Patch for dl-cache.c

[Jakub Jelinek]

On Wed, Nov 24, 1999 at 03:40:28PM +0100, Andreas Jaeger wrote:
> 
> Jakub found a bug in my version of ldconfig, which is also in glibc's
> dl-cache.  I'm appending a patch for dl-cache.c.
> 
> The bug is that the final NUL in CACHEMAGIC is part of the magic - but
> the data structure doesn't reserve space for it (this worked due to
> alignment).

That was a misunderstanding. Cache magic seems to be without the final NUL
in H.J.'s version I looked at, it was just my ldconfig hack to make it emit
0 in the pad and not random value, now when I look at it it would be better
to just make sure the whole structure with all its padding is zero:

--- ldconfig/cache.c.jj	Wed Nov 24 10:13:33 1999
+++ ldconfig/cache.c	Wed Nov 24 16:13:53 1999
@@ -54,7 +54,7 @@ struct file_entry
 
 struct cache_file
 {
-  char magic[sizeof CACHEMAGIC];
+  char magic[sizeof CACHEMAGIC - 1];
   unsigned int nlibs;
   struct file_entry libs[0];
 };
@@ -129,7 +129,7 @@ print_cache (const char *cache_name)
   cache_size = st.st_size;
 
   if (cache_size < sizeof (struct cache_file)
-      || memcmp (cache->magic, CACHEMAGIC, sizeof CACHEMAGIC))
+      || memcmp (cache->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1))
     return;
   /* This is where the strings start.  */
   cache_data = (const char *) &cache->libs[cache->nlibs];
@@ -248,7 +248,8 @@ save_cache (const char *cache_name)
   file_entries = (struct cache_file *) xmalloc (file_entries_size);
 
   /* Fill in the header.  */
-  memcpy (file_entries->magic, CACHEMAGIC, sizeof CACHEMAGIC);
+  memset (file_entries, 0, sizeof (struct cache_file));
+  memcpy (file_entries->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1);
   
   file_entries->nlibs = cache_entry_count;
 


Cheers,
    Jakub
___________________________________________________________________
Jakub Jelinek | jakub@redhat.com | http://sunsite.mff.cuni.cz/~jj
Linux version 2.3.18 on a sparc64 machine (1343.49 BogoMips)
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