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authorMaxim Ostapenko <m.ostapenko@partner.samsung.com>2015-08-10 10:47:54 +0300
committerAndreas Schwab <schwab@suse.de>2015-08-11 10:13:22 +0200
commitf25238ffe0455013174438376b3ee88df496f9d1 (patch)
tree6cd3e27f694193ddc4f45258d09f1f4fb9f17801 /elf
parentdc8a7ff24dfd1fd97a50b4b83a715958b31e4b92 (diff)
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Clear DF_1_NODELETE flag only for failed to load library.
https://sourceware.org/bugzilla/show_bug.cgi?id=18778 If dlopen fails to load an object that has triggered loading libpthread it causes ld.so to unload libpthread because its DF_1_NODELETE flags has been forcefully cleared. The next call to __rtdl_unlock_lock_recursive will crash since pthread_mutex_unlock no longer exists. This patch moves l->l_flags_1 &= ~DF_1_NODELETE out of loop through all loaded libraries and performs the action only on inconsistent one. [BZ #18778] * elf/Makefile (tests): Add Add tst-nodelete2. (modules-names): Add tst-nodelete2mod. (tst-nodelete2mod.so-no-z-defs): New. ($(objpfx)tst-nodelete2): Likewise. ($(objpfx)tst-nodelete2.out): Likewise. (LDFLAGS-tst-nodelete2): Likewise. * elf/dl-close.c (_dl_close_worker): Move DF_1_NODELETE clearing out of loop through all loaded libraries. * elf/tst-nodelete2.c: New file. * elf/tst-nodelete2mod.c: Likewise.
Diffstat (limited to 'elf')
-rw-r--r--elf/Makefile11
-rw-r--r--elf/dl-close.c15
-rw-r--r--elf/tst-nodelete2.c37
-rw-r--r--elf/tst-nodelete2mod.c (renamed from elf/tst-znodelete-zlib.cc)3
4 files changed, 56 insertions, 10 deletions
diff --git a/elf/Makefile b/elf/Makefile
index 4ceeaf8..71a18a1 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -148,7 +148,8 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
tst-unique1 tst-unique2 $(if $(CXX),tst-unique3 tst-unique4 \
tst-nodelete) \
tst-initorder tst-initorder2 tst-relsort1 tst-null-argv \
- tst-ptrguard1 tst-tlsalign tst-tlsalign-extern tst-nodelete-opened
+ tst-ptrguard1 tst-tlsalign tst-tlsalign-extern tst-nodelete-opened \
+ tst-nodelete2
# reldep9
ifeq ($(build-hardcoded-path-in-tests),yes)
tests += tst-dlopen-aout
@@ -218,7 +219,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
tst-initorder2d \
tst-relsort1mod1 tst-relsort1mod2 tst-array2dep \
tst-array5dep tst-null-argv-lib \
- tst-tlsalign-lib tst-nodelete-opened-lib
+ tst-tlsalign-lib tst-nodelete-opened-lib tst-nodelete2mod
ifeq (yes,$(have-protected-data))
modules-names += tst-protected1moda tst-protected1modb
tests += tst-protected1a tst-protected1b
@@ -594,6 +595,7 @@ tst-auditmod9b.so-no-z-defs = yes
tst-nodelete-uniquemod.so-no-z-defs = yes
tst-nodelete-rtldmod.so-no-z-defs = yes
tst-nodelete-zmod.so-no-z-defs = yes
+tst-nodelete2mod.so-no-z-defs = yes
ifeq ($(build-shared),yes)
# Build all the modules even when not actually running test programs.
@@ -1164,6 +1166,11 @@ $(objpfx)tst-nodelete.out: $(objpfx)tst-nodelete-uniquemod.so \
LDFLAGS-tst-nodelete = -rdynamic
LDFLAGS-tst-nodelete-zmod.so = -Wl,--enable-new-dtags,-z,nodelete
+$(objpfx)tst-nodelete2: $(libdl)
+$(objpfx)tst-nodelete2.out: $(objpfx)tst-nodelete2mod.so
+
+LDFLAGS-tst-nodelete2 = -rdynamic
+
$(objpfx)tst-initorder-cmp.out: tst-initorder.exp $(objpfx)tst-initorder.out
cmp $^ > $@; \
$(evaluate-test)
diff --git a/elf/dl-close.c b/elf/dl-close.c
index 9105277..c897247 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -144,6 +144,14 @@ _dl_close_worker (struct link_map *map, bool force)
char done[nloaded];
struct link_map *maps[nloaded];
+ /* Clear DF_1_NODELETE to force object deletion. We don't need to touch
+ l_tls_dtor_count because forced object deletion only happens when an
+ error occurs during object load. Destructor registration for TLS
+ non-POD objects should not have happened till then for this
+ object. */
+ if (force)
+ map->l_flags_1 &= ~DF_1_NODELETE;
+
/* Run over the list and assign indexes to the link maps and enter
them into the MAPS array. */
int idx = 0;
@@ -153,13 +161,6 @@ _dl_close_worker (struct link_map *map, bool force)
maps[idx] = l;
++idx;
- /* Clear DF_1_NODELETE to force object deletion. We don't need to touch
- l_tls_dtor_count because forced object deletion only happens when an
- error occurs during object load. Destructor registration for TLS
- non-POD objects should not have happened till then for this
- object. */
- if (force)
- l->l_flags_1 &= ~DF_1_NODELETE;
}
assert (idx == nloaded);
diff --git a/elf/tst-nodelete2.c b/elf/tst-nodelete2.c
new file mode 100644
index 0000000..388e8af
--- /dev/null
+++ b/elf/tst-nodelete2.c
@@ -0,0 +1,37 @@
+#include "../dlfcn/dlfcn.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <gnu/lib-names.h>
+
+static int
+do_test (void)
+{
+ int result = 0;
+
+ printf ("\nOpening pthread library.\n");
+ void *pthread = dlopen (LIBPTHREAD_SO, RTLD_LAZY);
+
+ /* This is a test for correct DF_1_NODELETE clearing when dlopen failure
+ happens. We should clear DF_1_NODELETE for failed library only, because
+ doing this for others (e.g. libpthread) might cause them to be unloaded,
+ that may lead to some global references (e.g. __rtld_lock_unlock) to be
+ broken. The dlopen should fail because of undefined symbols in shared
+ library, that cause DF_1_NODELETE to be cleared. For libpthread, this
+ flag should be set, because if not, SIGSEGV will happen in dlclose. */
+ if (dlopen ("tst-nodelete2mod.so", RTLD_NOW) != NULL)
+ {
+ printf ("Unique symbols test failed\n");
+ result = 1;
+ }
+
+ if (pthread)
+ dlclose (pthread);
+
+ if (result == 0)
+ printf ("SUCCESS\n");
+
+ return result;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/elf/tst-znodelete-zlib.cc b/elf/tst-nodelete2mod.c
index 1e8f368..e88c756 100644
--- a/elf/tst-znodelete-zlib.cc
+++ b/elf/tst-nodelete2mod.c
@@ -1,6 +1,7 @@
+/* Undefined symbol. */
extern int not_exist (void);
int foo (void)
{
- return not_exist ();
+ return not_exist ();
}