X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fcareadlinkat.c;h=751578b9a58fc6f46894cbbef3237d716f1c347b;hb=64ee293cdac319d0f38cd0d31e758a823b7163ad;hp=95611f876c454fd4fb9dc81036394ecb0b826321;hpb=6dce4dba9e10423045b81def590df4e6d3c540c6;p=gnulib.git

diff --git a/lib/careadlinkat.c b/lib/careadlinkat.c
index 95611f876..751578b9a 100644
--- a/lib/careadlinkat.c
+++ b/lib/careadlinkat.c
@@ -24,6 +24,7 @@
 
 #include <errno.h>
 #include <limits.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
@@ -38,18 +39,19 @@
 
 #include "allocator.h"
 
-#if ! HAVE_READLINKAT
-/* Ignore FD.  Get the symbolic link value of FILENAME and put it into
-   BUFFER, with size BUFFER_SIZE.  This function acts like readlink
-   but has readlinkat's signature.  */
+/* Get the symbolic link value of FILENAME and put it into BUFFER, with
+   size BUFFER_SIZE.  This function acts like readlink  but has
+   readlinkat's signature.  */
 ssize_t
 careadlinkatcwd (int fd, char const *filename, char *buffer,
                  size_t buffer_size)
 {
-  (void) fd;
+  /* FD must be AT_FDCWD here, otherwise the caller is using this
+     function in contexts for which it was not meant for.  */
+  if (fd != AT_FDCWD)
+    abort ();
   return readlink (filename, buffer, buffer_size);
 }
-#endif
 
 /* Assuming the current directory is FD, get the symbolic link value
    of FILENAME as a null-terminated string and put it into a buffer.
@@ -131,6 +133,7 @@ careadlinkat (int fd, char const *filename,
           if (buf == stack_buf)
             {
               char *b = (char *) alloc->allocate (link_size);
+              buf_size = link_size;
               if (! b)
                 break;
               memcpy (b, buf, link_size);
@@ -154,6 +157,11 @@ careadlinkat (int fd, char const *filename,
         buf_size *= 2;
       else if (buf_size < buf_size_max)
         buf_size = buf_size_max;
+      else if (buf_size_max < SIZE_MAX)
+        {
+          errno = ENAMETOOLONG;
+          return NULL;
+        }
       else
         break;
       buf = (char *) alloc->allocate (buf_size);
@@ -161,7 +169,7 @@ careadlinkat (int fd, char const *filename,
   while (buf);
 
   if (alloc->die)
-    alloc->die ();
+    alloc->die (buf_size);
   errno = ENOMEM;
   return NULL;
 }