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>

diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c
index 1e413a9..068e5c8 100644 (file)
--- 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