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[binutils-gdb] Fix overflow checking for 32-bit pc-relative relocations on x32.
- From: Cary Coutant <ccoutant at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 6 Feb 2016 22:47:23 -0000
- Subject: [binutils-gdb] Fix overflow checking for 32-bit pc-relative relocations on x32.
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=19ef3f4d2eaac10e98c7ba3f9eace8609ab5278e
commit 19ef3f4d2eaac10e98c7ba3f9eace8609ab5278e
Author: Cary Coutant <ccoutant@gmail.com>
Date: Sat Feb 6 14:47:05 2016 -0800
Fix overflow checking for 32-bit pc-relative relocations on x32.
The problem here is that x32 is really using 64-bit addressing,
while pretending to be 32-bit. Even though the object file format
is 32-bit, we need to do the overflow checking with 64-bit
arithmetic (because that's what the hardware will be using).
This patch overrides the pcrela32_check functions in reloc.h
with target-specific versions that do 64-bit checking.
I've also updated the test case to use -Tdata instead of adding
a huge .space directive, to reduce the size of the .o files.
gold/
PR gold/19567
* reloc.h (Relocate_functions::Overflow_check): Add comments.
* x86_64.cc (X86_64_relocate_functions): New class.
(Target_x86_64::Relocate::relocate): Use the new class.
* testsuite/Makefile.am (x86_64_overflow_pc32): Add -Tdata option.
(x32_overflow_pc32): New test case.
* testsuite/Makefile.in: Regenerate.
* testsuite/x32_overflow_pc32.sh: New script.
* testsuite/x86_64_overflow_pc32.s: Remove .space directive.
Diff:
---
gold/ChangeLog | 12 +++++++
gold/reloc.h | 5 +++
gold/testsuite/Makefile.am | 20 ++++++++++--
gold/testsuite/Makefile.in | 27 +++++++++++++---
gold/testsuite/x32_overflow_pc32.sh | 42 +++++++++++++++++++++++++
gold/testsuite/x86_64_overflow_pc32.s | 1 -
gold/x86_64.cc | 59 ++++++++++++++++++++++++++++++-----
7 files changed, 151 insertions(+), 15 deletions(-)
diff --git a/gold/ChangeLog b/gold/ChangeLog
index a8184fc..628547e 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,5 +1,17 @@
2016-02-06 Cary Coutant <ccoutant@gmail.com>
+ PR gold/19567
+ * reloc.h (Relocate_functions::Overflow_check): Add comments.
+ * x86_64.cc (X86_64_relocate_functions): New class.
+ (Target_x86_64::Relocate::relocate): Use the new class.
+ * testsuite/Makefile.am (x86_64_overflow_pc32): Add -Tdata option.
+ (x32_overflow_pc32): New test case.
+ * testsuite/Makefile.in: Regenerate.
+ * testsuite/x32_overflow_pc32.sh: New script.
+ * testsuite/x86_64_overflow_pc32.s: Remove .space directive.
+
+2016-02-06 Cary Coutant <ccoutant@gmail.com>
+
PR gold/19577
* reloc.h (Bits::has_unsigned_overflow32): Fix static_cast.
(Bits::has_unsigned_overflow): Remove unnecessary static_cast.
diff --git a/gold/reloc.h b/gold/reloc.h
index 9c09c7c..72f6c46 100644
--- a/gold/reloc.h
+++ b/gold/reloc.h
@@ -336,9 +336,14 @@ class Relocate_functions
enum Overflow_check
{
+ // No overflow checking.
CHECK_NONE,
+ // Check for overflow of a signed value.
CHECK_SIGNED,
+ // Check for overflow of an unsigned value.
CHECK_UNSIGNED,
+ // Check for overflow of a signed or unsigned value.
+ // (i.e., no error if either signed or unsigned fits.)
