diff options
Diffstat (limited to 'sysdeps/posix/getcwd.c')
| -rw-r--r-- | sysdeps/posix/getcwd.c | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/sysdeps/posix/getcwd.c b/sysdeps/posix/getcwd.c index 950ae613e7..886a0ba827 100644 --- a/sysdeps/posix/getcwd.c +++ b/sysdeps/posix/getcwd.c @@ -224,6 +224,7 @@ __getcwd (buf, size) register char *pathp; struct stat st; int prev_errno = errno; + size_t allocated = size; if (size == 0) { @@ -233,19 +234,19 @@ __getcwd (buf, size) return NULL; } - size = PATH_MAX + 1; + allocated = PATH_MAX + 1; } if (buf != NULL) path = buf; else { - path = malloc (size); + path = malloc (allocated); if (path == NULL) return NULL; } - pathp = path + size; + pathp = path + allocated; *--pathp = '\0'; if (__lstat (".", &st) < 0) @@ -362,7 +363,7 @@ __getcwd (buf, size) if ((size_t) (pathp - path) <= namlen) { - if (buf != NULL) + if (size != 0) { (void) __closedir (dirstream); __set_errno (ERANGE); @@ -371,20 +372,23 @@ __getcwd (buf, size) else { char *tmp; + size_t oldsize = allocated; - size = 2 * MAX (size, namlen); - tmp = realloc (path, size); + allocated = 2 * MAX (allocated, namlen); + tmp = realloc (path, allocated); if (tmp == NULL) { (void) __closedir (dirstream); __set_errno (ENOMEM);/* closedir might have changed it.*/ goto lose; } - pathp = &tmp[pathp - path + size / 2]; - path = tmp; + /* Move current contents up to the end of the buffer. This is guaranteed to be non-overlapping. */ - memcpy (pathp, pathp - size / 2, path + size - pathp); + pathp = memcpy (tmp + allocated - (path + oldsize - pathp), + tmp + (pathp - path), + path + oldsize - pathp); + path = tmp; } } pathp -= namlen; @@ -397,13 +401,13 @@ __getcwd (buf, size) thisino = dotino; } - if (pathp == &path[size - 1]) + if (pathp == &path[allocated - 1]) *--pathp = '/'; if (dotlist != dots) free ((__ptr_t) dotlist); - memmove (path, pathp, path + size - pathp); + memmove (path, pathp, path + allocated - pathp); /* Restore errno on successful return. */ __set_errno (prev_errno); |