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| author | Ard Biesheuvel <ardb@kernel.org> | 2022-04-20 09:46:17 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-25 09:57:33 +0200 |
| commit | 37bb8ea1542b70a0716484b23c5a46edc75f34b5 (patch) | |
| tree | cc94df398707f43949b2c6f39f5d8615c77c825a | |
| parent | b88e30dcdf64fc18802fed0d2576334fb5b7e269 (diff) | |
| download | linux-37bb8ea1542b70a0716484b23c5a46edc75f34b5.tar.gz linux-37bb8ea1542b70a0716484b23c5a46edc75f34b5.tar.bz2 linux-37bb8ea1542b70a0716484b23c5a46edc75f34b5.zip | |
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 46b697dfa4cf..68261a83b7ad 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -1038,7 +1038,7 @@ vector_bhb_loop8_\name: @ bhb workaround mov r0, #8 -3: b . + 4 +3: W(b) . + 4 subs r0, r0, #1 bne 3b dsb |