CHECK_SIGNED_OR_UNSIGNED
};
diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index 81f3464..ca24205 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -1080,14 +1080,30 @@ MOSTLYCLEANFILES += x86_64_overflow_pc32.err
x86_64_overflow_pc32.o: x86_64_overflow_pc32.s
$(TEST_AS) -o $@ $<
x86_64_overflow_pc32.err: x86_64_overflow_pc32.o gcctestdir/ld
- @echo $(CXXLINK) -Bgcctestdir/ -shared -o x86_64_overflow_pc32 x86_64_overflow_pc32.o "2>$@"
- @if $(CXXLINK) -Bgcctestdir/ -shared -o x86_64_overflow_pc32 x86_64_overflow_pc32.o 2>$@; \
+ @echo gcctestdir/ld -e bar -Tdata=0x81000000 -o x86_64_overflow_pc32 x86_64_overflow_pc32.o "2>$@"
+ @if gcctestdir/ld -e bar -Tdata=0x81000000 -o x86_64_overflow_pc32 x86_64_overflow_pc32.o 2>$@; \
then \
echo 1>&2 "Link of x86_64_overflow_pc32 should have failed"; \
rm -f $@; \
exit 1; \
fi
+check_SCRIPTS += x32_overflow_pc32.sh
+check_DATA += x32_overflow_pc32.err
+MOSTLYCLEANFILES += x32_overflow_pc32.err
+x86_64_overflow_pc32.o: x86_64_overflow_pc32.s
+ $(TEST_AS) -o $@ $<
+x32_overflow_pc32.o: x86_64_overflow_pc32.s
+ $(TEST_AS) --x32 -o $@ $<
+x32_overflow_pc32.err: x32_overflow_pc32.o gcctestdir/ld
+ @echo gcctestdir/ld -e bar -Tdata=0x81000000 -o x32_overflow_pc32 x32_overflow_pc32.o "2>$@"
+ @if gcctestdir/ld -e bar -Tdata=0x81000000 -o x32_overflow_pc32 x32_overflow_pc32.o 2>$@; \
+ then \
+ echo 1>&2 "Link of x32_overflow_pc32 should have failed"; \
+ rm -f $@; \
+ exit 1; \
+ fi
+
endif DEFAULT_TARGET_X86_64
if DEFAULT_TARGET_I386
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 49f3683..253493f 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -200,7 +200,8 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
@GCC_TRUE@@HAVE_STATIC_TRUE@@NATIVE_LINKER_TRUE@@STATIC_TLS_TRUE@@TLS_TRUE@ tls_static_pic_test
@FN_PTRS_IN_SO_WITHOUT_PIC_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_TRUE@am__append_25 = tls_shared_nonpic_test
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_26 = x86_64_mov_to_lea.sh \
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_overflow_pc32.sh
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_overflow_pc32.sh \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x32_overflow_pc32.sh
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_27 = x86_64_mov_to_lea1.stdout \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea2.stdout \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea3.stdout \
@@ -215,7 +216,8 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea12.stdout \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea13.stdout \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea14.stdout \
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_overflow_pc32.err
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_overflow_pc32.err \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x32_overflow_pc32.err
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_28 = x86_64_mov_to_lea1 \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea2 \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea3 \
@@ -230,7 +232,8 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea12 \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea13 \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_mov_to_lea14 \
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_overflow_pc32.err
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x86_64_overflow_pc32.err \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ x32_overflow_pc32.err
@DEFAULT_TARGET_I386_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_29 = i386_mov_to_lea.sh
@DEFAULT_TARGET_I386_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_30 = i386_mov_to_lea1.stdout i386_mov_to_lea2.stdout \
@DEFAULT_TARGET_I386_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ i386_mov_to_lea3.stdout i386_mov_to_lea4.stdout \
@@ -4445,6 +4448,8 @@ x86_64_mov_to_lea.sh.log: x86_64_mov_to_lea.sh
@p='x86_64_mov_to_lea.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
x86_64_overflow_pc32.sh.log: x86_64_overflow_pc32.sh
@p='x86_64_overflow_pc32.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
+x32_overflow_pc32.sh.log: x32_overflow_pc32.sh
+ @p='x32_overflow_pc32.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
i386_mov_to_lea.sh.log: i386_mov_to_lea.sh
