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-rw-r--r--arch/x86/kernel/kprobes/common.h4
-rw-r--r--arch/x86/kernel/kprobes/core.c66
-rw-r--r--arch/x86/kernel/kprobes/opt.c5
3 files changed, 36 insertions, 39 deletions
diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h
index d688826e5736..db2182d63ed0 100644
--- a/arch/x86/kernel/kprobes/common.h
+++ b/arch/x86/kernel/kprobes/common.h
@@ -67,7 +67,7 @@
#endif
/* Ensure if the instruction can be boostable */
-extern int can_boost(kprobe_opcode_t *instruction, void *addr);
+extern int can_boost(struct insn *insn, void *orig_addr);
/* Recover instruction if given address is probed */
extern unsigned long recover_probed_instruction(kprobe_opcode_t *buf,
unsigned long addr);
@@ -75,7 +75,7 @@ extern unsigned long recover_probed_instruction(kprobe_opcode_t *buf,
* Copy an instruction and adjust the displacement if the instruction
* uses the %rip-relative addressing mode.
*/
-extern int __copy_instruction(u8 *dest, u8 *src);
+extern int __copy_instruction(u8 *dest, u8 *src, struct insn *insn);
/* Generate a relative-jump/call instruction */
extern void synthesize_reljump(void *from, void *to);
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 722f54440e7e..19e1f2a6d7b0 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -164,33 +164,29 @@ static kprobe_opcode_t *skip_prefixes(kprobe_opcode_t *insn)
NOKPROBE_SYMBOL(skip_prefixes);
/*
- * Returns non-zero if opcode is boostable.
+ * Returns non-zero if INSN is boostable.
* RIP relative instructions are adjusted at copying time in 64 bits mode
*/
-int can_boost(kprobe_opcode_t *opcodes, void *addr)
+int can_boost(struct insn *insn, void *addr)
{
- struct insn insn;
kprobe_opcode_t opcode;
if (search_exception_tables((unsigned long)addr))
return 0; /* Page fault may occur on this address. */
- kernel_insn_init(&insn, (void *)opcodes, MAX_INSN_SIZE);
- insn_get_opcode(&insn);
-
/* 2nd-byte opcode */
- if (insn.opcode.nbytes == 2)
- return test_bit(insn.opcode.bytes[1],
+ if (insn->opcode.nbytes == 2)
+ return test_bit(insn->opcode.bytes[1],
(unsigned long *)twobyte_is_boostable);
- if (insn.opcode.nbytes != 1)
+ if (insn->opcode.nbytes != 1)
return 0;
/* Can't boost Address-size override prefix */
- if (unlikely(inat_is_address_size_prefix(insn.attr)))
+ if (unlikely(inat_is_address_size_prefix(insn->attr)))
return 0;
- opcode = insn.opcode.bytes[0];
+ opcode = insn->opcode.bytes[0];
switch (opcode & 0xf0) {
case 0x60:
@@ -351,35 +347,31 @@ static int is_IF_modifier(kprobe_opcode_t *insn)
* addressing mode.
* This returns the length of copied instruction, or 0 if it has an error.
*/
-int __copy_instruction(u8 *dest, u8 *src)
+int __copy_instruction(u8 *dest, u8 *src, struct insn *insn)
{
- struct insn insn;
kprobe_opcode_t buf[MAX_INSN_SIZE];
- int length;
unsigned long recovered_insn =
recover_probed_instruction(buf, (unsigned long)src);
- if (!recovered_insn)
+ if (!recovered_insn || !insn)
return 0;
- kernel_insn_init(&insn, (void *)recovered_insn, MAX_INSN_SIZE);
- insn_get_length(&insn);
- length = insn.length;
- /* Another subsystem puts a breakpoint, failed to recover */
- if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
+ /* This can access kernel text if given address is not recovered */
+ if (probe_kernel_read(dest, (void *)recovered_insn, MAX_INSN_SIZE))
return 0;
- /* This can access kernel text if given address is not recovered */
- if (kernel_probe_read(dest, insn.kaddr, length))
+ kernel_insn_init(insn, dest, MAX_INSN_SIZE);
+ insn_get_length(insn);
+
+ /* Another subsystem puts a breakpoint, failed to recover */
+ if (insn->opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
return 0;
#ifdef CONFIG_X86_64
/* Only x86_64 has RIP relative instructions */
- if (insn_rip_relative(&insn)) {
+ if (insn_rip_relative(insn)) {
s64 newdisp;
u8 *disp;
- kernel_insn_init(&insn, dest, length);
- insn_get_displacement(&insn);
/*
* The copied instruction uses the %rip-relative addressing
* mode. Adjust the displacement for the difference between
@@ -392,29 +384,32 @@ int __copy_instruction(u8 *dest, u8 *src)
* extension of the original signed 32-bit displacement would
* have given.
