diff options
| author | Josh Poimboeuf <jpoimboe@kernel.org> | 2023-09-05 08:04:57 +0300 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-10-20 13:26:59 +0300 |
| commit | 55ca9010c4a988b48278f81ae4129deea52d2488 (patch) | |
| tree | 8c626521727c9eaa4502fda56a9ce35e03396e60 /arch | |
| parent | eb54be26b0d25222809b16f335fe13756ff4a206 (diff) | |
| download | linux-55ca9010c4a988b48278f81ae4129deea52d2488.tar.xz | |
x86/srso: Remove 'pred_cmd' label
SBPB is only enabled in two distinct cases:
1) when SRSO has been disabled with srso=off
2) when SRSO has been fixed (in future HW)
Simplify the control flow by getting rid of the 'pred_cmd' label and
moving the SBPB enablement check to the two corresponding code sites.
This makes it more clear when exactly SBPB gets enabled.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/bb20e8569cfa144def5e6f25e610804bc4974de2.1693889988.git.jpoimboe@kernel.org
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index e45dd69aff7f..4f1ad2350f49 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2410,13 +2410,21 @@ static void __init srso_select_mitigation(void) { bool has_microcode = boot_cpu_has(X86_FEATURE_IBPB_BRTYPE); - if (!boot_cpu_has_bug(X86_BUG_SRSO) || cpu_mitigations_off()) - goto pred_cmd; + if (cpu_mitigations_off()) + return; + + if (!boot_cpu_has_bug(X86_BUG_SRSO)) { + if (boot_cpu_has(X86_FEATURE_SBPB)) + x86_pred_cmd = PRED_CMD_SBPB; + return; + } if (has_microcode) { /* * Zen1/2 with SMT off aren't vulnerable after the right * IBPB microcode has been applied. + * + * Zen1/2 don't have SBPB, no need to try to enable it here. */ if (boot_cpu_data.x86 < 0x19 && !cpu_smt_possible()) { setup_force_cpu_cap(X86_FEATURE_SRSO_NO); @@ -2439,7 +2447,9 @@ static void __init srso_select_mitigation(void) switch (srso_cmd) { case SRSO_CMD_OFF: - goto pred_cmd; + if (boot_cpu_has(X86_FEATURE_SBPB)) + x86_pred_cmd = PRED_CMD_SBPB; + return; case SRSO_CMD_MICROCODE: if (has_microcode) { @@ -2501,11 +2511,6 @@ static void __init srso_select_mitigation(void) out: pr_info("%s\n", srso_strings[srso_mitigation]); - -pred_cmd: - if ((!boot_cpu_has_bug(X86_BUG_SRSO) || srso_cmd == SRSO_CMD_OFF) && - boot_cpu_has(X86_FEATURE_SBPB)) - x86_pred_cmd = PRED_CMD_SBPB; } #undef pr_fmt |