x86/cfi: Standardize on common "CFI:" prefix for CFI reports

Use a regular "CFI:" prefix for CFI reports during alternatives setup,
including reporting when nothing has happened (i.e. CONFIG_FINEIBT=n).

Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250904034656.3670313-4-kees@kernel.org

Author: kees

arch/x86/kernel/alternative.c

@@ -1266,26 +1266,26 @@ static __init int cfi_parse_cmdline(char *str)
 		} else if (!strcmp(str, "norand")) {
 			cfi_rand = false;
 		} else if (!strcmp(str, "warn")) {
-			pr_alert("CFI mismatch non-fatal!\n");
+			pr_alert("CFI: mismatch non-fatal!\n");
 			cfi_warn = true;
 		} else if (!strcmp(str, "paranoid")) {
 			if (cfi_mode == CFI_FINEIBT) {
 				cfi_paranoid = true;
 			} else {
-				pr_err("Ignoring paranoid; depends on fineibt.\n");
+				pr_err("CFI: ignoring paranoid; depends on fineibt.\n");
 			}
 		} else if (!strcmp(str, "bhi")) {
 #ifdef CONFIG_FINEIBT_BHI
 			if (cfi_mode == CFI_FINEIBT) {
 				cfi_bhi = true;
 			} else {
-				pr_err("Ignoring bhi; depends on fineibt.\n");
+				pr_err("CFI: ignoring bhi; depends on fineibt.\n");
 			}
 #else
-			pr_err("Ignoring bhi; depends on FINEIBT_BHI=y.\n");
+			pr_err("CFI: ignoring bhi; depends on FINEIBT_BHI=y.\n");
 #endif
 		} else {
-			pr_err("Ignoring unknown cfi option (%s).", str);
+			pr_err("CFI: Ignoring unknown option (%s).", str);
 		}
 
 		str = next;
@@ -1757,7 +1757,7 @@ static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
 	switch (cfi_mode) {
 	case CFI_OFF:
 		if (builtin)
-			pr_info("Disabling CFI\n");
+			pr_info("CFI: disabled\n");
 		return;
 
 	case CFI_KCFI:
@@ -1766,7 +1766,8 @@ static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
 			goto err;
 
 		if (builtin)
-			pr_info("Using kCFI\n");
+			pr_info("CFI: Using %sretpoline kCFI\n",
+				cfi_rand ? "rehashed " : "");
 		return;
 
 	case CFI_FINEIBT:
@@ -2005,6 +2006,8 @@ bool decode_fineibt_insn(struct pt_regs *regs, unsigned long *target, u32 *type)
 static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
 			    s32 *start_cfi, s32 *end_cfi, bool builtin)
 {
+	if (IS_ENABLED(CONFIG_CFI) && builtin)
+		pr_info("CFI: Using standard kCFI\n");
 }
 
 #ifdef CONFIG_X86_KERNEL_IBT