ARM: kprobes: Reject probing of unprivileged load and store instructions

These occur extremely rarely in the kernel and writing test cases for
them is difficult.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c
index 1ee38adeb82d..70e540b7c53b 100644
--- a/arch/arm/kernel/kprobes-arm.c
+++ b/arch/arm/kernel/kprobes-arm.c
@@ -1262,6 +1262,13 @@ static const union decode_item arm_cccc_0001_____1001_table[] = {
 static const union decode_item arm_cccc_000x_____1xx1_table[] = {
         /* Extra load/store instructions                                */
 
+        /* STRHT                cccc 0000 xx10 xxxx xxxx xxxx 1011 xxxx */
+        /* ???                  cccc 0000 xx10 xxxx xxxx xxxx 11x1 xxxx */
+        /* LDRHT                cccc 0000 xx11 xxxx xxxx xxxx 1011 xxxx */
+        /* LDRSBT               cccc 0000 xx11 xxxx xxxx xxxx 1101 xxxx */
+        /* LDRSHT               cccc 0000 xx11 xxxx xxxx xxxx 1111 xxxx */
+        DECODE_REJECT   (0x0f200090, 0x00200090),
+
         /* LDRD/STRD lr,pc,{... cccc 000x x0x0 xxxx 111x xxxx 1101 xxxx */
         DECODE_REJECT   (0x0e10e0d0, 0x0000e0d0),
 
@@ -1564,6 +1571,12 @@ static const union decode_item arm_cccc_01xx_table[] = {
         /* LDRB/STRB pc,[...]   cccc 01xx x0xx xxxx xxxx xxxx xxxx xxxx */
         DECODE_REJECT   (0x0c40f000, 0x0440f000),
 
+        /* STRT                 cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */
+        /* LDRT                 cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */
+        /* STRBT                cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */
+        /* LDRBT                cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */
+        DECODE_REJECT   (0x0d200000, 0x04200000),
+
         /* STR (immediate)      cccc 010x x0x0 xxxx xxxx xxxx xxxx xxxx */
         /* STRB (immediate)     cccc 010x x1x0 xxxx xxxx xxxx xxxx xxxx */
         DECODE_EMULATEX (0x0e100000, 0x04000000, emulate_str,