| /* |
| * |
| * 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/uaccess.h> |
| #include <linux/ftrace.h> |
| #include <linux/interrupt.h> |
| #include <linux/slab.h> |
| #include <linux/fs.h> |
| |
| #include "trace.h" |
| #include "trace_output.h" |
| |
| static bool kill_ftrace_graph; |
| |
| /** |
| * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called |
| * |
| * ftrace_graph_stop() is called when a severe error is detected in |
| * the function graph tracing. This function is called by the critical |
| * paths of function graph to keep those paths from doing any more harm. |
| */ |
| bool ftrace_graph_is_dead(void) |
| { |
| return kill_ftrace_graph; |
| } |
| |
| /** |
| * ftrace_graph_stop - set to permanently disable function graph tracincg |
| * |
| * In case of an error int function graph tracing, this is called |
| * to try to keep function graph tracing from causing any more harm. |
| * Usually this is pretty severe and this is called to try to at least |
| * get a warning out to the user. |
| */ |
| void ftrace_graph_stop(void) |
| { |
| kill_ftrace_graph = true; |
| } |
| |
| /* When set, irq functions will be ignored */ |
| static int ftrace_graph_skip_irqs; |
| |
| struct fgraph_cpu_data { |
| pid_t last_pid; |
| int depth; |
| int depth_irq; |
| int ignore; |
| unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH]; |
| }; |
| |
| struct fgraph_data { |
| struct fgraph_cpu_data __percpu *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 |
| |
| static unsigned int max_depth; |
| |
| 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) }, |
| /* Display interrupts */ |
| { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) }, |
| /* Display function name after trailing } */ |
| { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) }, |
| /* Include sleep time (scheduled out) between entry and return */ |
| { TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) }, |
| /* Include time within nested functions */ |
| { TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) }, |
| { } /* Empty entry */ |
| }; |
| |
| static struct tracer_flags tracer_flags = { |
| /* Don't display overruns, proc, or tail by default */ |
| .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD | |
| TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS | |
| TRACE_GRAPH_SLEEP_TIME | TRACE_GRAPH_GRAPH_TIME, |
| .opts = trace_opts |
| }; |
| |
| static struct trace_array *graph_array; |
| |
| /* |
| * DURATION column is being also used to display IRQ signs, |
| * following values are used by print_graph_irq and others |
| * to fill in space into DURATION column. |
| */ |
| enum { |
| FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT, |
| FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT, |
| FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT, |
| }; |
| |
| static void |
| print_graph_duration(struct trace_array *tr, unsigned long long duration, |
| struct trace_seq *s, u32 flags); |
| |
| /* 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 *retp) |
| { |
| unsigned long long calltime; |
| int index; |
| |
| if (unlikely(ftrace_graph_is_dead())) |
| return -EBUSY; |
| |
| 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; |
| } |
| |
| /* |
| * The curr_ret_stack is an index to ftrace return stack of |
| * current task. Its value should be in [0, FTRACE_RETFUNC_ |
| * DEPTH) when the function graph tracer is used. To support |
| * filtering out specific functions, it makes the index |
| * negative by subtracting huge value (FTRACE_NOTRACE_DEPTH) |
| * so when it sees a negative index the ftrace will ignore |
| * the record. And the index gets recovered when returning |
| * from the filtered function by adding the FTRACE_NOTRACE_ |
| * DEPTH and then it'll continue to record functions normally. |
| * |
| * The curr_ret_stack is initialized to -1 and get increased |
| * in this function. So it can be less than -1 only if it was |
| * filtered out via ftrace_graph_notrace_addr() which can be |
| * set from set_graph_notrace file in tracefs by user. |
| */ |
| if (current->curr_ret_stack < -1) |
| return -EBUSY; |
| |
| calltime = trace_clock_local(); |
| |
