[LTP] thp04: Simplify to focus on CVE-2017-1000405 race test only

[linuxtestproject.agent@gmail.com]

Hi Jan,

On Tue, Jul 14 2026, Jan Polensky <japo@linux.ibm.com> wrote:
> thp04: Simplify to focus on CVE-2017-1000405 race test only

--- [PATCH 1/3] ---

> +static struct child_state *child;
> ...
> +	child = SAFE_MMAP(NULL, sizeof(*child), PROT_READ | PROT_WRITE,
> +		MAP_SHARED | MAP_ANONYMOUS, -1, 0);

> +static struct tst_test test = {
> +	.test_all = run,
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.runtime = 150,
> +	.forks_child = 1,

Is .forks_child = 1 intentional? tst_fzsync_pair_reset() is called
with thread_run as the second argument, which causes it to create a
pthread via SAFE_PTHREAD_CREATE -- not a child process.

tst_test.h: "@forks_child: Has to be set if the test intends to fork
children." No fork() or SAFE_FORK() is called anywhere in this test,
so .forks_child should not be set.

The child struct is also mapped with MAP_SHARED|MAP_ANONYMOUS.
MAP_SHARED is meaningful between a parent and a forked child; for
thread-only use MAP_PRIVATE is appropriate.

> -};
> +};
>  No newline at end of file

The file is missing a trailing newline. POSIX requires text files to
end with a newline; `make check` would catch this.

--- [PATCH 2/3] ---

> +/*\
> + * [Description]
> + *
> + * Verify that direct writes to /proc/self/mem are correctly rejected

The [Description] header is deprecated. Remove the [Description] line;
the RST block is treated as a description by default. See c-tests.md
rule 18.

> +	memfd = SAFE_OPEN("/proc/self/mem", O_RDWR);
> +}
> +
> +static void run(void)
> +{
> +	int test_val = 0xdeadbeef;
> +	ssize_t ret;
> +
> +	/* Seek to our test memory location */
> +	SAFE_LSEEK(memfd, (off_t)test_ptr, SEEK_SET);
> +
> +	/* Attempt to write to our own memory via /proc/self/mem */
> +	ret = write(memfd, &test_val, sizeof(test_val));

The write() here is the subject syscall and its result is being
checked, but it is not wrapped in TEST(). c-tests.md: "Subject
syscalls MUST still be wrapped in TEST() or a TST_EXP_* macro --
never called bare."

Use TEST(write(memfd, &test_val, sizeof(test_val))) and replace the
ret / errno checks with TST_RET and TST_ERR.

> +	/* Allocate a read-only page - writes via /proc/self/mem should fail */
> +	test_ptr = SAFE_MMAP(NULL, sizeof(int), PROT_READ | PROT_WRITE,

The comment says "read-only page" but the mmap uses PROT_READ|PROT_WRITE.
The page is made read-only by the SAFE_MPROTECT call two lines later.

Also the blank line immediately after '*test_ptr = 0;' contains a
trailing tab. Remove it.

There is no entry for ptrace12 in runtest/syscalls. The test will not
be picked up by any LTP run until that entry is added.

--- [PATCH 3/3] ---

> +/*\
> + * [Description]
> + *
> + * Verify that a parent process can write to a traced child's memory

Same [Description] issue as ptrace12 -- remove the deprecated header.

There is no entry for ptrace13 in runtest/syscalls.

The blank line after '*shared->test_ptr = 0;' in tracee_main() also
has a trailing tab.

Verdict - Needs revision

---
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LTP AI Reviewer