Commit 29060633 authored by Binbin Wu's avatar Binbin Wu Committed by Ingo Molnar
Browse files

selftests/x86/lam: Zero out buffer for readlink() 



Zero out the buffer for readlink() since readlink() does not append a
terminating null byte to the buffer.  Also change the buffer length
passed to readlink() to 'PATH_MAX - 1' to ensure the resulting string
is always null terminated.

Fixes: 833c12ce ("selftests/x86/lam: Add inherit test cases for linear-address masking")
Signed-off-by: default avatarBinbin Wu <binbin.wu@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20231016062446.695-1-binbin.wu@linux.intel.com
parent d6f274b7

tools/testing/selftests/x86/lam.c

+3 −3
Original line number Diff line number Diff line
@@ -573,7 +573,7 @@ int do_uring(unsigned long lam) 
	char path[PATH_MAX] = {0};



	/* get current process path */

	if (readlink("/proc/self/exe", path, PATH_MAX) <= 0)

	if (readlink("/proc/self/exe", path, PATH_MAX - 1) <= 0)

		return 1;



	int file_fd = open(path, O_RDONLY);
@@ -680,14 +680,14 @@ static int handle_execve(struct testcases *test) 
		perror("Fork failed.");

		ret = 1;

	} else if (pid == 0) {

		char path[PATH_MAX];

		char path[PATH_MAX] = {0};



		/* Set LAM mode in parent process */

		if (set_lam(lam) != 0)

			return 1;



		/* Get current binary's path and the binary was run by execve */

		if (readlink("/proc/self/exe", path, PATH_MAX) <= 0)

		if (readlink("/proc/self/exe", path, PATH_MAX - 1) <= 0)

			exit(-1);



		/* run binary to get LAM mode and return to parent process */