Code change:
<del> From 6737a6b34f4823deb7142f27b4074831a37ac1e1 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" <hjl.tools@gmail.com> Date: Fri, 20 Jul 2018 09:18:47 -0700 Subject: [PATCH] x86: Add a GNU_PROPERTY_X86_ISA_1_USED note if needed When -z separate-code, which is enabled by default for Linux/x86, is used to create executable, ld won't place any data in the code-only PT_LOAD segment.  If there are no data sections placed before the code-only PT_LOAD segment, the program headers won't be mapped into any PT_LOAD segment.  When the executable tries to access it (based on the program header address passed in AT_PHDR), it will lead to segfault.  This patch inserts a GNU_PROPERTY_X86_ISA_1_USED note if there may be no data sections before the text section so that the first PT_LOAD segment won't be code-only and will contain the program header. Testcases are adjusted to either pass "-z noseparate-code" to ld or discard the .note.gnu.property section.  A Linux/x86 run-time test is added. bfd/ PR ld/23428 * elfxx-x86.c (_bfd_x86_elf_link_setup_gnu_properties): If the separate code program header is needed, make sure that the first read-only PT_LOAD segment has no code by adding a GNU_PROPERTY_X86_ISA_1_USED note. ld/ PR ld/23428 * testsuite/ld-elf/linux-x86.S: New file. * testsuite/ld-elf/linux-x86.exp: Likewise. * testsuite/ld-elf/pr23428.c: Likewise. * testsuite/ld-elf/sec64k.exp: Pass "-z noseparate-code" to ld for Linux/x86 targets. * testsuite/ld-i386/abs-iamcu.d: Likewise. * testsuite/ld-i386/abs.d: Likewise. * testsuite/ld-i386/pr12718.d: Likewise. * testsuite/ld-i386/pr12921.d: Likewise. * testsuite/ld-x86-64/abs-k1om.d: Likewise. * testsuite/ld-x86-64/abs-l1om.d: Likewise. * testsuite/ld-x86-64/abs.d: Likewise. * testsuite/ld-x86-64/pr12718.d: Likewise. * testsuite/ld-x86-64/pr12921.d: Likewise. * testsuite/ld-linkonce/zeroeh.ld: Discard .note.gnu.property section. * testsuite/ld-scripts/print-memory-usage.t: Likewise. * testsuite/ld-scripts/size-2.t: Likewise. * testsuite/lib/ld-lib.exp (run_ld_link_exec_tests): Use ld to create executable if language is "asm". (cherry picked from commit 241e64e3b42cd9eba514b8e0ad2ef39a337f10a5) --- bfd/elfxx-x86.c                              | 60 ++++++++++++++----- ld/testsuite/ld-elf/linux-x86.S              | 63 ++++++++++++++++++++ ld/testsuite/ld-elf/linux-x86.exp            | 46 ++++++++++++++ ld/testsuite/ld-elf/pr23428.c                | 43 +++++++++++++ ld/testsuite/ld-elf/sec64k.exp               |  2 + ld/testsuite/ld-i386/abs-iamcu.d             |  2 +- ld/testsuite/ld-i386/abs.d                   |  2 +- ld/testsuite/ld-i386/pr12718.d               |  2 +- ld/testsuite/ld-i386/pr12921.d               |  2 +- ld/testsuite/ld-linkonce/zeroeh.ld           |  1 + ld/testsuite/ld-scripts/print-memory-usage.t |  2 + ld/testsuite/ld-scripts/size-2.t             |  1 + ld/testsuite/ld-x86-64/abs-k1om.d            |  2 +- ld/testsuite/ld-x86-64/abs-l1om.d            |  2 +- ld/testsuite/ld-x86-64/abs.d                 |  2 +- ld/testsuite/ld-x86-64/pr12718.d             |  2 +- ld/testsuite/ld-x86-64/pr12921.d             |  2 +- ld/testsuite/lib/ld-lib.exp                  |  5 +- 20 files changed, 248 insertions(+), 25 deletions(-) create mode 100644 ld/testsuite/ld-elf/linux-x86.S create mode 100644 ld/testsuite/ld-elf/linux-x86.exp create mode 100644 ld/testsuite/ld-elf/pr23428.c diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c index a2497aab86..2e4ff88f1f 100644 --- a/bfd/elfxx-x86.c +++ b/bfd/elfxx-x86.c @@ -2524,6 +2524,7 @@ _bfd_x86_elf_link_setup_gnu_properties const struct elf_backend_data *bed; unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2; unsigned int got_align; +  bfd_boolean has_text = FALSE; features = 0; if (info->ibt) @@ -2538,24 +2539,59 @@ _bfd_x86_elf_link_setup_gnu_properties if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour && bfd_count_sections (pbfd) != 0) { +	if (!has_text) +	  { +	    /* Check if there is no non-empty text section.  */ +	    sec = bfd_get_section_by_name (pbfd, ".text"); +	    if (sec != NULL && sec->size != 0) +	      has_text = TRUE; +	  } + ebfd = pbfd; if (elf_properties (pbfd) != NULL) break; } -  if (ebfd != NULL && features) +  bed = get_elf_backend_data (info->output_bfd); + +  htab = elf_x86_hash_table (info, bed->target_id); +  if (htab == NULL) +    return pbfd; + +  if (ebfd != NULL) { -      /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and -	 GNU_PROPERTY_X86_FEATURE_1_SHSTK.  */ -      prop = _bfd_elf_get_property (ebfd, -				    GNU_PROPERTY_X86_FEATURE_1_AND, -				    4); -      prop->u.number |= features; -      prop->pr_kind = property_number; +      prop = NULL; +      if (features) +	{ +	  /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and +	     GNU_PROPERTY_X86_FEATURE_1_SHSTK.  */ +	  prop = _bfd_elf_get_property (ebfd, +					GNU_PROPERTY_X86_FEATURE_1_AND, +					4); +	  prop->u.number |= features; +	  prop->pr_kind = property_number; +	} +      else if (has_text +	       && elf_properties (ebfd) == NULL +	       && elf_tdata (info->output_bfd)->o->build_id.sec == NULL +	       && !htab->elf.dynamic_sections_created +	       && !info->traditional_format +	       && (info->output_bfd->flags & D_PAGED) != 0 +	       && info->separate_code) +	{ +	  /* If the separate code program header is needed, make sure +	     that the first read-only PT_LOAD segment has no code by +	     adding a GNU_PROPERTY_X86_ISA_1_USED note.  */ +	  prop = _bfd_elf_get_property (ebfd, +					GNU_PROPERTY_X86_ISA_1_USED, +					4); +	  prop->u.number = GNU_PROPERTY_X86_ISA_1_486; +	  prop->pr_kind = property_number; +	} /* Create the GNU property note section if needed.  */ -      if (pbfd == NULL) +      if (prop != NULL && pbfd == NULL) { sec = bfd_make_section_with_flags (ebfd, NOTE_GNU_PROPERTY_SECTION_NAME, @@ -2581,12 +2617,6 @@ error_alignment: pbfd = _bfd_elf_link_setup_gnu_properties (info); -  bed = get_elf_backend_data (info->output_bfd); - -  htab = elf_x86_hash_table (info, bed->target_id); -  if (htab == NULL) -    return pbfd; - htab->r_info = init_table->r_info; htab->r_sym = init_table->r_sym; diff --git a/ld/testsuite/ld-elf/linux-x86.S