[PATCH 12/13] x86/kprobes: Use kprobe address iterator in in copy_optimized_instructions

[Jiri Olsa]

copy_optimized_instructions() copies whole instructions until it covers
the five-byte jump. Pass the iterator's kprobe to instruction recovery
at each instruction start, avoiding a separate lookup. Other
__copy_instruction() callers retain the lookup behavior by passing NULL.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 arch/x86/kernel/kprobes/common.h | 3 ++-
 arch/x86/kernel/kprobes/core.c   | 6 +++---
 arch/x86/kernel/kprobes/opt.c    | 9 +++++++--
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h
index 062746e20c35..c04d01fe075a 100644
--- a/arch/x86/kernel/kprobes/common.h
+++ b/arch/x86/kernel/kprobes/common.h
@@ -86,7 +86,8 @@ 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, u8 *real, struct insn *insn);
+extern int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn,
+			      struct kprobe **kp);
 
 /* Generate a relative-jump/call instruction */
 extern void synthesize_reljump(void *dest, void *from, void *to);
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 4d63826f6c04..ae6611fdb19a 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -395,10 +395,10 @@ kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offse
  * instruction, displacement must be adjust by @real, not @dest.
  * This returns the length of copied instruction, or 0 if it has an error.
  */
-int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn)
+int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn, struct kprobe **kp)
 {
 	kprobe_opcode_t buf[MAX_INSN_SIZE];
-	unsigned long recovered_insn = recover_probed_instruction(buf, (unsigned long)src, NULL);
+	unsigned long recovered_insn = recover_probed_instruction(buf, (unsigned long)src, kp);
 	int ret;
 
 	if (!recovered_insn || !insn)
@@ -735,7 +735,7 @@ static int arch_copy_kprobe(struct kprobe *p)
 	int ret, len;
 
 	/* Copy an instruction with recovering if other optprobe modifies it.*/
-	len = __copy_instruction(buf, p->addr, p->ainsn.insn, &insn);
+	len = __copy_instruction(buf, p->addr, p->ainsn.insn, &insn, NULL);
 	if (!len)
 		return -EINVAL;
 
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 9f0af24155ba..058b32564ea0 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -201,14 +201,19 @@ NOKPROBE_SYMBOL(optimized_callback);
 
 static int copy_optimized_instructions(u8 *dest, u8 *src, u8 *real)
 {
+	struct kprobe_iter iter;
+	unsigned long addr;
+	struct kprobe *kp;
 	struct insn insn;
 	int len = 0, ret;
 
-	while (len < JMP32_INSN_SIZE) {
-		ret = __copy_instruction(dest + len, src + len, real + len, &insn);
+	addr = (unsigned long)src;
+	for_each_addr_kprobe(iter, kp, addr, (unsigned long)src + JMP32_INSN_SIZE - 1) {
+		ret = __copy_instruction(dest + len, src + len, real + len, &insn, &kp);
 		if (!ret || !can_boost(&insn, src + len))
 			return -EINVAL;
 		len += ret;
+		addr += ret;
 	}
 	/* Check whether the address range is reserved */
 	if (ftrace_text_reserved(src, src + len - 1) ||
-- 
2.43.0