Befator-Inc-Firmen-Netzwerk/MINGW-packages
3
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 1 Wiki Activity

Merge pull request #8259 from lazka/binutils-reloc-backport

Browse Source 
binutils: backport fix for "relocation truncated to fit" errors
This commit is contained in:
Christoph Reiter
2021-04-01 19:55:52 +02:00
committed by GitHub
parent f02116d563 ea10978f3c
commit d0eb35f4ff
2 changed files with 195 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

189
mingw-w64-binutils/0500-fix-weak-undef-symbols-after-image-base-change.patch Normal file
View File

@@ -0,0 +1,189 @@
From 74edb473c9ecf5e2053ecf8e429ee608feafb9e1 Mon Sep 17 00:00:00 2001
From: Tamar Christina <tamar.christina@arm.com>
Date: Thu, 1 Apr 2021 17:10:38 +0100
Subject: [PATCH] PE/Windows x86_64: Fix weak undef symbols after image base
change
The change in PR19011 changed the image load address from being in the lower
32-bit address space to the higher 64-bit address space.
However when you have a weak undef symbol which stays undef at the end of
linking the linker has to resolve this (Windows loader does not support undef
symbols). As such typically these would resolve to 0.
The relocation used for these weak symbols are the normal 32-bit PC_REL call
relocs. So when doing the overflow check LD checks if the distance between the
symbol and the call is within range. However now that the load address is
> 32-bits and the symbol val is 0 this overflow check will always fail.
As such the linker gives a bogus error. This patch makes the linker not emit
the overflow failure but chooses to still let the check be performed (as it's
mid-end code).
One down side of this is that it does break the common convention that the call
be to sym at 0x0. i.e. before you'd get
401015: 74 05 je 40101c
401017: e8 e4 ef bf ff callq 0
and now you get
140001015: 74 05 je 14000101c
140001017: e8 e4 ef ff bf call 100000000
since the call is PC_REL there's no way to get the range large enough to
resolve to 0. As such I have chosen to leave it as the furthest simple range
that we can still represent.
By only ignoring the error we leave the symbol value itself to still be 0
such that the if(<symbol>) checks still work correctly.
bfd/ChangeLog:
2021-04-01 Tamar Christina <tamar.christina@arm.com>
PR ld/26659
* cofflink.c (_bfd_coff_generic_relocate_section): Ignore overflow.
ld/ChangeLog:
2021-04-01 Tamar Christina <tamar.christina@arm.com>
PR ld/26659
* testsuite/ld-pe/pe.exp: Add test.
* testsuite/ld-pe/pr26659-weak-undef-sym.d: New test.
* testsuite/ld-pe/pr26659-weak-undef-sym.s: New test.
---
bfd/ChangeLog | 5 +++
bfd/cofflink.c | 15 ++++++++
ld/ChangeLog | 7 ++++
ld/testsuite/ld-pe/pe.exp | 1 +
ld/testsuite/ld-pe/pr26659-weak-undef-sym.d | 32 +++++++++++++++++
ld/testsuite/ld-pe/pr26659-weak-undef-sym.s | 38 +++++++++++++++++++++
6 files changed, 98 insertions(+)
create mode 100644 ld/testsuite/ld-pe/pr26659-weak-undef-sym.d
create mode 100644 ld/testsuite/ld-pe/pr26659-weak-undef-sym.s
diff --git a/bfd/cofflink.c b/bfd/cofflink.c
index c6b65c761d7..dd3e8dd4bf6 100644
--- a/bfd/cofflink.c
+++ b/bfd/cofflink.c
@@ -3129,6 +3129,21 @@ _bfd_coff_generic_relocate_section (bfd *output_bfd,
return false;
case bfd_reloc_overflow:
{
+
+ /* Ignore any weak undef symbols that may have overflowed. Due to
+ PR ld/19011 the base address is now in the upper 64-bit address
+ range. This means that when _bfd_final_link_relocate calculates
+ the overlow it takes the distance between the symbol and the VMA
+ which will now always overflow as 0 - 64-bit addr > 32-bit range
+ of the relocation. This ends up creating PR ld/26659. */
+ if (val == 0
+ /* Reverse the hack where 4 is subtracted from the addend. */
+ && (addend + 4) == 0
+ && sym->n_sclass == C_NT_WEAK
+ && bfd_coff_classify_symbol (output_bfd, sym)
+ == COFF_SYMBOL_UNDEFINED)
+ break;
+
const char *name;
char buf[SYMNMLEN + 1];
diff --git a/ld/testsuite/ld-pe/pe.exp b/ld/testsuite/ld-pe/pe.exp
index b1a200180be..a536b51c3e6 100644
--- a/ld/testsuite/ld-pe/pe.exp
+++ b/ld/testsuite/ld-pe/pe.exp
@@ -81,6 +81,7 @@ run_dump_test "reloc"
run_dump_test "weakdef-1"
run_dump_test "pr19803"
+run_dump_test "pr26659-weak-undef-sym"
set pr19803_dll {
{ "PR 19803: not exporting swept symbols"
"-shared --out-implib dx.dll --gc-sections"
diff --git a/ld/testsuite/ld-pe/pr26659-weak-undef-sym.d b/ld/testsuite/ld-pe/pr26659-weak-undef-sym.d
new file mode 100644
index 00000000000..0b48994877d
--- /dev/null
+++ b/ld/testsuite/ld-pe/pr26659-weak-undef-sym.d
@@ -0,0 +1,32 @@
+#source: pr26659-weak-undef-sym.s
+#target: x86_64-*-cygwin* x86_64-*-pe x86_64-*-mingw*
+#ld: -e0
+#objdump: -d
+
+#...
+0000000140001000 <foo>:
+ 140001000: 55 push %rbp
+ 140001001: 48 89 e5 mov %rsp,%rbp
+ 140001004: 48 83 ec 20 sub \$0x20,%rsp
+ 140001008: 89 4d 10 mov %ecx,0x10\(%rbp\)
+ 14000100b: 48 8b 05 ee 0f 00 00 mov 0xfee\(%rip\),%rax # 140002000 <__data_end__>
+ 140001012: 48 85 c0 test %rax,%rax
+ 140001015: 74 05 je 14000101c <foo\+0x1c>
+ 140001017: e8 e4 ef ff bf call 100000000 <__size_of_stack_reserve__\+0xffe00000>
+ 14000101c: 48 8b 05 ed 0f 00 00 mov 0xfed\(%rip\),%rax # 140002010 <.refptr.bar2>
+ 140001023: 48 85 c0 test %rax,%rax
+ 140001026: 74 05 je 14000102d <foo\+0x2d>
+ 140001028: e8 d3 ef ff bf call 100000000 <__size_of_stack_reserve__\+0xffe00000>
+ 14000102d: 8b 45 10 mov 0x10\(%rbp\),%eax
+ 140001030: 0f af c0 imul %eax,%eax
+ 140001033: 48 83 c4 20 add \$0x20,%rsp
+ 140001037: 5d pop %rbp
+ 140001038: c3 ret
+ 140001039: 90 nop
+ 14000103a: 90 nop
+ 14000103b: 90 nop
+ 14000103c: 90 nop
+ 14000103d: 90 nop
+ 14000103e: 90 nop
+ 14000103f: 90 nop
+#pass
diff --git a/ld/testsuite/ld-pe/pr26659-weak-undef-sym.s b/ld/testsuite/ld-pe/pr26659-weak-undef-sym.s
new file mode 100644
index 00000000000..7a42759e752
--- /dev/null
+++ b/ld/testsuite/ld-pe/pr26659-weak-undef-sym.s
@@ -0,0 +1,38 @@
+ .text
+ .globl foo
+ .def foo; .scl 2; .type 32; .endef
+foo:
+ pushq %rbp
+ movq %rsp, %rbp
+ subq $32, %rsp
+ movl %ecx, 16(%rbp)
+ movq .refptr.bar1(%rip), %rax
+ testq %rax, %rax
+ je .L2
+ call bar1
+.L2:
+ movq .refptr.bar2(%rip), %rax
+ testq %rax, %rax
+ je .L3
+ call bar2
+.L3:
+ movl 16(%rbp), %eax
+ imull %eax, %eax
+ addq $32, %rsp
+ popq %rbp
+ ret
+ .weak bar2
+ .weak bar1
+ .def bar1; .scl 2; .type 32; .endef
+ .def bar2; .scl 2; .type 32; .endef
+ .section .rdata$.refptr.bar2, "dr"
+ .globl .refptr.bar2
+ .linkonce discard
+.refptr.bar2:
+ .quad bar2
+ .section .rdata$.refptr.bar1, "dr"
+ .globl .refptr.bar1
+ .linkonce discard
+.refptr.bar1:
+ .quad bar1
+
--
2.27.0