| index = ++current->curr_ret_stack; |
| if (ftrace_graph_notrace_addr(func)) |
| current->curr_ret_stack -= FTRACE_NOTRACE_DEPTH; |
| barrier(); |
| current->ret_stack[index].ret = ret; |
| current->ret_stack[index].func = func; |
| current->ret_stack[index].calltime = calltime; |
| #ifdef HAVE_FUNCTION_GRAPH_FP_TEST |
| current->ret_stack[index].fp = frame_pointer; |
| #endif |
| #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR |
| current->ret_stack[index].retp = retp; |
| #endif |
| *depth = current->curr_ret_stack; |
| |
| 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; |
| |
| /* |
| * A negative index here means that it's just returned from a |
| * notrace'd function. Recover index to get an original |
| * return address. See ftrace_push_return_trace(). |
| * |
| * TODO: Need to check whether the stack gets corrupted. |
| */ |
| if (index < 0) |
| index += FTRACE_NOTRACE_DEPTH; |
| |
| if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) { |
| ftrace_graph_stop(); |
| WARN_ON(1); |
| /* Might as well panic, otherwise we have no where to go */ |
| *ret = (unsigned long)panic; |
| return; |
| } |
| |
| #ifdef 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. |
| * |
| * Note, -mfentry does not use frame pointers, and this test |
| * is not needed if CC_USING_FENTRY is set. |
| */ |
| 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(); |
| barrier(); |
| current->curr_ret_stack--; |
| /* |
| * The curr_ret_stack can be less than -1 only if it was |
| * filtered out and it's about to return from the function. |
| * Recover the index and continue to trace normal functions. |
| */ |
| if (current->curr_ret_stack < -1) { |
| current->curr_ret_stack += FTRACE_NOTRACE_DEPTH; |
| return ret; |
| } |
| |
| /* |
| * The trace should run after decrementing the ret counter |
| * in case an interrupt were to come in. We don't want to |
| * lose the interrupt if max_depth is set. |
| */ |
| ftrace_graph_return(&trace); |
| |
| if (unlikely(!ret)) { |
| ftrace_graph_stop(); |
| WARN_ON(1); |
| /* Might as well panic. What else to do? */ |
| ret = (unsigned long)panic; |
| } |
| |
| return ret; |
| } |
| |
| /** |
| * ftrace_graph_ret_addr - convert a potentially modified stack return address |
| * to its original value |
| * |
| * This function can be called by stack unwinding code to convert a found stack |
| * return address ('ret') to its original value, in case the function graph |
| * tracer has modified it to be 'return_to_handler'. If the address hasn't |
| * been modified, the unchanged value of 'ret' is returned. |
| * |
| * 'idx' is a state variable which should be initialized by the caller to zero |
| * before the first call. |
| * |
| * 'retp' is a pointer to the return address on the stack. It's ignored if |
| * the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined. |
| */ |
| #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR |
| unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, |
| unsigned long ret, unsigned long *retp) |
| { |
| int index = task->curr_ret_stack; |
| int i; |
| |
| if (ret != (unsigned long)return_to_handler) |
| return ret; |
| |
| if (index < -1) |
| index += FTRACE_NOTRACE_DEPTH; |
| |
| if (index < 0) |
| return ret; |
| |
| for (i = 0; i <= index; i++) |
| if (task->ret_stack[i].retp == retp) |
| return task->ret_stack[i].ret; |
| |
| return ret; |
| } |
| #else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */ |
| unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, |
| unsigned long ret, unsigned long *retp) |
| { |
| int task_idx; |
| |
| if (ret != (unsigned long)return_to_handler) |
| return ret; |
| |
| task_idx = task->curr_ret_stack; |
| |
| if (!task->ret_stack || task_idx < *idx) |
| return ret; |
| |
| task_idx -= *idx; |
| (*idx)++; |
| |
| return task->ret_stack[task_idx].ret; |
| } |
| #endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */ |
| |
| int __trace_graph_entry(struct trace_array *tr, |
| struct ftrace_graph_ent *trace, |
| unsigned long flags, |
| int pc) |
| { |
| struct trace_event_call *call = &event_funcgraph_entry; |
| struct ring_buffer_event *event; |
| struct ring_buffer *buffer = tr->trace_buffer.buffer; |
