[PATCH 4.19 106/205] ARM: 8809/1: proc-v7: fix Thumb annotation of cpu_v7_hvc_switch_mm

Greg Kroah-Hartman
2018-11-19T18:00:17Z

From: Ard Biesheuvel <ard.biesheuvel@linaro.org>

commit 6282e916f774e37845c65d1eae9f8c649004f033 upstream.

Due to what appears to be a copy/paste error, the opening ENTRY()
of cpu_v7_hvc_switch_mm() lacks a matching ENDPROC(), and instead,
the one for cpu_v7_smc_switch_mm() is duplicated.

Given that it is ENDPROC() that emits the Thumb annotation, the
cpu_v7_hvc_switch_mm() routine will be called in ARM mode on a
Thumb2 kernel, resulting in the following splat:

Internal error: Oops - undefined instruction: 0 [#1] SMP THUMB2
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.0-rc1-00030-g4d28ad89189d-dirty #488
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
PC is at cpu_v7_hvc_switch_mm+0x12/0x18
LR is at flush_old_exec+0x31b/0x570
pc : [<c0316efe>] lr : [<c04117c7>] psr: 00000013
sp : ee899e50 ip : 00000000 fp : 00000001
r10: eda28f34 r9 : eda31800 r8 : c12470e0
r7 : eda1fc00 r6 : eda53000 r5 : 00000000 r4 : ee88c000
r3 : c0316eec r2 : 00000001 r1 : eda53000 r0 : 6da6c000
Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none

Note the 'ISA ARM' in the last line.

Fix this by using the correct name in ENDPROC().

Cc: <stable@vger.kernel.org>
Fixes: 10115105cb3a ("ARM: spectre-v2: add firmware based hardening")
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/arm/mm/proc-v7.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -112,7 +112,7 @@ ENTRY(cpu_v7_hvc_switch_mm)
hvc #0
ldmfd sp!, {r0 - r3}
b cpu_v7_switch_mm
-ENDPROC(cpu_v7_smc_switch_mm)
+ENDPROC(cpu_v7_hvc_switch_mm)
#endif
ENTRY(cpu_v7_iciallu_switch_mm)
mov r3, #0