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Merge tag 'x86-asm-2024-03-11' of git://git.kernel.org/pub/scm/linux/…
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…kernel/git/tip/tip

Pull x86 asm updates from Ingo Molnar:
 "Two changes to simplify the x86 decoder logic a bit"

* tag 'x86-asm-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/insn: Directly assign x86_64 state in insn_init()
  x86/insn: Remove superfluous checks from instruction decoding routines
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Linus Torvalds committed Mar 12, 2024
2 parents 89c572e + 07a5d4b commit 73f0d1d
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Showing 2 changed files with 44 additions and 72 deletions.
58 changes: 22 additions & 36 deletions arch/x86/lib/insn.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -71,7 +71,7 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
insn->kaddr = kaddr;
insn->end_kaddr = kaddr + buf_len;
insn->next_byte = kaddr;
insn->x86_64 = x86_64 ? 1 : 0;
insn->x86_64 = x86_64;
insn->opnd_bytes = 4;
if (x86_64)
insn->addr_bytes = 8;
Expand Down Expand Up @@ -268,11 +268,9 @@ int insn_get_opcode(struct insn *insn)
if (opcode->got)
return 0;

if (!insn->prefixes.got) {
ret = insn_get_prefixes(insn);
if (ret)
return ret;
}
ret = insn_get_prefixes(insn);
if (ret)
return ret;

/* Get first opcode */
op = get_next(insn_byte_t, insn);
Expand Down Expand Up @@ -339,11 +337,9 @@ int insn_get_modrm(struct insn *insn)
if (modrm->got)
return 0;

if (!insn->opcode.got) {
ret = insn_get_opcode(insn);
if (ret)
return ret;
}
ret = insn_get_opcode(insn);
if (ret)
return ret;

if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
Expand Down Expand Up @@ -386,11 +382,9 @@ int insn_rip_relative(struct insn *insn)
if (!insn->x86_64)
return 0;

if (!modrm->got) {
ret = insn_get_modrm(insn);
if (ret)
return 0;
}
ret = insn_get_modrm(insn);
if (ret)
return 0;
/*
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
Expand All @@ -417,11 +411,9 @@ int insn_get_sib(struct insn *insn)
if (insn->sib.got)
return 0;

if (!insn->modrm.got) {
ret = insn_get_modrm(insn);
if (ret)
return ret;
}
ret = insn_get_modrm(insn);
if (ret)
return ret;

if (insn->modrm.nbytes) {
modrm = insn->modrm.bytes[0];
Expand Down Expand Up @@ -460,11 +452,9 @@ int insn_get_displacement(struct insn *insn)
if (insn->displacement.got)
return 0;

if (!insn->sib.got) {
ret = insn_get_sib(insn);
if (ret)
return ret;
}
ret = insn_get_sib(insn);
if (ret)
return ret;

if (insn->modrm.nbytes) {
/*
Expand Down Expand Up @@ -628,11 +618,9 @@ int insn_get_immediate(struct insn *insn)
if (insn->immediate.got)
return 0;

if (!insn->displacement.got) {
ret = insn_get_displacement(insn);
if (ret)
return ret;
}
ret = insn_get_displacement(insn);
if (ret)
return ret;

if (inat_has_moffset(insn->attr)) {
if (!__get_moffset(insn))
Expand Down Expand Up @@ -703,11 +691,9 @@ int insn_get_length(struct insn *insn)
if (insn->length)
return 0;

if (!insn->immediate.got) {
ret = insn_get_immediate(insn);
if (ret)
return ret;
}
ret = insn_get_immediate(insn);
if (ret)
return ret;

insn->length = (unsigned char)((unsigned long)insn->next_byte
- (unsigned long)insn->kaddr);
Expand Down
58 changes: 22 additions & 36 deletions tools/arch/x86/lib/insn.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -71,7 +71,7 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
insn->kaddr = kaddr;
insn->end_kaddr = kaddr + buf_len;
insn->next_byte = kaddr;
insn->x86_64 = x86_64 ? 1 : 0;
insn->x86_64 = x86_64;
insn->opnd_bytes = 4;
if (x86_64)
insn->addr_bytes = 8;
Expand Down Expand Up @@ -268,11 +268,9 @@ int insn_get_opcode(struct insn *insn)
if (opcode->got)
return 0;

if (!insn->prefixes.got) {
ret = insn_get_prefixes(insn);
if (ret)
return ret;
}
ret = insn_get_prefixes(insn);
if (ret)
return ret;

/* Get first opcode */
op = get_next(insn_byte_t, insn);
Expand Down Expand Up @@ -339,11 +337,9 @@ int insn_get_modrm(struct insn *insn)
if (modrm->got)
return 0;

if (!insn->opcode.got) {
ret = insn_get_opcode(insn);
if (ret)
return ret;
}
ret = insn_get_opcode(insn);
if (ret)
return ret;

if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
Expand Down Expand Up @@ -386,11 +382,9 @@ int insn_rip_relative(struct insn *insn)
if (!insn->x86_64)
return 0;

if (!modrm->got) {
ret = insn_get_modrm(insn);
if (ret)
return 0;
}
ret = insn_get_modrm(insn);
if (ret)
return 0;
/*
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
Expand All @@ -417,11 +411,9 @@ int insn_get_sib(struct insn *insn)
if (insn->sib.got)
return 0;

if (!insn->modrm.got) {
ret = insn_get_modrm(insn);
if (ret)
return ret;
}
ret = insn_get_modrm(insn);
if (ret)
return ret;

if (insn->modrm.nbytes) {
modrm = insn->modrm.bytes[0];
Expand Down Expand Up @@ -460,11 +452,9 @@ int insn_get_displacement(struct insn *insn)
if (insn->displacement.got)
return 0;

if (!insn->sib.got) {
ret = insn_get_sib(insn);
if (ret)
return ret;
}
ret = insn_get_sib(insn);
if (ret)
return ret;

if (insn->modrm.nbytes) {
/*
Expand Down Expand Up @@ -628,11 +618,9 @@ int insn_get_immediate(struct insn *insn)
if (insn->immediate.got)
return 0;

if (!insn->displacement.got) {
ret = insn_get_displacement(insn);
if (ret)
return ret;
}
ret = insn_get_displacement(insn);
if (ret)
return ret;

if (inat_has_moffset(insn->attr)) {
if (!__get_moffset(insn))
Expand Down Expand Up @@ -703,11 +691,9 @@ int insn_get_length(struct insn *insn)
if (insn->length)
return 0;

if (!insn->immediate.got) {
ret = insn_get_immediate(insn);
if (ret)
return ret;
}
ret = insn_get_immediate(insn);
if (ret)
return ret;

insn->length = (unsigned char)((unsigned long)insn->next_byte
- (unsigned long)insn->kaddr);
Expand Down

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