| struct ftrace_graph_ent_entry *entry; |
| |
| 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 (!call_filter_check_discard(call, entry, buffer, event)) |
| __buffer_unlock_commit(buffer, event); |
| |
| return 1; |
| } |
| |
| static inline int ftrace_graph_ignore_irqs(void) |
| { |
| if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT)) |
| return 0; |
| |
| return in_irq(); |
| } |
| |
| 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(tr)) |
| return 0; |
| |
| /* trace it when it is-nested-in or is a function enabled. */ |
| if ((!(trace->depth || ftrace_graph_addr(trace->func)) || |
| ftrace_graph_ignore_irqs()) || (trace->depth < 0) || |
| (max_depth && trace->depth >= max_depth)) |
| return 0; |
| |
| /* |
| * Do not trace a function if it's filtered by set_graph_notrace. |
| * Make the index of ret stack negative to indicate that it should |
| * ignore further functions. But it needs its own ret stack entry |
| * to recover the original index in order to continue tracing after |
| * returning from the function. |
| */ |
| if (ftrace_graph_notrace_addr(trace->func)) |
| return 1; |
| |
| /* |
| * Stop here if tracing_threshold is set. We only write function return |
| * events to the ring buffer. |
| */ |
| if (tracing_thresh) |
| return 1; |
| |
| local_irq_save(flags); |
| cpu = raw_smp_processor_id(); |
| data = per_cpu_ptr(tr->trace_buffer.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; |
| } |
| |
| static void |
| __trace_graph_function(struct trace_array *tr, |
| unsigned long ip, unsigned long flags, int pc) |
| { |
| u64 time = trace_clock_local(); |
| struct ftrace_graph_ent ent = { |
| .func = ip, |
| .depth = 0, |
| }; |
| struct ftrace_graph_ret ret = { |
| .func = ip, |
| .depth = 0, |
| .calltime = time, |
| .rettime = time, |
| }; |
| |
| __trace_graph_entry(tr, &ent, flags, pc); |
| __trace_graph_return(tr, &ret, flags, pc); |
| } |
| |
| void |
| trace_graph_function(struct trace_array *tr, |
| unsigned long ip, unsigned long parent_ip, |
| unsigned long flags, int pc) |
| { |
| __trace_graph_function(tr, ip, flags, pc); |
| } |
| |
| void __trace_graph_return(struct trace_array *tr, |
| struct ftrace_graph_ret *trace, |
| unsigned long flags, |
| int pc) |
| { |
| struct trace_event_call *call = &event_funcgraph_exit; |
| struct ring_buffer_event *event; |
| struct ring_buffer *buffer = tr->trace_buffer.buffer; |
| struct ftrace_graph_ret_entry *entry; |
| |
| 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 (!call_filter_check_discard(call, entry, buffer, event)) |
| __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 = per_cpu_ptr(tr->trace_buffer.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(); |
| } |
| |
| static 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; |
| |
| set_graph_array(tr); |
| if (tracing_thresh) |
| ret = register_ftrace_graph(&trace_graph_thresh_return, |
| &trace_graph_entry); |
| else |
| ret = register_ftrace_graph(&trace_graph_return, |
| &trace_graph_entry); |
| if (ret) |
| return ret; |
| tracing_start_cmdline_record(); |
| |
| return 0; |
| } |
| |
| static void graph_trace_reset(struct trace_array *tr) |
| { |
| tracing_stop_cmdline_record(); |
| unregister_ftrace_graph(); |
| } |
| |
| static int graph_trace_update_thresh(struct trace_array *tr) |
| { |
| graph_trace_reset(tr); |
| return graph_trace_init(tr); |
| } |
| |
| static int max_bytes_for_cpu; |
| |
| static void print_graph_cpu(struct trace_seq *s, int cpu) |
| { |
| /* |
| * Start with a space character - to make it stand out |
| * to the right a bit when trace output is pasted into |
| * email: |
| */ |
| trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu); |
| } |
| |
| #define TRACE_GRAPH_PROCINFO_LENGTH 14 |
| |
| static void 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 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++) |
| trace_seq_putc(s, ' '); |
| |
| trace_seq_printf(s, "%s-%s", comm, pid_str); |
| |
| /* Last spaces to align center */ |
| for (i = 0; i < spaces - (spaces / 2); i++) |
| trace_seq_putc(s, ' '); |
| } |
| |
| |
| static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) |