b/ld/testsuite/ld-elf/linux-x86.S new file mode 100644 index 0000000000..bdf40c6e01 --- /dev/null +++ b/ld/testsuite/ld-elf/linux-x86.S @@ -0,0 +1,63 @@ +	.text +	.globl _start +	.type _start,@function +	.p2align 4 +_start: +	xorl %ebp, %ebp +#ifdef __LP64__ +	popq %rdi +	movq %rsp, %rsi +	andq  $~15, %rsp +#elif defined __x86_64__ +	mov (%rsp),%edi +	addl $4,%esp +	movl %esp, %esi +	andl  $~15, %esp +#else +	popl %esi +	movl %esp, %ecx +	andl  $~15, %esp + +	subl $8,%esp +	pushl %ecx +	pushl %esi +#endif + +	call main + +	hlt + +	.type syscall,  @function +	.globl syscall +	.p2align 4 +syscall: +#ifdef __x86_64__ +	movq %rdi, %rax		/* Syscall number -> rax.  */ +	movq %rsi, %rdi		/* shift arg1 - arg5.  */ +	movq %rdx, %rsi +	movq %rcx, %rdx +	movq %r8, %r10 +	movq %r9, %r8 +	movq 8(%rsp),%r9	/* arg6 is on the stack.  */ +	syscall			/* Do the system call.  */ +#else +	push %ebp +	push %edi +	push %esi +	push %ebx +	mov 0x2c(%esp),%ebp +	mov 0x28(%esp),%edi +	mov 0x24(%esp),%esi +	mov 0x20(%esp),%edx +	mov 0x1c(%esp),%ecx +	mov 0x18(%esp),%ebx +	mov 0x14(%esp),%eax +	int $0x80 +	pop %ebx +	pop %esi +	pop %edi +	pop %ebp +#endif +	ret			/* Return to caller.  */ +	.size syscall, .-syscall +	.section .note.GNU-stack,"",@progbits diff --git a/ld/testsuite/ld-elf/linux-x86.exp b/ld/testsuite/ld-elf/linux-x86.exp new file mode 100644 index 0000000000..36217c6fb4 --- /dev/null +++ b/ld/testsuite/ld-elf/linux-x86.exp @@ -0,0 +1,46 @@ +# Expect script for simple native Linux/x86 tests. +#   Copyright (C) 2018 Free Software Foundation, Inc. +# +# This file is part of the GNU Binutils. +# +# 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. +# + +# Test very simple native Linux/x86 programs with linux-x86.S. +if { ![isnative] || [which $CC] == 0  +     || (![istarget "i?86-*-linux*"]  +         && ![istarget "x86_64-*-linux*"]  +         && ![istarget "amd64-*-linux*"]) } { +    return +} + +# Add $PLT_CFLAGS if PLT is expected. +global PLT_CFLAGS +# Add $NOPIE_CFLAGS and $NOPIE_LDFLAGS if non-PIE is required. +global NOPIE_CFLAGS NOPIE_LDFLAGS + +run_ld_link_exec_tests [list  +    [list  +	"Run PR ld/23428 test"  +	"--no-dynamic-linker -z separate-code"  +	""  +	{ linux-x86.S pr23428.c }  +	"pr23428"  +	"pass.out"  +	"$NOPIE_CFLAGS -fno-asynchronous-unwind-tables"  +	"asm"  +    ]  +] diff --git a/ld/testsuite/ld-elf/pr23428.c b/ld/testsuite/ld-elf/pr23428.c new file mode 100644 index 0000000000..3631ed7926 --- /dev/null +++ b/ld/testsuite/ld-elf/pr23428.c @@ -0,0 +1,43 @@ +#include <unistd.h> +#include <link.h> +#include <syscall.h> + +#define STRING_COMMA_LEN(STR) (STR), (sizeof (STR) - 1) + +int +main (int argc, char **argv) +{ +  char **ev = &argv[argc + 1]; +  char **evp = ev; +  ElfW(auxv_t) *av; +  const ElfW(Phdr) *phdr = NULL; +  size_t phnum = 0; +  size_t loadnum = 0; +  int fd = STDOUT_FILENO; +  size_t i; + +  while (*evp++ != NULL) +    ; + +  av = (ElfW(auxv_t) *) evp; + +  for (; av->a_type != AT_NULL; ++av) +    switch (av->a_type) +      { +      case AT_PHDR: +	phdr = (const void *) av->a_un.a_val; +	break; +      case AT_PHNUM: +	