diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2020-11-13 19:09:54 +0300 |
|---|---|---|
| committer | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-01-14 03:13:17 +0300 |
| commit | 5ed934e57e712b676ca62e1904ad672a9fa1505a (patch) | |
| tree | 648beb17a7469cda7287483554316a66bc6dcf93 /arch/x86/lib | |
| parent | 7786032e52cb02982a7154993b5d88c9c7a31ba5 (diff) | |
| download | linux-5ed934e57e712b676ca62e1904ad672a9fa1505a.tar.xz | |
x86/insn: Fix vector instruction decoding on big endian cross-compiles
Running instruction decoder posttest on an s390 host with an x86 target
with allyesconfig shows errors. Instructions used in a couple of kernel
objects could not be correctly decoded on big endian system.
insn_decoder_test: warning: objdump says 6 bytes, but insn_get_length() says 5
insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this.
insn_decoder_test: warning: ffffffff831eb4e1: 62 d1 fd 48 7f 04 24 vmovdqa64 %zmm0,(%r12)
insn_decoder_test: warning: objdump says 7 bytes, but insn_get_length() says 6
insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this.
insn_decoder_test: warning: ffffffff831eb4e8: 62 51 fd 48 7f 44 24 01 vmovdqa64 %zmm8,0x40(%r12)
insn_decoder_test: warning: objdump says 8 bytes, but insn_get_length() says 6
This is because in a few places instruction field bytes are set directly
with further usage of "value". To address that introduce and use a
insn_set_byte() helper, which correctly updates "value" on big endian
systems.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/insn.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c index 520b31fc1f1a..435630a6ec97 100644 --- a/arch/x86/lib/insn.c +++ b/arch/x86/lib/insn.c @@ -161,9 +161,9 @@ found: b = insn->prefixes.bytes[3]; for (i = 0; i < nb; i++) if (prefixes->bytes[i] == lb) - prefixes->bytes[i] = b; + insn_set_byte(prefixes, i, b); } - insn->prefixes.bytes[3] = lb; + insn_set_byte(&insn->prefixes, 3, lb); } /* Decode REX prefix */ @@ -194,13 +194,13 @@ found: if (X86_MODRM_MOD(b2) != 3) goto vex_end; } - insn->vex_prefix.bytes[0] = b; - insn->vex_prefix.bytes[1] = b2; + insn_set_byte(&insn->vex_prefix, 0, b); + insn_set_byte(&insn->vex_prefix, 1, b2); if (inat_is_evex_prefix(attr)) { b2 = peek_nbyte_next(insn_byte_t, insn, 2); - insn->vex_prefix.bytes[2] = b2; + insn_set_byte(&insn->vex_prefix, 2, b2); b2 = peek_nbyte_next(insn_byte_t, insn, 3); - insn->vex_prefix.bytes[3] = b2; + insn_set_byte(&insn->vex_prefix, 3, b2); insn->vex_prefix.nbytes = 4; insn->next_byte += 4; if (insn->x86_64 && X86_VEX_W(b2)) @@ -208,7 +208,7 @@ found: insn->opnd_bytes = 8; } else if (inat_is_vex3_prefix(attr)) { b2 = peek_nbyte_next(insn_byte_t, insn, 2); - insn->vex_prefix.bytes[2] = b2; + insn_set_byte(&insn->vex_prefix, 2, b2); insn->vex_prefix.nbytes = 3; insn->next_byte += 3; if (insn->x86_64 && X86_VEX_W(b2)) @@ -220,7 +220,7 @@ found: * Makes it easier to decode vex.W, vex.vvvv, * vex.L and vex.pp. Masking with 0x7f sets vex.W == 0. */ - insn->vex_prefix.bytes[2] = b2 & 0x7f; + insn_set_byte(&insn->vex_prefix, 2, b2 & 0x7f); insn->vex_prefix.nbytes = 2; insn->next_byte += 2; } @@ -256,7 +256,7 @@ void insn_get_opcode(struct insn *insn) /* Get first opcode */ op = get_next(insn_byte_t, insn); - opcode->bytes[0] = op; + insn_set_byte(opcode, 0, op); opcode->nbytes = 1; /* Check if there is VEX prefix or not */ |