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Re: PATCH: Check 64-bit relocation addend overflow for x32
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: binutils at sourceware dot org
- Date: Sat, 12 May 2012 05:37:41 -0700
- Subject: Re: PATCH: Check 64-bit relocation addend overflow for x32
- References: <20120510032741.GA13387@intel.com>
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
On Wed, May 09, 2012 at 08:27:41PM -0700, H.J. Lu wrote:
> Hi,
>
> 64-bit relocation addend may overflow for x32. I checked in it this
> patch to prevent it.
> diff --git a/gas/ChangeLog b/gas/ChangeLog
> index 2cc6360..3b43ecd 100644
> --- a/gas/ChangeLog
> +++ b/gas/ChangeLog
> @@ -1,3 +1,8 @@
> +2012-05-09 H.J. Lu <hongjiu.lu@intel.com>
> +
> + * config/tc-i386.c (tc_gen_reloc): Check x32 addend overflow
> + for BFD_RELOC_64.
> +
> 2012-05-08 Alan Modra <amodra@gmail.com>
>
> * Makefile.am (check_DEJAGNU): Export LC_ALL=C in place of other
> diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
> index ccf54bc..06f9764 100644
> --- a/gas/config/tc-i386.c
> +++ b/gas/config/tc-i386.c
> @@ -9173,6 +9173,17 @@ tc_gen_reloc (asection *section ATTRIBUTE_UNUSED, fixS *fixp)
> if (disallow_64bit_reloc)
> switch (code)
> {
> + case BFD_RELOC_64:
> + /* Check addend overflow. */
> + if ((long long) fixp->fx_offset > 0x7fffffffLL
> + || (long long) fixp->fx_offset < -0x80000000LL)
> + {
> + as_bad_where (fixp->fx_file, fixp->fx_line,
> + _("cannot represent relocation %s with addend %lld in x32 mode"),
> + bfd_get_reloc_code_name (code),
> + (long long) fixp->fx_offset);
> + }
> + break;
> case BFD_RELOC_X86_64_DTPOFF64:
> case BFD_RELOC_X86_64_TPOFF64:
> case BFD_RELOC_64_PCREL:
It turns out that gcc loop optimization generates code like
movabsq $xtrn - 4294967295, %rbp
and expects address wrap around. I checked in this patch to remove
x32 addend overflow for BFD_RELOC_64.
H.J.
---
diff --git a/gas/ChangeLog b/gas/ChangeLog
index 5eb6d0a..82bfc0e 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2012-05-12 H.J. Lu <hongjiu.lu@intel.com>
+
+ * config/tc-i386.c (tc_gen_reloc): Remove x32 addend overflow
+ for BFD_RELOC_64.
+
2012-05-11 Daniel Richard G. <skunk@iskunk.org>
PR binutils/14028
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index e33fb6c..ccf54bc 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -9173,25 +9173,6 @@ tc_gen_reloc (asection *section ATTRIBUTE_UNUSED, fixS *fixp)
if (disallow_64bit_reloc)
switch (code)
{
- case BFD_RELOC_64:
- /* Check addend overflow. */
- if (!fits_in_signed_long (fixp->fx_offset))
- {
- bfd_signed_vma addend = fixp->fx_offset;
- if (addend < 0)
- as_bad_where (fixp->fx_file, fixp->fx_line,
- _("cannot represent relocation %s with "
- "addend -0x%" BFD_VMA_FMT "x in x32 "
- "mode"),
- bfd_get_reloc_code_name (code), -addend);
- else
- as_bad_where (fixp->fx_file, fixp->fx_line,
- _("cannot represent relocation %s with "
- "addend 0x%" BFD_VMA_FMT "x in x32 "
- "mode"),
- bfd_get_reloc_code_name (code), addend);
- }
- break;
case BFD_RELOC_X86_64_DTPOFF64:
case BFD_RELOC_X86_64_TPOFF64:
case BFD_RELOC_64_PCREL:
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index 7559561..f1df950 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,13 @@
+2012-05-12 H.J. Lu <hongjiu.lu@intel.com>
+
+ * gas/i386/ilp32/ilp32.exp: Don't run reloc64-inval.
+
+ * gas/i386/ilp32/reloc64.s: Add test for -4294967295 addend.
+ * gas/i386/ilp32/reloc64.d: Updated.
+
+ * gas/i386/ilp32/reloc64-inval.l: Removed.
+ * gas/i386/ilp32/reloc64-inval.s: Likewise.
+
2012-05-09 H.J. Lu <hongjiu.lu@intel.com>
* gas/i386/ilp32/ilp32.exp: Run reloc64-inval.
diff --git a/gas/testsuite/gas/i386/ilp32/ilp32.exp b/gas/testsuite/gas/i386/ilp32/ilp32.exp
index 95f3a2d..de43bf2 100644
--- a/gas/testsuite/gas/i386/ilp32/ilp32.exp
+++ b/gas/testsuite/gas/i386/ilp32/ilp32.exp
@@ -26,7 +26,6 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_64_check] &&
}
run_list_test "reloc64" "--defsym _bad_=1"
- run_list_test "reloc64-inval"
set ASFLAGS "$old_ASFLAGS"
}
diff --git a/gas/testsuite/gas/i386/ilp32/reloc64-inval.l b/gas/testsuite/gas/i386/ilp32/reloc64-inval.l
deleted file mode 100644
index 1328237..0000000
--- a/gas/testsuite/gas/i386/ilp32/reloc64-inval.l
+++ /dev/null
@@ -1,3 +0,0 @@
-.*: Assembler messages:
-.*:2: Error: .*
-.*:3: Error: .*
diff --git a/gas/testsuite/gas/i386/ilp32/reloc64-inval.s b/gas/testsuite/gas/i386/ilp32/reloc64-inval.s
deleted file mode 100644
index 14134aa..0000000
--- a/gas/testsuite/gas/i386/ilp32/reloc64-inval.s
+++ /dev/null
@@ -1,3 +0,0 @@
- .data
- .quad xtrn + 0x80000000
- .quad xtrn - 0x80000001
diff --git a/gas/testsuite/gas/i386/ilp32/reloc64.d b/gas/testsuite/gas/i386/ilp32/reloc64.d
index 140f24d..c2fd292 100644
--- a/gas/testsuite/gas/i386/ilp32/reloc64.d
+++ b/gas/testsuite/gas/i386/ilp32/reloc64.d
@@ -60,6 +60,7 @@ Disassembly of section \.text:
.*[ ]+R_X86_64_TPOFF32[ ]+xtrn
.*[ ]+R_X86_64_TPOFF32[ ]+xtrn
.*[ ]+R_X86_64_TPOFF32[ ]+xtrn
+.*[ ]+R_X86_64_64[ ]+xtrn\+0x1
Disassembly of section \.data:
#...
.*[ ]+R_X86_64_32[ ]+xtrn
diff --git a/gas/testsuite/gas/i386/ilp32/reloc64.s b/gas/testsuite/gas/i386/ilp32/reloc64.s
index 3a2dbb8..4149ec2 100644
--- a/gas/testsuite/gas/i386/ilp32/reloc64.s
+++ b/gas/testsuite/gas/i386/ilp32/reloc64.s
@@ -178,6 +178,7 @@ bad .byte xtrn@tpoff
.text
mov xtrn@tpoff (%rbx), %eax
+ movabsq $xtrn - 4294967295, %rbp
.data
.quad xtrn