diff options
| author | Josh Poimboeuf <jpoimboe@kernel.org> | 2025-04-08 14:47:31 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:59:24 +0200 |
| commit | 5c41b7913fe083967ef9cb5560172c80756e27c9 (patch) | |
| tree | e936f5f4fcec8ea5f19077c7812ffe02d7aa9e0e | |
| parent | 6f3e9b2566636738e8b342581a9068ff6c326418 (diff) | |
x86/bugs: Use SBPB in write_ibpb() if applicable
[ Upstream commit fc9fd3f98423367c79e0bd85a9515df26dc1b3cc ]
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>
| -rw-r--r-- | arch/x86/entry/entry.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S index b7ea3e8e9ecc..58e3124ee2b4 100644 --- a/arch/x86/entry/entry.S +++ b/arch/x86/entry/entry.S @@ -18,7 +18,7 @@ SYM_FUNC_START(entry_ibpb) movl $MSR_IA32_PRED_CMD, %ecx - movl $PRED_CMD_IBPB, %eax + movl _ASM_RIP(x86_pred_cmd), %eax xorl %edx, %edx wrmsr |