#include "trace.h"
#include "trace_output.h"
-struct fgraph_data {
+struct fgraph_cpu_data {
pid_t last_pid;
int depth;
+ int ignore;
+ unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
+};
+
+struct fgraph_data {
+ struct fgraph_cpu_data *cpu_data;
+
+ /* Place to preserve last processed entry. */
+ struct ftrace_graph_ent_entry ent;
+ struct ftrace_graph_ret_entry ret;
+ int failed;
+ int cpu;
};
#define TRACE_GRAPH_INDENT 2
.opts = trace_opts
};
-/* pid on the last trace processed */
+static struct trace_array *graph_array;
/* Add a function return address to the trace stack on thread info.*/
int
-ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth)
+ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
+ unsigned long frame_pointer)
{
unsigned long long calltime;
int index;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = calltime;
current->ret_stack[index].subtime = 0;
+ current->ret_stack[index].fp = frame_pointer;
*depth = index;
return 0;
/* Retrieve a function return address to the trace stack on thread info.*/
static void
-ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
+ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
+ unsigned long frame_pointer)
{
int index;
return;
}
+#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
+ /*
+ * The arch may choose to record the frame pointer used
+ * and check it here to make sure that it is what we expect it
+ * to be. If gcc does not set the place holder of the return
+ * address in the frame pointer, and does a copy instead, then
+ * the function graph trace will fail. This test detects this
+ * case.
+ *
+ * Currently, x86_32 with optimize for size (-Os) makes the latest
+ * gcc do the above.
+ */
+ if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
+ ftrace_graph_stop();
+ WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
+ " from func %ps return to %lx\n",
+ current->ret_stack[index].fp,
+ frame_pointer,
+ (void *)current->ret_stack[index].func,
+ current->ret_stack[index].ret);
+ *ret = (unsigned long)panic;
+ return;
+ }
+#endif
+
*ret = current->ret_stack[index].ret;
trace->func = current->ret_stack[index].func;
trace->calltime = current->ret_stack[index].calltime;
* Send the trace to the ring-buffer.
* @return the original return address.
*/
-unsigned long ftrace_return_to_handler(void)
+unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
{
struct ftrace_graph_ret trace;
unsigned long ret;
- ftrace_pop_return_trace(&trace, &ret);
+ ftrace_pop_return_trace(&trace, &ret, frame_pointer);
trace.rettime = trace_clock_local();
ftrace_graph_return(&trace);
barrier();
return ret;
}
+static int __trace_graph_entry(struct trace_array *tr,
+ struct ftrace_graph_ent *trace,
+ unsigned long flags,
+ int pc)
+{
+ struct ftrace_event_call *call = &event_funcgraph_entry;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer = tr->buffer;
+ struct ftrace_graph_ent_entry *entry;
+
+ if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
+ return 0;
+
+ event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
+ sizeof(*entry), flags, pc);
+ if (!event)
+ return 0;
+ entry = ring_buffer_event_data(event);
+ entry->graph_ent = *trace;
+ if (!filter_current_check_discard(buffer, call, entry, event))
+ ring_buffer_unlock_commit(buffer, event);
+
+ return 1;
+}
+
+int trace_graph_entry(struct ftrace_graph_ent *trace)
+{
+ struct trace_array *tr = graph_array;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int ret;
+ int cpu;
+ int pc;
+
+ if (!ftrace_trace_task(current))
+ return 0;
+
+ /* trace it when it is-nested-in or is a function enabled. */
+ if (!(trace->depth || ftrace_graph_addr(trace->func)))
+ return 0;
+
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+ if (likely(disabled == 1)) {
+ pc = preempt_count();
+ ret = __trace_graph_entry(tr, trace, flags, pc);
+ } else {
+ ret = 0;
+ }
+
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
+{
+ if (tracing_thresh)
+ return 1;
+ else
+ return trace_graph_entry(trace);
+}
+
+static void __trace_graph_return(struct trace_array *tr,
+ struct ftrace_graph_ret *trace,
+ unsigned long flags,
+ int pc)
+{
+ struct ftrace_event_call *call = &event_funcgraph_exit;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer = tr->buffer;
+ struct ftrace_graph_ret_entry *entry;
+
+ if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
+ return;
+
+ event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
+ sizeof(*entry), flags, pc);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ entry->ret = *trace;
+ if (!filter_current_check_discard(buffer, call, entry, event))
+ ring_buffer_unlock_commit(buffer, event);
+}
+
