Messages in this thread Patch in this message | | | Date | Tue, 16 Jan 2007 12:56:31 -0500 | From | Mathieu Desnoyers <> | Subject | [PATCH 2/2] lockdep reentrancy |
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Here is a patch to lockdep.c so it behaves correctly when a kprobe breakpoint is put on a marker within hardirq tracing functions as long as the marker is within the lockdep_recursion incremented boundaries. It should apply on 2.6.20-rc4-git3.
Mathieu
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
@@ -1841,33 +1843,36 @@ void trace_hardirqs_on(void) struct task_struct *curr = current; unsigned long ip;
if (unlikely(!debug_locks || current->lockdep_recursion)) return; + current->lockdep_recursion++; + barrier(); + if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled))) - return; + goto end; if (unlikely(curr->hardirqs_enabled)) { debug_atomic_inc(&redundant_hardirqs_on); - return; + goto end; } /* we'll do an OFF -> ON transition: */ curr->hardirqs_enabled = 1; ip = (unsigned long) __builtin_return_address(0); if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) - return; + goto end; if (DEBUG_LOCKS_WARN_ON(current->hardirq_context)) - return; + goto end; /* * We are going to turn hardirqs on, so set the * usage bit for all held locks: */ if (!mark_held_locks(curr, 1, ip)) - return; + goto end; /* * If we have softirqs enabled, then set the usage * bit for all held locks. (disabled hardirqs prevented @@ -1875,11 +1880,14 @@ void trace_hardirqs_on(void) */ if (curr->softirqs_enabled) if (!mark_held_locks(curr, 0, ip)) - return; + goto end; curr->hardirq_enable_ip = ip; curr->hardirq_enable_event = ++curr->irq_events; debug_atomic_inc(&hardirqs_on_events); +end: + barrier(); + current->lockdep_recursion--; } EXPORT_SYMBOL(trace_hardirqs_on); @@ -1888,14 +1896,17 @@ void trace_hardirqs_off(void) { struct task_struct *curr = current; if (unlikely(!debug_locks || current->lockdep_recursion)) return; + current->lockdep_recursion++; + barrier(); + if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) - return; + goto end; if (curr->hardirqs_enabled) { /* @@ -1910,6 +1921,9 @@ void trace_hardirqs_off(void) debug_atomic_inc(&hardirqs_off_events); } else debug_atomic_inc(&redundant_hardirqs_off); +end: + barrier(); + current->lockdep_recursion--; } EXPORT_SYMBOL(trace_hardirqs_off); -- OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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