7
mingw-w64-binutils/PKGBUILD
View File

@@ -6,7 +6,7 @@ _realname=binutils
pkgbase=mingw-w64-${_realname}
pkgname=("${MINGW_PACKAGE_PREFIX}-${_realname}")
pkgver=2.36.1
pkgrel=2
pkgrel=3
pkgdesc="A set of programs to assemble and manipulate binary and object files (mingw-w64)"
arch=('any')
mingw_arch=('mingw32' 'mingw64' 'ucrt64')
@@ -21,6 +21,7 @@ source=(https://ftp.gnu.org/gnu/binutils/${_realname}-${pkgver}.tar.xz{,.sig}
0010-bfd-Increase-_bfd_coff_max_nscns-to-65279.patch
0110-binutils-mingw-gnu-print.patch
0410-windres-handle-spaces.patch
0500-fix-weak-undef-symbols-after-image-base-change.patch
2001-ld-option-to-move-default-bases-under-4GB.patch)
sha256sums=('e81d9edf373f193af428a0f256674aea62a9d74dfe93f65192d4eae030b0f3b0'
'SKIP'
@@ -28,6 +29,7 @@ sha256sums=('e81d9edf373f193af428a0f256674aea62a9d74dfe93f65192d4eae030b0f3b0'
'604e76e0f702ced493ee22aa3c1768b4776b2008a7d70ae0dd35fe5be3522141'
'ec199975c6af5586f00730b7246b1db7d956879ef569c023d998226aa7960a1f'
'8d8608dc18a697138f9e51415e0c6559a85c49b11943700a823a74fb205419e9'
'd0cd7344421054fb38339cf8b6622e4e80ecda94750ffb429b702b247a5f28ae'
'35518b99189914b4700fad7a42b3268f67b5b6f4e23ffcc6cd9ef31b7b2b7c9f')
validpgpkeys=('EAF1C276A747E9ED86210CBAC3126D3B4AE55E93'
'3A24BC1E8FB409FA9F14371813FCEF89DD9E3C4F')
@@ -55,6 +57,9 @@ prepare() {
# https://github.com/msys2/MINGW-packages/issues/7027
# https://github.com/msys2/MINGW-packages/issues/7023
apply_patch_with_msg 2001-ld-option-to-move-default-bases-under-4GB.patch
# https://sourceware.org/pipermail/binutils/2021-April/116019.html
apply_patch_with_msg 0500-fix-weak-undef-symbols-after-image-base-change.patch
}
build() {