{
int len = (PAGE_SIZE - 1) - s->len;
va_list ap;
+ int ret;
if (!len)
return 0;
va_start(ap, fmt);
- len = vsnprintf(s->buffer + s->len, len, fmt, ap);
+ ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
va_end(ap);
- s->len += len;
+ /* If we can't write it all, don't bother writing anything */
+ if (ret > len)
+ return 0;
+
+ s->len += ret;
return len;
}
int len = strlen(str);
if (len > ((PAGE_SIZE - 1) - s->len))
- len = (PAGE_SIZE - 1) - s->len;
+ return 0;
memcpy(s->buffer + s->len, str, len);
s->len += len;
{
struct trace_entry *entry;
+ spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
tracing_generic_entry_update(entry, flags);
entry->type = TRACE_FN;
entry->fn.ip = ip;
entry->fn.parent_ip = parent_ip;
+ spin_unlock(&data->lock);
}
notrace void
{
struct trace_entry *entry;
+ spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
tracing_generic_entry_update(entry, flags);
entry->type = TRACE_CTX;
entry->ctx.prev_state = prev->state;
entry->ctx.next_pid = next->pid;
entry->ctx.next_prio = next->prio;
+ spin_unlock(&data->lock);
}
enum trace_file_type {
struct trace_entry *array;
if (iter->next_idx[cpu] >= tr->entries ||
- iter->next_idx[cpu] >= data->trace_idx)
+ iter->next_idx[cpu] >= data->trace_idx ||
+ (data->trace_head == data->trace_tail &&
+ data->trace_head_idx == data->trace_tail_idx))
return NULL;
if (!iter->next_page[cpu]) {
return next;
}
-static void *find_next_entry_inc(struct trace_iterator *iter)
+static notrace void
+trace_iterator_increment(struct trace_iterator *iter)
{
- struct trace_entry *next;
- int next_cpu = -1;
+ iter->idx++;
+ iter->next_idx[iter->cpu]++;
+ iter->next_page_idx[iter->cpu]++;
+ if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) {
+ struct trace_array_cpu *data = iter->tr->data[iter->cpu];
- next = find_next_entry(iter, &next_cpu);
+ iter->next_page_idx[iter->cpu] = 0;
+ iter->next_page[iter->cpu] =
+ trace_next_list(data, iter->next_page[iter->cpu]);
+ }
+}
- if (next) {
- iter->idx++;
- iter->next_idx[next_cpu]++;
- iter->next_page_idx[next_cpu]++;
+static notrace void
+trace_consume(struct trace_iterator *iter)
+{
+ struct trace_array_cpu *data = iter->tr->data[iter->cpu];
+
+ data->trace_tail_idx++;
+ if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
+ data->trace_tail = trace_next_page(data, data->trace_tail);
+ data->trace_tail_idx = 0;
+ }
- if (iter->next_page_idx[next_cpu] >= ENTRIES_PER_PAGE) {
- struct trace_array_cpu *data = iter->tr->data[next_cpu];
+ /* Check if we empty it, then reset the index */
+ if (data->trace_head == data->trace_tail &&
+ data->trace_head_idx == data->trace_tail_idx)
+ data->trace_idx = 0;
- iter->next_page_idx[next_cpu] = 0;
- iter->next_page[next_cpu] =
- trace_next_list(data, iter->next_page[next_cpu]);
+ trace_iterator_increment(iter);
+}
+
+static notrace void *
+find_next_entry_inc(struct trace_iterator *iter)
+{
+ struct trace_entry *next;
+ int next_cpu = -1;
+
+ next = find_next_entry(iter, &next_cpu);
- }
- }
iter->prev_ent = iter->ent;
iter->prev_cpu = iter->cpu;
iter->ent = next;
iter->cpu = next_cpu;
+ if (next)
+ trace_iterator_increment(iter);
+
return next ? iter : NULL;
}
mutex_unlock(&trace_types_lock);
}
-static void
+static int
seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
kallsyms_lookup(address, NULL, NULL, NULL, str);
- trace_seq_printf(s, fmt, str);
+ return trace_seq_printf(s, fmt, str);
#endif
+ return 1;
}
-static void
+static int
seq_print_sym_offset(struct trace_seq *s, const char *fmt,
unsigned long address)
{
char str[KSYM_SYMBOL_LEN];
sprint_symbol(str, address);
- trace_seq_printf(s, fmt, str);
+ return trace_seq_printf(s, fmt, str);
#endif
+ return 1;
}
#ifndef CONFIG_64BIT
# define IP_FMT "%016lx"
#endif
-static notrace void
+static notrace int
seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
{
- if (!ip) {
- trace_seq_printf(s, "0");
- return;
- }
+ int ret;
+
+ if (!ip)
+ return trace_seq_printf(s, "0");
if (sym_flags & TRACE_ITER_SYM_OFFSET)
- seq_print_sym_offset(s, "%s", ip);
+ ret = seq_print_sym_offset(s, "%s", ip);
else
- seq_print_sym_short(s, "%s", ip);
+ ret = seq_print_sym_short(s, "%s", ip);
+
+ if (!ret)
+ return 0;
if (sym_flags & TRACE_ITER_SYM_ADDR)
- trace_seq_printf(s, " <" IP_FMT ">", ip);
+ ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+ return ret;
}
static notrace void print_lat_help_header(struct seq_file *m)
array->time_offset += prev_t - t;
}
-static notrace void
+static notrace int
print_trace_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
unsigned long secs;
char *comm;
int S;
+ int ret;
sync_time_offset(iter);
entry = iter->ent;
usec_rem = do_div(t, 1000000ULL);
secs = (unsigned long)t;
- trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
- trace_seq_printf(s, "[%02d] ", iter->cpu);
- trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
+ ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
+ if (!ret)
+ return 0;
+ ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+ if (!ret)
+ return 0;
+ ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
+ if (!ret)
+ return 0;
switch (entry->type) {
case TRACE_FN:
- seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+ ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+ if (!ret)
+ return 0;
if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
entry->fn.parent_ip) {
- trace_seq_printf(s, " <-");
- seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+ ret = trace_seq_printf(s, " <-");
+ if (!ret)
+ return 0;
+ ret = seq_print_ip_sym(s, entry->fn.parent_ip,
+ sym_flags);
+ if (!ret)
+ return 0;
}
- trace_seq_printf(s, "\n");
+ ret = trace_seq_printf(s, "\n");
+ if (!ret)
+ return 0;
break;
case TRACE_CTX:
S = entry->ctx.prev_state < sizeof(state_to_char) ?
state_to_char[entry->ctx.prev_state] : 'X';
- trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
- S,
- entry->ctx.next_pid,
- entry->ctx.next_prio);
+ ret = trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S,
+ entry->ctx.next_pid,
+ entry->ctx.next_prio);
+ if (!ret)
+ return 0;
break;
}
+ return 1;
}
static int trace_empty(struct trace_iterator *iter)
for_each_possible_cpu(cpu) {
data = iter->tr->data[cpu];
- if (head_page(data) && data->trace_idx)
+ if (head_page(data) && data->trace_idx &&
+ (data->trace_tail != data->trace_head ||
+ data->trace_tail_idx != data->trace_head_idx))
return 0;
}
return 1;
return cnt;
}
+static atomic_t tracing_reader;
+
+static int tracing_open_pipe(struct inode *inode, struct file *filp)
+{
+ struct trace_iterator *iter;
+
+ if (tracing_disabled)
+ return -ENODEV;
+
+ /* We only allow for reader of the pipe */
+ if (atomic_inc_return(&tracing_reader) != 1) {
+ atomic_dec(&tracing_reader);
+ return -EBUSY;
+ }
+
+ /* create a buffer to store the information to pass to userspace */
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ iter->tr = &global_trace;
+
+ filp->private_data = iter;
+
+ return 0;
+}
+
+static int tracing_release_pipe(struct inode *inode, struct file *file)
+{
+ struct trace_iterator *iter = file->private_data;
+
+ kfree(iter);
+ atomic_dec(&tracing_reader);
+
+ return 0;
+}
+
+/*
+ * Consumer reader.
+ */
+static ssize_t
+tracing_read_pipe(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_iterator *iter = filp->private_data;
+ struct trace_array_cpu *data;
+ static cpumask_t mask;
+ struct trace_entry *entry;
+ static int start;
+ unsigned long flags;
+ int read = 0;
+ int cpu;
+ int len;
+ int ret;
+
+ /* return any leftover data */
+ if (iter->seq.len > start) {
+ len = iter->seq.len - start;
+ if (cnt > len)
+ cnt = len;
+ ret = copy_to_user(ubuf, iter->seq.buffer + start, cnt);
+ if (ret)
+ cnt = -EFAULT;
+
+ start += len;
+
+ return cnt;
+ }
+
+ trace_seq_reset(&iter->seq);
+ start = 0;
+
+ while (trace_empty(iter)) {
+ /*
+ * This is a make-shift waitqueue. The reason we don't use
+ * an actual wait queue is because:
+ * 1) we only ever have one waiter
+ * 2) the tracing, traces all functions, we don't want
+ * the overhead of calling wake_up and friends
+ * (and tracing them too)
+ * Anyway, this is really very primitive wakeup.
