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author | Ken Brown <kbrown@cornell.edu> | 2019-12-27 17:17:35 -0500 |
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committer | Ken Brown <kbrown@cornell.edu> | 2020-01-17 10:27:48 -0500 |
commit | 6cc05784e16af56750417b73d778efb09c3b122e (patch) | |
tree | 203af440538a710b74f92f1fdaf39bdad29fc43d /winsup | |
parent | 35a1a6dbdf03df1e33bae51f679820a3a868d0c0 (diff) | |
download | newlib-6cc05784e16af56750417b73d778efb09c3b122e.zip newlib-6cc05784e16af56750417b73d778efb09c3b122e.tar.gz newlib-6cc05784e16af56750417b73d778efb09c3b122e.tar.bz2 |
Cygwin: readlinkat: allow pathname to be empty
Following Linux, allow the pathname argument to be an empty string,
provided the dirfd argument refers to a symlink opened with
O_PATH | O_NOFOLLOW. The readlinkat call then operates on that
symlink.
Diffstat (limited to 'winsup')
-rw-r--r-- | winsup/cygwin/syscalls.cc | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc index 038a316..282d9e0 100644 --- a/winsup/cygwin/syscalls.cc +++ b/winsup/cygwin/syscalls.cc @@ -4979,8 +4979,23 @@ readlinkat (int dirfd, const char *__restrict pathname, char *__restrict buf, __try { char *path = tp.c_get (); - if (gen_full_path_at (path, dirfd, pathname)) - __leave; + int res = gen_full_path_at (path, dirfd, pathname); + if (res) + { + if (errno != ENOENT) + __leave; + /* pathname is an empty string. This is OK if dirfd refers + to a symlink that was opened with O_PATH | O_NOFOLLOW. + In this case, readlinkat operates on the symlink. */ + cygheap_fdget cfd (dirfd); + if (cfd < 0) + __leave; + if (!(cfd->issymlink () + && cfd->get_flags () & O_PATH + && cfd->get_flags () & O_NOFOLLOW)) + __leave; + strcpy (path, cfd->get_name ()); + } return readlink (path, buf, bufsize); } __except (EFAULT) {} |