From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
To: x86@kernel.org
Cc: David Kaplan <david.kaplan@amd.com>,
linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Josh Poimboeuf <jpoimboe@kernel.org>
Subject: [PATCH 1/2] x86/spectre_v2: Fix mitigation default on Intel
Date: Tue, 20 May 2025 22:35:20 -0700 [thread overview]
Message-ID: <20250520-eibrs-fix-v1-1-91bacd35ed09@linux.intel.com> (raw)
In-Reply-To: <20250520-eibrs-fix-v1-0-91bacd35ed09@linux.intel.com>
commit 480e803dacf8 ("x86/bugs: Restructure spectre_v2 mitigation")
inadvertently changed the spectre-v2 mitigation default from eIBRS to IBRS
on Intel. While splitting the spectre_v2 mitigation in select/update/apply
functions, eIBRS and IBRS selection logic was separated in select and
update.
This caused IBRS selection to not consider that eIBRS mitigation is already
selected, fix it.
Fixes: commit 480e803dacf8 ("x86/bugs: Restructure spectre_v2 mitigation")
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
---
arch/x86/kernel/cpu/bugs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 3d5796d25f786837df59f9ce6358bc875cabe731..7f94e6a5497d9a2d312a76095e48d6b364565777 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2105,7 +2105,8 @@ static void __init spectre_v2_select_mitigation(void)
static void __init spectre_v2_update_mitigation(void)
{
- if (spectre_v2_cmd == SPECTRE_V2_CMD_AUTO) {
+ if (spectre_v2_cmd == SPECTRE_V2_CMD_AUTO &&
+ !spectre_v2_in_eibrs_mode(spectre_v2_enabled)) {
if (IS_ENABLED(CONFIG_MITIGATION_IBRS_ENTRY) &&
boot_cpu_has_bug(X86_BUG_RETBLEED) &&
retbleed_mitigation != RETBLEED_MITIGATION_NONE &&
--
2.34.1
next prev parent reply other threads:[~2025-05-21 5:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-21 5:35 [PATCH 0/2] eIBRS fixes Pawan Gupta
2025-05-21 5:35 ` Pawan Gupta [this message]
2025-05-21 10:03 ` [tip: x86/core] x86/bugs: Fix spectre_v2 mitigation default on Intel tip-bot2 for Pawan Gupta
2025-05-21 5:35 ` [PATCH 2/2] x86/its: Allow "=stuff" mitigation when eIBRS is enabled Pawan Gupta
2025-05-21 9:59 ` Borislav Petkov
2025-05-21 16:44 ` Pawan Gupta
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