| { |
| trace_seq_putc(s, ' '); |
| trace_print_lat_fmt(s, entry); |
| } |
| |
| /* If the pid changed since the last trace, output this event */ |
| static void |
| verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) |
| { |
| pid_t prev_pid; |
| pid_t *last_pid; |
| |
| if (!data) |
| return; |
| |
| last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); |
| |
| if (*last_pid == pid) |
| return; |
| |
| prev_pid = *last_pid; |
| *last_pid = pid; |
| |
| if (prev_pid == -1) |
| return; |
| /* |
| * Context-switch trace line: |
| |
| ------------------------------------------ |
| | 1) migration/0--1 => sshd-1755 |
| ------------------------------------------ |
| |
| */ |
| trace_seq_puts(s, " ------------------------------------------\n"); |
| print_graph_cpu(s, cpu); |
| print_graph_proc(s, prev_pid); |
| trace_seq_puts(s, " => "); |
| print_graph_proc(s, pid); |
| trace_seq_puts(s, "\n ------------------------------------------\n\n"); |
| } |
| |
| 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 = trace_buffer_iter(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->trace_buffer->buffer, iter->cpu, |
| NULL, NULL); |
| event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu, |
| NULL, 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; |
| /* |
| * If the next event is not a return type, then |
| * we only care about what type it is. Otherwise we can |
| * safely copy the entire event. |
| */ |
| if (next->ent.type == TRACE_GRAPH_RET) |
| data->ret = *next; |
| else |
| data->ret.ent.type = next->ent.type; |
| } |
| } |
| |
| 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; |
| } |
| |
| static void 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; |
| |
| trace_seq_printf(s, "%5lu.%06lu | ", |
| (unsigned long)t, usecs_rem); |
| } |
| |
| static void |
| print_graph_irq(struct trace_iterator *iter, unsigned long addr, |
| enum trace_type type, int cpu, pid_t pid, u32 flags) |
| { |
| struct trace_array *tr = iter->tr; |
| struct trace_seq *s = &iter->seq; |
| struct trace_entry *ent = iter->ent; |
| |
| if (addr < (unsigned long)__irqentry_text_start || |
| addr >= (unsigned long)__irqentry_text_end) |
| return; |
| |
| if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
| /* Absolute time */ |
| if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| print_graph_abs_time(iter->ts, s); |
| |
| /* Cpu */ |
| if (flags & TRACE_GRAPH_PRINT_CPU) |
| print_graph_cpu(s, cpu); |
| |
| /* Proc */ |
| if (flags & TRACE_GRAPH_PRINT_PROC) { |
| print_graph_proc(s, pid); |
| trace_seq_puts(s, " | "); |
| } |
| |
| /* Latency format */ |
| if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
| print_graph_lat_fmt(s, ent); |
| } |
| |
| /* No overhead */ |
| print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START); |
| |
| if (type == TRACE_GRAPH_ENT) |
| trace_seq_puts(s, "==========>"); |
| else |
| trace_seq_puts(s, "<=========="); |
| |
| print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END); |
| trace_seq_putc(s, '\n'); |
| } |
| |
| void |
| 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 usecs_str[21]; |
| char nsecs_str[5]; |
| int len; |
| int i; |
| |
| sprintf(usecs_str, "%lu", (unsigned long) duration); |
| |
| /* Print msecs */ |
| trace_seq_printf(s, "%s", usecs_str); |
| |
| len = strlen(usecs_str); |
| |
| /* Print nsecs (we don't want to exceed 7 numbers) */ |
| if (len < 7) { |
| size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len); |
| |
| snprintf(nsecs_str, slen, "%03lu", nsecs_rem); |
| trace_seq_printf(s, ".%s", nsecs_str); |
| len += strlen(nsecs_str) + 1; |
| } |
| |
| trace_seq_puts(s, " us "); |
| |
| /* Print remaining spaces to fit the row's width */ |
| for (i = len; i < 8; i++) |
| trace_seq_putc(s, ' '); |
| } |
| |
| static void |
| print_graph_duration(struct trace_array *tr, unsigned long long duration, |
| struct trace_seq *s, u32 flags) |
| { |
| if (!(flags & TRACE_GRAPH_PRINT_DURATION) || |
| !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO)) |
| return; |
| |
| /* No real adata, just filling the column with spaces */ |
| switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) { |
| case FLAGS_FILL_FULL: |
| trace_seq_puts(s, " | "); |
| return; |
| case FLAGS_FILL_START: |
| trace_seq_puts(s, " "); |
| return; |
| case FLAGS_FILL_END: |
| trace_seq_puts(s, " |"); |
| return; |
| } |
| |
| /* Signal a overhead of time execution to the output */ |
| if (flags & TRACE_GRAPH_PRINT_OVERHEAD) |
| trace_seq_printf(s, "%c ", trace_find_mark(duration)); |
| else |
| trace_seq_puts(s, " "); |
| |
| trace_print_graph_duration(duration, s); |
| trace_seq_puts(s, "| "); |
| } |
| |
| /* 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, u32 flags) |
| { |
| struct fgraph_data *data = iter->private; |
| struct trace_array *tr = iter->tr; |
| struct ftrace_graph_ret *graph_ret; |
| struct ftrace_graph_ent *call; |
| unsigned long long duration; |
| int i; |
| |
| graph_ret = &ret_entry->ret; |
| call = &entry->graph_ent; |
| duration = graph_ret->rettime - graph_ret->calltime; |
| |
| if (data) { |
| struct fgraph_cpu_data *cpu_data; |
| int cpu = iter->cpu; |
| |
| cpu_data = per_cpu_ptr(data->cpu_data, cpu); |
| |
| /* If a graph tracer ignored set_graph_notrace */ |
| if (call->depth < -1) |
| call->depth += FTRACE_NOTRACE_DEPTH; |
| |
| /* |
| * Comments display at + 1 to depth. Since |
| * this is a leaf function, keep the comments |
| * equal to this depth. |
| */ |
| cpu_data->depth = call->depth - 1; |
| |
| /* No need to keep this function around for this depth */ |
| if (call->depth < FTRACE_RETFUNC_DEPTH && |
| !WARN_ON_ONCE(call->depth < 0)) |
| cpu_data->enter_funcs[call->depth] = 0; |
| } |
| |
| /* Overhead and duration */ |
| print_graph_duration(tr, duration, s, flags); |
| |
| /* Function */ |
| for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) |
| trace_seq_putc(s, ' '); |
| |
| trace_seq_printf(s, "%ps();\n", (void *)call->func); |
| |
| return trace_handle_return(s); |
| } |
| |
| 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, u32 flags) |
| { |
| struct ftrace_graph_ent *call = &entry->graph_ent; |
| struct fgraph_data *data = iter->private; |
| struct trace_array *tr = iter->tr; |
| int i; |
| |
| if (data) { |
| struct fgraph_cpu_data *cpu_data; |
| int cpu = iter->cpu; |
| |
| /* If a graph tracer ignored set_graph_notrace */ |
| if (call->depth < -1) |
| call->depth += FTRACE_NOTRACE_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 && |
| !WARN_ON_ONCE(call->depth < 0)) |
| cpu_data->enter_funcs[call->depth] = call->func; |
| } |
| |
| /* No time */ |
| print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL); |
| |
| /* Function */ |
| for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) |
| trace_seq_putc(s, ' '); |
| |
| trace_seq_printf(s, "%ps() {\n", (void *)call->func); |
| |
| if (trace_seq_has_overflowed(s)) |
| 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 void |
| print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s, |
| int type, unsigned long addr, u32 flags) |
| { |
| struct fgraph_data *data = iter->private; |
| struct trace_entry *ent = iter->ent; |
| struct trace_array *tr = iter->tr; |
| int cpu = iter->cpu; |
| |
| /* Pid */ |
| verif_pid(s, ent->pid, cpu, data); |
| |
| if (type) |
| /* Interrupt */ |
| print_graph_irq(iter, addr, type, cpu, ent->pid, flags); |
| |
| if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO)) |
| return; |
| |
| /* Absolute time */ |
| if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| print_graph_abs_time(iter->ts, s); |
| |
| /* Cpu */ |
| if (flags & TRACE_GRAPH_PRINT_CPU) |
| print_graph_cpu(s, cpu); |
| |
| /* Proc */ |
| if (flags & TRACE_GRAPH_PRINT_PROC) { |
| print_graph_proc(s, ent->pid); |
| trace_seq_puts(s, " | "); |
| } |
| |
| /* Latency format */ |
| if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
| print_graph_lat_fmt(s, ent); |
| |
| return; |
| } |
| |
| /* |
| * Entry check for irq code |
| * |
| * returns 1 if |
| * - we are inside irq code |
| * - we just entered irq code |
| * |
| * retunns 0 if |
| * - funcgraph-interrupts option is set |
| * - we are not inside irq code |
| */ |
| static int |
| check_irq_entry(struct trace_iterator *iter, u32 flags, |
| unsigned long addr, int depth) |
| { |
| int cpu = iter->cpu; |
| int *depth_irq; |
