernel(uint64_t flag)
>  				    fanotify_mark_supported_by_kernel(mark_type)); \
>  } while (0)
>  
> +#define REQUIRE_FANOTIFY_EVENTS_SUPPORTED_ON_FS(init_flags, mark_type, mask, fname) do { \
> +	if (mark_type)							\
> +		REQUIRE_MARK_TYPE_SUPPORTED_ON_KERNEL(mark_type);	\
> +	if (init_flags)							\
> +		REQUIRE_FANOTIFY_INIT_FLAGS_SUPPORTED_ON_FS(init_flags, fname); \
> +	fanotify_init_flags_err_msg(#mask, __FILE__, __LINE__, tst_brk_, \
> +		fanotify_events_supported_by_kernel(mask, init_flags, mark_type)); \
> +} while (0)
> +
>  #endif /* __FANOTIFY_H__ */
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify03.c b/testcases/kernel/syscalls/fanotify/fanotify03.c
> index 26d17e64d1f5..2081f0bd1b57 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify03.c
> +++ b/testcases/kernel/syscalls/fanotify/fanotify03.c
> @@ -323,8 +323,8 @@ static void setup(void)
>  	require_fanotify_access_permissions_supported_by_kernel();
>  
>  	filesystem_mark_unsupported = fanotify_mark_supported_by_kernel(FAN_MARK_FILESYSTEM);
> -	exec_events_unsupported = fanotify_events_supported_by_kernel(FAN_OPEN_EXEC_PERM);
> -
> +	exec_events_unsupported = fanotify_events_supported_by_kernel(FAN_OPEN_EXEC_PERM,
> +								      FAN_CLASS_CONTENT, 0);
>  	sprintf(fname, MOUNT_PATH"/fname_%d", getpid());
>  	SAFE_FILE_PRINTF(fname, "1");
>  
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify10.c b/testcases/kernel/syscalls/fanotify/fanotify10.c
> index 92e4d3ff3054..0fa9d1f4f7e4 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify10.c
> +++ b/testcases/kernel/syscalls/fanotify/fanotify10.c
> @@ -509,7 +509,8 @@ cleanup:
>  
>  static void setup(void)
>  {
> -	exec_events_unsupported = fanotify_events_supported_by_kernel(FAN_OPEN_EXEC);
> +	exec_events_unsupported = fanotify_events_supported_by_kernel(FAN_OPEN_EXEC,
> +								      FAN_CLASS_CONTENT, 0);

I'm wondering whether this is the best combination of mask and
init_flags to use in this particular case? Maybe not to confuse future
readers, using FAN_CLASS_NOTIF explicitly here would be better, WDYT?
It doesn't make a difference, but it's something that caught my eye
while parsing this patch.

>  	filesystem_mark_unsupported = fanotify_mark_supported_by_kernel(FAN_MARK_FILESYSTEM);
>  	fan_report_dfid_unsupported = fanotify_init_flags_supported_on_fs(FAN_REPORT_DFID_NAME,
>  									  MOUNT_PATH);
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify12.c b/testcases/kernel/syscalls/fanotify/fanotify12.c
> index 76f1aca77615..c77dbfd8c23d 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify12.c
> +++ b/testcases/kernel/syscalls/fanotify/fanotify12.c
> @@ -222,7 +222,8 @@ cleanup:
>  
>  static void do_setup(void)
>  {
> -	exec_events_unsupported = fanotify_events_supported_by_kernel(FAN_OPEN_EXEC);
> +	exec_events_unsupported = fanotify_events_supported_by_kernel(FAN_OPEN_EXEC,
> +								      FAN_CLASS_NOTIF, 0);
>  
>  	sprintf(fname, "fname_%d", getpid());
>  	SAFE_FILE_PRINTF(fname, "1");
> -- 
> 2.33.0

/M