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Re: [PATCH 2/2] Add a testcase for copy reloc against protected data
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Joseph Myers <joseph at codesourcery dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>
- Date: Fri, 6 Mar 2015 11:40:59 -0800
- Subject: Re: [PATCH 2/2] Add a testcase for copy reloc against protected data
- Authentication-results: sourceware.org; auth=none
- References: <20150306002424 dot GA17971 at intel dot com> <alpine dot DEB dot 2 dot 10 dot 1503061903280 dot 24477 at digraph dot polyomino dot org dot uk>
On Fri, Mar 6, 2015 at 11:09 AM, Joseph Myers <joseph@codesourcery.com> wrote:
> On Thu, 5 Mar 2015, H.J. Lu wrote:
>
>> if test $libc_cv_visibility_attribute = yes; then
>> + AC_CACHE_CHECK(linker support for protected data symbol,
>> + libc_cv_protected_data,
>> + [cat > conftest.c <<EOF
>> + int bar __attribute__ ((visibility ("protected"))) = 1;
>> +EOF
>> + libc_cv_protected_data=no
>> + if AC_TRY_COMMAND(${CC-cc} -fPIC -shared conftest.c -o conftest.so); then
>
> Use -nostdlib -nostartfiles on all configure tests involving linking so
> that they work correctly in bootstrap configurations, unless there is a
> clear reason they cannot work with -nostdlib -nostartfiles (in which case
> there should be thorough comments about the issue).
>
>> + cat > conftest.c <<EOF
>> + extern int bar;
>> + int main (void) { return bar; }
>> +EOF
>> + if AC_TRY_COMMAND(${CC-cc} conftest.c -o conftest conftest.so); then
>
> Likewise; you may need to use -static as well (or LIBC_TRY_LINK_STATIC).
>
Done. Here is an updated patch.
> Suppose I configure / build with new binutils but a GCC version without
> your patches. What will the results be? That the tests don't build /
> run? That they build / run but fail (best avoided if possible)? In
> either case, you need clear documentation for architecture maintainers on
> what GCC versions (*not* requiring any uncommitted GCC patches) must be
> used to identify whether architecture-specific changes are needed and to
> test such changes.
>
I will submit a separate patch to address GCC issue.
--
H.J.
From ab16864ad041c68a3ae514fc1e9b62e69a037ea2 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 5 Mar 2015 11:36:35 -0800
Subject: [PATCH 2/3] Add a testcase for copy reloc against protected data
Linkers in some versions of binutils 2.25 and 2.26 don't support protected
data symbol with error messsage like:
/usr/bin/ld: copy reloc against protected `bar' is invalid
/usr/bin/ld: failed to set dynamic section sizes: Bad value
We check if linker supports copy reloc against protected data symbol to
avoid running the test if linker is broken.
[BZ #17711]
* config.make.in (have-protected-data): New.
* configure.ac: Check linker support for protected data symbol.
* configure: Regenerated.
* elf/Makefile (modules-names): Add tst-protected1moda and
tst-protected1modb if $(have-protected-data) is yes.
(tests): Add tst-protected1a and tst-protected1b if
$(have-protected-data) is yes.
($(objpfx)tst-protected1a): New.
($(objpfx)tst-protected1b): Likewise.
(tst-protected1modb.so-no-z-defs): Likewise.
* elf/tst-protected1a.c: New file.
* elf/tst-protected1b.c: Likewise.
* elf/tst-protected1mod.h: Likewise.
* elf/tst-protected1moda.c: Likewise.
* elf/tst-protected1modb.c: Likewise.
