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authorWaldemar Brodkorb <wbx@uclibc-ng.org>2018-01-20 21:10:56 +0100
committerWaldemar Brodkorb <wbx@uclibc-ng.org>2018-01-21 11:44:19 +0000
commitb08d5b5caca499902844099ab6ddf016a7ec8e3d (patch)
tree6a96803aa633d7446cdfc62d653a62b23b67f8b1 /libc/sysdeps/linux/common/getcwd.c
parentdf350133f24e6202c4eaf57a1941aa2836f258ae (diff)
simplify and fix getcwd
The fallback code is not used as all supported kernels have the syscall. Check if a absolute path is returned from syscall.
Diffstat (limited to 'libc/sysdeps/linux/common/getcwd.c')
-rw-r--r--libc/sysdeps/linux/common/getcwd.c146
1 files changed, 1 insertions, 145 deletions
diff --git a/libc/sysdeps/linux/common/getcwd.c b/libc/sysdeps/linux/common/getcwd.c
index 87510019e..6ec105a98 100644
--- a/libc/sysdeps/linux/common/getcwd.c
+++ b/libc/sysdeps/linux/common/getcwd.c
@@ -16,154 +16,10 @@
#include <sys/syscall.h>
-
-#ifdef __NR_getcwd
-
# define __NR___syscall_getcwd __NR_getcwd
static __always_inline
_syscall2(int, __syscall_getcwd, char *, buf, unsigned long, size)
-#else
-
-/* If the syscall is not present, we have to walk up the
- * directory tree till we hit the root. Now we _could_
- * use /proc/self/cwd if /proc is mounted... That approach
- * is left an an exercise for the reader... */
-
-
-/* Seems a few broken filesystems (like coda) don't like this */
-/* #undef FAST_DIR_SEARCH_POSSIBLE on Linux */
-
-
-/* Routine to find the step back down */
-static char *search_dir(dev_t this_dev, ino_t this_ino, char *path_buf, int path_size)
-{
- DIR *dp;
- struct dirent *d;
- char *ptr;
- int slen;
- struct stat st;
-
-# ifdef FAST_DIR_SEARCH_POSSIBLE
- /* The test is for ELKS lib 0.0.9, this should be fixed in the real kernel */
- int slow_search = (sizeof(ino_t) != sizeof(d->d_ino));
-# endif
-
- if (stat(path_buf, &st) < 0) {
- goto oops;
- }
-# ifdef FAST_DIR_SEARCH_POSSIBLE
- if (this_dev != st.st_dev)
- slow_search = 1;
-# endif
-
- slen = strlen(path_buf);
- ptr = path_buf + slen - 1;
- if (*ptr != '/') {
- if (slen + 2 > path_size) {
- goto oops;
- }
- strcpy(++ptr, "/");
- slen++;
- }
- slen++;
-
- dp = opendir(path_buf);
- if (!dp) {
- goto oops;
- }
-
- while ((d = readdir(dp)) != 0) {
-# ifdef FAST_DIR_SEARCH_POSSIBLE
- if (slow_search || this_ino == d->d_ino) {
-# endif
- if (slen + strlen(d->d_name) > path_size) {
- closedir(dp);
- goto oops;
- }
- strcpy(ptr + 1, d->d_name);
- if (stat(path_buf, &st) < 0)
- continue;
- if (st.st_ino == this_ino && st.st_dev == this_dev) {
- closedir(dp);
- return path_buf;
- }
-# ifdef FAST_DIR_SEARCH_POSSIBLE
- }
-# endif
- }
-
- closedir(dp);
- return 0;
-
-oops:
- __set_errno(ERANGE);
- return 0;
-}
-
-/* Routine to go up tree */
-static char *recurser(char *path_buf, int path_size, dev_t root_dev, ino_t root_ino)
-{
- struct stat st;
- dev_t this_dev;
- ino_t this_ino;
-
- if (stat(path_buf, &st) < 0) {
- if (errno != EFAULT)
- goto oops;
- return 0;
- }
- this_dev = st.st_dev;
- this_ino = st.st_ino;
- if (this_dev == root_dev && this_ino == root_ino) {
- if (path_size < 2) {
- goto oops;
- }
- strcpy(path_buf, "/");
- return path_buf;
- }
- if (strlen(path_buf) + 4 > path_size) {
- goto oops;
- }
- strcat(path_buf, "/..");
- if (recurser(path_buf, path_size, root_dev, root_ino) == 0)
- return 0;
-
- return search_dir(this_dev, this_ino, path_buf, path_size);
-oops:
- __set_errno(ERANGE);
- return 0;
-}
-
-static __always_inline
-int __syscall_getcwd(char * buf, unsigned long size)
-{
- int len;
- char *cwd;
- struct stat st;
- int olderrno;
-
- olderrno = errno;
- len = -1;
-
- /* get stat for root to have a valid parameters for the terminating condition */
- if (stat("/", &st) < 0) {
- /* root dir not found! */
- return -1;
- }
- /* start with actual dir */
- if (buf) strncpy(buf, ".", size);
-
- cwd = recurser(buf, size, st.st_dev, st.st_ino);
- if (cwd) {
- len = strlen(buf) + 1;
- __set_errno(olderrno);
- }
- return len;
-}
-
-#endif /* __NR_getcwd */
-
char *getcwd(char *buf, size_t size)
{
int ret;
@@ -184,7 +40,7 @@ char *getcwd(char *buf, size_t size)
return NULL;
}
ret = __syscall_getcwd(path, alloc_size);
- if (ret >= 0)
+ if (ret > 0 && path[0] == '/')
{
if (buf == NULL && size == 0)
buf = realloc(path, ret);