In preparation to allow ITS to also enable stuffing a.k.a. Call Depth
Tracking(CDT) independently of retbleed, introduce a helper cdt_possible().
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
---
arch/x86/kernel/cpu/bugs.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index fbfc08f5f9f652beb677a1b5310e4322600082ac..59a1f59bf6e2ceda624b6567c5b09ebc524cb9a2 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1123,6 +1123,19 @@ early_param("nospectre_v1", nospectre_v1_cmdline);
enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init = SPECTRE_V2_NONE;
+/* Depends on spectre_v2 mitigation selected already */
+static inline bool cdt_possible(enum spectre_v2_mitigation mode)
+{
+ if (!IS_ENABLED(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) ||
+ !IS_ENABLED(CONFIG_MITIGATION_RETPOLINE))
+ return false;
+
+ if (mode == SPECTRE_V2_RETPOLINE)
+ return true;
+
+ return false;
+}
+
#undef pr_fmt
#define pr_fmt(fmt) "RETBleed: " fmt
@@ -1266,7 +1279,7 @@ static void __init retbleed_update_mitigation(void)
retbleed_mitigation = RETBLEED_MITIGATION_STUFF;
if (retbleed_mitigation == RETBLEED_MITIGATION_STUFF &&
- spectre_v2_enabled != SPECTRE_V2_RETPOLINE) {
+ !cdt_possible(spectre_v2_enabled)) {
pr_err("WARNING: retbleed=stuff depends on spectre_v2=retpoline\n");
retbleed_mitigation = RETBLEED_MITIGATION_AUTO;
}
--
2.34.1