From 6737a6b34f4823deb7142f27b4074831a37ac1e1 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" 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/ChangeLog | 8 ++++ bfd/elfxx-x86.c | 60 +++++++++++++++++++------- ld/ChangeLog | 24 +++++++++++ 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/ChangeLog b/bfd/ChangeLog index 1c1174a..d3831b7 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,11 @@ +2018-07-23 H.J. Lu + + 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. + 2018-07-18 Nick Clifton * development.sh: Set to true. diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c index a2497aa..2e4ff88 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/ChangeLog b/ld/ChangeLog index c07e442..cfadbd4 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,27 @@ +2018-07-23 H.J. Lu + + 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". + 2018-07-18 Nick Clifton 2.31.1 Release point. diff --git a/ld/testsuite/ld-elf/linux-x86.S b/ld/testsuite/ld-elf/linux-x86.S new file mode 100644 index 0000000..bdf40c6 --- /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 0000000..36217c6 --- /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 0000000..3631ed7 --- /dev/null +++ b/ld/testsuite/ld-elf/pr23428.c @@ -0,0 +1,43 @@ +#include +#include +#include + +#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 ("PASS\n")); + + syscall (SYS_exit, !loadnum); + return 0; +} diff --git a/ld/testsuite/ld-elf/sec64k.exp b/ld/testsuite/ld-elf/sec64k.exp index b58139e..3909c0e 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 ac9beff..aba7d6b 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 e660aca..191ee44 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 ec51540..7eba52d 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 e49079b..ea2da3e 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 b22eaa1..f89855a 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 5ff057a..6eda1d2 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 7238639..c3c4edd 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 2c26639..6b0fde0 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 1fb96d4..f87869f 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 b24b018..d99ab46 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 07d1732..2c503ff 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 6fe6abe..1162d55 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 cfbefe9..1095091 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 { -- 2.9.3