The patch titled
lockdep: do not recurse in printk
has been removed from the -mm tree. Its filename is
lockdep-do-not-recurse-in-printk.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: lockdep: do not recurse in printk
From: Ingo Molnar <mingo@xxxxxxx>
Make printk()-ing from within the lock validation code safer by using the
lockdep-recursion counter.
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/printk.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff -puN kernel/printk.c~lockdep-do-not-recurse-in-printk kernel/printk.c
--- a/kernel/printk.c~lockdep-do-not-recurse-in-printk
+++ a/kernel/printk.c
@@ -518,7 +518,9 @@ asmlinkage int vprintk(const char *fmt,
zap_locks();
/* This stops the holder of console_sem just where we want him */
- spin_lock_irqsave(&logbuf_lock, flags);
+ local_irq_save(flags);
+ lockdep_off();
+ spin_lock(&logbuf_lock);
printk_cpu = smp_processor_id();
/* Emit the output into the temporary buffer */
@@ -588,7 +590,7 @@ asmlinkage int vprintk(const char *fmt,
*/
console_locked = 1;
printk_cpu = UINT_MAX;
- spin_unlock_irqrestore(&logbuf_lock, flags);
+ spin_unlock(&logbuf_lock);
/*
* Console drivers may assume that per-cpu resources have
@@ -604,6 +606,8 @@ asmlinkage int vprintk(const char *fmt,
console_locked = 0;
up(&console_sem);
}
+ lockdep_on();
+ local_irq_restore(flags);
} else {
/*
* Someone else owns the drivers. We drop the spinlock, which
@@ -611,7 +615,9 @@ asmlinkage int vprintk(const char *fmt,
* console drivers with the output which we just produced.
*/
printk_cpu = UINT_MAX;
- spin_unlock_irqrestore(&logbuf_lock, flags);
+ spin_unlock(&logbuf_lock);
+ lockdep_on();
+ local_irq_restore(flags);
}
preempt_enable();
@@ -809,8 +815,15 @@ void release_console_sem(void)
console_may_schedule = 0;
up(&console_sem);
spin_unlock_irqrestore(&logbuf_lock, flags);
- if (wake_klogd && !oops_in_progress && waitqueue_active(&log_wait))
- wake_up_interruptible(&log_wait);
+ if (wake_klogd && !oops_in_progress && waitqueue_active(&log_wait)) {
+ /*
+ * If we printk from within the lock dependency code,
+ * from within the scheduler code, then do not lock
+ * up due to self-recursion:
+ */
+ if (!lockdep_internal())
+ wake_up_interruptible(&log_wait);
+ }
}
EXPORT_SYMBOL(release_console_sem);
_
Patches currently in -mm which might be from mingo@xxxxxxx are
origin.patch
disable-debugging-version-of-write_lock.patch
lock-validator-fix-ns83820c-irq-flags-bug.patch
revert-gregkh-pci-pci-test-that-drivers-properly-call-pci_set_master.patch
my-name-is-ingo-molnar-you-killed-my-make-allyesconfig-prepare-to-die.patch
sched-fix-bug-in-__migrate_task.patch
small-kernel-schedc-cleanup.patch
x86-re-enable-generic-numa.patch
sched-add-above-background-load-function.patch
mm-implement-swap-prefetching.patch
sched-cleanup-remove-task_t-convert-to-struct-task_struct-prefetch.patch
genirq-convert-the-x86_64-architecture-to-irq-chips.patch
genirq-convert-the-i386-architecture-to-irq-chips.patch
genirq-irq-convert-the-move_irq-flag-from-a-32bit-word-to-a-single-bit.patch
genirq-irq-add-moved_masked_irq.patch
genirq-x86_64-irq-reenable-migrating-irqs-to-other-cpus.patch
genirq-msi-simplify-msi-enable-and-disable.patch
genirq-msi-make-the-msi-boolean-tests-return-either-0-or-1.patch
genirq-msi-implement-helper-functions-read_msi_msg-and-write_msi_msg.patch
genirq-msi-refactor-the-msi_ops.patch
genirq-msi-simplify-the-msi-irq-limit-policy.patch
genirq-irq-add-a-dynamic-irq-creation-api.patch
genirq-ia64-irq-dynamic-irq-support.patch
genirq-i386-irq-dynamic-irq-support.patch
genirq-x86_64-irq-dynamic-irq-support.patch
genirq-msi-make-the-msi-code-irq-based-and-not-vector-based.patch
genirq-x86_64-irq-move-msi-message-composition-into-io_apicc.patch
genirq-i386-irq-move-msi-message-composition-into-io_apicc.patch
genirq-msi-only-build-msi-apicc-on-ia64.patch
genirq-x86_64-irq-remove-the-msi-assumption-that-irq-==-vector.patch
genirq-i386-irq-remove-the-msi-assumption-that-irq-==-vector.patch
genirq-irq-remove-msi-hacks.patch
genirq-irq-generalize-the-check-for-hardirq_bits.patch
genirq-x86_64-irq-make-the-external-irq-handlers-report-their-vector-not-the-irq-number.patch
genirq-x86_64-irq-make-vector_irq-per-cpu.patch
genirq-x86_64-irq-kill-gsi_irq_sharing.patch
genirq-x86_64-irq-kill-irq-compression.patch
detect-atomic-counter-underflows.patch
debug-shared-irqs.patch
make-frame_pointer-default=y.patch
mutex-subsystem-synchro-test-module.patch
vdso-print-fatal-signals.patch
vdso-improve-print_fatal_signals-support-by-adding-memory-maps.patch
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