| /* |
| * |
| * Function graph tracer. |
| * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com> |
| * Mostly borrowed from function tracer which |
| * is Copyright (c) Steven Rostedt <srostedt@redhat.com> |
| * |
| */ |
| #include <linux/debugfs.h> |
| #include <linux/uaccess.h> |
| #include <linux/ftrace.h> |
| #include <linux/fs.h> |
| |
| #include "trace.h" |
| #include "trace_output.h" |
| |
| struct fgraph_cpu_data { |
| pid_t last_pid; |
| int depth; |
| int ignore; |
| }; |
| |
| 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 |
| |
| /* Flag options */ |
| #define TRACE_GRAPH_PRINT_OVERRUN 0x1 |
| #define TRACE_GRAPH_PRINT_CPU 0x2 |
| #define TRACE_GRAPH_PRINT_OVERHEAD 0x4 |
| #define TRACE_GRAPH_PRINT_PROC 0x8 |
| #define TRACE_GRAPH_PRINT_DURATION 0x10 |
| #define TRACE_GRAPH_PRINT_ABS_TIME 0X20 |
| |
| static struct tracer_opt trace_opts[] = { |
| /* Display overruns? (for self-debug purpose) */ |
| { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) }, |
| /* Display CPU ? */ |
| { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) }, |
| /* Display Overhead ? */ |
| { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) }, |
| /* Display proc name/pid */ |
| { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) }, |
| /* Display duration of execution */ |
| { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) }, |
| /* Display absolute time of an entry */ |
| { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, |
| { } /* Empty entry */ |
| }; |
| |
| static struct tracer_flags tracer_flags = { |
| /* Don't display overruns and proc by default */ |
| .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD | |
| TRACE_GRAPH_PRINT_DURATION, |
| .opts = trace_opts |
| }; |
| |
| 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, |
| unsigned long frame_pointer) |
| { |
| unsigned long long calltime; |
| int index; |
| |
| if (!current->ret_stack) |
| return -EBUSY; |
| |
| /* |
| * We must make sure the ret_stack is tested before we read |
| * anything else. |
| */ |
| smp_rmb(); |
| |
| /* The return trace stack is full */ |
| if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) { |
| atomic_inc(¤t->trace_overrun); |
| return -EBUSY; |
| } |
| |
| calltime = trace_clock_local(); |
| |
| index = ++current->curr_ret_stack; |
| barrier(); |
| current->ret_stack[index].ret = ret; |
| 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, |
| unsigned long frame_pointer) |
| { |
| int index; |
| |
| index = current->curr_ret_stack; |
| |
| if (unlikely(index < 0)) { |
| ftrace_graph_stop(); |
| WARN_ON(1); |
| /* Might as well panic, otherwise we have no where to go */ |
| *ret = (unsigned long)panic; |
| 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; |
| trace->overrun = atomic_read(¤t->trace_overrun); |
| trace->depth = index; |
| } |
| |
| /* |
| * Send the trace to the ring-buffer. |
| * @return the original return address. |
| */ |
| unsigned long ftrace_return_to_handler(unsigned long frame_pointer) |
| { |
| struct ftrace_graph_ret trace; |
| unsigned long ret; |
| |
| ftrace_pop_return_trace(&trace, &ret, frame_pointer); |
| trace.rettime = trace_clock_local(); |
| ftrace_graph_return(&trace); |
| barrier(); |
| current->curr_ret_stack--; |
| |
| if (unlikely(!ret)) { |
| ftrace_graph_stop(); |
| WARN_ON(1); |
| /* Might as well panic. What else to do? */ |
| ret = (unsigned long)panic; |
| } |
| |
| 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(per_cpu_var(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 (unlikely(!tr)) |
| return 0; |
| |
| if (!ftrace_trace_task(current)) |
| return 0; |
| |
| if (!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; |
| } |
| /* Only do the atomic if it is not already set */ |
| if (!test_tsk_trace_graph(current)) |
| set_tsk_trace_graph(current); |
| |
| atomic_dec(&data->disabled); |
| local_irq_restore(flags); |
| |
| return ret; |
| } |
| |
| 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(per_cpu_var(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); |
| } |
| if (!trace->depth) |
| clear_tsk_trace_graph(current); |
| atomic_dec(&data->disabled); |
| local_irq_restore(flags); |
| } |
| |
| static int graph_trace_init(struct trace_array *tr) |
| { |
| int ret; |
| |
| graph_array = tr; |
| ret = register_ftrace_graph(&trace_graph_return, |
| &trace_graph_entry); |
| if (ret) |
| return ret; |
| tracing_start_cmdline_record(); |
| |
| return 0; |
| } |
| |
| void set_graph_array(struct trace_array *tr) |
| { |
| graph_array = tr; |
| } |
| |
| static void graph_trace_reset(struct trace_array *tr) |
| { |
| tracing_stop_cmdline_record(); |
| unregister_ftrace_graph(); |
| } |
| |
| static int max_bytes_for_cpu; |
| |
| static enum print_line_t |
| print_graph_cpu(struct trace_seq *s, int cpu) |
| { |
| int ret; |
| |
| /* |
| * 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, " %*d) ", max_bytes_for_cpu, cpu); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| #define TRACE_GRAPH_PROCINFO_LENGTH 14 |
| |
| static enum print_line_t |
| print_graph_proc(struct trace_seq *s, pid_t pid) |
| { |
| char comm[TASK_COMM_LEN]; |
| /* sign + log10(MAX_INT) + '\0' */ |
| char pid_str[11]; |
| int spaces = 0; |
| int ret; |
| int len; |
| int i; |
| |
| trace_find_cmdline(pid, comm); |
| comm[7] = '\0'; |
| sprintf(pid_str, "%d", pid); |
| |
| /* 1 stands for the "-" character */ |
| len = strlen(comm) + strlen(pid_str) + 1; |
| |
| if (len < TRACE_GRAPH_PROCINFO_LENGTH) |
| spaces = TRACE_GRAPH_PROCINFO_LENGTH - len; |
| |
| /* First spaces to align center */ |
| for (i = 0; i < spaces / 2; i++) { |
| ret = trace_seq_printf(s, " "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| ret = trace_seq_printf(s, "%s-%s", comm, pid_str); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* Last spaces to align center */ |
| for (i = 0; i < spaces - (spaces / 2); i++) { |
| ret = trace_seq_printf(s, " "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| |
| 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) |
| { |
| pid_t prev_pid; |
| pid_t *last_pid; |
| int ret; |
| |
| if (!data) |
| return TRACE_TYPE_HANDLED; |
| |
| last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); |
| |
| if (*last_pid == pid) |
| return TRACE_TYPE_HANDLED; |
| |
| prev_pid = *last_pid; |
| *last_pid = pid; |
| |
| if (prev_pid == -1) |
| return TRACE_TYPE_HANDLED; |
| /* |
| * Context-switch trace line: |
| |
| ------------------------------------------ |
| | 1) migration/0--1 => sshd-1755 |
| ------------------------------------------ |
| |
| */ |
| ret = trace_seq_printf(s, |
| " ------------------------------------------\n"); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| ret = print_graph_cpu(s, cpu); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| ret = print_graph_proc(s, prev_pid); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| ret = trace_seq_printf(s, " => "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| ret = print_graph_proc(s, pid); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| ret = trace_seq_printf(s, |
| "\n ------------------------------------------\n\n"); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| static struct ftrace_graph_ret_entry * |
| get_return_for_leaf(struct trace_iterator *iter, |
| struct ftrace_graph_ent_entry *curr) |
| { |
| struct fgraph_data *data = iter->private; |
| struct ring_buffer_iter *ring_iter = NULL; |
| struct ring_buffer_event *event; |
| struct ftrace_graph_ret_entry *next; |
| |
| /* |
| * 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); |
| } |
| |
| if (!event) |
| return NULL; |
| |
| 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 (curr->ent.pid != next->ent.pid || |
| curr->graph_ent.func != next->ret.func) |
| return NULL; |
| |
| /* this is a leaf, now advance the iterator */ |
| if (ring_iter) |
| ring_buffer_read(ring_iter, NULL); |
| |
| return next; |
| } |
| |
| /* Signal a overhead of time execution to the output */ |
| static int |
| print_graph_overhead(unsigned long long duration, struct trace_seq *s) |
| { |
| /* If duration disappear, we don't need anything */ |
| if (!(tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)) |
| return 1; |
| |
| /* Non nested entry or return */ |
| if (duration == -1) |
| return trace_seq_printf(s, " "); |
| |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) { |
| /* Duration exceeded 100 msecs */ |
| if (duration > 100000ULL) |
| return trace_seq_printf(s, "! "); |
| |
| /* Duration exceeded 10 msecs */ |
| if (duration > 10000ULL) |
| return trace_seq_printf(s, "+ "); |
| } |
| |
| return trace_seq_printf(s, " "); |
| } |
| |
| static int print_graph_abs_time(u64 t, struct trace_seq *s) |
| { |
| unsigned long usecs_rem; |
| |
| usecs_rem = do_div(t, NSEC_PER_SEC); |
| usecs_rem /= 1000; |
| |
| return trace_seq_printf(s, "%5lu.%06lu | ", |
| (unsigned long)t, usecs_rem); |
| } |
| |
| static enum print_line_t |
| print_graph_irq(struct trace_iterator *iter, unsigned long addr, |
| enum trace_type type, int cpu, pid_t pid) |
| { |
| int ret; |
| struct trace_seq *s = &iter->seq; |
| |
| if (addr < (unsigned long)__irqentry_text_start || |
| addr >= (unsigned long)__irqentry_text_end) |
| return TRACE_TYPE_UNHANDLED; |
| |
| /* Absolute time */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) { |
| ret = print_graph_abs_time(iter->ts, s); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* Cpu */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) { |
| ret = print_graph_cpu(s, cpu); |
| 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); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| ret = trace_seq_printf(s, " | "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* No overhead */ |
| ret = print_graph_overhead(-1, s); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| if (type == TRACE_GRAPH_ENT) |
| ret = trace_seq_printf(s, "==========>"); |
| else |
| ret = trace_seq_printf(s, "<=========="); |
| |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* Don't close the duration column if haven't one */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) |
