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author | Ard Biesheuvel <ardb@kernel.org> | 2022-04-20 11:46:17 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-25 10:59:10 +0300 |
commit | dbe6b6a3f6c4e0c5524e8b0411e4739ff9cd2b32 (patch) | |
tree | 622b6e45d120d24051e36e9ee63784207a5b16b9 | |
parent | 6db976400affb4294e21fda3f75a865c1bc73b02 (diff) | |
download | linux-dbe6b6a3f6c4e0c5524e8b0411e4739ff9cd2b32.tar.xz |
ARM: 9197/1: spectre-bhb: fix loop8 sequence for Thumb2
[ 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>
-rw-r--r-- | arch/arm/kernel/entry-armv.S | 2 |
1 files changed, 1 insertions, 1 deletions
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 |