---
config.make.in | 1 +
configure | 40 +++++++++++++
configure.ac | 23 +++++++
elf/Makefile | 7 +++
elf/tst-protected1a.c | 153 +++++++++++++++++++++++++++++++++++++++++++++++
elf/tst-protected1b.c | 152 ++++++++++++++++++++++++++++++++++++++++++++++
elf/tst-protected1mod.h | 31 ++++++++++
elf/tst-protected1moda.c | 64 ++++++++++++++++++++
elf/tst-protected1modb.c | 33 ++++++++++
9 files changed, 504 insertions(+)
create mode 100644 elf/tst-protected1a.c
create mode 100644 elf/tst-protected1b.c
create mode 100644 elf/tst-protected1mod.h
create mode 100644 elf/tst-protected1moda.c
create mode 100644 elf/tst-protected1modb.c
diff --git a/config.make.in b/config.make.in
index ad4dd30..5a18dae 100644
--- a/config.make.in
+++ b/config.make.in
@@ -50,6 +50,7 @@ enable-werror = @enable_werror@
have-z-combreloc = @libc_cv_z_combreloc@
have-z-execstack = @libc_cv_z_execstack@
have-Bgroup = @libc_cv_Bgroup@
+have-protected-data = @libc_cv_protected_data@
with-fp = @with_fp@
old-glibc-headers = @old_glibc_headers@
unwind-find-fde = @libc_cv_gcc_unwind_find_fde@
diff --git a/configure b/configure
index 71cc6bb..79864b7 100755
--- a/configure
+++ b/configure
@@ -634,6 +634,7 @@ libc_cv_z_combreloc
ASFLAGS_config
libc_cv_Bgroup
libc_cv_cc_with_libunwind
+libc_cv_protected_data
BISON
INSTALL_INFO
PERL
@@ -5734,6 +5735,45 @@ $as_echo "$libc_cv_visibility_attribute" >&6; }
fi
if test $libc_cv_visibility_attribute = yes; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking linker support for protected data symbol" >&5
+$as_echo_n "checking linker support for protected data symbol... " >&6; }
+if ${libc_cv_protected_data+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.c <<EOF
+ int bar __attribute__ ((visibility ("protected"))) = 1;
+EOF
+ libc_cv_protected_data=no
+ if { ac_try='${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.c -o conftest.so'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }; then
+ cat > conftest.c <<EOF
+ extern int bar;
+ int main (void) { return bar; }
+EOF
+ if { ac_try='${CC-cc} -nostdlib -nostartfiles conftest.c -o conftest conftest.so'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }; then
+ libc_cv_protected_data=yes
+ fi
+ fi
+ rm -f conftest.*
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_protected_data" >&5
+$as_echo "$libc_cv_protected_data" >&6; }
+else
+ libc_cv_protected_data=no
+fi
+
+
+if test $libc_cv_visibility_attribute = yes; then
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for broken __attribute__((visibility()))" >&5
$as_echo_n "checking for broken __attribute__((visibility()))... " >&6; }
if ${libc_cv_broken_visibility_attribute+:} false; then :
diff --git a/configure.ac b/configure.ac
index 678c739..39f3e86 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1220,6 +1220,29 @@ EOF
fi
if test $libc_cv_visibility_attribute = yes; then
+ AC_CACHE_CHECK(linker support for protected data symbol,
+ libc_cv_protected_data,
+ [cat > conftest.c <<EOF
+ int bar __attribute__ ((visibility ("protected"))) = 1;
+EOF
+ libc_cv_protected_data=no
+ if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.c -o conftest.so); then
+ cat > conftest.c <<EOF
+ extern int bar;
+ int main (void) { return bar; }
+EOF
+ if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles conftest.c -o conftest conftest.so); then
+ libc_cv_protected_data=yes
+ fi
+ fi
+ rm -f conftest.*
+ ])
+else
+ libc_cv_protected_data=no
+fi
+AC_SUBST(libc_cv_protected_data)
+
+if test $libc_cv_visibility_attribute = yes; then
AC_CACHE_CHECK(for broken __attribute__((visibility())),
libc_cv_broken_visibility_attribute,
[cat > conftest.c <<EOF
diff --git a/elf/Makefile b/elf/Makefile
index c8af5ba..e852b5f 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -213,6 +213,13 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
tst-initorder2d \
tst-relsort1mod1 tst-relsort1mod2 tst-array2dep \
tst-array5dep tst-null-argv-lib
+ifeq (yes,$(have-protected-data))
+modules-names += tst-protected1moda tst-protected1modb
+tests += tst-protected1a tst-protected1b
+$(objpfx)tst-protected1a: $(addprefix $(objpfx),tst-protected1moda.so tst-protected1modb.so)
+$(objpfx)tst-protected1b: $(addprefix $(objpfx),tst-protected1modb.so tst-protected1moda.so)
+tst-protected1modb.so-no-z-defs = yes
+endif
ifeq (yesyes,$(have-fpie)$(build-shared))
modules-names += tst-piemod1
tests += tst-pie1 tst-pie2
diff --git a/elf/tst-protected1a.c b/elf/tst-protected1a.c
new file mode 100644
index 0000000..ec95d60
--- /dev/null
+++ b/elf/tst-protected1a.c
@@ -0,0 +1,153 @@
+/* Test the protected visibility when main is linked with moda and modb
+ in that order:
+ 1. Protected symbols, protected1 and protected2, defined in moda, are
+ used in moda.
