1 files changed, 12 insertions, 11 deletions

diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c
index e5bc576ba3fb..4ab83f4c47cf 100644
--- a/arch/arm/kernel/kprobes-decode.c
+++ b/arch/arm/kernel/kprobes-decode.c
@@ -451,6 +451,14 @@ static void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs)
                 regs->ARM_cpsr |= PSR_T_BIT;
 }
 
+static void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs)
+{
+        kprobe_opcode_t insn = p->opcode;
+        int rd = (insn >> 12) & 0xf;
+        unsigned long mask = 0xf8ff03df; /* Mask out execution state */
+        regs->uregs[rd] = regs->ARM_cpsr & mask;
+}
+
 static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs)
 {
         kprobe_opcode_t insn = p->opcode;
@@ -896,15 +904,6 @@ prep_emulate_rd12rm0(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 }
 
 static enum kprobe_insn __kprobes
-prep_emulate_rd12(kprobe_opcode_t insn, struct arch_specific_insn *asi)
-{
-        insn &= 0xffff0fff;     /* Rd = r0 */
-        asi->insn[0] = insn;
-        asi->insn_handler = emulate_rd12;
-        return INSN_GOOD;
-}
-
-static enum kprobe_insn __kprobes
 prep_emulate_rd12rn16rm0_wflags(kprobe_opcode_t insn,
                                 struct arch_specific_insn *asi)
 {
@@ -1035,8 +1034,10 @@ space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi)
                         return INSN_REJECTED;
 
                 /* MRS cpsr : cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */
-                if ((insn & 0x0ff000f0) == 0x01000000)
-                        return prep_emulate_rd12(insn, asi);
+                if ((insn & 0x0ff000f0) == 0x01000000) {
+                        asi->insn_handler = simulate_mrs;
+                        return INSN_GOOD_NO_SLOT;
+                }
 
                 /* SMLALxy : cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */
                 if ((insn & 0x0ff00090) == 0x01400080)