diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_stack.c | 90 |
1 files changed, 73 insertions, 17 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 4d1e522e3fe8..74c5d9a3afae 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -16,8 +16,10 @@ #define STACK_TRACE_ENTRIES 500 -static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES] = - { [0 ... (STACK_TRACE_ENTRIES-1)] = ULONG_MAX }; +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] = + { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX }; +static unsigned stack_dump_index[STACK_TRACE_ENTRIES]; + static struct stack_trace max_stack_trace = { .max_entries = STACK_TRACE_ENTRIES, .entries = stack_dump_trace, @@ -32,8 +34,9 @@ static DEFINE_PER_CPU(int, trace_active); static inline void check_stack(void) { - unsigned long this_size; - unsigned long flags; + unsigned long this_size, flags; + unsigned long *p, *top, *start; + int i; this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1); this_size = THREAD_SIZE - this_size; @@ -51,10 +54,42 @@ static inline void check_stack(void) max_stack_size = this_size; max_stack_trace.nr_entries = 0; - max_stack_trace.skip = 1; + max_stack_trace.skip = 3; save_stack_trace(&max_stack_trace); + /* + * Now find where in the stack these are. + */ + i = 0; + start = &this_size; + top = (unsigned long *) + (((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE); + + /* + * Loop through all the entries. One of the entries may + * for some reason be missed on the stack, so we may + * have to account for them. If they are all there, this + * loop will only happen once. This code only takes place + * on a new max, so it is far from a fast path. + */ + while (i < max_stack_trace.nr_entries) { + + stack_dump_index[i] = this_size; + p = start; + + for (; p < top && i < max_stack_trace.nr_entries; p++) { + if (*p == stack_dump_trace[i]) { + this_size = stack_dump_index[i++] = + (top - p) * sizeof(unsigned long); + /* Start the search from here */ + start = p + 1; + } + } + + i++; + } + out: __raw_spin_unlock(&max_stack_lock); raw_local_irq_restore(flags); @@ -145,22 +180,24 @@ static struct file_operations stack_max_size_fops = { static void * t_next(struct seq_file *m, void *v, loff_t *pos) { - unsigned long *t = m->private; + long i = (long)m->private; (*pos)++; - if (!t || *t == ULONG_MAX) + i++; + + if (i >= max_stack_trace.nr_entries || + stack_dump_trace[i] == ULONG_MAX) return NULL; - t++; - m->private = t; + m->private = (void *)i; - return t; + return &m->private; } static void *t_start(struct seq_file *m, loff_t *pos) { - unsigned long *t = m->private; + void *t = &m->private; loff_t l = 0; local_irq_disable(); @@ -178,14 +215,15 @@ static void t_stop(struct seq_file *m, void *p) local_irq_enable(); } -static int trace_lookup_stack(struct seq_file *m, unsigned long addr) +static int trace_lookup_stack(struct seq_file *m, long i) { + unsigned long addr = stack_dump_trace[i]; #ifdef CONFIG_KALLSYMS char str[KSYM_SYMBOL_LEN]; sprint_symbol(str, addr); - return seq_printf(m, "[<%p>] %s\n", (void*)addr, str); + return seq_printf(m, "%s\n", str); #else return seq_printf(m, "%p\n", (void*)addr); #endif @@ -193,12 +231,30 @@ static int trace_lookup_stack(struct seq_file *m, unsigned long addr) static int t_show(struct seq_file *m, void *v) { - unsigned long *t = v; + long i = *(long *)v; + int size; + + if (i < 0) { + seq_printf(m, " Depth Size Location" + " (%d entries)\n" + " ----- ---- --------\n", + max_stack_trace.nr_entries); + return 0; + } - if (!t || *t == ULONG_MAX) + if (i >= max_stack_trace.nr_entries || + stack_dump_trace[i] == ULONG_MAX) return 0; - trace_lookup_stack(m, *t); + if (i+1 == max_stack_trace.nr_entries || + stack_dump_trace[i+1] == ULONG_MAX) + size = stack_dump_index[i]; + else + size = stack_dump_index[i] - stack_dump_index[i+1]; + + seq_printf(m, "%3ld) %8d %5d ", i, stack_dump_index[i], size); + + trace_lookup_stack(m, i); return 0; } @@ -217,7 +273,7 @@ static int stack_trace_open(struct inode *inode, struct file *file) ret = seq_open(file, &stack_trace_seq_ops); if (!ret) { struct seq_file *m = file->private_data; - m->private = stack_dump_trace; + m->private = (void *)-1; } return ret; |