phnum = av->a_un.a_val; +	break; +      } + +  for (i = 0; i < phnum; i++, phdr++) +    if (phdr->p_type == PT_LOAD) +      loadnum++; + +  syscall (SYS_write, fd, STRING_COMMA_LEN ("PASSn")); + +  syscall (SYS_exit, !loadnum); +  return 0; +} diff --git a/ld/testsuite/ld-elf/sec64k.exp b/ld/testsuite/ld-elf/sec64k.exp index b58139e9dd..3909c0eaa1 100644 --- a/ld/testsuite/ld-elf/sec64k.exp +++ b/ld/testsuite/ld-elf/sec64k.exp @@ -177,6 +177,8 @@ if { ![istarget "d10v-*-*"] foreach sfile $sfiles { puts $ofd "#source: $sfile" } if { [istarget spu*-*-*] } { puts $ofd "#ld: --local-store 0:0" +    } elseif { [istarget "i?86-*-linux*"] || [istarget "x86_64-*-linux*"] } { +	puts $ofd "#ld: -z noseparate-code" } else { puts $ofd "#ld:" } diff --git a/ld/testsuite/ld-i386/abs-iamcu.d b/ld/testsuite/ld-i386/abs-iamcu.d index ac9beff2e5..aba7d6b03f 100644 --- a/ld/testsuite/ld-i386/abs-iamcu.d +++ b/ld/testsuite/ld-i386/abs-iamcu.d @@ -2,7 +2,7 @@ #source: abs.s #source: zero.s #as: --32 -march=iamcu -#ld: -m elf_iamcu +#ld: -m elf_iamcu -z noseparate-code #objdump: -rs -j .text .*:     file format .* diff --git a/ld/testsuite/ld-i386/abs.d b/ld/testsuite/ld-i386/abs.d index e660aca524..191ee4456a 100644 --- a/ld/testsuite/ld-i386/abs.d +++ b/ld/testsuite/ld-i386/abs.d @@ -2,7 +2,7 @@ #as: --32 #source: abs.s #source: zero.s -#ld: -melf_i386 +#ld: -melf_i386 -z noseparate-code #objdump: -rs .*:     file format .* diff --git a/ld/testsuite/ld-i386/pr12718.d b/ld/testsuite/ld-i386/pr12718.d index ec51540a42..7eba52d95e 100644 --- a/ld/testsuite/ld-i386/pr12718.d +++ b/ld/testsuite/ld-i386/pr12718.d @@ -1,6 +1,6 @@ #name: PR ld/12718 #as: --32 -#ld: -melf_i386 +#ld: -melf_i386 -z noseparate-code #readelf: -S There are 5 section headers, starting at offset 0x[0-9a-f]+: diff --git a/ld/testsuite/ld-i386/pr12921.d b/ld/testsuite/ld-i386/pr12921.d index e49079b3c8..ea2da3eb51 100644 --- a/ld/testsuite/ld-i386/pr12921.d +++ b/ld/testsuite/ld-i386/pr12921.d @@ -1,6 +1,6 @@ #name: PR ld/12921 #as: --32 -#ld: -melf_i386 +#ld: -melf_i386 -z noseparate-code #readelf: -S --wide There are 7 section headers, starting at offset 0x[0-9a-f]+: diff --git a/ld/testsuite/ld-linkonce/zeroeh.ld b/ld/testsuite/ld-linkonce/zeroeh.ld index b22eaa12c9..f89855a08f 100644 --- a/ld/testsuite/ld-linkonce/zeroeh.ld +++ b/ld/testsuite/ld-linkonce/zeroeh.ld @@ -2,4 +2,5 @@ SECTIONS { .text 0xa00 : { *(.text); *(.gnu.linkonce.t.*) } .gcc_except_table 0x2000 : { *(.gcc_except_table) } .eh_frame 0x4000 : { *(.eh_frame) } +  /DISCARD/ : { *(.note.gnu.property) } } diff --git a/ld/testsuite/ld-scripts/print-memory-usage.t b/ld/testsuite/ld-scripts/print-memory-usage.t index 5ff057a5e3..6eda1d2dc4 100644 --- a/ld/testsuite/ld-scripts/print-memory-usage.t +++ b/ld/testsuite/ld-scripts/print-memory-usage.t @@ -11,4 +11,6 @@ SECTIONS *(.data) *(.rw) } + +  /DISCARD/ : { *(.note.gnu.property) } } diff --git a/ld/testsuite/ld-scripts/size-2.t b/ld/testsuite/ld-scripts/size-2.t index 723863995e..c3c4eddab4 100644 --- a/ld/testsuite/ld-scripts/size-2.t +++ b/ld/testsuite/ld-scripts/size-2.t @@ -18,4 +18,5 @@ SECTIONS LONG (SIZEOF (.tdata)) LONG (SIZEOF (.tbss)) } :image +  /DISCARD/ : { *(.note.gnu.property) } } diff --git a/ld/testsuite/ld-x86-64/abs-k1om.d b/ld/testsuite/ld-x86-64/abs-k1om.d index 2c26639fc0..6b0fde0eed 100644 --- a/ld/testsuite/ld-x86-64/abs-k1om.d +++ b/ld/testsuite/ld-x86-64/abs-k1om.d @@ -2,7 +2,7 @@ #source: ../ld-i386/abs.s #source: ../ld-i386/zero.s #as: --64 -march=k1om -#ld: -m elf_k1om +#ld: -m elf_k1om -z noseparate-code #objdump: -rs -j .text .*:     file format .* diff --git a/ld/testsuite/ld-x86-64/abs-l1om.d b/ld/testsuite/ld-x86-64/abs-l1om.d index 1fb96d44b7..f87869f9d0 100644 --- a/ld/testsuite/ld-x86-64/abs-l1om.d +++ b/ld/testsuite/ld-x86-64/abs-l1om.d @@ -2,7 +2,7 @@ #source: ../ld-i386/abs.s #source: ../ld-i386/zero.s #as: --64 -march=l1om -#ld: -m elf_l1om +#ld: -m elf_l1om -z noseparate-code #objdump: -rs -j .text #target: x86_64-*-linux* diff --git a/ld/testsuite/ld-x86-64/abs.d b/ld/testsuite/ld-x86-64/abs.d index b24b018639..d99ab4685d 100644 --- a/ld/testsuite/ld-x86-64/abs.d +++ b/ld/testsuite/ld-x86-64/abs.d @@ -1,7 +1,7 @@ #name: Absolute non-overflowing relocs #source: ../ld-i386/abs.s #source: ../ld-i386/zero.s -#ld: +#ld: -z noseparate-code #objdump: -rs .*:     file format .* diff --git a/ld/testsuite/ld-x86-64/pr12718.d b/ld/testsuite/ld-x86-64/pr12718.d index 07d17325d0..2c503ffbaa 100644 --- a/ld/testsuite/ld-x86-64/pr12718.d +++ b/ld/testsuite/ld-x86-64/pr12718.d @@ -1,6 +1,6 @@ #name: PR ld/12718 #as: --64 -#ld: -melf_x86_64 +#ld: -melf_x86_64 -z noseparate-code #readelf: -S --wide There are 5 section headers, starting at offset 0x[0-9a-f]+: diff --git a/ld/testsuite/ld-x86-64/pr12921.d b/ld/testsuite/ld-x86-64/pr12921.d index 6fe6abee09..1162d55818 100644 --- a/ld/testsuite/ld-x86-64/pr12921.d +++ b/ld/testsuite/ld-x86-64/pr12921.d @@ -1,6 +1,6 @@ #name: PR ld/12921 #as: --64 -#ld: -melf_x86_64 +#ld: -melf_x86_64 -z noseparate-code #readelf: -S --wide There are 7 section headers, starting at offset 0x[0-9a-f]+: diff --git a/ld/testsuite/lib/ld-lib.exp b/ld/testsuite/lib/ld-lib.exp index cfbefe9028..1095091882 100644 --- a/ld/testsuite/lib/ld-lib.exp +++ b/ld/testsuite/lib/ld-lib.exp @@ -1482,7 +1482,10 @@ proc run_ld_link_exec_tests { ldtests args } { continue } -	if { [ string match "c++" $lang ] } { +	if { [ string match "asm" $lang ] } { +	    set link_proc ld_link +	    set link_cmd $ld +	} elseif { [ string match "c++" $lang ] } { set link_proc ld_link set link_cmd $CXX } else { -- 2.20.1 </del>

Related discussion:
text: Describe the bug is currently in nixpkgs master. It was released in July 2018. was released in October 2019. It contains a few improvements and may also contains fix for some vulnerabilities: Is there a reason to keep the old version in nixpkgs, other than a lack of manpower? I'd be happy to do this work, but I just want to be sure that I was not starting a long, difficult and redundant work. I already tried a "naive" bump of the and but it does not work, mostly because most of the patchs are not valid anymore.
This was solved by cc.
Thank you for continuing this work!