From: Ard Biesheuvel ardb@kernel.org
[ Upstream commit 3cfb3019979666bdf33a1010147363cf05e0f17b ]
In Thumb2, 'b . + 4' produces a branch instruction that uses a narrow encoding, and so it does not jump to the following instruction as expected. So use W(b) instead.
Fixes: 6c7cb60bff7a ("ARM: fix Thumb2 regression with Spectre BHB") Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/kernel/entry-armv.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index ee3f7a599181..4bbd92d41031 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -1040,7 +1040,7 @@ vector_bhb_loop8_\name:
@ bhb workaround mov r0, #8 -3: b . + 4 +3: W(b) . + 4 subs r0, r0, #1 bne 3b dsb