[LTP] [PATCH v2] syscalls/prctl05.c: New test for prctl() with PR_{SET, GET}_NAME

[Xiao Yang]

On 05/23/2019 07:35 PM, Yang Xu wrote:
> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> ---
>   include/lapi/prctl.h                       |  5 ++
>   runtest/syscalls                           |  1 +
>   testcases/kernel/syscalls/prctl/.gitignore |  1 +
>   testcases/kernel/syscalls/prctl/prctl05.c  | 71 ++++++++++++++++++++++
>   4 files changed, 78 insertions(+)
>   create mode 100644 testcases/kernel/syscalls/prctl/prctl05.c
>
> diff --git a/include/lapi/prctl.h b/include/lapi/prctl.h
> index f42bd6459..ad0b12bce 100644
> --- a/include/lapi/prctl.h
> +++ b/include/lapi/prctl.h
> @@ -9,6 +9,11 @@
>   
>   #include <sys/prctl.h>
>   
> +#ifndef PR_SET_NAME
> +# define PR_SET_NAME 15
> +# define PR_GET_NAME 16
> +#endif
> +
>   #ifndef PR_SET_SECCOMP
>   # define PR_GET_SECCOMP  21
>   # define PR_SET_SECCOMP  22
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 04558a580..d2dcd2152 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -862,6 +862,7 @@ prctl01 prctl01
>   prctl02 prctl02
>   prctl03 prctl03
>   prctl04 prctl04
> +prctl05 prctl05
>   
>   pread01 pread01
>   pread01_64 pread01_64
> diff --git a/testcases/kernel/syscalls/prctl/.gitignore b/testcases/kernel/syscalls/prctl/.gitignore
> index 1c3da3052..9ecaf9854 100644
> --- a/testcases/kernel/syscalls/prctl/.gitignore
> +++ b/testcases/kernel/syscalls/prctl/.gitignore
> @@ -2,3 +2,4 @@
>   /prctl02
>   /prctl03
>   /prctl04
> +/prctl05
> diff --git a/testcases/kernel/syscalls/prctl/prctl05.c b/testcases/kernel/syscalls/prctl/prctl05.c
> new file mode 100644
> index 000000000..fad5b23bf
> --- /dev/null
> +++ b/testcases/kernel/syscalls/prctl/prctl05.c
> @@ -0,0 +1,71 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
> + * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> + *
> + * Test PR_GET_NAME and PR_SET_NAME of prctl(2).
> + * 1)Set the name of the calling thread, the name can be up to 16 bytes
> + *   long, including the terminating null byte. If exceeds 16 bytes, the
> + *   string is silently truncated.
> + * 2)Return the name of the calling thread, the buffer should allow space
> + *   for up to 16 bytes, the returned string will be null-terminated.
> + * 3)Check /proc/self/task/[tid]/comm name whether matches the thread_name.
> + */
> +
> +#include <errno.h>
> +#include <sys/types.h>
> +#include <sys/prctl.h>
> +#include <string.h>
> +#include <stdio.h>
> +#include "lapi/syscalls.h"
> +#include "lapi/prctl.h"
> +#include "tst_test.h"
> +
> +#define thread_name "prctl05_test_xxxxx"
Hi Xu,

It seems better to use upper case for macro.

> +
> +static void verify_prctl(void)
> +{
> +	char buf[20];
> +	char comm_buf[20];
> +	char PROC_NAME_PATH[40];
> +	pid_t tid;
> +
> +	TEST(prctl(PR_SET_NAME, &thread_name));

Why do you want to use the address of macro?

> +	if (TST_RET == -1) {
> +		tst_res(TFAIL | TTERRNO, "prctl(PR_SET_NAME) failed");
> +		return;
> +	}
> +	tst_res(TPASS,
> +		"prctl(PR_SET_NAME) succeeded, set thread name as prctl05_test_xxxxx");

How about using ("...set thread name as %s", thread_name)?

> +
> +	TEST(prctl(PR_GET_NAME, &buf));

&buf is the same as buf here so we can use buf directly.

> +	if (TST_RET == -1) {
> +		tst_res(TFAIL | TTERRNO, "prctl(PR_GET_NAME) failed");
> +		return;
> +	}
> +
> +	buf[19] = '\0';
> +	if (!strncmp(thread_name, buf, 15) && strlen(buf) == 15)
> +		tst_res(TPASS, "prctl(PR_GET_NAME) succeeded, "
> +				"thread name is %s", buf);
> +	else
> +		tst_res(TFAIL,
> +			"prctl(PR_GET_NAME) failed to truncate the name into 16 byte long");

Can we test the shorter name of the calling thread(i.e. shorter than 16 
byte) as well?

Best Regards,
Xiao Yang
> +
> +	tid = tst_syscall(__NR_gettid);
> +
> +	sprintf(PROC_NAME_PATH, "/proc/self/task/%d/comm", tid);
> +	SAFE_FILE_SCANF(PROC_NAME_PATH, "%s", comm_buf);
> +	if (strcmp(buf, comm_buf))
> +		tst_res(TFAIL,
> +			"%s sets name failed, expected prctl105_test_xx, got %s",
> +			PROC_NAME_PATH, comm_buf);
> +	else
> +		tst_res(TPASS, "%s sets thread name succeed as %s",
> +			PROC_NAME_PATH, comm_buf);
> +
> +}
> +
> +static struct tst_test test = {
> +	.test_all = verify_prctl,
> +};