[PATCH v2 01/14] x86: Add insn_decode_kernel()

From: Peter Zijlstra
Date: Thu Mar 18 2021 - 13:24:36 EST


Add a helper to decode kernel instructions; there's no point in
endlessly repeating those last two arguments.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/x86/include/asm/insn.h | 2 ++
arch/x86/kernel/alternative.c | 2 +-
arch/x86/kernel/cpu/mce/severity.c | 2 +-
arch/x86/kernel/kprobes/core.c | 4 ++--
arch/x86/kernel/kprobes/opt.c | 2 +-
arch/x86/kernel/traps.c | 2 +-
tools/arch/x86/include/asm/insn.h | 4 +++-
7 files changed, 11 insertions(+), 7 deletions(-)

--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -150,6 +150,8 @@ enum insn_mode {

extern int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m);

+#define insn_decode_kernel(_insn, _ptr) insn_decode((_insn), (_ptr), MAX_INSN_SIZE, INSN_MODE_KERN)
+
/* Attribute will be determined after getting ModRM (for opcode groups) */
static inline void insn_get_attribute(struct insn *insn)
{
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -1160,7 +1160,7 @@ static void text_poke_loc_init(struct te
if (!emulate)
emulate = opcode;

- ret = insn_decode(&insn, emulate, MAX_INSN_SIZE, INSN_MODE_KERN);
+ ret = insn_decode_kernel(&insn, emulate);

BUG_ON(ret < 0);
BUG_ON(len != insn.length);
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -225,7 +225,7 @@ static bool is_copy_from_user(struct pt_
if (copy_from_kernel_nofault(insn_buf, (void *)regs->ip, MAX_INSN_SIZE))
return false;

- ret = insn_decode(&insn, insn_buf, MAX_INSN_SIZE, INSN_MODE_KERN);
+ ret = insn_decode_kernel(&insn, insn_buf);
if (ret < 0)
return false;

--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -279,7 +279,7 @@ static int can_probe(unsigned long paddr
if (!__addr)
return 0;

- ret = insn_decode(&insn, (void *)__addr, MAX_INSN_SIZE, INSN_MODE_KERN);
+ ret = insn_decode_kernel(&insn, (void *)__addr);
if (ret < 0)
return 0;

@@ -316,7 +316,7 @@ int __copy_instruction(u8 *dest, u8 *src
MAX_INSN_SIZE))
return 0;

- ret = insn_decode(insn, dest, MAX_INSN_SIZE, INSN_MODE_KERN);
+ ret = insn_decode_kernel(insn, dest);
if (ret < 0)
return 0;

--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -324,7 +324,7 @@ static int can_optimize(unsigned long pa
if (!recovered_insn)
return 0;

- ret = insn_decode(&insn, (void *)recovered_insn, MAX_INSN_SIZE, INSN_MODE_KERN);
+ ret = insn_decode_kernel(&insn, (void *)recovered_insn);
if (ret < 0)
return 0;

--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -504,7 +504,7 @@ static enum kernel_gp_hint get_kernel_gp
MAX_INSN_SIZE))
return GP_NO_HINT;

- ret = insn_decode(&insn, insn_buf, MAX_INSN_SIZE, INSN_MODE_KERN);
+ ret = insn_decode_kernel(&insn, insn_buf);
if (ret < 0)
return GP_NO_HINT;

--- a/tools/arch/x86/include/asm/insn.h
+++ b/tools/arch/x86/include/asm/insn.h
@@ -150,6 +150,8 @@ enum insn_mode {

extern int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m);

+#define insn_decode_kernel(_insn, _ptr) insn_decode((_insn), (_ptr), MAX_INSN_SIZE, INSN_MODE_KERN)
+
/* Attribute will be determined after getting ModRM (for opcode groups) */
static inline void insn_get_attribute(struct insn *insn)
{