ARM: 9199/1: spectre-bhb: use local DSB and elide ISB in loop8 sequence

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The loop8 mitigation for Spectre-BHB only requires a CPU local DSB
rather than a systemwide one, which is much more costly. And by the same
reasoning as why it is justified to omit the ISB after BPIALL, we can
also elide the ISB and rely on the exception return for the context
synchronization.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

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Ard Biesheuvel 2022-04-20 09:57:45 +01:00 • committed by Russell King (Oracle)

parent c4f486f1e7

commit 892c608a7d

2 changed files with 4 additions and 3 deletions

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arch/arm/kernel/entry-armv.S

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2

arch/arm/kernel/entry-common.S

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