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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-03-11 17:10:07 +1100 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-03-11 17:10:07 +1100 |
commit | e14eee56c2280953c6e3d24d5dce42bd90836b81 (patch) | |
tree | 21ab792d9ad6fbbab460058f352a0158f995644e /kernel/trace | |
parent | d6ee6f7e4c74d9a0fed7544f4d389bde004651d3 (diff) | |
parent | 99adcd9d67aaf04e28f5ae96df280f236bde4b66 (diff) | |
download | op-kernel-dev-e14eee56c2280953c6e3d24d5dce42bd90836b81.zip op-kernel-dev-e14eee56c2280953c6e3d24d5dce42bd90836b81.tar.gz |
Merge commit 'origin/master' into next
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/Kconfig | 2 | ||||
-rw-r--r-- | kernel/trace/ftrace.c | 6 | ||||
-rw-r--r-- | kernel/trace/trace_selftest.c | 19 |
3 files changed, 26 insertions, 1 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 58a93fbd..34e707e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -52,6 +52,7 @@ config FUNCTION_TRACER depends on HAVE_FUNCTION_TRACER depends on DEBUG_KERNEL select FRAME_POINTER + select KALLSYMS select TRACING select CONTEXT_SWITCH_TRACER help @@ -238,6 +239,7 @@ config STACK_TRACER depends on DEBUG_KERNEL select FUNCTION_TRACER select STACKTRACE + select KALLSYMS help This special tracer records the maximum stack footprint of the kernel and displays it in debugfs/tracing/stack_trace. diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 9a236ff..fdf913d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2033,7 +2033,7 @@ free: static int start_graph_tracing(void) { struct ftrace_ret_stack **ret_stack_list; - int ret; + int ret, cpu; ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * sizeof(struct ftrace_ret_stack *), @@ -2042,6 +2042,10 @@ static int start_graph_tracing(void) if (!ret_stack_list) return -ENOMEM; + /* The cpu_boot init_task->ret_stack will never be freed */ + for_each_online_cpu(cpu) + ftrace_graph_init_task(idle_task(cpu)); + do { ret = alloc_retstack_tasklist(ret_stack_list); } while (ret == -EAGAIN); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 88c8eb7..bc8e80a 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -23,10 +23,20 @@ static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) { struct ring_buffer_event *event; struct trace_entry *entry; + unsigned int loops = 0; while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) { entry = ring_buffer_event_data(event); + /* + * The ring buffer is a size of trace_buf_size, if + * we loop more than the size, there's something wrong + * with the ring buffer. + */ + if (loops++ > trace_buf_size) { + printk(KERN_CONT ".. bad ring buffer "); + goto failed; + } if (!trace_valid_entry(entry)) { printk(KERN_CONT ".. invalid entry %d ", entry->type); @@ -57,11 +67,20 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) cnt = ring_buffer_entries(tr->buffer); + /* + * The trace_test_buffer_cpu runs a while loop to consume all data. + * If the calling tracer is broken, and is constantly filling + * the buffer, this will run forever, and hard lock the box. + * We disable the ring buffer while we do this test to prevent + * a hard lock up. + */ + tracing_off(); for_each_possible_cpu(cpu) { ret = trace_test_buffer_cpu(tr, cpu); if (ret) break; } + tracing_on(); __raw_spin_unlock(&ftrace_max_lock); local_irq_restore(flags); |