From 50c95a739c91ae70cf8481936611aa1f5397a384 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 26 May 2021 12:13:13 -0700 Subject: x86: Propery check PC16 reloc overflow in 16-bit mode instructions commit a7664973b24a242cd9ea17deb5eaf503065fc0bd Author: Jan Beulich Date: Mon Apr 26 10:41:35 2021 +0200 x86: correct overflow checking for 16-bit PC-relative relocs caused linker failure when building 16-bit program in a 32-bit ELF container. Update GNU_PROPERTY_X86_FEATURE_2_USED with #define GNU_PROPERTY_X86_FEATURE_2_CODE16 (1U << 12) to indicate that 16-bit mode instructions are used in the input object: https://groups.google.com/g/x86-64-abi/c/UvvXWeHIGMA to indicate that 16-bit mode instructions are used in the object to allow linker to properly perform relocation overflow check for 16-bit PC-relative relocations in 16-bit mode instructions. 1. Update x86 assembler to always generate the GNU property note with GNU_PROPERTY_X86_FEATURE_2_CODE16 for .code16 in ELF object. 2. Update i386 and x86-64 linkers to use 16-bit PC16 relocations if input object is marked with GNU_PROPERTY_X86_FEATURE_2_CODE16. bfd/ PR ld/27905 * elf32-i386.c: Include "libiberty.h". (elf_howto_table): Add 16-bit R_386_PC16 entry. (elf_i386_rtype_to_howto): Add a BFD argument. Use 16-bit R_386_PC16 if input has 16-bit mode instructions. (elf_i386_info_to_howto_rel): Update elf_i386_rtype_to_howto call. (elf_i386_tls_transition): Likewise. (elf_i386_relocate_section): Likewise. * elf64-x86-64.c (x86_64_elf_howto_table): Add 16-bit R_X86_64_PC16 entry. (elf_x86_64_rtype_to_howto): Use 16-bit R_X86_64_PC16 if input has 16-bit mode instructions. * elfxx-x86.c (_bfd_x86_elf_parse_gnu_properties): Set elf_x86_has_code16 if relocatable input is marked with GNU_PROPERTY_X86_FEATURE_2_CODE16. * elfxx-x86.h (elf_x86_obj_tdata): Add has_code16. (elf_x86_has_code16): New. binutils/ PR ld/27905 * readelf.c (decode_x86_feature_2): Support GNU_PROPERTY_X86_FEATURE_2_CODE16. gas/ PR ld/27905 * config/tc-i386.c (set_code_flag): Update x86_feature_2_used with GNU_PROPERTY_X86_FEATURE_2_CODE16 for .code16 in ELF object. (set_16bit_gcc_code_flag): Likewise. (x86_cleanup): Always generate the GNU property note if x86_feature_2_used isn't 0. * testsuite/gas/i386/code16-2.d: New file. * testsuite/gas/i386/code16-2.s: Likewise. * testsuite/gas/i386/x86-64-code16-2.d: Likewise. * testsuite/gas/i386/i386.exp: Run code16-2 and x86-64-code16-2. include/ PR ld/27905 * elf/common.h (GNU_PROPERTY_X86_FEATURE_2_CODE16): New. ld/ PR ld/27905 * testsuite/ld-i386/code16.d: New file. * testsuite/ld-i386/code16.t: Likewise. * testsuite/ld-x86-64/code16.d: Likewise. * testsuite/ld-x86-64/code16.t: Likewise. * testsuite/ld-i386/i386.exp: Run code16. * testsuite/ld-x86-64/x86-64.exp: Likewise. --- ld/ChangeLog | 10 ++++++++++ ld/testsuite/ld-i386/code16.d | 19 +++++++++++++++++++ ld/testsuite/ld-i386/code16.t | 7 +++++++ ld/testsuite/ld-i386/i386.exp | 1 + ld/testsuite/ld-x86-64/code16.d | 19 +++++++++++++++++++ ld/testsuite/ld-x86-64/code16.t | 7 +++++++ ld/testsuite/ld-x86-64/x86-64.exp | 1 + 7 files changed, 64 insertions(+) create mode 100644 ld/testsuite/ld-i386/code16.d create mode 100644 ld/testsuite/ld-i386/code16.t create mode 100644 ld/testsuite/ld-x86-64/code16.d create mode 100644 ld/testsuite/ld-x86-64/code16.t (limited to 'ld') diff --git a/ld/ChangeLog b/ld/ChangeLog index fca75bd..8d25dd87 