[LTP] [PATCH v4] syscalls/prctl06: New test for prctl() with PR_{SET, GET}_NO_NEW_PRIVS

[Yang Xu]

> Hi!
> Pushed with two changes, thanks.
>
>
> diff --git a/testcases/kernel/syscalls/prctl/prctl06.c b/testcases/kernel/syscalls/prctl/prctl06.c
> index eafbedfef..0e1274a2a 100644
> --- a/testcases/kernel/syscalls/prctl/prctl06.c
> +++ b/testcases/kernel/syscalls/prctl/prctl06.c
> @@ -81,8 +81,8 @@ static void setup(void)
>
>   	SAFE_CP(TESTBIN, TEST_REL_BIN_DIR);
>
> -	SAFE_CHMOD(BIN_PATH, SUID_MODE);
>   	SAFE_CHOWN(BIN_PATH, 0, 0);
> +	SAFE_CHMOD(BIN_PATH, SUID_MODE);
>
>   	TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
>   	if (TST_RET == 0) {
>
> This is actually important fix, you have to set the SUID bits last since
> they are cleared if you change owner of the file.
Hi Cyril

OK. I learn a lot from this case. Thanks for kindly reply.

>
> diff --git a/testcases/kernel/syscalls/prctl/prctl06.h b/testcases/kernel/syscalls/prctl/prctl06.h
> index 72f9c4e5a..f5c66e809 100644
> --- a/testcases/kernel/syscalls/prctl/prctl06.h
> +++ b/testcases/kernel/syscalls/prctl/prctl06.h
> @@ -25,12 +25,14 @@
>   #define BIN_PATH           MNTPOINT"/"TESTBIN
>   #define SUID_MODE          (S_ISUID|S_ISGID|S_IXUSR|S_IXGRP|S_IXOTH)
>
> -static int flag = 1;
> -
>   void check_proc_field(int val, char *name)
>   {
> +	static int flag = 1;
>   	int field = 0;
>
> +	if (!flag)
> +		return;
> +
>   	TEST(FILE_LINES_SCANF(PROC_STATUS, "NoNewPrivs:%d",&field));
>   	if (TST_RET == 1) {
>   		tst_res(TCONF,
> @@ -57,8 +59,8 @@ void check_no_new_privs(int val, char *name)
>   		tst_res(TFAIL,
>   			"%s prctl(PR_GET_NO_NEW_PRIVS) expected %d got %ld",
>   			name, val, TST_RET);
> -	if (flag)
> -		check_proc_field(val, name);
> +
> +	check_proc_field(val, name);
>   }
>
>   #endif
>
> This is merely cosmetic and moves the flag to the function so that it's
> not global.
Yes. static local variable is better.