Patchwork elf: Fix LD_AUDIT for modules with invalid version (BZ#24122)

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Submitter Florian Weimer
Date Jan. 25, 2019, 8:20 p.m.
Message ID <87imyczdy4.fsf@oldenburg2.str.redhat.com>
Download mbox | patch
Permalink /patch/31215/
State Committed
Headers show

Comments

Florian Weimer - Jan. 25, 2019, 8:20 p.m.
* Florian Weimer:

> * Adhemerval Zanella:
>
>>> No, the missing symbol case is covered earlier, where lookup_doit will
>>> fail.  This is really about a NULL symbol, a different error case.
>>> Maybe this is so bizarre that we should drop this check?  (You need an
>>> SHN_ABS symbol or an IFUNC resolver that returns NULL to get this.)
>>
>> I tend to agree that we should just assert as Carlos suggested.
>
> Okay, I put in an assert, but maybe I shoul even drop that.
>
>>> This doesn't say that it's ignored as an audit module.
>>
>> Maybe as original patch "\nfile=%s cannot be loaded as audit interface; ignored.\n", name);?
>
> The new patch uses this:
>
>       6066:     file=elf/tst-audit13mod1.so [1]; audit interface function la_version returned zero; ignored.
>
> It uses the l_name and l_ns, like must LD_DEBUG=files output.

And I suggest to reinstantiate the test like this.

Thanks,
Florian

From: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Subject: elf: Test for LD_AUDIT module returning zero from la_version [BZ #24122]

This includes the original test case from commit
8e889c5da3c5981c5a46a93fec02de40131ac5a6 ("elf: Fix LD_AUDIT for
modules with invalid version (BZ#24122)).

2019-01-24  Adhemerval Zanella  <adhemerval.zanella@linaro.org>

	[BZ #24122]
	* elf/Makefile (tests): Add tst-audit13.
	(modules-names): Add tst-audit13mod1.
	(tst-audit13.out, LDFLAGS-tst-audit13mod1.so, tst-audit13-ENV): New
	rule.
	* elf/tst-audit13.c: New file.
	* elf/tst-audit13mod1.c: Likewise.

Patch

diff --git a/elf/Makefile b/elf/Makefile
index 9cf5cd8dfd..c24d765730 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -187,7 +187,7 @@  tests += restest1 preloadtest loadfail multiload origtest resolvfail \
 	 tst-nodelete2 tst-audit11 tst-audit12 tst-dlsym-error tst-noload \
 	 tst-latepthread tst-tls-manydynamic tst-nodelete-dlclose \
 	 tst-debug1 tst-main1 tst-absolute-sym tst-absolute-zero tst-big-note \
-	 tst-unwind-ctor tst-unwind-main
+	 tst-unwind-ctor tst-unwind-main tst-audit13
 #	 reldep9
 tests-internal += loadtest unload unload2 circleload1 \
 	 neededtest neededtest2 neededtest3 neededtest4 \
@@ -275,7 +275,8 @@  modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
 		tst-latepthreadmod $(tst-tls-many-dynamic-modules) \
 		tst-nodelete-dlclose-dso tst-nodelete-dlclose-plugin \
 		tst-main1mod tst-libc_dlvsym-dso tst-absolute-sym-lib \
-		tst-absolute-zero-lib tst-big-note-lib tst-unwind-ctor-lib
+		tst-absolute-zero-lib tst-big-note-lib tst-unwind-ctor-lib \
+		tst-audit13mod1
 # Most modules build with _ISOMAC defined, but those filtered out
 # depend on internal headers.
 modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\
@@ -1382,6 +1383,10 @@  tst-audit12-ENV = LD_AUDIT=$(objpfx)tst-auditmod12.so
 $(objpfx)tst-audit12mod1.so: $(objpfx)tst-audit12mod2.so
 LDFLAGS-tst-audit12mod2.so = -Wl,--version-script=tst-audit12mod2.map
 
+$(objpfx)tst-audit13.out: $(objpfx)tst-audit13mod1.so
+LDFLAGS-tst-audit13mod1.so = -Wl,-z,lazy
+tst-audit13-ENV = LD_AUDIT=$(objpfx)tst-audit13mod1.so
+
 # Override -z defs, so that we can reference an undefined symbol.
 # Force lazy binding for the same reason.
 LDFLAGS-tst-latepthreadmod.so = \
diff --git a/elf/tst-audit13.c b/elf/tst-audit13.c
new file mode 100644
index 0000000000..6f587baf58
--- /dev/null
+++ b/elf/tst-audit13.c
@@ -0,0 +1,28 @@ 
+/* Check for invalid audit version (BZ#24122).
+   Copyright (C) 2019 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 <stdio.h>
+
+static int
+do_test (void)
+{
+  puts ("plt call");
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/elf/tst-audit13mod1.c b/elf/tst-audit13mod1.c
new file mode 100644
index 0000000000..cf017e235c
--- /dev/null
+++ b/elf/tst-audit13mod1.c
@@ -0,0 +1,93 @@ 
+/* Check for invalid audit version (BZ#24122).
+   Copyright (C) 2019 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 <link.h>
+#include <stdlib.h>
+
+unsigned int
+la_version (unsigned int version)
+{
+  /* The audit specification says that a version of 0 or a version
+     greater than any version supported by the dynamic loader shall
+     cause the module to be ignored.  */
+  return 0;
+}
+
+void
+la_activity (uintptr_t *cookie, unsigned int flag)
+{
+  exit (EXIT_FAILURE);
+}
+
+char *
+la_objsearch (const char *name, uintptr_t *cookie, unsigned int flag)
+{
+  exit (EXIT_FAILURE);
+}
+
+unsigned int
+la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t * cookie)
+{
+  exit (EXIT_FAILURE);
+}
+
+void
+la_preinit (uintptr_t * cookie)
+{
+  exit (EXIT_FAILURE);
+}
+
+uintptr_t
+#if __ELF_NATIVE_CLASS == 32
+la_symbind32 (Elf32_Sym *sym, unsigned int ndx, uintptr_t *refcook,
+              uintptr_t *defcook, unsigned int *flags, const char *symname)
+#else
+la_symbind64 (Elf64_Sym *sym, unsigned int ndx, uintptr_t *refcook,
+              uintptr_t *defcook, unsigned int *flags, const char *symname)
+#endif
+{
+  exit (EXIT_FAILURE);
+}
+
+unsigned int
+la_objclose (uintptr_t * cookie)
+{
+  exit (EXIT_FAILURE);
+}
+
+#include <tst-audit.h>
+#if (!defined (pltenter) || !defined (pltexit) || !defined (La_regs) \
+     || !defined (La_retval) || !defined (int_retval))
+# error "architecture specific code needed in sysdeps/CPU/tst-audit.h"
+#endif
+
+ElfW(Addr)
+pltenter (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook,
+          uintptr_t *defcook, La_regs *regs, unsigned int *flags,
+          const char *symname, long int *framesizep)
+{
+  exit (EXIT_FAILURE);
+}
+
+unsigned int
+pltexit (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook,
+         uintptr_t *defcook, const La_regs *inregs, La_retval *outregs,
+         const char *symname)
+{
+  exit (EXIT_FAILURE);
+}