| struct fgraph_data *data = iter->private; |
| |
| /* |
| * If we are either displaying irqs, or we got called as |
| * a graph event and private data does not exist, |
| * then we bypass the irq check. |
| */ |
| if ((flags & TRACE_GRAPH_PRINT_IRQS) || |
| (!data)) |
| return 0; |
| |
| depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); |
| |
| /* |
| * We are inside the irq code |
| */ |
| if (*depth_irq >= 0) |
| return 1; |
| |
| if ((addr < (unsigned long)__irqentry_text_start) || |
| (addr >= (unsigned long)__irqentry_text_end)) |
| return 0; |
| |
| /* |
| * We are entering irq code. |
| */ |
| *depth_irq = depth; |
| return 1; |
| } |
| |
| /* |
| * Return check for irq code |
| * |
| * returns 1 if |
| * - we are inside irq code |
| * - we just left irq code |
| * |
| * returns 0 if |
| * - funcgraph-interrupts option is set |
| * - we are not inside irq code |
| */ |
| static int |
| check_irq_return(struct trace_iterator *iter, u32 flags, int depth) |
| { |
| int cpu = iter->cpu; |
| int *depth_irq; |
| struct fgraph_data *data = iter->private; |
| |
| /* |
| * If we are either displaying irqs, or we got called as |
| * a graph event and private data does not exist, |
| * then we bypass the irq check. |
| */ |
| if ((flags & TRACE_GRAPH_PRINT_IRQS) || |
| (!data)) |
| return 0; |
| |
| depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); |
| |
| /* |
| * We are not inside the irq code. |
| */ |
| if (*depth_irq == -1) |
| return 0; |
| |
| /* |
| * We are inside the irq code, and this is returning entry. |
| * Let's not trace it and clear the entry depth, since |
| * we are out of irq code. |
| * |
| * This condition ensures that we 'leave the irq code' once |
| * we are out of the entry depth. Thus protecting us from |
| * the RETURN entry loss. |
| */ |
| if (*depth_irq >= depth) { |
| *depth_irq = -1; |
| return 1; |
| } |
| |
| /* |
| * We are inside the irq code, and this is not the entry. |
| */ |
| return 1; |
| } |
| |
| static enum print_line_t |
| print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, |
| struct trace_iterator *iter, u32 flags) |
| { |
| 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 (check_irq_entry(iter, flags, call->func, call->depth)) |
| return TRACE_TYPE_HANDLED; |
| |
| print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags); |
| |
| leaf_ret = get_return_for_leaf(iter, field); |
| if (leaf_ret) |
| ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags); |
| else |
| ret = print_graph_entry_nested(iter, field, s, cpu, flags); |
| |
| 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, |
| u32 flags) |
| { |
| unsigned long long duration = trace->rettime - trace->calltime; |
| struct fgraph_data *data = iter->private; |
| struct trace_array *tr = iter->tr; |
| pid_t pid = ent->pid; |
| int cpu = iter->cpu; |
| int func_match = 1; |
| int i; |
| |
| if (check_irq_return(iter, flags, trace->depth)) |
| return TRACE_TYPE_HANDLED; |
| |
| if (data) { |
| struct fgraph_cpu_data *cpu_data; |
| int cpu = iter->cpu; |
| |
| 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. |
| */ |
| cpu_data->depth = trace->depth - 1; |
| |
| if (trace->depth < FTRACE_RETFUNC_DEPTH && |
| !WARN_ON_ONCE(trace->depth < 0)) { |
| if (cpu_data->enter_funcs[trace->depth] != trace->func) |
| func_match = 0; |
| cpu_data->enter_funcs[trace->depth] = 0; |
| } |
| } |
| |
| print_graph_prologue(iter, s, 0, 0, flags); |
| |
| /* Overhead and duration */ |
| print_graph_duration(tr, duration, s, flags); |
| |
| /* Closing brace */ |
| for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) |
| trace_seq_putc(s, ' '); |
| |
| /* |
| * 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. Always do |
| * that if the funcgraph-tail option is enabled. |
| */ |
| if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) |
| trace_seq_puts(s, "}\n"); |
| else |
| trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func); |
| |
| /* Overrun */ |
| if (flags & TRACE_GRAPH_PRINT_OVERRUN) |
| trace_seq_printf(s, " (Overruns: %lu)\n", |
| trace->overrun); |
| |
| print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, |
| cpu, pid, flags); |
