2 Commits

Author	SHA1	Message	Date
H.J. Lu	caa65211bb	Add "-z call-nop=PADDING" option to ld ... The ld linker can transform indirect call to a locally defined function, foo, via its GOT slot, to either "NOP call foo" or "call foo NOP" where NOP is a 1-byte NOP padding. This patch adds a "-z call-nop=PADDING" option to x86 ld to control 1-byte NOP padding for x86 call instruction. PADDING is one of prefix-addr, prefix-nop, suffix-nop, prefix-NUMBER or suffix-NUMBER. bfd/ * elf32-i386.c (elf_i386_convert_load): Use call_nop_byte and check call_nop_as_suffix for 1-byte NOP padding to pad call. * elf64-x86-64.c (elf_x86_64_convert_load): Likewise. include/ * bfdlink.h (bfd_link_info): Add call_nop_as_suffix and call_nop_byte. ld/ * ld/ld.texinfo: Document "-z call-nop=PADDING" option. * emulparams/call_nop.sh: New file. * emulparams/elf_i386_be.sh: Source ${srcdir}/emulparams/call_nop.sh. * emulparams/elf_i386_chaos.sh: Likewise. * emulparams/elf_i386_ldso.sh: Likewise. * emulparams/elf_i386_vxworks.sh: Likewise. * emulparams/elf_iamcu.sh: Likewise. * emulparams/elf_k1om.sh: Likewise. * emulparams/elf_l1om.sh: Likewise. * emulparams/elf_x86_64.sh: Likewise. * emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Set link_info.call_nop_byte if $CALL_NOP_BYTE isn't empty. ld/testsuite/ * ld-i386/call3.s: New file. * ld-i386/call3a.d: Likewise. * ld-i386/call3b.d: Likewise. * ld-i386/call3c.d: Likewise. * ld-i386/call3d.d: Likewise. * ld-i386/call3e.d: Likewise. * ld-i386/call3f.d: Likewise. * ld-i386/call3g.d: Likewise. * ld-i386/call3h.d: Likewise. * ld-i386/load1-nacl.d: Likewise. * ld-x86-64/call1.s: Likewise. * ld-x86-64/call1a.d: Likewise. * ld-x86-64/call1b.d: Likewise. * ld-x86-64/call1c.d: Likewise. * ld-x86-64/call1d.d: Likewise. * ld-x86-64/call1e.d: Likewise. * ld-x86-64/call1f.d: Likewise. * ld-x86-64/call1g.d: Likewise. * ld-x86-64/call1h.d: Likewise. * ld-x86-64/call1i.d: Likewise. * ld-x86-64/load1a-nacl.d: Likewise. * ld-x86-64/load1b-nacl.d: Likewise. * ld-x86-64/load1c-nacl.d: Likewise. * ld-x86-64/load1d-nacl.d: Likewise.	2015-10-22 04:56:39 -07:00
H.J. Lu	02a866936d	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.	2015-10-22 04:47:07 -07:00