This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCHv5][PING^3][BZ #17833] _dl_close_worker() does not release inconsistent objects.
- From: Pavel Kopyl <p dot kopyl at samsung dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>, Yury Gribov <y dot gribov at samsung dot com>, Carlos O'Donell <carlos at redhat dot com>, Roland McGrath <roland at hack dot frob dot com>, Viacheslav Garbuzov <v dot garbuzov at samsung dot com>
- Date: Fri, 03 Jul 2015 01:53:44 +0300
- Subject: Re: [PATCHv5][PING^3][BZ #17833] _dl_close_worker() does not release inconsistent objects.
- Authentication-results: sourceware.org; auth=none
- References: <54BD4F65 dot 2090108 at samsung dot com> <54BEF851 dot 70902 at redhat dot com> <54DBC3CB dot 5080703 at samsung dot com> <54F071DB dot 9040106 at samsung dot com> <20150301191710 dot GB19363 at vapier> <54F57B52 dot 6080202 at samsung dot com> <553A1BEE dot 6070705 at samsung dot com> <CAMe9rOqiyuyNAtJDZGbfs+0kk0j16-Vowp5f0z_x2zfsd76fMQ at mail dot gmail dot com> <5553382F dot 3020906 at samsung dot com> <5565B5E5 dot 7060101 at samsung dot com> <CAMe9rOr8yDpnHtRFbL3M56Sx5FWX-FVqEstnwsgtW6H+khvziQ at mail dot gmail dot com> <5565C2A8 dot 60306 at samsung dot com> <CAMe9rOq++pD-ugdYFEte49v8TLZEM505J+=WzPTOT_Lo-MdDHQ at mail dot gmail dot com> <5565C862 dot 1040003 at samsung dot com> <CAMe9rOo7TStj3SX8OK8s3H3G=2Pyr1WKTW=R-=SzVFBWY8PF0A at mail dot gmail dot com> <5566395A dot 3090605 at samsung dot com> <CAMe9rOp4Jrz4AE3-C5VmJ0PLmxoST3phyEQt3t59ag6UGbimBw at mail dot gmail dot com> <5567892C dot 4070004 at samsung dot com> <5568A408 dot 2080903 at samsung dot com> <5592AB91 dot 2050709 at samsung dot com> <CAMe9rOoK64VuNfgZ-8_BTqes0tJcpc55atKw1k6ewBTwFzuGKg at mail dot gmail dot com>
On 06/30/2015 06:12 PM, H.J. Lu wrote:
On Tue, Jun 30, 2015 at 7:45 AM, Pavel Kopyl <p.kopyl@samsung.com> wrote:
This patch changes DF_1_NODELETE path. Do we have a testcase for
sucessfully loading/unloading DF_1_NODELETE DSO with undefined
symbols?
It may have been asked before. Can we reset unique symbols
in _dl_open before calling _dl_close_worker?
Yes, I added testcases for three possible ways where we can get
DF_1_NODELETE:
1. Unique symbols
2. Load with RTLD_NODELETE flag.
3. Link with '-z nodelete' option
>Can we reset unique symbols in _dl_open before calling _dl_close_worker?
But I clear unique symbols exactly in
_dl_close_worker.<https://slovari.yandex.ru/exactly/en-ru>
commit eebadd0f414fe6aa5163a184ddae35c57a5fa454
Author: Pavel Kopyl <p.kopyl@samsung.com>
Date: Fri May 29 20:15:33 2015 +0300
2015-05-29 Pavel Kopyl <p.kopyl@samsung.com>
Mikhail Ilin <m.ilin@samsung.com>
[BZ #17833]
* elf/Makefile: Add build test commands.
* elf/dl-close.c (_dl_close_worker): Implement force object deletion.
* elf/dl-open.c (_dl_open): Forced _dl_close_worker call.
(_dl_close): Default _dl_close_worker call.
* elf/tst-nodelete.cc: Test executable. New file.
* elf/tst-nodeletelib.cc: Test library. New file.
* elf/tst-znodeletelib.cc: Likewise.