| |
| return trace_handle_return(s); |
| } |
| |
| static enum print_line_t |
| print_graph_comment(struct trace_seq *s, struct trace_entry *ent, |
| struct trace_iterator *iter, u32 flags) |
| { |
| struct trace_array *tr = iter->tr; |
| unsigned long sym_flags = (tr->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; |
| |
| print_graph_prologue(iter, s, 0, 0, flags); |
| |
| /* No time */ |
| print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL); |
| |
| /* Indentation */ |
| if (depth > 0) |
| for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) |
| trace_seq_putc(s, ' '); |
| |
| /* The comment */ |
| trace_seq_puts(s, "/* "); |
| |
| switch (iter->ent->type) { |
| case TRACE_BPUTS: |
| ret = trace_print_bputs_msg_only(iter); |
| if (ret != TRACE_TYPE_HANDLED) |
| return ret; |
| break; |
| 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->funcs->trace(iter, sym_flags, event); |
| if (ret != TRACE_TYPE_HANDLED) |
| return ret; |
| } |
| |
| if (trace_seq_has_overflowed(s)) |
| goto out; |
| |
| /* Strip ending newline */ |
| if (s->buffer[s->seq.len - 1] == '\n') { |
| s->buffer[s->seq.len - 1] = '\0'; |
| s->seq.len--; |
| } |
| |
| trace_seq_puts(s, " */\n"); |
| out: |
| return trace_handle_return(s); |
| } |
| |
| |
| enum print_line_t |
| print_graph_function_flags(struct trace_iterator *iter, u32 flags) |
| { |
| 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, flags); |
| 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, flags); |
| } |
| case TRACE_GRAPH_RET: { |
| struct ftrace_graph_ret_entry *field; |
| trace_assign_type(field, entry); |
| return print_graph_return(&field->ret, s, entry, iter, flags); |
| } |
| case TRACE_STACK: |
| case TRACE_FN: |
| /* dont trace stack and functions as comments */ |
| return TRACE_TYPE_UNHANDLED; |
| |
| default: |
| return print_graph_comment(s, entry, iter, flags); |
| } |
| |
| return TRACE_TYPE_HANDLED; |
| } |
| |
| static enum print_line_t |
| print_graph_function(struct trace_iterator *iter) |
| { |
| return print_graph_function_flags(iter, tracer_flags.val); |
| } |
| |
| static enum print_line_t |
| print_graph_function_event(struct trace_iterator *iter, int flags, |
| struct trace_event *event) |
| { |
| return print_graph_function(iter); |
| } |
| |
| static void print_lat_header(struct seq_file *s, u32 flags) |
| { |
| static const char spaces[] = " " /* 16 spaces */ |
| " " /* 4 spaces */ |
| " "; /* 17 spaces */ |
| int size = 0; |
| |
| if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| size += 16; |
| if (flags & TRACE_GRAPH_PRINT_CPU) |
| size += 4; |
| if (flags & 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||| / \n", size, spaces); |
| } |
| |
| static void __print_graph_headers_flags(struct trace_array *tr, |
| struct seq_file *s, u32 flags) |
| { |
| int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT; |
| |
| if (lat) |
| print_lat_header(s, flags); |
| |
| /* 1st line */ |
| seq_putc(s, '#'); |
| if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| seq_puts(s, " TIME "); |
| if (flags & TRACE_GRAPH_PRINT_CPU) |
| seq_puts(s, " CPU"); |
| if (flags & TRACE_GRAPH_PRINT_PROC) |
| seq_puts(s, " TASK/PID "); |
| if (lat) |
| seq_puts(s, "||||"); |
| if (flags & TRACE_GRAPH_PRINT_DURATION) |
| seq_puts(s, " DURATION "); |
| seq_puts(s, " FUNCTION CALLS\n"); |
| |
| /* 2nd line */ |
| seq_putc(s, '#'); |
| if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| seq_puts(s, " | "); |
| if (flags & TRACE_GRAPH_PRINT_CPU) |
| seq_puts(s, " | "); |
| if (flags & TRACE_GRAPH_PRINT_PROC) |
| seq_puts(s, " | | "); |
| if (lat) |
| seq_puts(s, "||||"); |
| if (flags & TRACE_GRAPH_PRINT_DURATION) |
| seq_puts(s, " | | "); |
| seq_puts(s, " | | | |\n"); |
| } |
| |
| static void print_graph_headers(struct seq_file *s) |
| { |
| print_graph_headers_flags(s, tracer_flags.val); |
| } |
| |
| void print_graph_headers_flags(struct seq_file *s, u32 flags) |
| { |
| struct trace_iterator *iter = s->private; |
| struct trace_array *tr = iter->tr; |
| |
| if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO)) |
| return; |
| |
| if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) { |