+ 2. Symbol, protected1, defined in moda, is also used in main and modb.
+ 3. Symbol, protected2, defined in main, is used in main.
+
+ 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/>. */
+
+/* This file must be compiled as PIE to avoid copy relocation when
+ accessing protected symbols defined in shared libaries since copy
+ relocation doesn't work with protected symbols and linker in
+ binutils 2.26 enforces this rule. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tst-protected1mod.h"
+
+/* Prototype for our test function. */
+extern int do_test (void);
+
+int protected2 = -1;
+
+#define TEST_FUNCTION do_test ()
+
+/* This defines the `main' function and some more. */
+#include <test-skeleton.c>
+
+int
+do_test (void)
+{
+ int res = 0;
+
+ /* Check if we get the same address for the protected data symbol. */
+ if (&protected1 != protected1a_p ())
+ {
+ puts ("`protected1' in main and moda doesn't have same address");
+ res = 1;
+ }
+ if (&protected1 != protected1b_p ())
+ {
+ puts ("`protected1' in main and modb doesn't have same address");
+ res = 1;
+ }
+
+ /* Check if we get the right value for the protected data symbol. */
+ if (protected1 != 3)
+ {
+ puts ("`protected1' in main and moda doesn't have same value");
+ res = 1;
+ }
+
+ /* Check if we get the right value for data defined in executable. */
+ if (protected2 != -1)
+ {
+ puts ("`protected2' in main has the wrong value");
+ res = 1;
+ }
+
+ /* Check `protected1' in moda. */
+ if (!check_protected1 ())
+ {
+ puts ("`protected1' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check `protected2' in moda. */
+ if (!check_protected2 ())
+ {
+ puts ("`protected2' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Set `protected2' in moda to 30. */
+ set_protected2 (300);
+
+ /* Check `protected2' in moda. */
+ if (!check_protected2 ())
+ {
+ puts ("`protected2' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Set `protected1' in moda to 30. */
+ set_protected1a (30);
+
+ /* Check `protected1' in moda. */
+ if (!check_protected1 ())
+ {
+ puts ("`protected1' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check if we get the updated value for the protected data symbol. */
+ if (protected1 != 30)
+ {
+ puts ("`protected1' in main doesn't have the updated value");
+ res = 1;
+ }
+
+ protected2 = -300;
+
+ /* Check `protected2' in moda. */
+ if (!check_protected2 ())
+ {
+ puts ("`protected2' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check if data defined in executable is changed. */
+ if (protected2 != -300)
+ {
+ puts ("`protected2' in main is changed");
+ res = 1;
+ }
+
+ /* Set `protected1' in modb to 40. */
+ set_protected1b (40);
+ set_expected_protected1 (40);
+
+ /* Check `protected1' in moda. */
+ if (!check_protected1 ())
+ {
+ puts ("`protected1' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check if we get the updated value for the protected data symbol. */
+ if (protected1 != 40)
+ {
+ puts ("`protected1' in main doesn't have the updated value");
+ res = 1;
+ }
+
+ return res;
+}
diff --git a/elf/tst-protected1b.c b/elf/tst-protected1b.c
new file mode 100644
index 0000000..afc34f1
--- /dev/null
+++ b/elf/tst-protected1b.c
@@ -0,0 +1,152 @@
+/* Test the protected visibility when main is linked with modb and moda
+ in that order:
+ 1. Protected symbols, protected1 and protected2, defined in moda, are
+ used in moda.
+ 2. Symbol, protected1, defined in modb, is used in main and modb.
+ 3. Symbol, protected2, defined in main, is used in main.
