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>

diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c
index 1ee38adeb82dd23040b8381254c0510ec1c4f03a..70e540b7c53b7328fea67a5fae7f011c32122b54 100644 (file)
--- 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,