Attack vector controls (part 1)

[PATCH v5 08/16] x86/bugs: Restructure spectre_v1 mitigation

Posted by David Kaplan 7 months, 4 weeks ago

Restructure spectre_v1 to use select/apply functions to create
consistent vulnerability handling.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
---
 arch/x86/kernel/cpu/bugs.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 57f9ebf90472..72e04938fdcb 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -54,6 +54,7 @@
  */
 
 static void __init spectre_v1_select_mitigation(void);
+static void __init spectre_v1_apply_mitigation(void);
 static void __init spectre_v2_select_mitigation(void);
 static void __init retbleed_select_mitigation(void);
 static void __init spectre_v2_user_select_mitigation(void);
@@ -223,6 +224,7 @@ void __init cpu_select_mitigations(void)
 	mmio_update_mitigation();
 	rfds_update_mitigation();
 
+	spectre_v1_apply_mitigation();
 	mds_apply_mitigation();
 	taa_apply_mitigation();
 	mmio_apply_mitigation();
@@ -1017,10 +1019,14 @@ static bool smap_works_speculatively(void)
 
 static void __init spectre_v1_select_mitigation(void)
 {
-	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off()) {
+	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off())
 		spectre_v1_mitigation = SPECTRE_V1_MITIGATION_NONE;
+}
+
+static void __init spectre_v1_apply_mitigation(void)
+{
+	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off())
 		return;
-	}
 
 	if (spectre_v1_mitigation == SPECTRE_V1_MITIGATION_AUTO) {
 		/*
-- 
2.34.1

[tip: x86/bugs] x86/bugs: Restructure spectre_v1 mitigation

Posted by tip-bot2 for David Kaplan 7 months, 2 weeks ago

The following commit has been merged into the x86/bugs branch of tip:

Commit-ID:     46d5925b8eb8c7a8d634147c23db24669cfc2f76
Gitweb:        https://git.kernel.org/tip/46d5925b8eb8c7a8d634147c23db24669cfc2f76
Author:        David Kaplan <david.kaplan@amd.com>
AuthorDate:    Fri, 18 Apr 2025 11:17:13 -05:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Mon, 28 Apr 2025 19:40:10 +02:00

x86/bugs: Restructure spectre_v1 mitigation

Restructure spectre_v1 to use select/apply functions to create
consistent vulnerability handling.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/20250418161721.1855190-9-david.kaplan@amd.com
---
 arch/x86/kernel/cpu/bugs.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index b070ad7..1a42abb 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -54,6 +54,7 @@
  */
 
 static void __init spectre_v1_select_mitigation(void);
+static void __init spectre_v1_apply_mitigation(void);
 static void __init spectre_v2_select_mitigation(void);
 static void __init retbleed_select_mitigation(void);
 static void __init spectre_v2_user_select_mitigation(void);
@@ -223,6 +224,7 @@ void __init cpu_select_mitigations(void)
 	mmio_update_mitigation();
 	rfds_update_mitigation();
 
+	spectre_v1_apply_mitigation();
 	mds_apply_mitigation();
 	taa_apply_mitigation();
 	mmio_apply_mitigation();
@@ -1021,10 +1023,14 @@ static bool smap_works_speculatively(void)
 
 static void __init spectre_v1_select_mitigation(void)
 {
-	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off()) {
+	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off())
 		spectre_v1_mitigation = SPECTRE_V1_MITIGATION_NONE;
+}
+
+static void __init spectre_v1_apply_mitigation(void)
+{
+	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off())
 		return;
-	}
 
 	if (spectre_v1_mitigation == SPECTRE_V1_MITIGATION_AUTO) {
 		/*