Commit: df82d659c340312c5d7e32a5660168624d5fa265 - uclibc-ng (git)

Commit MetaInfo

• Revision: df82d659c340312c5d7e32a5660168624d5fa265 (tree)
• Time: 2019-04-14 17:02:19
• Author: Yann Sionneau <ysionneau@kalr...>
• Commiter: Waldemar Brodkorb

Log Message

Fix _dl_deallocate_tls in !SHARED case

This patch seems needed in builds where
- SHARED is not defined (no shared lib support)
- and USE_TLS is set

Without this patch, static_dtv is free'ed.
See the following backtrace:
0 do_check_chunk (p=0x52638 <fork_handler_pool+2296>) at libc/stdlib/malloc-standard/malloc.c:80
1 0x0000000000017fa0 in do_check_inuse_chunk (p=0x52638 <fork_handler_pool+2296>) at libc/stdlib/malloc-standard/malloc.c:143
2 0x0000000000017354 in free (mem=0x52648 <static_dtv>) at libc/stdlib/malloc-standard/free.c:293
3 0x000000000002d5b0 in _dl_deallocate_tls (tcb=0x58690, dealloc_tcb=false) at libpthread/nptl/sysdeps/generic/dl-tls.c:588
4 0x0000000000021c0c in deallocate_stack (pd=0x58000) at libpthread/nptl/allocatestack.c:717
5 0x0000000000024408 in free_tcb (pd=0x58000) at libpthread/nptl/pthread_create.c:217
6 0x00000000000200ac in pthread_join (threadid=360448, thread_return=0x0 <k1c_start>) at libpthread/nptl/pthread_join.c:109
7 0x0000000000010354 in tf (a=0x58000) at tst-basic3.c:42
8 0x00000000000247c8 in start_thread (arg=0x4000200960) at libpthread/nptl/pthread_create.c:285
9 0x0000000000026560 in ?? ()

This backtrace is obtained while debugging tst-basic3 from the uclibc-ng nptl testsuite.
It aborts because of the assert in malloc:
https://elixir.bootlin.com/uclibc-ng/v1.0.31/source/libc/stdlib/malloc-standard/malloc.c#L80

Signed-off-by: Yann Sionneau <[e-mail]>

Change Summary

• modified: libpthread/nptl/sysdeps/generic/dl-tls.c
• modified: libpthread/nptl/sysdeps/generic/libc-tls.c

Incremental Difference

--- a/libpthread/nptl/sysdeps/generic/dl-tls.c
+++ b/libpthread/nptl/sysdeps/generic/dl-tls.c
@@ -48,6 +48,9 @@
 /* Value used for dtv entries for which the allocation is delayed.  */
 # define TLS_DTV_UNALLOCATED	((void *) -1l)
 
+#ifndef SHARED
+extern dtv_t static_dtv;
+#endif
 
 /* Out-of-memory handler.  */
 # ifdef SHARED
@@ -584,6 +587,8 @@ _dl_deallocate_tls (void *tcb, bool dealloc_tcb)
   /* The array starts with dtv[-1].  */
 #ifdef SHARED
   if (dtv != GL(dl_initial_dtv))
+#else
+  if ((dtv - 1) != &static_dtv)
 #endif
     free (dtv - 1);
 

--- a/libpthread/nptl/sysdeps/generic/libc-tls.c
+++ b/libpthread/nptl/sysdeps/generic/libc-tls.c
@@ -42,7 +42,10 @@ extern size_t _dl_phnum;
 extern int __tdata_start;
 #endif
 
-static dtv_t static_dtv[2 + TLS_SLOTINFO_SURPLUS];
+#ifdef SHARED
+static
+#endif
+dtv_t static_dtv[2 + TLS_SLOTINFO_SURPLUS];
 
 
 static struct