*/
- newdisp = (u8 *) src + (s64) insn.displacement.value - (u8 *) dest;
+ newdisp = (u8 *) src + (s64) insn->displacement.value
+ - (u8 *) dest;
if ((s64) (s32) newdisp != newdisp) {
pr_err("Kprobes error: new displacement does not fit into s32 (%llx)\n", newdisp);
- pr_err("\tSrc: %p, Dest: %p, old disp: %x\n", src, dest, insn.displacement.value);
+ pr_err("\tSrc: %p, Dest: %p, old disp: %x\n",
+ src, dest, insn->displacement.value);
return 0;
}
- disp = (u8 *) dest + insn_offset_displacement(&insn);
+ disp = (u8 *) dest + insn_offset_displacement(insn);
*(s32 *) disp = (s32) newdisp;
}
#endif
- return length;
+ return insn->length;
}
/* Prepare reljump right after instruction to boost */
-static void prepare_boost(struct kprobe *p, int length)
+static void prepare_boost(struct kprobe *p, struct insn *insn)
{
- if (can_boost(p->ainsn.insn, p->addr) &&
- MAX_INSN_SIZE - length >= RELATIVEJUMP_SIZE) {
+ if (can_boost(insn, p->addr) &&
+ MAX_INSN_SIZE - insn->length >= RELATIVEJUMP_SIZE) {
/*
* These instructions can be executed directly if it
* jumps back to correct address.
*/
- synthesize_reljump(p->ainsn.insn + length, p->addr + length);
+ synthesize_reljump(p->ainsn.insn + insn->length,
+ p->addr + insn->length);
p->ainsn.boostable = true;
} else {
p->ainsn.boostable = false;
@@ -423,12 +418,13 @@ static void prepare_boost(struct kprobe *p, int length)
static int arch_copy_kprobe(struct kprobe *p)
{
+ struct insn insn;
int len;
set_memory_rw((unsigned long)p->ainsn.insn & PAGE_MASK, 1);
/* Copy an instruction with recovering if other optprobe modifies it.*/
- len = __copy_instruction(p->ainsn.insn, p->addr);
+ len = __copy_instruction(p->ainsn.insn, p->addr, &insn);
if (!len)
return -EINVAL;
@@ -436,7 +432,7 @@ static int arch_copy_kprobe(struct kprobe *p)
* __copy_instruction can modify the displacement of the instruction,
* but it doesn't affect boostable check.
*/
- prepare_boost(p, len);
+ prepare_boost(p, &insn);
set_memory_ro((unsigned long)p->ainsn.insn & PAGE_MASK, 1);
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 5b5233441d30..9aadff3d0902 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -177,11 +177,12 @@ NOKPROBE_SYMBOL(optimized_callback);
static int copy_optimized_instructions(u8 *dest, u8 *src)
{
+ struct insn insn;
int len = 0, ret;
while (len < RELATIVEJUMP_SIZE) {
- ret = __copy_instruction(dest + len, src + len);
- if (!ret || !can_boost(dest + len, src + len))
+ ret = __copy_instruction(dest + len, src + len, &insn);
+ if (!ret || !can_boost(&insn, src + len))
return -EINVAL;
len += ret;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-08 12:36:43 +0000