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authorSiddhesh Poyarekar <siddhesh@redhat.com>2015-07-16 08:53:28 +0530
committerSiddhesh Poyarekar <siddhesh@redhat.com>2015-07-16 08:53:28 +0530
commitb632bdd3f7c0ba0c79f23f5e4404eebb87ebdaa8 (patch)
treeac6ac90ea020f5d02ee411528ce2d165ca4ecc11 /elf
parentc59f721c7377106888bff47064bf7da5a082e129 (diff)
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Set NODELETE flag when opening already open objects with RTLD_NODELETE
The DF_1_NODELETE flag is set too late when opening a DSO, due to which, if a DSO is already open, subsequently opening it with RTLD_NODELETE fails to set the DF_1_NODELETE flag. This patch fixes this by setting the flag immediately after bumping the opencount. Verified on x86_64. [BZ #18676] * elf/tst-nodelete-opened.c: New test case. * elf/tst-nodelete-opened-lib.c: New test case module. * elf/Makefile (tests, modules-names): Use them. * elf/dl-open.c (dl_open_worker): Set DF_1_NODELETE flag early.
Diffstat (limited to 'elf')
-rw-r--r--elf/Makefile6
-rw-r--r--elf/dl-open.c11
-rw-r--r--elf/tst-nodelete-opened-lib.c19
-rw-r--r--elf/tst-nodelete-opened.c67
4 files changed, 96 insertions, 7 deletions
diff --git a/elf/Makefile b/elf/Makefile
index 90d5058..4ceeaf8 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -148,7 +148,7 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
tst-unique1 tst-unique2 $(if $(CXX),tst-unique3 tst-unique4 \
tst-nodelete) \
tst-initorder tst-initorder2 tst-relsort1 tst-null-argv \
- tst-ptrguard1 tst-tlsalign tst-tlsalign-extern
+ tst-ptrguard1 tst-tlsalign tst-tlsalign-extern tst-nodelete-opened
# reldep9
ifeq ($(build-hardcoded-path-in-tests),yes)
tests += tst-dlopen-aout
@@ -218,7 +218,7 @@ 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-tlsalign-lib tst-nodelete-opened-lib
ifeq (yes,$(have-protected-data))
modules-names += tst-protected1moda tst-protected1modb
tests += tst-protected1a tst-protected1b
@@ -525,6 +525,8 @@ $(objpfx)tst-initordera4.so: $(objpfx)tst-initordera3.so
$(objpfx)tst-initorder: $(objpfx)tst-initordera4.so $(objpfx)tst-initordera1.so $(objpfx)tst-initorderb2.so
$(objpfx)tst-null-argv: $(objpfx)tst-null-argv-lib.so
$(objpfx)tst-tlsalign: $(objpfx)tst-tlsalign-lib.so
+$(objpfx)tst-nodelete-opened.out: $(objpfx)tst-nodelete-opened-lib.so
+$(objpfx)tst-nodelete-opened: $(libdl)
$(objpfx)tst-tlsalign-extern: $(objpfx)tst-tlsalign-vars.o
$(objpfx)tst-tlsalign-extern-static: $(objpfx)tst-tlsalign-vars.o
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 027c1e0..2db1c02 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -226,6 +226,12 @@ dl_open_worker (void *a)
args->map = new = _dl_map_object (call_map, file, lt_loaded, 0,
mode | __RTLD_CALLMAP, args->nsid);
+ /* Mark the object as not deletable if the RTLD_NODELETE flags was passed.
+ Do this early so that we don't skip marking the object if it was
+ already loaded. */
+ if (__glibc_unlikely (mode & RTLD_NODELETE))
+ new->l_flags_1 |= DF_1_NODELETE;
+
/* If the pointer returned is NULL this means the RTLD_NOLOAD flag is
set and the object is not already loaded. */
if (new == NULL)
@@ -564,11 +570,6 @@ TLS generation counter wrapped! Please report this."));
/* It failed. */
return;
- /* Mark the object as not deletable if the RTLD_NODELETE flags was
- passed. */
- if (__glibc_unlikely (mode & RTLD_NODELETE))
- new->l_flags_1 |= DF_1_NODELETE;
-
#ifndef SHARED
/* We must be the static _dl_open in libc.a. A static program that
has loaded a dynamic object now has competition. */
diff --git a/elf/tst-nodelete-opened-lib.c b/elf/tst-nodelete-opened-lib.c
new file mode 100644
index 0000000..994702a
--- /dev/null
+++ b/elf/tst-nodelete-opened-lib.c
@@ -0,0 +1,19 @@
+/* Verify that objects opened with RTLD_NODELETE are not unloaded - the DSO.
+ Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+int foo_var = 42;
diff --git a/elf/tst-nodelete-opened.c b/elf/tst-nodelete-opened.c
new file mode 100644
index 0000000..43b00fa
--- /dev/null
+++ b/elf/tst-nodelete-opened.c
@@ -0,0 +1,67 @@
+/* Verify that an already opened DSO opened agained with RTLD_NODELETE actually
+ sets the NODELETE flag.
+
+ Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <dlfcn.h>
+#include <stdio.h>
+
+int
+do_test (void)
+{
+ void *h1 = dlopen ("$ORIGIN/tst-nodelete-opened-lib.so", RTLD_LAZY);
+ if (h1 == NULL)
+ {
+ printf ("h1: failed to open DSO: %s\n", dlerror ());
+ return 1;
+ }
+
+ void *h2 = dlopen ("$ORIGIN/tst-nodelete-opened-lib.so",
+ RTLD_LAZY | RTLD_NODELETE);
+ if (h2 == NULL)
+ {
+ printf ("h2: failed to open DSO: %s\n", dlerror ());
+ return 1;
+ }
+
+ int *foo = dlsym (h2, "foo_var");
+ if (foo == NULL)
+ {
+ printf ("failed to load symbol foo_var: %s\n", dlerror ());
+ return 1;
+ }
+
+ if (dlclose (h1) != 0)
+ {
+ printf ("h1: dlclose failed: %s\n", dlerror ());
+ return 1;
+ }
+
+ if (dlclose (h2) != 0)
+ {
+ printf ("h2: dlclose failed: %s\n", dlerror ());
+ return 1;
+ }
+
+ printf ("foo == %d\n", *foo);
+
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"