[PATCH v2 4/9] x86/cfi: Standardize on common "CFI:" prefix for CFI reports

Kees Cook
2025-09-04T03:58:16Z

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>
---
Cc: Peter Zijlstra <peterz@infradead.org>
---
arch/x86/kernel/alternative.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 7bde68247b5f..d8f4ac95b4df 100644
--- a/arch/x86/kernel/alternative.c
+++ b/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
--
2.34.1