* include/dlfcn.h (_dl_close_worker): Add new parameter.
diff --git a/elf/Makefile b/elf/Makefile
index dedf3c7..a46eaff 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -131,7 +131,7 @@ tests += $(tests-static)
ifeq (yes,$(build-shared))
tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
constload1 order noload filter unload \
- reldep reldep2 reldep3 reldep4 nodelete nodelete2 \
+ reldep reldep2 reldep3 reldep4 nodelete nodelete2 tst-nodelete \
nodlopen nodlopen2 neededtest neededtest2 \
neededtest3 neededtest4 unload2 lateglobal initfirst global \
restest2 next dblload dblunload reldep5 reldep6 reldep7 reldep8 \
@@ -205,7 +205,9 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
tst-unique1mod1 tst-unique1mod2 \
tst-unique2mod1 tst-unique2mod2 \
tst-auditmod9a tst-auditmod9b \
- $(if $(CXX),tst-unique3lib tst-unique3lib2 tst-unique4lib) \
+ $(if $(CXX),tst-unique3lib tst-unique3lib2 tst-unique4lib \
+ tst-nodelete-uniquemod) \
+ tst-nodelete-rtldmod tst-nodelete-zmod \
tst-initordera1 tst-initorderb1 \
tst-initordera2 tst-initorderb2 \
tst-initordera3 tst-initordera4 \
@@ -592,6 +594,9 @@ ifuncmod5.so-no-z-defs = yes
ifuncmod6.so-no-z-defs = yes
tst-auditmod9a.so-no-z-defs = yes
tst-auditmod9b.so-no-z-defs = yes
+tst-nodelete-uniquemod.so-no-z-defs = yes
+tst-nodelete-rtldmod.so-no-z-defs = yes
+tst-nodelete-zmod.so-no-z-defs = yes
ifeq ($(build-shared),yes)
# Build all the modules even when not actually running test programs.
@@ -1154,6 +1159,13 @@ $(objpfx)tst-unique3.out: $(objpfx)tst-unique3lib2.so
$(objpfx)tst-unique4: $(objpfx)tst-unique4lib.so
+$(objpfx)tst-nodelete: $(libdl)
+$(objpfx)tst-nodelete.out: $(objpfx)tst-nodelete-uniquemod.so \
+ $(objpfx)tst-nodelete-rtldmod.so \
+ $(objpfx)tst-nodelete-zmod.so
+
+LDFLAGS-tst-nodelete = -rdynamic
+LDFLAGS-tst-nodelete-zmod.so = -Wl,--enable-new-dtags,-z,nodelete
$(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 412f71d..0595675 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -108,7 +108,7 @@ remove_slotinfo (size_t idx, struct dtv_slotinfo_list *listp, size_t disp,
void
-_dl_close_worker (struct link_map *map)
+_dl_close_worker (struct link_map *map, bool force)
{
/* One less direct use. */
--map->l_direct_opencount;
@@ -152,6 +152,10 @@ _dl_close_worker (struct link_map *map)
l->l_idx = idx;
maps[idx] = l;
++idx;
+
+ /* clear DF_1_NODELETE to force object deletion. */
+ if (force)
+ l->l_flags_1 &= ~DF_1_NODELETE;
}
assert (idx == nloaded);
@@ -635,6 +639,31 @@ _dl_close_worker (struct link_map *map)
}
}
+ /* Reset unique symbols if forced. */
+ if (force)
+ {
+ struct unique_sym_table *tab = &ns->_ns_unique_sym_table;
+ __rtld_lock_lock_recursive (tab->lock);
+ struct unique_sym *entries = tab->entries;
+ if (entries != NULL)
+ {
+ size_t idx, size = tab->size;
+ for (idx = 0; idx < size; ++idx)
+ {
+ /* Clear unique symbol entries
+ that belong to this object. */
+ if (entries[idx].name != NULL
+ && entries[idx].map == imap)
+ {
+ entries[idx].name = NULL;
+ entries[idx].hashval = 0;
+ tab->n_elements--;
+ }
+ }
+ }
+ __rtld_lock_unlock_recursive (tab->lock);
+ }
+
/* We can unmap all the maps at once. We determined the
start address and length when we loaded the object and
the `munmap' call does the rest. */
@@ -782,7 +811,7 @@ _dl_close (void *_map)
/* Acquire the lock. */
__rtld_lock_lock_recursive (GL(dl_load_lock));
- _dl_close_worker (map);
+ _dl_close_worker (map, false);
__rtld_lock_unlock_recursive (GL(dl_load_lock));
}
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 2d0e082..027c1e0 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -670,7 +670,7 @@ no more namespaces available for dlmopen()"));
if ((mode & __RTLD_AUDIT) == 0)
GL(dl_tls_dtv_gaps) = true;
- _dl_close_worker (args.map);
+ _dl_close_worker (args.map, true);
}
assert (_dl_debug_initialize (0, args.nsid)->r_state == RT_CONSISTENT);
diff --git a/elf/tst-nodelete-rtldmod.cc b/elf/tst-nodelete-rtldmod.cc
new file mode 100644
index 0000000..740e1d8
--- /dev/null
+++ b/elf/tst-nodelete-rtldmod.cc
@@ -0,0 +1,6 @@
+extern int not_exist (void);
+
+int foo (void)
+{
+ return not_exist ();
+}
diff --git a/elf/tst-nodelete-uniquemod.cc b/elf/tst-nodelete-uniquemod.cc
new file mode 100644
index 0000000..632b303
--- /dev/null
+++ b/elf/tst-nodelete-uniquemod.cc
@@ -0,0 +1,14 @@
+extern int not_exist (void);
+
+inline int make_unique (void)
+{
+ /* Static variables in inline functions and classes
+ generate STB_GNU_UNIQUE symbols. */
+ static int unique;
+ return ++unique;
+}
+
+int foo (void)
+{
+ return make_unique () + not_exist ();
+}
diff --git a/elf/tst-nodelete-zmod.cc b/elf/tst-nodelete-zmod.cc
new file mode 100644
index 0000000..740e1d8
--- /dev/null
+++ b/elf/tst-nodelete-zmod.cc
@@ -0,0 +1,6 @@
+extern int not_exist (void);
+
+int foo (void)
+{
+ return not_exist ();
+}
diff --git a/elf/tst-nodelete.cc b/elf/tst-nodelete.cc
new file mode 100644
index 0000000..176cb68
--- /dev/null
+++ b/elf/tst-nodelete.cc
@@ -0,0 +1,51 @@
+#include "../dlfcn/dlfcn.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+static int
+do_test (void)
+{
+ int result = 0;
+
+ /* This is a test for correct handling of dlopen failures for library that
+ is loaded with RTLD_NODELETE flag. The first dlopen should fail because
+ of undefined symbols in shared library. The second dlopen then verifies
+ that library was properly unloaded. */
+ if (dlopen ("tst-nodelete-rtldmod.so", RTLD_NOW | RTLD_NODELETE) != NULL
+ || dlopen ("tst-nodelete-rtldmod.so", RTLD_LAZY | RTLD_NOLOAD) != NULL)
+ {
+ printf ("RTLD_NODELETE test failed\n");
+ result = 1;
+ }
+
+ /* This is a test for correct handling of dlopen failures for library that
+ is linked with '-z nodelete' option and hence has DF_1_NODELETE flag.
+ The first dlopen should fail because of undefined symbols in shared
+ library. The second dlopen then verifies that library was properly
+ unloaded. */
+ if (dlopen ("tst-nodelete-zmod.so", RTLD_NOW) != NULL
+ || dlopen ("tst-nodelete-zmod.so", RTLD_LAZY | RTLD_NOLOAD) != NULL)
+ {
+ printf ("-z nodelete test failed\n");
+ result = 1;
+ }
+
+ /* This is a test for correct handling of dlopen failures for library
+ with unique symbols. The first dlopen should fail because of undefined
+ symbols in shared library. The second dlopen then verifies that library
+ was properly unloaded. */
+ if (dlopen ("tst-nodelete-uniquemod.so", RTLD_NOW) != NULL
+ || dlopen ("tst-nodelete-uniquemod.so", RTLD_LAZY | RTLD_NOLOAD) != NULL)
+ {
+ printf ("Unique symbols test failed\n");
+ result = 1;
+ }
+
+ 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-znodelete-zlib.cc
new file mode 100644
index 0000000..1e8f368
--- /dev/null
+++ b/elf/tst-znodelete-zlib.cc
@@ -0,0 +1,6 @@
+extern int not_exist (void);
+
+int foo (void)
+{
+ return not_exist ();
+}
diff --git a/include/dlfcn.h b/include/dlfcn.h
index a67b2e3..0ce0af5 100644
--- a/include/dlfcn.h
+++ b/include/dlfcn.h
@@ -54,7 +54,8 @@ struct link_map;
extern void _dl_close (void *map) attribute_hidden;
/* Same as above, but without locking and safety checks for user
provided map arguments. */
-extern void _dl_close_worker (struct link_map *map) attribute_hidden;
+extern void _dl_close_worker (struct link_map *map, bool force)
+ attribute_hidden;
/* Look up NAME in shared object HANDLE (which may be RTLD_DEFAULT or
RTLD_NEXT). WHO is the calling function, for RTLD_NEXT. Returns