The split_lock_detect command line parameter is handled in sld_setup
shortly after cpu_parse_early_param but still before parse_early_param.

Add a dummy __setup function so that parse_early_param doesn't later
complain about the "unknown" parameter split_lock_detect=, and pass it
along to init.
---
 arch/x86/kernel/cpu/bus_lock.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kernel/cpu/bus_lock.c b/arch/x86/kernel/cpu/bus_lock.c
index fb166662bc0d..c8fec79ed557 100644
--- a/arch/x86/kernel/cpu/bus_lock.c
+++ b/arch/x86/kernel/cpu/bus_lock.c
@@ -132,6 +132,12 @@ static void __init sld_state_setup(void)
 	sld_state = state;
 }
 
+static __init int setup_split_lock_detect(char *arg)
+{
+	return 1;
+}
+__setup("split_lock_detect=", setup_split_lock_detect);
+
 static void __init __split_lock_setup(void)
 {
 	if (!split_lock_verify_msr(false)) {
-- 
2.53.0

On Sun, Apr 05, 2026 at 01:30:50AM -0700, Ronan Pigott wrote:
> The split_lock_detect command line parameter is handled in sld_setup
> shortly after cpu_parse_early_param but still before parse_early_param.

Please end function names with parentheses.

When a function is mentioned in the changelog, either the text body or the
subject line, please use the format 'function_name()'. Omitting the
brackets after the function name can be ambiguous.

> Add a dummy __setup function so that parse_early_param doesn't later
> complain about the "unknown" parameter split_lock_detect=, and pass it
> along to init.

verify_tags: WARNING: Sender [Ronan Pigott <ronan@rjp.ie>] hasn't signed off on the patch!

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette