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author | H.J. Lu <hjl.tools@gmail.com> | 2021-05-26 12:13:13 -0700 |
---|---|---|
committer | H.J. Lu <hjl.tools@gmail.com> | 2021-05-26 12:13:24 -0700 |
commit | 50c95a739c91ae70cf8481936611aa1f5397a384 (patch) | |
tree | f539432154713f55c321e9dbd16251eb4f51eec7 /bfd | |
parent | 11bb5c41eb98d8e7d4d75dfcf620f6f627523e77 (diff) | |
download | fsf-binutils-gdb-50c95a739c91ae70cf8481936611aa1f5397a384.zip fsf-binutils-gdb-50c95a739c91ae70cf8481936611aa1f5397a384.tar.gz fsf-binutils-gdb-50c95a739c91ae70cf8481936611aa1f5397a384.tar.bz2 |
x86: Propery check PC16 reloc overflow in 16-bit mode instructions
commit a7664973b24a242cd9ea17deb5eaf503065fc0bd
Author: Jan Beulich <jbeulich@suse.com>
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.
Diffstat (limited to 'bfd')
-rw-r--r-- | bfd/ChangeLog | 21 | ||||
-rw-r--r-- | bfd/elf32-i386.c | 23 | ||||
-rw-r--r-- | bfd/elf64-x86-64.c | 12 | ||||
-rw-r--r-- | bfd/elfxx-x86.c | 9 | ||||
-rw-r--r-- | bfd/elfxx-x86.h | 6 |
5 files changed, 64 insertions, 7 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 608ea54..82005a4 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,24 @@ +2021-05-26 H.J. Lu <hongjiu.lu@intel.com> + + 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. + 2021-05-26 Nelson Chu <nelson.chu@sifive.com> * elfxx-riscv.h (check_unknown_prefixed_ext): New bool. diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 4451f9b..c68741a 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -22,6 +22,7 @@ #include "elf-vxworks.h" #include "dwarf2.h" #include "opcode/i386.h" +#include "libiberty.h" /* 386 uses REL relocations instead of RELA. */ #define USE_REL 1 @@ -175,10 +176,14 @@ static reloc_howto_type elf_howto_table[]= false, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ - false) /* pcrel_offset */ + false), /* pcrel_offset */ #define R_386_vt (R_386_GNU_VTENTRY + 1 - R_386_vt_offset) +/* Use complain_overflow_bitfield on R_386_PC16 for code16. */ + HOWTO(R_386_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield, + bfd_elf_generic_reloc, "R_386_PC16", + true, 0xffff, 0xffff, true) }; #define X86_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32) @@ -369,7 +374,7 @@ elf_i386_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, } static reloc_howto_type * -elf_i386_rtype_to_howto (unsigned r_type) +elf_i386_rtype_to_howto (bfd *abfd, unsigned r_type) { unsigned int indx; @@ -384,6 +389,11 @@ elf_i386_rtype_to_howto (unsigned r_type) /* PR 17512: file: 0f67f69d. */ if (elf_howto_table [indx].type != r_type) return NULL; + + /* Use complain_overflow_bitfield on R_386_PC16 for code16. */ + if (r_type == (unsigned int) R_386_PC16 && elf_x86_has_code16 (abfd)) + indx = ARRAY_SIZE (elf_howto_table) - 1; + return &elf_howto_table[indx]; } @@ -394,7 +404,8 @@ elf_i386_info_to_howto_rel (bfd *abfd, { unsigned int r_type = ELF32_R_TYPE (dst->r_info); - if ((cache_ptr->howto = elf_i386_rtype_to_howto (r_type)) == NULL) + if ((cache_ptr->howto = elf_i386_rtype_to_howto (abfd, r_type)) + == NULL) { /* xgettext:c-format */ _bfd_error_handler (_("%pB: unsupported relocation type %#x"), @@ -1142,8 +1153,8 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, reloc_howto_type *from, *to; const char *name; - from = elf_i386_rtype_to_howto (from_type); - to = elf_i386_rtype_to_howto (to_type); + from = elf_i386_rtype_to_howto (abfd, from_type); + to = elf_i386_rtype_to_howto (abfd, to_type); if (h) name = h->root.root.string; @@ -2074,7 +2085,7 @@ elf_i386_relocate_section (bfd *output_bfd, continue; } - howto = elf_i386_rtype_to_howto (r_type); + howto = elf_i386_rtype_to_howto (input_bfd, r_type); if (howto == NULL) return _bfd_unrecognized_reloc (input_bfd, input_section, r_type); diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index d0c994e..d420561 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -187,6 +187,10 @@ static reloc_howto_type x86_64_elf_howto_table[] = _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", false, 0, 0, false), +/* Use complain_overflow_bitfield on R_X86_64_PC16 for code16. */ + HOWTO(R_X86_64_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield, + bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0, 0xffff, true), + /* Use complain_overflow_bitfield on R_X86_64_32 for x32. */ HOWTO(R_X86_64_32, 0, 2, 32, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_32", false, 0, 0xffffffff, @@ -270,6 +274,14 @@ elf_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type) else i = ARRAY_SIZE (x86_64_elf_howto_table) - 1; } + else if (r_type == (unsigned int) R_X86_64_PC16) + { + /* Use complain_overflow_bitfield on R_X86_64_PC16 for code16. */ + if (elf_x86_has_code16 (abfd)) + i = ARRAY_SIZE (x86_64_elf_howto_table) - 2; + else + i = r_type; + } else if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT || r_type >= (unsigned int) R_X86_64_max) { diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c index 62d516a..29dc7f0 100644 --- a/bfd/elfxx-x86.c +++ b/bfd/elfxx-x86.c @@ -2353,6 +2353,7 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type, || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI)) { + unsigned int number; if (datasz != 4) { _bfd_error_handler @@ -2361,7 +2362,13 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type, return property_corrupt; } prop = _bfd_elf_get_property (abfd, type, datasz); - prop->u.number |= bfd_h_get_32 (abfd, ptr); + number = bfd_h_get_32 (abfd, ptr); + if ((abfd->flags + & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0 + && type == GNU_PROPERTY_X86_FEATURE_2_USED + && (number & GNU_PROPERTY_X86_FEATURE_2_CODE16) != 0) + elf_x86_has_code16 (abfd) = 1; + prop->u.number |= number; prop->pr_kind = property_number; return property_number; } diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h index db11327..e834430 100644 --- a/bfd/elfxx-x86.h +++ b/bfd/elfxx-x86.h @@ -549,6 +549,9 @@ struct elf_x86_obj_tdata /* GOTPLT entries for TLS descriptors. */ bfd_vma *local_tlsdesc_gotent; + + /* Set if the objec file has 16-bit code. */ + unsigned int has_code16 : 1; }; enum elf_x86_plt_type @@ -584,6 +587,9 @@ struct elf_x86_plt #define elf_x86_local_tlsdesc_gotent(abfd) \ (elf_x86_tdata (abfd)->local_tlsdesc_gotent) +#define elf_x86_has_code16(abfd) \ + (elf_x86_tdata (abfd)->has_code16) + #define elf_x86_compute_jump_table_size(htab) \ ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size) |