caa65211bb
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.
49 lines
1.5 KiB
Bash
49 lines
1.5 KiB
Bash
PARSE_AND_LIST_OPTIONS_CALL_NOP='
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fprintf (file, _("\
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-z call-nop=PADDING Use PADDING as 1-byte NOP for branch\n"));
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'
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PARSE_AND_LIST_ARGS_CASE_Z_CALL_NOP='
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else if (strncmp (optarg, "call-nop=", 9) == 0)
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{
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if (strcmp (optarg + 9, "prefix-addr") == 0)
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{
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link_info.call_nop_as_suffix = FALSE;
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link_info.call_nop_byte = 0x67;
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}
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else if (strcmp (optarg + 9, "prefix-nop") == 0)
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{
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link_info.call_nop_as_suffix = FALSE;
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link_info.call_nop_byte = 0x90;
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}
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else if (strcmp (optarg + 9, "suffix-nop") == 0)
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{
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link_info.call_nop_as_suffix = TRUE;
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link_info.call_nop_byte = 0x90;
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}
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else if (strncmp (optarg + 9, "prefix-", 7) == 0)
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{
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char *end;
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link_info.call_nop_byte = strtoul (optarg + 16 , &end, 0);
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if (*end)
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einfo (_("%P%F: invalid number for -z call-nop=prefix-: %s\n"),
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optarg + 16);
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link_info.call_nop_as_suffix = FALSE;
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}
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else if (strncmp (optarg + 9, "suffix-", 7) == 0)
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{
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char *end;
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link_info.call_nop_byte = strtoul (optarg + 16, &end, 0);
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if (*end)
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einfo (_("%P%F: invalid number for -z call-nop=suffix-: %s\n"),
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optarg + 16);
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link_info.call_nop_as_suffix = TRUE;
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}
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else
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einfo (_("%P%F: unsupported option: -z %s\n"), optarg);
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}
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'
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PARSE_AND_LIST_OPTIONS="$PARSE_AND_LIST_OPTIONS $PARSE_AND_LIST_OPTIONS_CALL_NOP"
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PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_CALL_NOP"
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CALL_NOP_BYTE=0x67
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