x86/bugs: Rename CONFIG_CPU_IBPB_ENTRY => CONFIG_MITIGATION_IBPB_ENTRY

Step 2/10 of the namespace unification of CPU mitigations related Kconfig options.
Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-3-leitao@debian.org

arch/x86/Kconfig

@@ -2554,7 +2554,7 @@ config CALL_THUNKS_DEBUG
 	  Only enable this when you are debugging call thunks as this
 	  creates a noticeable runtime overhead. If unsure say N.
 
-config CPU_IBPB_ENTRY
+config MITIGATION_IBPB_ENTRY
 	bool "Enable IBPB on kernel entry"
 	depends on CPU_SUP_AMD && X86_64
 	default y

arch/x86/include/asm/nospec-branch.h

@@ -289,7 +289,7 @@
  * where we have a stack but before any RET instruction.
  */
 .macro __UNTRAIN_RET ibpb_feature, call_depth_insns
-#if defined(CONFIG_RETHUNK) || defined(CONFIG_CPU_IBPB_ENTRY)
+#if defined(CONFIG_RETHUNK) || defined(CONFIG_MITIGATION_IBPB_ENTRY)
 	VALIDATE_UNRET_END
 	ALTERNATIVE_3 "",						\
 		      CALL_UNTRAIN_RET, X86_FEATURE_UNRET,		\

arch/x86/kernel/cpu/bugs.c

@@ -994,10 +994,10 @@ static void __init retbleed_select_mitigation(void)
 		if (!boot_cpu_has(X86_FEATURE_IBPB)) {
 			pr_err("WARNING: CPU does not support IBPB.\n");
 			goto do_cmd_auto;
-		} else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
+		} else if (IS_ENABLED(CONFIG_MITIGATION_IBPB_ENTRY)) {
 			retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
 		} else {
-			pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n");
+			pr_err("WARNING: kernel not compiled with MITIGATION_IBPB_ENTRY.\n");
 			goto do_cmd_auto;
 		}
 		break;
@@ -1023,7 +1023,8 @@ static void __init retbleed_select_mitigation(void)
 		    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
 			if (IS_ENABLED(CONFIG_CPU_UNRET_ENTRY))
 				retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
-			else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY) && boot_cpu_has(X86_FEATURE_IBPB))
+			else if (IS_ENABLED(CONFIG_MITIGATION_IBPB_ENTRY) &&
+				 boot_cpu_has(X86_FEATURE_IBPB))
 				retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
 		}
 
@@ -2482,13 +2483,13 @@ static void __init srso_select_mitigation(void)
 		break;
 
 	case SRSO_CMD_IBPB:
-		if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
+		if (IS_ENABLED(CONFIG_MITIGATION_IBPB_ENTRY)) {
 			if (has_microcode) {
 				setup_force_cpu_cap(X86_FEATURE_ENTRY_IBPB);
 				srso_mitigation = SRSO_MITIGATION_IBPB;
 			}
 		} else {
-			pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n");
+			pr_err("WARNING: kernel not compiled with MITIGATION_IBPB_ENTRY.\n");
 		}
 		break;