From: David Kaplan david.kaplan@amd.com
[ Upstream commit 1dbb6b1495d472806fef1f4c94f5b3e4c89a3c1d ]
When the SRSO mitigation is disabled, either via mitigations=off or spec_rstack_overflow=off, the warning about the lack of IBPB-enhancing microcode is printed anyway.
This is unnecessary since the user has turned off the mitigation.
[ bp: Massage, drop SBPB rationale as it doesn't matter because when mitigations are disabled x86_pred_cmd is not being used anyway. ]
Signed-off-by: David Kaplan david.kaplan@amd.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Acked-by: Josh Poimboeuf jpoimboe@kernel.org Link: https://lore.kernel.org/r/20240904150711.193022-1-david.kaplan@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/cpu/bugs.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 45675da354f33..468449f73a957 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2551,10 +2551,9 @@ static void __init srso_select_mitigation(void) { bool has_microcode = boot_cpu_has(X86_FEATURE_IBPB_BRTYPE);
- if (cpu_mitigations_off()) - return; - - if (!boot_cpu_has_bug(X86_BUG_SRSO)) { + if (!boot_cpu_has_bug(X86_BUG_SRSO) || + cpu_mitigations_off() || + srso_cmd == SRSO_CMD_OFF) { if (boot_cpu_has(X86_FEATURE_SBPB)) x86_pred_cmd = PRED_CMD_SBPB; return; @@ -2585,11 +2584,6 @@ static void __init srso_select_mitigation(void) }
switch (srso_cmd) { - case SRSO_CMD_OFF: - if (boot_cpu_has(X86_FEATURE_SBPB)) - x86_pred_cmd = PRED_CMD_SBPB; - return; - case SRSO_CMD_MICROCODE: if (has_microcode) { srso_mitigation = SRSO_MITIGATION_MICROCODE; @@ -2643,6 +2637,8 @@ static void __init srso_select_mitigation(void) pr_err("WARNING: kernel not compiled with MITIGATION_SRSO.\n"); } break; + default: + break; }
out: