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 v2 2/7] x86/retbleed: Simplify the =stuff checks
Date: Wed, 21 May 2025 19:44:37 -0700 [thread overview]
Message-ID: <20250521-eibrs-fix-v2-2-70e2598e932c@linux.intel.com> (raw)
In-Reply-To: <20250521-eibrs-fix-v2-0-70e2598e932c@linux.intel.com>
Simplify the nested checks, remove redundant print and comment.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
---
arch/x86/kernel/cpu/bugs.c | 24 ++++++++----------------
1 file changed, 8 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 19ff705b3128eacad5659990ed345d7a19bcb0f4..20d7d14b08298d4f610f2ebc7f13a490ee3d957a 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1258,24 +1258,16 @@ static void __init retbleed_update_mitigation(void)
if (retbleed_mitigation == RETBLEED_MITIGATION_NONE)
goto out;
- /*
- * retbleed=stuff is only allowed on Intel. If stuffing can't be used
- * then a different mitigation will be selected below.
- *
- * its=stuff will also attempt to enable stuffing.
- */
- if (retbleed_mitigation == RETBLEED_MITIGATION_STUFF ||
- its_mitigation == ITS_MITIGATION_RETPOLINE_STUFF) {
- if (spectre_v2_enabled != SPECTRE_V2_RETPOLINE) {
- pr_err("WARNING: retbleed=stuff depends on spectre_v2=retpoline\n");
- retbleed_mitigation = RETBLEED_MITIGATION_AUTO;
- } else {
- if (retbleed_mitigation != RETBLEED_MITIGATION_STUFF)
- pr_info("Retbleed mitigation updated to stuffing\n");
+ /* ITS can also enable stuffing */
+ if (its_mitigation == ITS_MITIGATION_RETPOLINE_STUFF)
+ retbleed_mitigation = RETBLEED_MITIGATION_STUFF;
- retbleed_mitigation = RETBLEED_MITIGATION_STUFF;
- }
+ if (retbleed_mitigation == RETBLEED_MITIGATION_STUFF &&
+ spectre_v2_enabled != SPECTRE_V2_RETPOLINE) {
+ pr_err("WARNING: retbleed=stuff depends on spectre_v2=retpoline\n");
+ retbleed_mitigation = RETBLEED_MITIGATION_AUTO;
}
+
/*
* Let IBRS trump all on Intel without affecting the effects of the
* retbleed= cmdline option except for call depth based stuffing
--
2.34.1
next prev parent reply other threads:[~2025-05-22 2:44 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-22 2:44 [PATCH v2 0/7] eIBRS fixes Pawan Gupta
2025-05-22 2:44 ` [PATCH v2 1/7] x86/retbleed: Check for AUTO in all cases Pawan Gupta
2025-05-22 9:52 ` Nikolay Borisov
2025-05-22 11:27 ` Borislav Petkov
2025-05-22 17:42 ` Pawan Gupta
2025-05-22 2:44 ` Pawan Gupta [this message]
2025-05-22 10:18 ` [PATCH v2 2/7] x86/retbleed: Simplify the =stuff checks Nikolay Borisov
2025-05-22 11:42 ` Borislav Petkov
2025-05-22 18:02 ` Pawan Gupta
2025-05-22 2:44 ` [PATCH v2 3/7] x86/bugs: Exit early if return thunk is already set Pawan Gupta
2025-05-22 10:22 ` Nikolay Borisov
2025-05-22 10:26 ` Nikolay Borisov
2025-05-22 18:03 ` Pawan Gupta
2025-05-22 2:45 ` [PATCH v2 4/7] x86/its: Use switch/case to apply mitigation Pawan Gupta
2025-05-22 11:15 ` Nikolay Borisov
2025-05-22 18:04 ` Pawan Gupta
2025-05-22 2:45 ` [PATCH v2 5/7] x86/retbleed: Introduce cdt_possible() Pawan Gupta
2025-05-22 2:45 ` [PATCH v2 6/7] x86/its: Remove =stuff dependency on retbleed Pawan Gupta
2025-05-22 2:45 ` [PATCH v2 7/7] x86/its: Allow stuffing in eIBRS+retpoline mode also Pawan Gupta
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