ARM: kprobes: Fix emulation of SMUAD, SMUSD and SMMUL instructions

The signed multiply instructions were being decoded incorrectly.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>

1 files changed, 15 insertions, 7 deletions

diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c
index 1e413a9c17ef..068e5c846571 100644
--- a/arch/arm/kernel/kprobes-decode.c
+++ b/arch/arm/kernel/kprobes-decode.c
@@ -1436,18 +1436,26 @@ space_cccc_0111__1(kprobe_opcode_t insn, struct arch_specific_insn *asi)
                 return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, asi);
 
         /* SMLAD  : cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx :Q */
+        /* SMUAD  : cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx :Q */
         /* SMLSD  : cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx :Q */
+        /* SMUSD  : cccc 0111 0000 xxxx 1111 xxxx 01x1 xxxx :  */
         /* SMMLA  : cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx :  */
-        /* SMMLS  : cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx :  */
+        /* SMMUL  : cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx :  */
         if ((insn & 0x0ff00090) == 0x07000010 ||
-            (insn & 0x0ff000d0) == 0x07500010 ||
-            (insn & 0x0ff000d0) == 0x075000d0)
+            (insn & 0x0ff000d0) == 0x07500010) {
+
+                if ((insn & 0x0000f000) == 0x0000f000) {
+                        return prep_emulate_rd16rs8rm0_wflags(insn, asi);
+                } else {
+                        return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi);
+                }
+        }
+
+        /* SMMLS  : cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx :  */
+        if ((insn & 0x0ff000d0) == 0x075000d0)
                 return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi);
 
-        /* SMUSD  : cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx :  */
-        /* SMUAD  : cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx :Q */
-        /* SMMUL  : cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx :  */
-        return prep_emulate_rd16rs8rm0_wflags(insn, asi);
+        return INSN_REJECTED;
 }
 
 static enum kprobe_insn __kprobes