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authorPetr Mladek <pmladek@suse.com>2025-12-01 14:16:45 +0100
committerPetr Mladek <pmladek@suse.com>2025-12-01 14:16:45 +0100
commit4f132d81f9f8e47a8866d162698adb7df7184466 (patch)
treea45d7073449f9e549d9630f18728e3b3e42753bd /kernel
parent3a9a3f5fb224155bb719c337527ffdffca0c1d7f (diff)
parent20793955835fe29a5582f68ff031fdcd35cc98ed (diff)
Merge branch 'rework/threaded-printk' into for-linus
Diffstat (limited to 'kernel')
-rw-r--r--kernel/printk/printk.c17
1 files changed, 7 insertions, 10 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 54ea492d0c97..7394f1b6033b 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3023,21 +3023,18 @@ out:
}
/*
- * Legacy console printing from printk() caller context does not respect
- * raw_spinlock/spinlock nesting. For !PREEMPT_RT the lockdep warning is a
- * false positive. For PREEMPT_RT the false positive condition does not
- * occur.
- *
- * This map is used to temporarily establish LD_WAIT_SLEEP context for the
- * console write() callback when legacy printing to avoid false positive
- * lockdep complaints, thus allowing lockdep to continue to function for
- * real issues.
+ * The legacy console always acquires a spinlock_t from its printing
+ * callback. This violates lock nesting if the caller acquired an always
+ * spinning lock (raw_spinlock_t) while invoking printk(). This is not a
+ * problem on PREEMPT_RT because legacy consoles print always from a
+ * dedicated thread and never from within printk(). Therefore we tell
+ * lockdep that a sleeping spin lock (spinlock_t) is valid here.
*/
#ifdef CONFIG_PREEMPT_RT
static inline void printk_legacy_allow_spinlock_enter(void) { }
static inline void printk_legacy_allow_spinlock_exit(void) { }
#else
-static DEFINE_WAIT_OVERRIDE_MAP(printk_legacy_map, LD_WAIT_SLEEP);
+static DEFINE_WAIT_OVERRIDE_MAP(printk_legacy_map, LD_WAIT_CONFIG);
static inline void printk_legacy_allow_spinlock_enter(void)
{