@p='i386_mov_to_lea.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
debug_msg.sh.log: debug_msg.sh
@@ -5491,13 +5496,25 @@ uninstall-am:
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@x86_64_overflow_pc32.o: x86_64_overflow_pc32.s
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_AS) -o $@ $<
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@x86_64_overflow_pc32.err: x86_64_overflow_pc32.o gcctestdir/ld
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ @echo $(CXXLINK) -Bgcctestdir/ -shared -o x86_64_overflow_pc32 x86_64_overflow_pc32.o "2>$@"
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ @if $(CXXLINK) -Bgcctestdir/ -shared -o x86_64_overflow_pc32 x86_64_overflow_pc32.o 2>$@; \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ @echo gcctestdir/ld -e bar -Tdata=0x81000000 -o x86_64_overflow_pc32 x86_64_overflow_pc32.o "2>$@"
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ @if gcctestdir/ld -e bar -Tdata=0x81000000 -o x86_64_overflow_pc32 x86_64_overflow_pc32.o 2>$@; \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ then \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ echo 1>&2 "Link of x86_64_overflow_pc32 should have failed"; \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ rm -f $@; \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ exit 1; \
@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ fi
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@x86_64_overflow_pc32.o: x86_64_overflow_pc32.s
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_AS) -o $@ $<
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@x32_overflow_pc32.o: x86_64_overflow_pc32.s
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_AS) --x32 -o $@ $<
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@x32_overflow_pc32.err: x32_overflow_pc32.o gcctestdir/ld
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ @echo gcctestdir/ld -e bar -Tdata=0x81000000 -o x32_overflow_pc32 x32_overflow_pc32.o "2>$@"
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ @if gcctestdir/ld -e bar -Tdata=0x81000000 -o x32_overflow_pc32 x32_overflow_pc32.o 2>$@; \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ then \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ echo 1>&2 "Link of x32_overflow_pc32 should have failed"; \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ rm -f $@; \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ exit 1; \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ fi
@DEFAULT_TARGET_I386_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@i386_mov_to_lea1.o: i386_mov_to_lea1.s
@DEFAULT_TARGET_I386_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_AS) --32 -o $@ $<
diff --git a/gold/testsuite/x32_overflow_pc32.sh b/gold/testsuite/x32_overflow_pc32.sh
new file mode 100755
index 0000000..3a5bcba
--- /dev/null
+++ b/gold/testsuite/x32_overflow_pc32.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+
+# x86_64_overflow_pc32.sh -- a test case for overflow checking.
+
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# Written by Cary Coutant <ccoutant@gmail.com>.
+
+# This file is part of gold.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# This program 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 General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+# MA 02110-1301, USA.
+
+check()
+{
+ if ! grep -q "$2" "$1"
+ then
+ echo "Did not find expected error in $1:"
+ echo " $2"
+ echo ""
+ echo "Actual error output below:"
+ cat "$1"
+ exit 1
+ fi
+}
+
+# We don't know how the compiler might order these variables, so we
+# can't test for the actual offset from .data, hence the regexp.
+check x86_64_overflow_pc32.err "function bar: error: relocation overflow"
+
+exit 0
diff --git a/gold/testsuite/x86_64_overflow_pc32.s b/gold/testsuite/x86_64_overflow_pc32.s
index 7494c53..85d9e82 100644
--- a/gold/testsuite/x86_64_overflow_pc32.s
+++ b/gold/testsuite/x86_64_overflow_pc32.s
@@ -1,5 +1,4 @@
.data
- .space 0x8ff00000
.hidden foo
.globl foo
foo:
diff --git a/gold/x86_64.cc b/gold/x86_64.cc
index 82bb658..494b312 100644
--- a/gold/x86_64.cc
+++ b/gold/x86_64.cc
@@ -3347,6 +3347,52 @@ Target_x86_64<size>::do_finalize_sections(
}
}
+// For x32, we need to handle PC-relative relocations using full 64-bit
+// arithmetic, so that we can detect relocation overflows properly.