+void trace_graph_return(struct ftrace_graph_ret *trace)
+{
+ struct trace_array *tr = graph_array;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu;
+ int pc;
+
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+ if (likely(disabled == 1)) {
+ pc = preempt_count();
+ __trace_graph_return(tr, trace, flags, pc);
+ }
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
+}
+
+void set_graph_array(struct trace_array *tr)
+{
+ graph_array = tr;
+
+ /* Make graph_array visible before we start tracing */
+
+ smp_mb();
+}
+
+void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
+{
+ if (tracing_thresh &&
+ (trace->rettime - trace->calltime < tracing_thresh))
+ return;
+ else
+ trace_graph_return(trace);
+}
+
static int graph_trace_init(struct trace_array *tr)
{
- int ret = register_ftrace_graph(&trace_graph_return,
- &trace_graph_entry);
+ int ret;
+
+ set_graph_array(tr);
+ if (tracing_thresh)
+ ret = register_ftrace_graph(&trace_graph_thresh_return,
+ &trace_graph_thresh_entry);
+ else
+ ret = register_ftrace_graph(&trace_graph_return,
+ &trace_graph_entry);
if (ret)
return ret;
tracing_start_cmdline_record();
unregister_ftrace_graph();
}
-static inline int log10_cpu(int nb)
-{
- if (nb / 100)
- return 3;
- if (nb / 10)
- return 2;
- return 1;
-}
+static int max_bytes_for_cpu;
static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
- int i;
int ret;
- int log10_this = log10_cpu(cpu);
- int log10_all = log10_cpu(cpumask_weight(cpu_online_mask));
-
/*
* Start with a space character - to make it stand out
* to the right a bit when trace output is pasted into
* email:
*/
- ret = trace_seq_printf(s, " ");
-
- /*
- * Tricky - we space the CPU field according to the max
- * number of online CPUs. On a 2-cpu system it would take
- * a maximum of 1 digit - on a 128 cpu system it would
- * take up to 3 digits:
- */
- for (i = 0; i < log10_all - log10_this; i++) {
- ret = trace_seq_printf(s, " ");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
- }
- ret = trace_seq_printf(s, "%d) ", cpu);
+ ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
+static enum print_line_t
+print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
+{
+ if (!trace_seq_putc(s, ' '))
+ return 0;
+
+ return trace_print_lat_fmt(s, entry);
+}
+
/* If the pid changed since the last trace, output this event */
static enum print_line_t
verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
if (!data)
return TRACE_TYPE_HANDLED;
- last_pid = &(per_cpu_ptr(data, cpu)->last_pid);
+ last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
if (*last_pid == pid)
return TRACE_TYPE_HANDLED;
get_return_for_leaf(struct trace_iterator *iter,
struct ftrace_graph_ent_entry *curr)
{
- struct ring_buffer_iter *ring_iter;
+ struct fgraph_data *data = iter->private;
+ struct ring_buffer_iter *ring_iter = NULL;
struct ring_buffer_event *event;
struct ftrace_graph_ret_entry *next;
- ring_iter = iter->buffer_iter[iter->cpu];
+ /*
+ * If the previous output failed to write to the seq buffer,
+ * then we just reuse the data from before.
+ */
+ if (data && data->failed) {
+ curr = &data->ent;
+ next = &data->ret;
+ } else {
+
+ ring_iter = iter->buffer_iter[iter->cpu];
+
+ /* First peek to compare current entry and the next one */
+ if (ring_iter)
+ event = ring_buffer_iter_peek(ring_iter, NULL);
+ else {
+ /*
+ * We need to consume the current entry to see
+ * the next one.
+ */
+ ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
+ event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
+ NULL);
+ }
- /* First peek to compare current entry and the next one */
- if (ring_iter)
- event = ring_buffer_iter_peek(ring_iter, NULL);
- else {
- /* We need to consume the current entry to see the next one */
- ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
- event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
- NULL);
- }
+ if (!event)
+ return NULL;
- if (!event)
- return NULL;
+ next = ring_buffer_event_data(event);
- next = ring_buffer_event_data(event);
+ if (data) {
+ /*
+ * Save current and next entries for later reference
+ * if the output fails.
+ */
+ data->ent = *curr;
+ data->ret = *next;
+ }
+ }
if (next->ent.type != TRACE_GRAPH_RET)
return NULL;
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
}
+
/* Proc */
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
ret = print_graph_proc(s, pid);
duration = graph_ret->rettime - graph_ret->calltime;
if (data) {
+ struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
- int *depth = &(per_cpu_ptr(data, cpu)->depth);
+
+ cpu_data = per_cpu_ptr(data->cpu_data, cpu);
/*
* Comments display at + 1 to depth. Since
* this is a leaf function, keep the comments
* equal to this depth.
