ARM: kprobes: Decode 32-bit Thumb memory hint instructions

We'll treat the preload instructions as nops as they are just
performance hints.

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

1 files changed, 33 insertions, 0 deletions

diff --git a/arch/arm/kernel/kprobes-thumb.c b/arch/arm/kernel/kprobes-thumb.c
index 6cc51b48762f..bf1113c89b15 100644
--- a/arch/arm/kernel/kprobes-thumb.c
+++ b/arch/arm/kernel/kprobes-thumb.c
@@ -489,6 +489,33 @@ static const union decode_item t32_table_1111_0xxx___1[] = {
         DECODE_END
 };
 
+static const union decode_item t32_table_1111_100x_x0x1__1111[] = {
+        /* Memory hints                                                 */
+
+        /* PLD (literal)        1111 1000 x001 1111 1111 xxxx xxxx xxxx */
+        /* PLI (literal)        1111 1001 x001 1111 1111 xxxx xxxx xxxx */
+        DECODE_SIMULATE (0xfe7ff000, 0xf81ff000, kprobe_simulate_nop),
+
+        /* PLD{W} (immediate)   1111 1000 10x1 xxxx 1111 xxxx xxxx xxxx */
+        DECODE_OR       (0xffd0f000, 0xf890f000),
+        /* PLD{W} (immediate)   1111 1000 00x1 xxxx 1111 1100 xxxx xxxx */
+        DECODE_OR       (0xffd0ff00, 0xf810fc00),
+        /* PLI (immediate)      1111 1001 1001 xxxx 1111 xxxx xxxx xxxx */
+        DECODE_OR       (0xfff0f000, 0xf990f000),
+        /* PLI (immediate)      1111 1001 0001 xxxx 1111 1100 xxxx xxxx */
+        DECODE_SIMULATEX(0xfff0ff00, 0xf910fc00, kprobe_simulate_nop,
+                                                 REGS(NOPCX, 0, 0, 0, 0)),
+
+        /* PLD{W} (register)    1111 1000 00x1 xxxx 1111 0000 00xx xxxx */
+        DECODE_OR       (0xffd0ffc0, 0xf810f000),
+        /* PLI (register)       1111 1001 0001 xxxx 1111 0000 00xx xxxx */
+        DECODE_SIMULATEX(0xfff0ffc0, 0xf910f000, kprobe_simulate_nop,
+                                                 REGS(NOPCX, 0, 0, 0, NOSPPC)),
+
+        /* Other unallocated instructions...                            */
+        DECODE_END
+};
+
 const union decode_item kprobe_decode_thumb32_table[] = {
 
         /*
@@ -540,6 +567,12 @@ const union decode_item kprobe_decode_thumb32_table[] = {
         DECODE_REJECT   (0xff100000, 0xf9000000),
 
         /*
+         * Memory hints
+         *                      1111 100x x0x1 xxxx 1111 xxxx xxxx xxxx
+         */
+        DECODE_TABLE    (0xfe50f000, 0xf810f000, t32_table_1111_100x_x0x1__1111),
+
+        /*
          * Coprocessor instructions
          *                      1111 11xx xxxx xxxx xxxx xxxx xxxx xxxx
          */