RepoMirrors/musl
1
0
Fork 0
mirror of git://git.musl-libc.org/musl synced 2025-01-11 09:09:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

drop direct use of stat syscalls in fchmodat

Browse Source 
instead, use the fstatat/stat functions, so that the logic for which
syscalls are present and usable is all in fstatat.

this results in a slight increase in cost for old kernels on 32-bit
archs: now statx will be attempted first rather than just using the
legacy time32 syscalls, despite us not caring about timestamps.
however, it's not even clear that the legacy syscalls *should* succeed
if the timestamps are out of range; arguably they should fail with
EOVERFLOW. as such, paying a small cost here on old kernels seems
well-motivated.

with this change, fchmodat itself is no longer blocking ports to new
archs that lack the legacy syscalls.
This commit is contained in:
Rich Felker 2022-04-28 02:02:38 -04:00
parent 9a93749555
commit 7edbcbeb76
1 changed files with 7 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/stat/fchmodat.c
View File

@ -2,7 +2,6 @@
#include <fcntl.h>
#include <errno.h>
#include "syscall.h"
#include "kstat.h"
int fchmodat(int fd, const char *path, mode_t mode, int flag)
{
@ -11,12 +10,12 @@ int fchmodat(int fd, const char *path, mode_t mode, int flag)
if (flag != AT_SYMLINK_NOFOLLOW)
return __syscall_ret(-EINVAL);
struct kstat st;
struct stat st;
int ret, fd2;
char proc[15+3*sizeof(int)];
if ((ret = __syscall(SYS_fstatat, fd, path, &st, flag)))
return __syscall_ret(ret);
if (fstatat(fd, path, &st, flag))
return -1;
if (S_ISLNK(st.st_mode))
return __syscall_ret(-EOPNOTSUPP);
@ -27,12 +26,12 @@ int fchmodat(int fd, const char *path, mode_t mode, int flag)
}
__procfdname(proc, fd2);
ret = __syscall(SYS_fstatat, AT_FDCWD, proc, &st, 0);
ret = stat(proc, &st);
if (!ret) {
if (S_ISLNK(st.st_mode)) ret = -EOPNOTSUPP;
else ret = __syscall(SYS_fchmodat, AT_FDCWD, proc, mode);
if (S_ISLNK(st.st_mode)) ret = __syscall_ret(-EOPNOTSUPP);
else ret = syscall(SYS_fchmodat, AT_FDCWD, proc, mode);
}
__syscall(SYS_close, fd2);
return __syscall_ret(ret);
return ret;
}