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Commit | Line | Data |
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256d7bf6 GKH |
1 | From 5ca918e5e3f9df4634077c06585c42bc6a8d699a Mon Sep 17 00:00:00 2001 |
2 | From: Robin Murphy <robin.murphy@arm.com> | |
3 | Date: Thu, 25 Sep 2014 11:56:19 +0100 | |
4 | Subject: ARM: 8165/1: alignment: don't break misaligned NEON load/store | |
5 | ||
6 | From: Robin Murphy <robin.murphy@arm.com> | |
7 | ||
8 | commit 5ca918e5e3f9df4634077c06585c42bc6a8d699a upstream. | |
9 | ||
10 | The alignment fixup incorrectly decodes faulting ARM VLDn/VSTn | |
11 | instructions (where the optional alignment hint is given but incorrect) | |
12 | as LDR/STR, leading to register corruption. Detect these and correctly | |
13 | treat them as unhandled, so that userspace gets the fault it expects. | |
14 | ||
15 | Reported-by: Simon Hosie <simon.hosie@arm.com> | |
16 | Signed-off-by: Robin Murphy <robin.murphy@arm.com> | |
17 | Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> | |
18 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
19 | ||
20 | --- | |
21 | arch/arm/mm/alignment.c | 3 +++ | |
22 | 1 file changed, 3 insertions(+) | |
23 | ||
24 | --- a/arch/arm/mm/alignment.c | |
25 | +++ b/arch/arm/mm/alignment.c | |
26 | @@ -39,6 +39,7 @@ | |
27 | * This code is not portable to processors with late data abort handling. | |
28 | */ | |
29 | #define CODING_BITS(i) (i & 0x0e000000) | |
30 | +#define COND_BITS(i) (i & 0xf0000000) | |
31 | ||
32 | #define LDST_I_BIT(i) (i & (1 << 26)) /* Immediate constant */ | |
33 | #define LDST_P_BIT(i) (i & (1 << 24)) /* Preindex */ | |
34 | @@ -812,6 +813,8 @@ do_alignment(unsigned long addr, unsigne | |
35 | break; | |
36 | ||
37 | case 0x04000000: /* ldr or str immediate */ | |
38 | + if (COND_BITS(instr) == 0xf0000000) /* NEON VLDn, VSTn */ | |
39 | + goto bad; | |
40 | offset.un = OFFSET_BITS(instr); | |
41 | handler = do_alignment_ldrstr; | |
42 | break; |