| /* print nothing if the buffers are empty */ |
| if (trace_empty(iter)) |
| return; |
| |
| print_trace_header(s, iter); |
| } |
| |
| __print_graph_headers_flags(tr, s, flags); |
| } |
| |
| void graph_trace_open(struct trace_iterator *iter) |
| { |
| /* pid and depth on the last trace processed */ |
| struct fgraph_data *data; |
| gfp_t gfpflags; |
| int cpu; |
| |
| iter->private = NULL; |
| |
| /* We can be called in atomic context via ftrace_dump() */ |
| gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL; |
| |
| data = kzalloc(sizeof(*data), gfpflags); |
| if (!data) |
| goto out_err; |
| |
| data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags); |
| 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); |
| int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); |
| |
| *pid = -1; |
| *depth = 0; |
| *ignore = 0; |
| *depth_irq = -1; |
| } |
| |
| iter->private = data; |
| |
| return; |
| |
| out_err_free: |
| kfree(data); |
| out_err: |
| pr_warn("function graph tracer: not enough memory\n"); |
| } |
| |
| void graph_trace_close(struct trace_iterator *iter) |
| { |
| struct fgraph_data *data = iter->private; |
| |
| if (data) { |
| free_percpu(data->cpu_data); |
| kfree(data); |
| } |
| } |
| |
| static int |
| func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) |
| { |
| if (bit == TRACE_GRAPH_PRINT_IRQS) |
| ftrace_graph_skip_irqs = !set; |
| |
| if (bit == TRACE_GRAPH_SLEEP_TIME) |
| ftrace_graph_sleep_time_control(set); |
| |
| if (bit == TRACE_GRAPH_GRAPH_TIME) |
| ftrace_graph_graph_time_control(set); |
| |
| return 0; |
| } |
| |
| static struct trace_event_functions graph_functions = { |
| .trace = print_graph_function_event, |
| }; |
| |
| static struct trace_event graph_trace_entry_event = { |
| .type = TRACE_GRAPH_ENT, |
| .funcs = &graph_functions, |
| }; |
| |
| static struct trace_event graph_trace_ret_event = { |
| .type = TRACE_GRAPH_RET, |
| .funcs = &graph_functions |
| }; |
| |
| static struct tracer graph_trace __tracer_data = { |
| .name = "function_graph", |
| .update_thresh = graph_trace_update_thresh, |
| .open = graph_trace_open, |
| .pipe_open = graph_trace_open, |
| .close = graph_trace_close, |
| .pipe_close = graph_trace_close, |
| .init = graph_trace_init, |
| .reset = graph_trace_reset, |
| .print_line = print_graph_function, |
| .print_header = print_graph_headers, |
| .flags = &tracer_flags, |
| .set_flag = func_graph_set_flag, |
| #ifdef CONFIG_FTRACE_SELFTEST |
| .selftest = trace_selftest_startup_function_graph, |
| #endif |
| }; |
| |
| |
| static ssize_t |
| graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt, |
| loff_t *ppos) |
| { |
| unsigned long val; |
| int ret; |
| |
| ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
| if (ret) |
| return ret; |
| |
| max_depth = val; |
| |
| *ppos += cnt; |
| |
| return cnt; |
| } |
| |
| static ssize_t |
| graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt, |
| loff_t *ppos) |
| { |
| char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/ |
| int n; |
| |
| n = sprintf(buf, "%d\n", max_depth); |
| |
| return simple_read_from_buffer(ubuf, cnt, ppos, buf, n); |
| } |
| |
| static const struct file_operations graph_depth_fops = { |
| .open = tracing_open_generic, |
| .write = graph_depth_write, |
| .read = graph_depth_read, |
| .llseek = generic_file_llseek, |
| }; |
| |
| static __init int init_graph_tracefs(void) |
| { |
| struct dentry *d_tracer; |
| |
| d_tracer = tracing_init_dentry(); |
| if (IS_ERR(d_tracer)) |
| return 0; |
| |
| trace_create_file("max_graph_depth", 0644, d_tracer, |
| NULL, &graph_depth_fops); |
| |
| return 0; |
| } |
| fs_initcall(init_graph_tracefs); |
| |
| static __init int init_graph_trace(void) |
| { |
| max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1); |
| |
| if (!register_trace_event(&graph_trace_entry_event)) { |
| pr_warn("Warning: could not register graph trace events\n"); |
| return 1; |
| } |
| |
| if (!register_trace_event(&graph_trace_ret_event)) { |
| pr_warn("Warning: could not register graph trace events\n"); |
| return 1; |
| } |
| |
| return register_tracer(&graph_trace); |
| } |
| |
| core_initcall(init_graph_trace); |