[LTP] [PATCH] syscalls/{fanotify17, getxattr05}: simplify code by using save_restore

[杨晓]

At 2024-09-17 19:10:39, "Cyril Hrubis" <chrubis@suse.cz> wrote:
>Hi!
>> -	/*
>> -	 * The default value of max_user_namespaces is set to 0 on some distros,
>> -	 * We need to change the default value to call unshare().
>> -	 */
>> -	if (access(SELF_USERNS, F_OK) != 0) {
>> +	if (access(SELF_USERNS, F_OK) != 0)
>>  		user_ns_supported = 0;
>> -	} else if (!access(MAX_USERNS, F_OK)) {
>> -		SAFE_FILE_SCANF(MAX_USERNS, "%d", &orig_max_userns);
>> -		SAFE_FILE_PRINTF(MAX_USERNS, "%d", 10);
>
>Here the original code writes 10 to the MAX_USERNS.
>
>> -	}
>>  
>>  	/*
>>  	 * In older kernels those limits were fixed in kernel and fanotify is
>> @@ -244,21 +234,18 @@ static void setup(void)
>>  	setup_rlimit(max_groups * 2);
>>  }
>>  
>> -static void cleanup(void)
>> -{
>> -	if (orig_max_userns != -1)
>> -		SAFE_FILE_PRINTF(MAX_USERNS, "%d", orig_max_userns);
>> -}
>> -
>>  static struct tst_test test = {
>>  	.test = test_fanotify,
>>  	.tcnt = ARRAY_SIZE(tcases),
>>  	.setup = setup,
>> -	.cleanup = cleanup,
>>  	.needs_root = 1,
>>  	.forks_child = 1,
>>  	.mount_device = 1,
>>  	.mntpoint = MOUNT_PATH,
>> +	.save_restore = (const struct tst_path_val[]) {
>> +		{"/proc/sys/user/max_user_namespaces", "1024", TST_SR_SKIP},
>> +		{}
>> +	},
>
>And here you are initializing it to 1024? Shouldn't the value here be 10

>too?


Hi Cyril,


Sorry for the late reply.



If more than 10 user namspaces is currently used on system, it is still successfully to set
max_user_namespaces to 10.  However, these tests fail with ENOSPC. for example:
# lsns -t user -l -n | wc -l
17

root@fedora40:~/ltp/testcases/kernel/syscalls/fanotify# ./fanotify17
...
fanotify17.c:174: TINFO: Test #0: Global groups limit in init user ns
fanotify17.c:130: TPASS: Created 128 groups - below groups limit (128)
fanotify17.c:174: TINFO: Test #1: Global groups limit in privileged user ns
fanotify17.c:154: TFAIL: unshare(CLONE_NEWUSER) failed: ENOSPC (28)
tst_test.c:452: TBROK: Invalid child (6958) exit value 1



Just try to fix the issue by increasing the setting of max_user_namespaces.
BTW, it may be better to get the number of user namespaces in use and then add 10.


Best Regards,
Xiao Yang

>
>>  };
>>  #else
>>  	TST_TEST_TCONF("system doesn't have required fanotify support");
>> diff --git a/testcases/kernel/syscalls/getxattr/getxattr05.c b/testcases/kernel/syscalls/getxattr/getxattr05.c
>> index d9717a695..3dff8e27f 100644
>> --- a/testcases/kernel/syscalls/getxattr/getxattr05.c
>> +++ b/testcases/kernel/syscalls/getxattr/getxattr05.c
>> @@ -40,11 +40,9 @@
>>  
>>  #define TEST_FILE	"testfile"
>>  #define SELF_USERNS	"/proc/self/ns/user"
>> -#define MAX_USERNS	"/proc/sys/user/max_user_namespaces"
>>  #define UID_MAP	"/proc/self/uid_map"
>>  
>>  static acl_t acl;
>> -static int orig_max_userns = -1;
>>  static int user_ns_supported = 1;
>>  
>>  static struct tcase {
>> @@ -149,23 +147,13 @@ static void setup(void)
>>  		tst_brk(TBROK | TERRNO, "acl_set_file(%s) failed", TEST_FILE);
>>  	}
>>  
>> -	/* The default value of max_user_namespaces is set to 0 on some distros,
>> -	 * We need to change the default value to call unshare().
>> -	 */
>> -	if (access(SELF_USERNS, F_OK) != 0) {
>> +	if (access(SELF_USERNS, F_OK) != 0)
>>  		user_ns_supported = 0;
>> -	} else if (!access(MAX_USERNS, F_OK)) {
>> -		SAFE_FILE_SCANF(MAX_USERNS, "%d", &orig_max_userns);
>> -		SAFE_FILE_PRINTF(MAX_USERNS, "%d", 10);
>> -	}
>>  
>>  }
>>  
>>  static void cleanup(void)
>>  {
>> -	if (orig_max_userns != -1)
>> -		SAFE_FILE_PRINTF(MAX_USERNS, "%d", orig_max_userns);
>> -
>>  	if (acl)
>>  		acl_free(acl);
>>  }
>> @@ -181,7 +169,11 @@ static struct tst_test test = {
>>  	.tags = (const struct tst_tag[]) {
>>  		{"linux-git", "82c9a927bc5d"},
>>  		{}
>> -},
>> +	},
>> +	.save_restore = (const struct tst_path_val[]) {
>> +		{"/proc/sys/user/max_user_namespaces", "1024", TST_SR_SKIP},
>
>And same here.
>
>> +		{}
>> +	},
>>  };
>>  
>>  #else /* HAVE_SYS_XATTR_H && HAVE_LIBACL*/
>> -- 
>> 2.45.2
>> 
>> 
>> -- 
>> Mailing list info: https://lists.linux.it/listinfo/ltp
>
>-- 
>Cyril Hrubis
>chrubis@suse.cz