+ */
+ set_current_state(TASK_INTERRUPTIBLE);
+ iter->tr->waiter = current;
+
+ /* sleep for one second, and try again. */
+ schedule_timeout(HZ);
+
+ iter->tr->waiter = NULL;
+
+ if (signal_pending(current))
+ return -EINTR;
+
+ /*
+ * We block until we read something and tracing is disabled.
+ * We still block if tracing is disabled, but we have never
+ * read anything. This allows a user to cat this file, and
+ * then enable tracing. But after we have read something,
+ * we give an EOF when tracing is again disabled.
+ *
+ * iter->pos will be 0 if we haven't read anything.
+ */
+ if (!tracer_enabled && iter->pos)
+ break;
+
+ continue;
+ }
+
+ /* stop when tracing is finished */
+ if (trace_empty(iter))
+ return 0;
+
+ if (cnt >= PAGE_SIZE)
+ cnt = PAGE_SIZE - 1;
+
+ memset(iter, 0, sizeof(*iter));
+ iter->tr = &global_trace;
+ iter->pos = -1;
+
+ /*
+ * We need to stop all tracing on all CPUS to read the
+ * the next buffer. This is a bit expensive, but is
+ * not done often. We fill all what we can read,
+ * and then release the locks again.
+ */
+
+ cpus_clear(mask);
+ local_irq_save(flags);
+ for_each_possible_cpu(cpu) {
+ data = iter->tr->data[cpu];
+
+ if (!head_page(data) || !data->trace_idx)
+ continue;
+
+ atomic_inc(&data->disabled);
+ spin_lock(&data->lock);
+ cpu_set(cpu, mask);
+ }
+
+ while ((entry = find_next_entry(iter, &cpu))) {
+
+ if (!entry)
+ break;
+
+ iter->ent = entry;
+ iter->cpu = cpu;
+
+ ret = print_trace_fmt(iter);
+ if (!ret)
+ break;
+
+ trace_consume(iter);
+
+ if (iter->seq.len >= cnt)
+ break;
+
+ }
+
+ for_each_possible_cpu(cpu) {
+ data = iter->tr->data[cpu];
+
+ if (!cpu_isset(cpu, mask))
+ continue;
+ spin_unlock(&data->lock);
+ atomic_dec(&data->disabled);
+ }
+ local_irq_restore(flags);
+
+ /* Now copy what we have to the user */
+ read = iter->seq.len;
+ if (read > cnt)
+ read = cnt;
+
+ ret = copy_to_user(ubuf, iter->seq.buffer, read);
+
+ if (read < iter->seq.len)
+ start = read;
+ else
+ trace_seq_reset(&iter->seq);
+
+ if (ret)
+ read = -EFAULT;
+
+ return read;
+}
+
static struct file_operations tracing_max_lat_fops = {
.open = tracing_open_generic,
.read = tracing_max_lat_read,
.write = tracing_set_trace_write,
};
+static struct file_operations tracing_pipe_fops = {
+ .open = tracing_open_pipe,
+ .read = tracing_read_pipe,
+ .release = tracing_release_pipe,
+};
+
#ifdef CONFIG_DYNAMIC_FTRACE
static ssize_t
if (!entry)
pr_warning("Could not create debugfs 'README' entry\n");
+ entry = debugfs_create_file("trace_pipe", 0644, d_tracer,
+ NULL, &tracing_pipe_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'tracing_threash' entry\n");
#ifdef CONFIG_DYNAMIC_FTRACE
entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
/* Now that we successfully allocate a page per CPU, add them */
for_each_possible_cpu(i) {
data = global_trace.data[i];
+ spin_lock_init(&data->lock);
page = list_entry(pages.next, struct page, lru);
list_del_init(&page->lru);
list_add_tail(&page->lru, &data->trace_pages);
#ifdef CONFIG_TRACER_MAX_TRACE
data = max_tr.data[i];
+ spin_lock_init(&data->lock);
page = list_entry(pages.next, struct page, lru);
list_del_init(&page->lru);
list_add_tail(&page->lru, &data->trace_pages);
projects / linux-2.6-omap-h63xx.git / commitdiff