/* * * 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/slab.h>#include <linux/fs.h> #include "trace.h"#include "trace_output.h" 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 /* 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.*/intftrace_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 voidftrace_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(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; 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(); return 0;} 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_tprint_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_tprint_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_tprint_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_tverif_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; Lines 1–500 of 1225. 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/* * * 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/slab.h> #include <linux/fs.h> #include "trace.h" #include "trace_output.h" 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 /* 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(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; 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(); return 0; } 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;