drop direct use of stat syscalls in fchmodat

[musl] / src / stat / fchmodat.c

diff --git a/src/stat/fchmodat.c b/src/stat/fchmodat.c
index f4f22b2..bc58105 100644 (file)
--- a/src/stat/fchmodat.c
+++ b/src/stat/fchmodat.c
@@ -1,7 +1,37 @@
 #include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
 #include "syscall.h"
 
 int fchmodat(int fd, const char *path, mode_t mode, int flag)
 {
-       return syscall4(__NR_fchmodat, fd, (long)path, mode, flag);
+       if (!flag) return syscall(SYS_fchmodat, fd, path, mode, flag);
+
+       if (flag != AT_SYMLINK_NOFOLLOW)
+               return __syscall_ret(-EINVAL);
+
+       struct stat st;
+       int ret, fd2;
+       char proc[15+3*sizeof(int)];
+
+       if (fstatat(fd, path, &st, flag))
+               return -1;
+       if (S_ISLNK(st.st_mode))
+               return __syscall_ret(-EOPNOTSUPP);
+
+       if ((fd2 = __syscall(SYS_openat, fd, path, O_RDONLY|O_PATH|O_NOFOLLOW|O_NOCTTY|O_CLOEXEC)) < 0) {
+               if (fd2 == -ELOOP)
+                       return __syscall_ret(-EOPNOTSUPP);
+               return __syscall_ret(fd2);
+       }
+
+       __procfdname(proc, fd2);
+       ret = stat(proc, &st);
+       if (!ret) {
+               if (S_ISLNK(st.st_mode)) ret = __syscall_ret(-EOPNOTSUPP);
+               else ret = syscall(SYS_fchmodat, AT_FDCWD, proc, mode);
+       }
+
+       __syscall(SYS_close, fd2);
+       return ret;
 }