[PATCH v2] sched: Fix preemption string of preempt_dynamic_none

[Thomas Weißschuh]

Zero is a valid value for "preempt_dynamic_mode", namely
"preempt_dynamic_none".

Fix the off-by-one in preempt_model_str(), so that "preempty_dynamic_none"
is correctly formatted as PREEMPT(none) instead of PREEMPT(undef).

Fixes: 8bdc5daaa01e ("sched: Add a generic function to return the preemption string")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
Tested-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
Changes in v2:
- Pick up Reviewed-by and Tested-by
- Rebase on v6.16-rc1
- Link to v1: https://lore.kernel.org/r/20250603-preempt-str-none-v1-1-f0e9916dcf44@xxxxxxxxxxxxx
---
 kernel/sched/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index dce50fa57471dffc4311b9d393ae300a43d38d20..021b0a703d094b3386c5ba50e0e111e3a7c2b3df 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7663,7 +7663,7 @@ const char *preempt_model_str(void)
 
 		if (IS_ENABLED(CONFIG_PREEMPT_DYNAMIC)) {
 			seq_buf_printf(&s, "(%s)%s",
-				       preempt_dynamic_mode > 0 ?
+				       preempt_dynamic_mode >= 0 ?
 				       preempt_modes[preempt_dynamic_mode] : "undef",
 				       brace ? "}" : "");
 			return seq_buf_str(&s);

---
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
change-id: 20250603-preempt-str-none-d21231cc2238

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>