diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2009-10-12 17:31:20 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-10-14 10:33:05 +0100 |
| commit | a771fe6e4e3e58f2056823ef9c30a554ec48f453 (patch) | |
| tree | 06f60c5b96bd4b7c1690f86b0e44d74f6e3ffcc9 /arch/arm | |
| parent | 80f506918fdaaca6b574ba931536a58ce015c7be (diff) | |
| download | lwn-a771fe6e4e3e58f2056823ef9c30a554ec48f453.tar.gz lwn-a771fe6e4e3e58f2056823ef9c30a554ec48f453.zip | |
ARM: 5757/1: Thumb-2: Correct "mov.w pc, lr" instruction which is unpredictable
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>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 28 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-header.S | 15 |
2 files changed, 29 insertions, 14 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 322410be573c..0022b4d57f8b 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -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 diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S index ac34c0d9384b..7e9ed1eea40a 100644 --- a/arch/arm/kernel/entry-header.S +++ b/arch/arm/kernel/entry-header.S @@ -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 */ /* |