On 2025-03-04 07:58:15+0000, Louis Taylor wrote:
openat is useful to avoid needing to construct relative paths, so expose a wrapper for using it directly.
Signed-off-by: Louis Taylor louis@kragniz.eu
Looks good. I have some tiny nitpicks inline, but if you prefer I can also pick it up as-is.
Acked-by: Thomas Weißschuh linux@weissschuh.net
tools/include/nolibc/sys.h | 25 ++++++++++++++++++++ tools/testing/selftests/nolibc/nolibc-test.c | 21 ++++++++++++++++ 2 files changed, 46 insertions(+)
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index 8f44c33b1213..3cd938f9abda 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -765,6 +765,31 @@ int mount(const char *src, const char *tgt, return __sysret(sys_mount(src, tgt, fst, flags, data)); } +/*
- int openat(int dirfd, const char *path, int flags[, mode_t mode]);
- */
+static __attribute__((unused)) +int sys_openat(int dirfd, const char *path, int flags, mode_t mode) +{
- return my_syscall4(__NR_openat, dirfd, path, flags, mode);
+}
+static __attribute__((unused)) +int openat(int dirfd, const char *path, int flags, ...) +{
- mode_t mode = 0;
- if (flags & O_CREAT) {
va_list args;va_start(args, flags);mode = va_arg(args, mode_t);va_end(args);- }
- return __sysret(sys_openat(dirfd, path, flags, mode));
+} /*
- int open(const char *path, int flags[, mode_t mode]);
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 79c3e6a845f3..2a1629938dd6 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -1028,6 +1028,26 @@ int test_rlimit(void) return 0; } +static int test_openat(void)
As mentioned in my other mail, this in fact should not be static. Sorry for the back and forth.
+{
- int dev;
- int null;
Can be on a single line.
- dev = openat(AT_FDCWD, "/dev", O_DIRECTORY);
- if (dev < 0)
return -1;- null = openat(dev, "null", 0);
As per the standard:
The argument flags must include one of the following access modes: O_RDONLY, O_WRONLY, or O_RDWR.
The other tests don't do it either and on Linux it doesn't matter because O_RDONLY == 0. But if we are here anyways.
close(dev) could be moved here for some saved lines.
- if (null < 0) {
close(dev);return -1;- }
- close(dev);
- close(null);
- return 0;
+} /* Run syscall tests between IDs <min> and <max>.
- Return 0 on success, non-zero on failure.
@@ -1116,6 +1136,7 @@ int run_syscall(int min, int max) CASE_TEST(mmap_munmap_good); EXPECT_SYSZR(1, test_mmap_munmap()); break; CASE_TEST(open_tty); EXPECT_SYSNE(1, tmp = open("/dev/null", 0), -1); if (tmp != -1) close(tmp); break; CASE_TEST(open_blah); EXPECT_SYSER(1, tmp = open("/proc/self/blah", 0), -1, ENOENT); if (tmp != -1) close(tmp); break;
CASE_TEST(openat_dir); EXPECT_SYSNE(1, test_openat(), -1); break;
EXPECT_SYSZR() should work here.
CASE_TEST(pipe); EXPECT_SYSZR(1, test_pipe()); break; CASE_TEST(poll_null); EXPECT_SYSZR(1, poll(NULL, 0, 0)); break; CASE_TEST(poll_stdout); EXPECT_SYSNE(1, ({ struct pollfd fds = { 1, POLLOUT, 0}; poll(&fds, 1, 0); }), -1); break;-- 2.45.2