| trace_seq_printf(s, " |"); |
| ret = trace_seq_printf(s, "\n"); |
| |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| enum print_line_t |
| trace_print_graph_duration(unsigned long long duration, struct trace_seq *s) |
| { |
| unsigned long nsecs_rem = do_div(duration, 1000); |
| /* log10(ULONG_MAX) + '\0' */ |
| char msecs_str[21]; |
| char nsecs_str[5]; |
| int ret, len; |
| int i; |
| |
| sprintf(msecs_str, "%lu", (unsigned long) duration); |
| |
| /* Print msecs */ |
| ret = trace_seq_printf(s, "%s", msecs_str); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| len = strlen(msecs_str); |
| |
| /* Print nsecs (we don't want to exceed 7 numbers) */ |
| if (len < 7) { |
| snprintf(nsecs_str, 8 - len, "%03lu", nsecs_rem); |
| ret = trace_seq_printf(s, ".%s", nsecs_str); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| len += strlen(nsecs_str); |
| } |
| |
| ret = trace_seq_printf(s, " us "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* Print remaining spaces to fit the row's width */ |
| for (i = len; i < 7; i++) { |
| ret = trace_seq_printf(s, " "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| static enum print_line_t |
| print_graph_duration(unsigned long long duration, struct trace_seq *s) |
| { |
| int ret; |
| |
| ret = trace_print_graph_duration(duration, s); |
| if (ret != TRACE_TYPE_HANDLED) |
| return ret; |
| |
| ret = trace_seq_printf(s, "| "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| /* Case of a leaf function on its call entry */ |
| static enum print_line_t |
| print_graph_entry_leaf(struct trace_iterator *iter, |
| struct ftrace_graph_ent_entry *entry, |
| struct ftrace_graph_ret_entry *ret_entry, struct trace_seq *s) |
| { |
| struct fgraph_data *data = iter->private; |
| struct ftrace_graph_ret *graph_ret; |
| struct ftrace_graph_ent *call; |
| unsigned long long duration; |
| int ret; |
| int i; |
| |
| graph_ret = &ret_entry->ret; |
| call = &entry->graph_ent; |
| duration = graph_ret->rettime - graph_ret->calltime; |
| |
| if (data) { |
| int cpu = iter->cpu; |
| int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); |
| |
| /* |
| * Comments display at + 1 to depth. Since |
| * this is a leaf function, keep the comments |
| * equal to this depth. |
| */ |
| *depth = call->depth - 1; |
| } |
| |
| /* Overhead */ |
| ret = print_graph_overhead(duration, s); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* Duration */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) { |
| ret = print_graph_duration(duration, s); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* Function */ |
| for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) { |
| ret = trace_seq_printf(s, " "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| ret = trace_seq_printf(s, "%ps();\n", (void *)call->func); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| static enum print_line_t |
| print_graph_entry_nested(struct trace_iterator *iter, |
| struct ftrace_graph_ent_entry *entry, |
| struct trace_seq *s, int cpu) |
| { |
| struct ftrace_graph_ent *call = &entry->graph_ent; |
| struct fgraph_data *data = iter->private; |
| int ret; |
| int i; |
| |
| if (data) { |
| int cpu = iter->cpu; |
| int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); |
| |
| *depth = call->depth; |
| } |
| |
| /* No overhead */ |
| ret = print_graph_overhead(-1, s); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* No time */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) { |
| ret = trace_seq_printf(s, " | "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* Function */ |
| for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) { |
| ret = trace_seq_printf(s, " "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* |
| * we already consumed the current entry to check the next one |
| * and see if this is a leaf. |
| */ |
| return TRACE_TYPE_NO_CONSUME; |
| } |
| |
| static enum print_line_t |
| print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s, |
| int type, unsigned long addr) |
| { |
| struct fgraph_data *data = iter->private; |
| struct trace_entry *ent = iter->ent; |
| int cpu = iter->cpu; |
| int ret; |
| |
| /* Pid */ |
| if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| if (type) { |
| /* Interrupt */ |
| ret = print_graph_irq(iter, addr, type, cpu, ent->pid); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* Absolute time */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) { |
| ret = print_graph_abs_time(iter->ts, s); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* Cpu */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) { |
| ret = print_graph_cpu(s, cpu); |
| 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, ent->pid); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| ret = trace_seq_printf(s, " | "); |
| if (!ret) |
| 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; |
| } |
| |
| static enum print_line_t |
| print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, |
| struct trace_iterator *iter) |
| { |
| 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) |
