Re: [LTP] [PATCH v2 04/10] setxattr02: add setxattrat variant

[Cyril Hrubis <chrubis@suse.cz>]

On Tue, Oct 07, 2025 at 08:46:56AM +0200, Andrea Cervesato wrote:
> From: Andrea Cervesato <andrea.cervesato@suse.com>
> 
> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
>  testcases/kernel/syscalls/setxattr/setxattr02.c | 79 +++++++++++++++++++------
>  1 file changed, 60 insertions(+), 19 deletions(-)
> 
> diff --git a/testcases/kernel/syscalls/setxattr/setxattr02.c b/testcases/kernel/syscalls/setxattr/setxattr02.c
> index 9f5f998da..b5042a0df 100644
> --- a/testcases/kernel/syscalls/setxattr/setxattr02.c
> +++ b/testcases/kernel/syscalls/setxattr/setxattr02.c
> @@ -19,6 +19,10 @@
>   */
>  
>  #include "config.h"
> +#include "tst_test.h"
> +
> +#ifdef HAVE_SYS_XATTR_H
> +
>  #include <sys/types.h>
>  #include <sys/stat.h>
>  #include <sys/sysmacros.h>
> @@ -30,12 +34,10 @@
>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <string.h>
> -#ifdef HAVE_SYS_XATTR_H
> -# include <sys/xattr.h>
> -#endif
> -#include "tst_test.h"
> +#include "lapi/xattr.h"
> +#include "lapi/fcntl.h"
> +#include <sys/xattr.h>
>  
> -#ifdef HAVE_SYS_XATTR_H
>  #define XATTR_TEST_KEY "user.testkey"
>  #define XATTR_TEST_VALUE "this is a test value"
>  #define XATTR_TEST_VALUE_SIZE 20
> @@ -49,6 +51,8 @@
>  #define BLK      "setxattr02blk"
>  #define SOCK     "setxattr02sock"
>  
> +static int tmpdir_fd = -1;
> +
>  struct test_case {
>  	char *fname;
>  	char *key;
> @@ -120,39 +124,58 @@ static struct test_case tc[] = {
>  
>  static void verify_setxattr(unsigned int i)
>  {
> +	char *sysname;
> +
>  	/* some tests might require existing keys for each iteration */
>  	if (tc[i].needskeyset) {
>  		SAFE_SETXATTR(tc[i].fname, tc[i].key, tc[i].value, tc[i].size,
> -				XATTR_CREATE);
> +			XATTR_CREATE);
>  	}
>  
> -	TEST(setxattr(tc[i].fname, tc[i].key, tc[i].value, tc[i].size,
> -			tc[i].flags));
> +	if (tst_variant) {
> +		sysname = "setxattrat";
> +
> +		struct xattr_args args = {
> +			.value = (uint64_t)tc[i].value,
> +			.size = tc[i].size,
> +			.flags = tc[i].flags,
> +		};
> +
> +		int at_flags = tc[i].needskeyset ? 0 : AT_SYMLINK_NOFOLLOW;


I do not get why this is needed.

In kernel:

SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
                const char __user *, name, const void __user *, value,
                size_t, size, int, flags)
{
        return path_setxattrat(AT_FDCWD, pathname, 0, name, value, size, flags);
	                                           ^
						   the setxattr() the
						   always sets the
						   at_flags to 0
}


So shouldn't setxattrat() just work the same if we pass 0 there?

It's the lsetxattr() syscall that passes AT_SYMLINK_NOFOLLOW:

SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
                const char __user *, name, const void __user *, value,
                size_t, size, int, flags)
{
        return path_setxattrat(AT_FDCWD, pathname, AT_SYMLINK_NOFOLLOW, name,
                               value, size, flags);
}

>  static void setup(void)
> @@ -185,12 +208,30 @@ static void setup(void)
>  	SAFE_MKNOD(CHR, S_IFCHR | 0777, dev);
>  	SAFE_MKNOD(BLK, S_IFBLK | 0777, 0);
>  	SAFE_MKNOD(SOCK, S_IFSOCK | 0777, 0);
> +
> +	tmpdir_fd = SAFE_OPEN(tst_tmpdir_path(), O_DIRECTORY);

This is memleak, on the top of that can't we just use the AT_FDCWD
instead? Or if you want to make sure that the syscall works with a real
fd we can do SAFE_OPEN(".", O_DIRECTORY) instead....


-- 
Cyril Hrubis
chrubis@suse.cz

-- 
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