*/
- *depth = call->depth - 1;
+ cpu_data->depth = call->depth - 1;
+
+ /* No need to keep this function around for this depth */
+ if (call->depth < FTRACE_RETFUNC_DEPTH)
+ cpu_data->enter_funcs[call->depth] = 0;
}
/* Overhead */
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = seq_print_ip_sym(s, call->func, 0);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- ret = trace_seq_printf(s, "();\n");
+ ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
int i;
if (data) {
+ struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
- int *depth = &(per_cpu_ptr(data, cpu)->depth);
- *depth = call->depth;
+ cpu_data = per_cpu_ptr(data->cpu_data, cpu);
+ cpu_data->depth = call->depth;
+
+ /* Save this function pointer to see if the exit matches */
+ if (call->depth < FTRACE_RETFUNC_DEPTH)
+ cpu_data->enter_funcs[call->depth] = call->func;
}
/* No overhead */
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = seq_print_ip_sym(s, call->func, 0);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- ret = trace_seq_printf(s, "() {\n");
+ ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_PARTIAL_LINE;
}
+ /* Latency format */
+ if (trace_flags & TRACE_ITER_LATENCY_FMT) {
+ ret = print_graph_lat_fmt(s, ent);
+ if (ret == TRACE_TYPE_PARTIAL_LINE)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
return 0;
}
print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
struct trace_iterator *iter)
{
- int cpu = iter->cpu;
+ struct fgraph_data *data = iter->private;
struct ftrace_graph_ent *call = &field->graph_ent;
struct ftrace_graph_ret_entry *leaf_ret;
+ static enum print_line_t ret;
+ int cpu = iter->cpu;
if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func))
return TRACE_TYPE_PARTIAL_LINE;
leaf_ret = get_return_for_leaf(iter, field);
if (leaf_ret)
- return print_graph_entry_leaf(iter, field, leaf_ret, s);
+ ret = print_graph_entry_leaf(iter, field, leaf_ret, s);
else
- return print_graph_entry_nested(iter, field, s, cpu);
+ ret = print_graph_entry_nested(iter, field, s, cpu);
+
+ if (data) {
+ /*
+ * If we failed to write our output, then we need to make
+ * note of it. Because we already consumed our entry.
+ */
+ if (s->full) {
+ data->failed = 1;
+ data->cpu = cpu;
+ } else
+ data->failed = 0;
+ }
+ return ret;
}
static enum print_line_t
struct fgraph_data *data = iter->private;
pid_t pid = ent->pid;
int cpu = iter->cpu;
+ int func_match = 1;
int ret;
int i;
if (data) {
+ struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
- int *depth = &(per_cpu_ptr(data, cpu)->depth);
+
+ cpu_data = per_cpu_ptr(data->cpu_data, cpu);
/*
* Comments display at + 1 to depth. This is the
* return from a function, we now want the comments
* to display at the same level of the bracket.
*/
- *depth = trace->depth - 1;
+ cpu_data->depth = trace->depth - 1;
+
+ if (trace->depth < FTRACE_RETFUNC_DEPTH) {
+ if (cpu_data->enter_funcs[trace->depth] != trace->func)
+ func_match = 0;
+ cpu_data->enter_funcs[trace->depth] = 0;
+ }
}
if (print_graph_prologue(iter, s, 0, 0))
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = trace_seq_printf(s, "}\n");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ /*
+ * If the return function does not have a matching entry,
+ * then the entry was lost. Instead of just printing
+ * the '}' and letting the user guess what function this
+ * belongs to, write out the function name.
+ */
+ if (func_match) {
+ ret = trace_seq_printf(s, "}\n");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ } else {
+ ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
/* Overrun */
if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
int i;
if (data)
- depth = per_cpu_ptr(data, iter->cpu)->depth;
+ depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
if (print_graph_prologue(iter, s, 0, 0))
return TRACE_TYPE_PARTIAL_LINE;
enum print_line_t
print_graph_function(struct trace_iterator *iter)
{
+ struct ftrace_graph_ent_entry *field;
+ struct fgraph_data *data = iter->private;
struct trace_entry *entry = iter->ent;
struct trace_seq *s = &iter->seq;
+ int cpu = iter->cpu;
+ int ret;
+
+ if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
+ per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
+ return TRACE_TYPE_HANDLED;
+ }
+
+ /*
+ * If the last output failed, there's a possibility we need
+ * to print out the missing entry which would never go out.
