From 02a866936de7e63ad4962ccba56c8cd05c231275 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 22 Oct 2015 04:46:51 -0700 Subject: Add R_386_GOT32X support to gas and ld This patch adds support for the R_386_GOT32X relocation proposed in https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I to gas and ld. It updates gas to generate R_386_GOT32X relocation for memory operand, foo@GOT[(%reg)]. We must encode "mov foo@GOT, %eax" with the 0x8b opcode, instead of the 0xb8 opcode, so that it can be transformed to "lea foo, %eax". With the locally defined symbol, foo, we convert mov foo@GOT[(%reg1)], %reg2 to lea foo[@GOTOFF(%reg1)], %reg2 and convert call/jmp *foo@GOT[(%reg)] to nop call foo/jmp foo nop When PIC is false, convert test %reg1, foo@GOT[(%reg2)] to test $foo, %reg1 and convert binop foo@GOT[(%reg1)], %reg2 to binop $foo, %reg2 where binop is one of adc, add, and, cmp, or, sbb, sub, xor instructions. bfd/ * elf32-i386.c: Include opcode/i386.h. (elf_howto_table): Add R_386_GOT32X. (R_386_ext2): Replace R_386_IRELATIVE with R_386_GOT32X. (elf_i386_reloc_type_lookup): Handle BFD_RELOC_386_GOT32X. (need_convert_mov_to_lea): Renamed to ... (need_convert_load): This. (elf_i386_check_relocs): Handle R_386_GOT32X. Replace need_convert_mov_to_lea with need_convert_load. (elf_i386_gc_sweep_hook): Handle R_386_GOT32X. (elf_i386_size_dynamic_sections): Likewise. (elf_i386_relocate_section): Likewise. (elf_i386_convert_mov_to_lea): Renamed to ... (elf_i386_convert_load): This. Replace need_convert_mov_to_lea with need_convert_load. Support R_386_GOT32X transformations. * reloc.c (BFD_RELOC_386_GOT32X): New. * bfd-in2.h: Regenerated. * libbfd.h: Likewise. gas/ * config/tc-i386.c (tc_i386_fix_adjustable): Handle BFD_RELOC_386_GOT32X. (tc_gen_reloc): Likewise. (match_template): Force 0x8b encoding for "mov foo@GOT, %eax". (output_disp): Check for "call/jmp *mem", "mov mem, %reg", "test %reg, mem" and "binop mem, %reg" where binop is one of adc, add, and, cmp, or, sbb, sub, xor instructions. Set fx_tcbit if the REX prefix is generated. Set fx_tcbit2 if BFD_RELOC_386_GOT32X should be generated. (i386_validate_fix): Generate BFD_RELOC_386_GOT32X if fx_tcbit2 is set. gas/testsuite/ * gas/i386/got.d: New file. * gas/i386/got.s: Likewise. * gas/i386/i386.exp: Run got. * gas/i386/localpic.d: Replace R_386_GOT32 with R_386_GOT32X. * gas/i386/mixed-mode-reloc32.d: Likewise. * gas/i386/reloc32.d: Likewise. include/elf/ * i386.h (R_386_GOT32X): New relocation. ld/testsuite/ * ld-i386/branch1.d: New file. * ld-i386/branch1.s: Likewise. * ld-i386/call1.d: Likewise. * ld-i386/call1.s: Likewise. * ld-i386/call2.d: Likewise. * ld-i386/call2.s: Likewise. * ld-i386/got1.dd: Likewise. * ld-i386/got1.out: Likewise. * ld-i386/got1a.S: Likewise. * ld-i386/got1b.c: Likewise. * ld-i386/got1c.c: Likewise. * ld-i386/got1d.S: Likewise. * ld-i386/jmp1.d: Likewise. * ld-i386/jmp1.s: Likewise. * ld-i386/jmp2.d: Likewise. * ld-i386/jmp2.s: Likewise. * ld-i386/load1.d: Likewise. * ld-i386/load1.s: Likewise. * ld-i386/load2.d: Likewise. * ld-i386/load2.s: Likewise. * ld-i386/load3.d: Likewise. * ld-i386/load3.s: Likewise. * ld-i386/load4.s: Likewise. * ld-i386/load4a.d: Likewise. * ld-i386/load4b.d: Likewise. * ld-i386/load5.s: Likewise. * ld-i386/load5a.d: Likewise. * ld-i386/load5b.d: Likewise. * ld-i386/load6.d: Likewise. * ld-i386/load6.s: Likewise. * ld-i386/i386.exp: Run branch1, call1, call2, jmp1, jmp2, load1, load2, load3, load4a, load4b, load5a, load5b and load6 tests. Run got1 test. --- include/elf/ChangeLog | 4 ++++ include/elf/i386.h | 2 ++ 2 files changed, 6 insertions(+) (limited to 'include') diff --git a/include/elf/ChangeLog b/include/elf/ChangeLog index 5e4605d..8dc601c 100644 --- a/include/elf/ChangeLog +++ b/include/elf/ChangeLog @@ -1,3 +1,7 @@ +2015-10-22 H.J. Lu + + * i386.h (R_386_GOT32X): New relocation. + 2015-10-07 Cupertino Miranda * arc-reloc.def: Macro file with definition of all relocation diff --git a/include/elf/i386.h b/include/elf/i386.h index 08c9455..dea65f4 100644 --- a/include/elf/i386.h +++ b/include/elf/i386.h @@ -66,6 +66,8 @@ START_RELOC_NUMBERS (elf_i386_reloc_type) RELOC_NUMBER (R_386_TLS_DESC_CALL,40) RELOC_NUMBER (R_386_TLS_DESC, 41) RELOC_NUMBER (R_386_IRELATIVE, 42) /* Adjust indirectly by program base */ + /* Load from 32 bit GOT entry, relaxable. */ + RELOC_NUMBER (R_386_GOT32X, 43) /* Used by Intel. */ RELOC_NUMBER (R_386_USED_BY_INTEL_200, 200) -- cgit v1.1