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,5 +1,15 @@ 2021-05-26 H.J. Lu + PR ld/27905 + * testsuite/ld-i386/code16.d: New file. + * testsuite/ld-i386/code16.t: Likewise. + * testsuite/ld-x86-64/code16.d: Likewise. + * testsuite/ld-x86-64/code16.t: Likewise. + * testsuite/ld-i386/i386.exp: Run code16. + * testsuite/ld-x86-64/x86-64.exp: Likewise. + +2021-05-26 H.J. Lu + * testsuite/ld-x86-64/ilp32-12.d: New file. * testsuite/ld-x86-64/ilp32-12.s: Likewise. * testsuite/ld-x86-64/x86-64.exp: Run ilp32-12. diff --git a/ld/testsuite/ld-i386/code16.d b/ld/testsuite/ld-i386/code16.d new file mode 100644 index 0000000..8b67861 --- /dev/null +++ b/ld/testsuite/ld-i386/code16.d @@ -0,0 +1,19 @@ +#name: i386 R_386_PC16 reloc in 16-bit mode +#as: --32 -mx86-used-note=no --generate-missing-build-notes=no +#source: ${srcdir}/../../../gas/testsuite/gas/i386/code16-2.s +#ld: -T code16.t +#objdump: -dw -Mi8086 + +.*: +file format .* + + +Disassembly of section .text.default_process_op.isra.0: + +0+737c : + +[a-f0-9]+: 66 c3 retl + +Disassembly of section .text.mpt_scsi_process_op: + +0+f869 : + +[a-f0-9]+: e9 10 7b jmp 737c +#pass diff --git a/ld/testsuite/ld-i386/code16.t b/ld/testsuite/ld-i386/code16.t new file mode 100644 index 0000000..0cf9904 --- /dev/null +++ b/ld/testsuite/ld-i386/code16.t @@ -0,0 +1,7 @@ +OUTPUT_FORMAT("elf32-i386") +OUTPUT_ARCH("i386") +SECTIONS +{ +.text.default_process_op.isra.0 0x737c : { *(.text.default_process_op.isra.0) } +.text.mpt_scsi_process_op 0xf869 : { *(.text.mpt_scsi_process_op) } +} diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp index d0b3f69..3d6047b 100644 --- a/ld/testsuite/ld-i386/i386.exp +++ b/ld/testsuite/ld-i386/i386.exp @@ -492,6 +492,7 @@ run_dump_test "property-x86-isa2" run_dump_test "property-x86-isa3" run_dump_test "property-x86-isa4" run_dump_test "pr26869" +run_dump_test "code16" if { !([istarget "i?86-*-linux*"] || [istarget "i?86-*-gnu*"] diff --git a/ld/testsuite/ld-x86-64/code16.d b/ld/testsuite/ld-x86-64/code16.d new file mode 100644 index 0000000..20096ab --- /dev/null +++ b/ld/testsuite/ld-x86-64/code16.d @@ -0,0 +1,19 @@ +#name: x86-64 R_X86_64_PC16 reloc in 16-bit mode +#as: --64 -mx86-used-note=no --generate-missing-build-notes=no +#source: ${srcdir}/../../../gas/testsuite/gas/i386/code16-2.s +#ld: -T code16.t +#objdump: -dw -Mi8086 + +.*: +file format .* + + +Disassembly of section .text.default_process_op.isra.0: + +0+737c : + +[a-f0-9]+: 66 c3 retl + +Disassembly of section .text.mpt_scsi_process_op: + +0+f869 : + +[a-f0-9]+: e9 10 7b jmp 737c +#pass diff --git a/ld/testsuite/ld-x86-64/code16.t b/ld/testsuite/ld-x86-64/code16.t new file mode 100644 index 0000000..9ef00a3 --- /dev/null +++ b/ld/testsuite/ld-x86-64/code16.t @@ -0,0 +1,7 @@ +OUTPUT_FORMAT("elf64-x86-64") +OUTPUT_ARCH("i386:x86-64") +SECTIONS +{ +.text.default_process_op.isra.0 0x737c : { *(.text.default_process_op.isra.0) } +.text.mpt_scsi_process_op 0xf869 : { *(.text.mpt_scsi_process_op) } +} diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp index 37cf998..8071666 100644 --- a/ld/testsuite/ld-x86-64/x86-64.exp +++ b/ld/testsuite/ld-x86-64/x86-64.exp @@ -474,6 +474,7 @@ run_dump_test "property-x86-isa3" run_dump_test "property-x86-isa3-x32" run_dump_test "property-x86-isa4" run_dump_test "property-x86-isa4-x32" +run_dump_test "code16" if ![istarget "x86_64-*-linux*"] { return -- cgit v1.1