+
+ 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/>. */
+
+/* This file must be compiled as PIE to avoid copy relocation when
+ accessing protected symbols defined in shared libaries since copy
+ relocation doesn't work with protected symbols and linker in
+ binutils 2.26 enforces this rule. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tst-protected1mod.h"
+
+/* Prototype for our test function. */
+extern int do_test (void);
+
+int protected2 = -1;
+
+#define TEST_FUNCTION do_test ()
+
+/* This defines the `main' function and some more. */
+#include <test-skeleton.c>
+
+int
+do_test (void)
+{
+ int res = 0;
+
+ /* Check if we get the same address for the protected data symbol. */
+ if (&protected1 == protected1a_p ())
+ {
+ puts ("`protected1' in main and moda has same address");
+ res = 1;
+ }
+ if (&protected1 != protected1b_p ())
+ {
+ puts ("`protected1' in main and modb doesn't have same address");
+ res = 1;
+ }
+
+ /* Check if we get the right value for the protected data symbol. */
+ if (protected1 != -3)
+ {
+ puts ("`protected1' in main and modb doesn't have same value");
+ res = 1;
+ }
+
+ /* Check if we get the right value for data defined in executable. */
+ if (protected2 != -1)
+ {
+ puts ("`protected2' in main has the wrong value");
+ res = 1;
+ }
+
+ /* Check `protected1' in moda. */
+ if (!check_protected1 ())
+ {
+ puts ("`protected1' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check `protected2' in moda. */
+ if (!check_protected2 ())
+ {
+ puts ("`protected2' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Set `protected2' in moda to 30. */
+ set_protected2 (300);
+
+ /* Check `protected2' in moda. */
+ if (!check_protected2 ())
+ {
+ puts ("`protected2' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Set `protected1' in moda to 30. */
+ set_protected1a (30);
+
+ /* Check `protected1' in moda. */
+ if (!check_protected1 ())
+ {
+ puts ("`protected1' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check if we get the same value for the protected data symbol. */
+ if (protected1 != -3)
+ {
+ puts ("`protected1' in main has the wrong value");
+ res = 1;
+ }
+
+ protected2 = -300;
+
+ /* Check `protected2' in moda. */
+ if (!check_protected2 ())
+ {
+ puts ("`protected2' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check if data defined in executable is changed. */
+ if (protected2 != -300)
+ {
+ puts ("`protected2' in main is changed");
+ res = 1;
+ }
+
+ /* Set `protected1' in modb to 40. */
+ set_protected1b (40);
+
+ /* Check `protected1' in moda. */
+ if (!check_protected1 ())
+ {
+ puts ("`protected1' in moda has the wrong value");
+ res = 1;
+ }
+
+ /* Check if we get the updated value for the protected data symbol. */
+ if (protected1 != 40)
+ {
+ puts ("`protected1' in main doesn't have the updated value");
+ res = 1;
+ }
+
+ return res;
+}
diff --git a/elf/tst-protected1mod.h b/elf/tst-protected1mod.h
new file mode 100644
index 0000000..818208a
--- /dev/null
+++ b/elf/tst-protected1mod.h
@@ -0,0 +1,31 @@
+/* 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/>. */
+
+/* Prototypes for the functions in the DSOs. */
+extern int protected1;
+extern int protected2;
+
+extern void set_protected1a (int);
+extern void set_protected1b (int);
+extern int *protected1a_p (void);
+extern int *protected1b_p (void);
+
+extern void set_expected_protected1 (int);
+extern int check_protected1 (void);
+
+extern void set_protected2 (int);
+extern int check_protected2 (void);
diff --git a/elf/tst-protected1moda.c b/elf/tst-protected1moda.c
new file mode 100644
index 0000000..1ae9e32
--- /dev/null
+++ b/elf/tst-protected1moda.c
@@ -0,0 +1,64 @@
+/* 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 "tst-protected1mod.h"
+
+int protected1 = 3;
+static int expected_protected1 = 3;
+int protected2 = 4;
+static int expected_protected2 = 4;
+
+asm (".protected protected1");
+asm (".protected protected2");
+
+void
+set_protected1a (int i)
+{
+ protected1 = i;
+ set_expected_protected1 (i);
+}
+
+void
+set_expected_protected1 (int i)
+{
+ expected_protected1 = i;
+}
+
+int *
+protected1a_p (void)
+{
+ return &protected1;
+}
+
+int
+check_protected1 (void)
+{
+ return protected1 == expected_protected1;
+}
+
+void
+set_protected2 (int i)
+{
+ protected2 = i;
+ expected_protected2 = i;
+}
+
+int
+check_protected2 (void)
+{
+ return protected2 == expected_protected2;
+}
diff --git a/elf/tst-protected1modb.c b/elf/tst-protected1modb.c
new file mode 100644
index 0000000..e98bbac
--- /dev/null
+++ b/elf/tst-protected1modb.c
@@ -0,0 +1,33 @@
+/* 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 <stdlib.h>
+#include "tst-protected1mod.h"
+
+int protected1 = -3;
+
+void
+set_protected1b (int i)
+{
+ protected1 = i;
+}
+
+int *
+protected1b_p (void)
+{
+ return &protected1;
+}
--
1.9.3