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authorDavid Kaplan <david.kaplan@amd.com>2025-07-07 13:33:13 -0500
committerBorislav Petkov (AMD) <bp@alien8.de>2025-07-11 17:56:41 +0200
commit0cdd2c4f35cf9bb9466b36724b658d11ff453f04 (patch)
tree0ea491906f754d7fbbfec4c5481c72e2dddc1776 /arch/x86/kernel/cpu/bugs.c
parenteda718fde6159b2e64978637ebb3f1ae98180555 (diff)
x86/bugs: Add attack vector controls for ITS
Use attack vector controls to determine if ITS mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-19-david.kaplan@amd.com
Diffstat (limited to 'arch/x86/kernel/cpu/bugs.c')
-rw-r--r--arch/x86/kernel/cpu/bugs.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index eef6ccd17c79..f41d871f0622 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1518,13 +1518,17 @@ early_param("indirect_target_selection", its_parse_cmdline);
static void __init its_select_mitigation(void)
{
- if (!boot_cpu_has_bug(X86_BUG_ITS) || cpu_mitigations_off()) {
+ if (!boot_cpu_has_bug(X86_BUG_ITS)) {
its_mitigation = ITS_MITIGATION_OFF;
return;
}
- if (its_mitigation == ITS_MITIGATION_AUTO)
- its_mitigation = ITS_MITIGATION_ALIGNED_THUNKS;
+ if (its_mitigation == ITS_MITIGATION_AUTO) {
+ if (should_mitigate_vuln(X86_BUG_ITS))
+ its_mitigation = ITS_MITIGATION_ALIGNED_THUNKS;
+ else
+ its_mitigation = ITS_MITIGATION_OFF;
+ }
if (its_mitigation == ITS_MITIGATION_OFF)
return;
@@ -1555,12 +1559,13 @@ static void __init its_select_mitigation(void)
static void __init its_update_mitigation(void)
{
- if (!boot_cpu_has_bug(X86_BUG_ITS) || cpu_mitigations_off())
+ if (!boot_cpu_has_bug(X86_BUG_ITS))
return;
switch (spectre_v2_enabled) {
case SPECTRE_V2_NONE:
- pr_err("WARNING: Spectre-v2 mitigation is off, disabling ITS\n");
+ if (its_mitigation != ITS_MITIGATION_OFF)
+ pr_err("WARNING: Spectre-v2 mitigation is off, disabling ITS\n");
its_mitigation = ITS_MITIGATION_OFF;
break;
case SPECTRE_V2_RETPOLINE: