lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-07-28 00:21:52 +03:00
Code Activity

Fix recursive dlopen.

Browse Source 
The ability to recursively call dlopen is useful for malloc
implementations that wish to load other dynamic modules that
implement reentrant/AS-safe functions to use in their own
implementation.

Given that a user malloc implementation may be called by an
ongoing dlopen to allocate memory the user malloc
implementation interrupts dlopen and if it calls dlopen again
that's a reentrant call.

This patch fixes the issues with the ld.so.cache mapping
and the _r_debug assertion which prevent this from working
as expected.

See:
https://sourceware.org/ml/libc-alpha/2014-12/msg00446.html
This commit is contained in:
Carlos O'Donell
2015-01-21 01:51:10 -05:00
parent 042e1521c7
commit ccdb048df4
10 changed files with 222 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
elf/dl-load.c
View File

@ -2051,7 +2051,7 @@ _dl_map_object (struct link_map *loader, const char *name,
{
/* Check the list of libraries in the file /etc/ld.so.cache,
for compatibility with Linux's ldconfig program. */
const char *cached = _dl_load_cache_lookup (name);
char *cached = _dl_load_cache_lookup (name);
if (cached != NULL)
{
@ -2075,6 +2075,7 @@ _dl_map_object (struct link_map *loader, const char *name,
if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
{
/* The prefix matches. Don't use the entry. */
free (cached);
cached = NULL;
break;
}
@ -2092,14 +2093,9 @@ _dl_map_object (struct link_map *loader, const char *name,
LA_SER_CONFIG, mode, &found_other_class,
false);
if (__glibc_likely (fd != -1))
{
realname = __strdup (cached);
if (realname == NULL)
{
__close (fd);
fd = -1;
}
}
realname = cached;
else
free (cached);
}
}
}