First patch removes some duplicated checks in caller/callee second one is
trivial to remove a check in init_ins()
Nikolay Borisov (2):
x86/insn: Remove superfluous checks from instruction decoding routines
x86/insn: Directly assign x86_64 state in init_ins
arch/x86/lib/insn.c | 58 +++++++++++++++------------------------
tools/arch/x86/lib/insn.c | 58 +++++++++++++++------------------------
2 files changed, 44 insertions(+), 72 deletions(-)
--
2.34.1
It's pointless checking if a particular part of an instruction is
decoded before calling the routine responsible for decoding it as this
check is duplicated in the routines itself. Streamline the code by
removing the superfluous checks. No functional difference.
Signed-off-by: Nikolay Borisov <[email protected]>
---
arch/x86/lib/insn.c | 56 +++++++++++++++------------------------
tools/arch/x86/lib/insn.c | 56 +++++++++++++++------------------------
2 files changed, 42 insertions(+), 70 deletions(-)
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 55e371cc69fd..3946bdc75087 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -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);
@@ -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);
@@ -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.
@@ -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];
@@ -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) {
/*
@@ -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))
@@ -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);
diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c
index 8fd63a067308..5d81924478d9 100644
--- a/tools/arch/x86/lib/insn.c
+++ b/tools/arch/x86/lib/insn.c
@@ -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);
@@ -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);
@@ -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.
@@ -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];
@@ -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) {
/*
@@ -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))
@@ -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);
--
2.34.1
The following commit has been merged into the x86/asm branch of tip:
Commit-ID: 427e1646f1ef6c714a5bade30ca0302edc5d46a0
Gitweb: https://git.kernel.org/tip/427e1646f1ef6c714a5bade30ca0302edc5d46a0
Author: Nikolay Borisov <[email protected]>
AuthorDate: Thu, 22 Feb 2024 13:16:35 +02:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Thu, 22 Feb 2024 12:23:04 +01:00
x86/insn: Remove superfluous checks from instruction decoding routines
It's pointless checking if a particular part of an instruction is
decoded before calling the routine responsible for decoding it as this
check is duplicated in the routines itself. Streamline the code by
removing the superfluous checks. No functional difference.
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/lib/insn.c | 56 ++++++++++++++------------------------
tools/arch/x86/lib/insn.c | 56 ++++++++++++++------------------------
2 files changed, 42 insertions(+), 70 deletions(-)
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 55e371c..3946bdc 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -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);
@@ -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);
@@ -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.
@@ -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];
@@ -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) {
/*
@@ -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))
@@ -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);
diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c
index 8fd63a0..5d81924 100644
--- a/tools/arch/x86/lib/insn.c
+++ b/tools/arch/x86/lib/insn.c
@@ -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);
@@ -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);
@@ -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.
@@ -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];
@@ -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) {
/*
@@ -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))
@@ -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);