| ret = print_graph_entry_leaf(iter, field, leaf_ret, s); |
| else |
| 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 |
| print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, |
| struct trace_entry *ent, struct trace_iterator *iter) |
| { |
| unsigned long long duration = trace->rettime - trace->calltime; |
| struct fgraph_data *data = iter->private; |
| pid_t pid = ent->pid; |
| int cpu = iter->cpu; |
| int ret; |
| int i; |
| |
| if (data) { |
| int cpu = iter->cpu; |
| int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); |
| |
| /* |
| * 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; |
| } |
| |
| if (print_graph_prologue(iter, s, 0, 0)) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* Overhead */ |
| ret = print_graph_overhead(duration, s); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* Duration */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) { |
| ret = print_graph_duration(duration, s); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* Closing brace */ |
| for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) { |
| ret = trace_seq_printf(s, " "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| ret = trace_seq_printf(s, "}\n"); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* Overrun */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) { |
| ret = trace_seq_printf(s, " (Overruns: %lu)\n", |
| trace->overrun); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, cpu, pid); |
| if (ret == TRACE_TYPE_PARTIAL_LINE) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| static enum print_line_t |
| print_graph_comment(struct trace_seq *s, struct trace_entry *ent, |
| struct trace_iterator *iter) |
| { |
| unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
| struct fgraph_data *data = iter->private; |
| struct trace_event *event; |
| int depth = 0; |
| int ret; |
| int i; |
| |
| if (data) |
| depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth; |
| |
| if (print_graph_prologue(iter, s, 0, 0)) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* No overhead */ |
| ret = print_graph_overhead(-1, s); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| /* No time */ |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) { |
| ret = trace_seq_printf(s, " | "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* Indentation */ |
| if (depth > 0) |
| for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) { |
| ret = trace_seq_printf(s, " "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| } |
| |
| /* The comment */ |
| ret = trace_seq_printf(s, "/* "); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| switch (iter->ent->type) { |
| case TRACE_BPRINT: |
| ret = trace_print_bprintk_msg_only(iter); |
| if (ret != TRACE_TYPE_HANDLED) |
| return ret; |
| break; |
| case TRACE_PRINT: |
| ret = trace_print_printk_msg_only(iter); |
| if (ret != TRACE_TYPE_HANDLED) |
| return ret; |
| break; |
| default: |
| event = ftrace_find_event(ent->type); |
| if (!event) |
| return TRACE_TYPE_UNHANDLED; |
| |
| ret = event->trace(iter, sym_flags); |
| if (ret != TRACE_TYPE_HANDLED) |
| return ret; |
| } |
| |
| /* Strip ending newline */ |
| if (s->buffer[s->len - 1] == '\n') { |
| s->buffer[s->len - 1] = '\0'; |
| s->len--; |
| } |
| |
| ret = trace_seq_printf(s, " */\n"); |
| if (!ret) |
| return TRACE_TYPE_PARTIAL_LINE; |
| |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| |
| 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: { |
| /* |
| * 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); |
| saved = *field; |
| return print_graph_entry(&saved, s, iter); |
| } |
| case TRACE_GRAPH_RET: { |
| struct ftrace_graph_ret_entry *field; |
| trace_assign_type(field, entry); |
| return print_graph_return(&field->ret, s, entry, iter); |
| } |
| default: |
| return print_graph_comment(s, entry, iter); |
| } |
| |
| 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, "#"); |
| 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"); |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) |
| 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, "#"); |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) |
| seq_printf(s, " | "); |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) |
| seq_printf(s, " | "); |
| if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) |
| 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; |
| int cpu; |
| |
| iter->private = NULL; |
| |
| data = kzalloc(sizeof(*data), GFP_KERNEL); |
| if (!data) |
| 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) |
| { |
| 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, |
| .print_line = print_graph_function, |
| .print_header = print_graph_headers, |
| .flags = &tracer_flags, |
| #ifdef CONFIG_FTRACE_SELFTEST |
| .selftest = trace_selftest_startup_function_graph, |
| #endif |
| }; |
| |
| static __init int init_graph_trace(void) |
| { |
| max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1); |
| |
| return register_tracer(&graph_trace); |
| } |
| |
| device_initcall(init_graph_trace); |