Re: [PATCH v2] selftests: prctl: Add new prctl test for PR_SET_NAME

[Muhammad Usama Anjum]

Unrelated to this patch:
You can build the user header files by running `make headers` in a kernel
repository to process the kernel header files. They are generated in
<kernel_source>/include/uapi Then run `make -C
tools/testing/selftests/prctl` to build the test etc.

On 6/7/23 8:36 PM, Osama Muhammad wrote:
> This patch will add the new test, which covers the prctl call
> PR_SET_NAME command. The test tries to give a name using the PR_SET_NAME
> call and then confirm it that it changed correctly by using  PR_GET_NAME.
> It also tries to rename it with empty name.In the test PR_GET_NAME is
> tested by passing null pointer to it and check its behaviour.
> 
> Signed-off-by: Osama Muhammad <osmtendev@xxxxxxxxx>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Tested-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>

> 
> ---
> changes since v1:
> 	-Used TASK_COMM_LEN instead of using numerical value 16.
> 	 
> ---
>  tools/testing/selftests/prctl/Makefile        |  2 +-
>  .../selftests/prctl/set-process-name.c        | 62 +++++++++++++++++++
>  2 files changed, 63 insertions(+), 1 deletion(-)
>  create mode 100644 tools/testing/selftests/prctl/set-process-name.c
> 
> diff --git a/tools/testing/selftests/prctl/Makefile b/tools/testing/selftests/prctl/Makefile
> index c058b81ee..cfc35d29f 100644
> --- a/tools/testing/selftests/prctl/Makefile
> +++ b/tools/testing/selftests/prctl/Makefile
> @@ -5,7 +5,7 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)
>  
>  ifeq ($(ARCH),x86)
>  TEST_PROGS := disable-tsc-ctxt-sw-stress-test disable-tsc-on-off-stress-test \
> -		disable-tsc-test set-anon-vma-name-test
> +		disable-tsc-test set-anon-vma-name-test set-process-name
>  all: $(TEST_PROGS)
>  
>  include ../lib.mk
> diff --git a/tools/testing/selftests/prctl/set-process-name.c b/tools/testing/selftests/prctl/set-process-name.c
> new file mode 100644
> index 000000000..3bc5e0e09
> --- /dev/null
> +++ b/tools/testing/selftests/prctl/set-process-name.c
> @@ -0,0 +1,62 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * This test covers the PR_SET_NAME functionality of prctl calls
> + */
> +
> +#include <errno.h>
> +#include <sys/prctl.h>
> +#include <string.h>
> +
> +#include "../kselftest_harness.h"
> +
> +#define CHANGE_NAME "changename"
> +#define EMPTY_NAME ""
> +#define TASK_COMM_LEN 16
> +
> +int set_name(char *name)
> +{
> +	int res;
> +
> +	res = prctl(PR_SET_NAME, name, NULL, NULL, NULL);
> +
> +	if (res < 0)
> +		return -errno;
> +	return res;
> +}
> +
> +int check_is_name_correct(char *check_name)
> +{
> +	char name[TASK_COMM_LEN];
> +	int res;
> +
> +	res = prctl(PR_GET_NAME, name, NULL, NULL, NULL);
> +
> +	if (res < 0)
> +		return -errno;
> +
> +	return !strcmp(name, check_name);
> +}
> +
> +int check_null_pointer(char *check_name)
> +{
> +	char *name = NULL;
> +	int res;
> +
> +	res = prctl(PR_GET_NAME, name, NULL, NULL, NULL);
> +
> +	return res;
> +}
> +
> +TEST(rename_process) {
> +
> +	EXPECT_GE(set_name(CHANGE_NAME), 0);
> +	EXPECT_TRUE(check_is_name_correct(CHANGE_NAME));
> +
> +	EXPECT_GE(set_name(EMPTY_NAME), 0);
> +	EXPECT_TRUE(check_is_name_correct(EMPTY_NAME));
> +
> +	EXPECT_GE(set_name(CHANGE_NAME), 0);
> +	EXPECT_LT(check_null_pointer(CHANGE_NAME), 0);
> +}
> +
> +TEST_HARNESS_MAIN

-- 
BR,
Muhammad Usama Anjum