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ARM: 5757/1: Thumb-2: Correct "mov.w pc, lr" instruction which is unpredictable

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The 32-bit wide variant of "mov pc, reg" in Thumb-2 is unpredictable
causing improper handling of the undefined instructions not caught by
the kernel. This patch adds a movw_pc macro for such situations
(currently only used in call_fpe).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Catalin Marinas 2009-10-12 17:31:20 +01:00 committed by Russell King
parent 80f506918f
commit a771fe6e4e
2 changed files with 29 additions and 14 deletions
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28
arch/arm/kernel/entry-armv.S
View file

@ -608,33 +608,33 @@ call_fpe:
THUMB( add pc, r8 )
nop
W(mov) pc, lr @ CP#0
movw_pc lr @ CP#0
W(b) do_fpe @ CP#1 (FPE)
W(b) do_fpe @ CP#2 (FPE)
W(mov) pc, lr @ CP#3
movw_pc lr @ CP#3
#ifdef CONFIG_CRUNCH
b crunch_task_enable @ CP#4 (MaverickCrunch)
b crunch_task_enable @ CP#5 (MaverickCrunch)
b crunch_task_enable @ CP#6 (MaverickCrunch)
#else
W(mov) pc, lr @ CP#4
W(mov) pc, lr @ CP#5
W(mov) pc, lr @ CP#6
movw_pc lr @ CP#4
movw_pc lr @ CP#5
movw_pc lr @ CP#6
#endif
W(mov) pc, lr @ CP#7
W(mov) pc, lr @ CP#8
W(mov) pc, lr @ CP#9
movw_pc lr @ CP#7
movw_pc lr @ CP#8
movw_pc lr @ CP#9
#ifdef CONFIG_VFP
W(b) do_vfp @ CP#10 (VFP)
W(b) do_vfp @ CP#11 (VFP)
#else
W(mov) pc, lr @ CP#10 (VFP)
W(mov) pc, lr @ CP#11 (VFP)
movw_pc lr @ CP#10 (VFP)
movw_pc lr @ CP#11 (VFP)
#endif
W(mov) pc, lr @ CP#12
W(mov) pc, lr @ CP#13
W(mov) pc, lr @ CP#14 (Debug)
W(mov) pc, lr @ CP#15 (Control)
movw_pc lr @ CP#12
movw_pc lr @ CP#13
movw_pc lr @ CP#14 (Debug)
movw_pc lr @ CP#15 (Control)
#ifdef CONFIG_NEON
.align 6

15
arch/arm/kernel/entry-header.S
View file

@ -110,6 +110,13 @@
mov \rd, sp, lsr #13
mov \rd, \rd, lsl #13
.endm
@
@ 32-bit wide "mov pc, reg"
@
.macro movw_pc, reg
mov pc, \reg
.endm
#else /* CONFIG_THUMB2_KERNEL */
.macro svc_exit, rpsr
clrex @ clear the exclusive monitor
@ -146,6 +153,14 @@
lsr \rd, \rd, #13
mov \rd, \rd, lsl #13
.endm
@
@ 32-bit wide "mov pc, reg"
@
.macro movw_pc, reg
mov pc, \reg
nop
.endm
#endif /* !CONFIG_THUMB2_KERNEL */
/*