ARM: kprobes: introduces checker

This patch introdces 'checker' to decoding phase, and calls checkers
when instruction decoding. This allows further decoding for specific
instructions.  This patch introduces a stub call of checkers in kprobe
arch_prepare_kprobe() as an example and for further expansion.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reviewed-by: Jon Medhurst <tixy@linaro.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/arm/probes/decode-thumb.c b/arch/arm/probes/decode-thumb.c
index 2f0453a895dc..985e7dd4cac6 100644
--- a/arch/arm/probes/decode-thumb.c
+++ b/arch/arm/probes/decode-thumb.c
@@ -863,20 +863,22 @@ static void __kprobes thumb32_singlestep(probes_opcode_t opcode,
 
 enum probes_insn __kprobes
 thumb16_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
-			   bool emulate, const union decode_action *actions)
+			   bool emulate, const union decode_action *actions,
+			   const struct decode_checker *checkers[])
 {
 	asi->insn_singlestep = thumb16_singlestep;
 	asi->insn_check_cc = thumb_check_cc;
 	return probes_decode_insn(insn, asi, probes_decode_thumb16_table, true,
-				  emulate, actions);
+				  emulate, actions, checkers);
 }
 
 enum probes_insn __kprobes
 thumb32_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
-			   bool emulate, const union decode_action *actions)
+			   bool emulate, const union decode_action *actions,
+			   const struct decode_checker *checkers[])
 {
 	asi->insn_singlestep = thumb32_singlestep;
 	asi->insn_check_cc = thumb_check_cc;
 	return probes_decode_insn(insn, asi, probes_decode_thumb32_table, true,
-				  emulate, actions);
+				  emulate, actions, checkers);
 }