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twx-linux/arch/x86/entry
Josh Poimboeuf 56332c566f x86/bugs: Use SBPB in write_ibpb() if applicable
[ Upstream commit fc9fd3f984 ]

write_ibpb() does IBPB, which (among other things) flushes branch type
predictions on AMD.  If the CPU has SRSO_NO, or if the SRSO mitigation
has been disabled, branch type flushing isn't needed, in which case the
lighter-weight SBPB can be used.

The 'x86_pred_cmd' variable already keeps track of whether IBPB or SBPB
should be used.  Use that instead of hardcoding IBPB.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/17c5dcd14b29199b75199d67ff7758de9d9a4928.1744148254.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02 07:44:37 +02:00
..