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[uclibc-ng-devel] Fix _dl_deallocate_tls in !SHARED case

Message ID 20190409110421.23987-1-ysionneau@kalray.eu
State Accepted
Headers show
Series [uclibc-ng-devel] Fix _dl_deallocate_tls in !SHARED case | expand

Commit Message

Yann Sionneau April 9, 2019, 11:04 a.m. UTC 
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 <ysionneau@kalray.eu>
---
 libpthread/nptl/sysdeps/generic/dl-tls.c   | 5 +++++
 libpthread/nptl/sysdeps/generic/libc-tls.c | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)
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Patch

diff --git a/libpthread/nptl/sysdeps/generic/dl-tls.c b/libpthread/nptl/sysdeps/generic/dl-tls.c
index 989e587a2..7d25e4706 100644
--- 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);
 
diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c b/libpthread/nptl/sysdeps/generic/libc-tls.c
index a6df4cdc4..d746c9a38 100644
--- 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