+// This class overrides the pcrela32_check methods from the defaults in
+// Relocate_functions in reloc.h.
+
+template<int size>
+class X86_64_relocate_functions : public Relocate_functions<size, false>
+{
+ public:
+ typedef Relocate_functions<size, false> Base;
+
+ // Do a simple PC relative relocation with the addend in the
+ // relocation.
+ static inline typename Base::Reloc_status
+ pcrela32_check(unsigned char* view,
+ typename elfcpp::Elf_types<64>::Elf_Addr value,
+ typename elfcpp::Elf_types<64>::Elf_Swxword addend,
+ typename elfcpp::Elf_types<64>::Elf_Addr address)
+ {
+ typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ value = value + addend - address;
+ elfcpp::Swap<32, false>::writeval(wv, value);
+ return (Bits<32>::has_overflow(value)
+ ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
+ }
+
+ // Do a simple PC relative relocation with a Symbol_value with the
+ // addend in the relocation.
+ static inline typename Base::Reloc_status
+ pcrela32_check(unsigned char* view,
+ const Sized_relobj_file<size, false>* object,
+ const Symbol_value<size>* psymval,
+ typename elfcpp::Elf_types<64>::Elf_Swxword addend,
+ typename elfcpp::Elf_types<64>::Elf_Addr address)
+ {
+ typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ typename elfcpp::Elf_types<64>::Elf_Addr value =
+ psymval->value(object, addend) - address;
+ elfcpp::Swap<32, false>::writeval(wv, value);
+ return (Bits<32>::has_overflow(value)
+ ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
+ }
+};
+
// Perform a relocation.
template<int size>
@@ -3364,7 +3410,7 @@ Target_x86_64<size>::Relocate::relocate(
typename elfcpp::Elf_types<size>::Elf_Addr address,
section_size_type view_size)
{
- typedef Relocate_functions<size, false> Reloc_funcs;
+ typedef X86_64_relocate_functions<size> Reloc_funcs;
const elfcpp::Rela<size, false> rela(preloc);
unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
@@ -3476,7 +3522,7 @@ Target_x86_64<size>::Relocate::relocate(
case elfcpp::R_X86_64_PC32:
case elfcpp::R_X86_64_PC32_BND:
rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
- address, Reloc_funcs::CHECK_SIGNED);
+ address);
break;
case elfcpp::R_X86_64_16:
@@ -3507,7 +3553,7 @@ Target_x86_64<size>::Relocate::relocate(
// behaves differently because psymval was set to point to
// the PLT entry, rather than the symbol, in Scan::global().
rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
- address, Reloc_funcs::CHECK_SIGNED);
+ address);
break;
case elfcpp::R_X86_64_PLTOFF64:
@@ -3532,7 +3578,7 @@ Target_x86_64<size>::Relocate::relocate(
gold_assert(gsym);
typename elfcpp::Elf_types<size>::Elf_Addr value;
value = target->got_plt_section()->address();
- Reloc_funcs::pcrela32(view, value, addend, address);
+ Reloc_funcs::pcrela32_check(view, value, addend, address);
}
break;
@@ -3577,8 +3623,7 @@ Target_x86_64<size>::Relocate::relocate(
&& Target_x86_64<size>::can_convert_mov_to_lea(gsym))))
{
view[-2] = 0x8d;
- Reloc_funcs::pcrela32(view, object, psymval, addend,
- address);
+ Reloc_funcs::pcrela32(view, object, psymval, addend, address);
}
else
{
@@ -3596,7 +3641,7 @@ Target_x86_64<size>::Relocate::relocate(
}
typename elfcpp::Elf_types<size>::Elf_Addr value;
value = target->got_plt_section()->address() + got_offset;
- Reloc_funcs::pcrela32(view, value, addend, address);
+ Reloc_funcs::pcrela32_check(view, value, addend, address);
}
}
break;