+ */
+ if (data && data->failed) {
+ field = &data->ent;
+ iter->cpu = data->cpu;
+ ret = print_graph_entry(field, s, iter);
+ if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
+ per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
+ ret = TRACE_TYPE_NO_CONSUME;
+ }
+ iter->cpu = cpu;
+ return ret;
+ }
switch (entry->type) {
case TRACE_GRAPH_ENT: {
- struct ftrace_graph_ent_entry *field;
+ /*
+ * print_graph_entry() may consume the current event,
+ * thus @field may become invalid, so we need to save it.
+ * sizeof(struct ftrace_graph_ent_entry) is very small,
+ * it can be safely saved at the stack.
+ */
+ struct ftrace_graph_ent_entry saved;
trace_assign_type(field, entry);
- return print_graph_entry(field, s, iter);
+ saved = *field;
+ return print_graph_entry(&saved, s, iter);
}
case TRACE_GRAPH_RET: {
struct ftrace_graph_ret_entry *field;
return TRACE_TYPE_HANDLED;
}
+static void print_lat_header(struct seq_file *s)
+{
+ static const char spaces[] = " " /* 16 spaces */
+ " " /* 4 spaces */
+ " "; /* 17 spaces */
+ int size = 0;
+
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
+ size += 16;
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
+ size += 4;
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
+ size += 17;
+
+ seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
+ seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
+ seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
+ seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
+ seq_printf(s, "#%.*s||| / _-=> lock-depth \n", size, spaces);
+ seq_printf(s, "#%.*s|||| / \n", size, spaces);
+}
+
static void print_graph_headers(struct seq_file *s)
{
+ int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
+
+ if (lat)
+ print_lat_header(s);
+
/* 1st line */
- seq_printf(s, "# ");
+ seq_printf(s, "#");
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
seq_printf(s, " TIME ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
- seq_printf(s, "CPU");
+ seq_printf(s, " CPU");
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
- seq_printf(s, " TASK/PID ");
+ seq_printf(s, " TASK/PID ");
+ if (lat)
+ seq_printf(s, "|||||");
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
seq_printf(s, " DURATION ");
seq_printf(s, " FUNCTION CALLS\n");
/* 2nd line */
- seq_printf(s, "# ");
+ seq_printf(s, "#");
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
seq_printf(s, " | ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
- seq_printf(s, "| ");
+ seq_printf(s, " | ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
- seq_printf(s, " | | ");
+ seq_printf(s, " | | ");
+ if (lat)
+ seq_printf(s, "|||||");
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
seq_printf(s, " | | ");
seq_printf(s, " | | | |\n");
static void graph_trace_open(struct trace_iterator *iter)
{
/* pid and depth on the last trace processed */
- struct fgraph_data *data = alloc_percpu(struct fgraph_data);
+ struct fgraph_data *data;
int cpu;
+ iter->private = NULL;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
- pr_warning("function graph tracer: not enough memory\n");
- else
- for_each_possible_cpu(cpu) {
- pid_t *pid = &(per_cpu_ptr(data, cpu)->last_pid);
- int *depth = &(per_cpu_ptr(data, cpu)->depth);
- *pid = -1;
- *depth = 0;
- }
+ goto out_err;
+
+ data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
+ if (!data->cpu_data)
+ goto out_err_free;
+
+ for_each_possible_cpu(cpu) {
+ pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
+ int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
+ int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
+ *pid = -1;
+ *depth = 0;
+ *ignore = 0;
+ }
iter->private = data;
+
+ return;
+
+ out_err_free:
+ kfree(data);
+ out_err:
+ pr_warning("function graph tracer: not enough memory\n");
}
static void graph_trace_close(struct trace_iterator *iter)
{
- free_percpu(iter->private);
+ struct fgraph_data *data = iter->private;
+
+ if (data) {
+ free_percpu(data->cpu_data);
+ kfree(data);
+ }
}
static struct tracer graph_trace __read_mostly = {
.name = "function_graph",
.open = graph_trace_open,
+ .pipe_open = graph_trace_open,
.close = graph_trace_close,
+ .pipe_close = graph_trace_close,
.wait_pipe = poll_wait_pipe,
.init = graph_trace_init,
.reset = graph_trace_reset,
static __init int init_graph_trace(void)
{
+ max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
+
return register_tracer(&graph_trace);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff