diff mbox

[2/2] Add a testcase for copy reloc against protected data

Message ID 20150306002424.GA17971@intel.com
State Superseded
Headers show

Commit Message

H.J. Lu March 6, 2015, 12:24 a.m. UTC
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.

Tested on x86-32 and x86-64.  OK for master?

Thanks.

H.J.
---
	[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.
---
 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

Comments

Joseph Myers March 6, 2015, 7:09 p.m. UTC | #1
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).

(Running tests may not work well in a build tree from a bootstrap build at 
present, but the principle still applies that the normal case is configure 
tests that allow for such configurations and any deviation needs 
thoroughly justifying.)

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.
diff mbox

Patch

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..a399031 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} -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} 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..910bc91 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} -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} 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;
+}