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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 | /* * ring buffer based initcalls tracer * * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com> * */ #include <linux/init.h> #include <linux/debugfs.h> #include <linux/ftrace.h> #include <linux/kallsyms.h> #include "trace.h" static struct trace_array *boot_trace; static bool pre_initcalls_finished; /* Tells the boot tracer that the pre_smp_initcalls are finished. * So we are ready . * It doesn't enable sched events tracing however. * You have to call enable_boot_trace to do so. */ void start_boot_trace(void) { pre_initcalls_finished = true; } void enable_boot_trace(void) { if (pre_initcalls_finished) tracing_start_sched_switch_record(); } void disable_boot_trace(void) { if (pre_initcalls_finished) tracing_stop_sched_switch_record(); } static int boot_trace_init(struct trace_array *tr) { int cpu; boot_trace = tr; for_each_cpu(cpu, cpu_possible_mask) tracing_reset(tr, cpu); tracing_sched_switch_assign_trace(tr); return 0; } static enum print_line_t initcall_call_print_line(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; struct trace_seq *s = &iter->seq; struct trace_boot_call *field; struct boot_trace_call *call; u64 ts; unsigned long nsec_rem; int ret; trace_assign_type(field, entry); call = &field->boot_call; ts = iter->ts; nsec_rem = do_div(ts, 1000000000); ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n", (unsigned long)ts, nsec_rem, call->func, call->caller); if (!ret) return TRACE_TYPE_PARTIAL_LINE; else return TRACE_TYPE_HANDLED; } static enum print_line_t initcall_ret_print_line(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; struct trace_seq *s = &iter->seq; struct trace_boot_ret *field; struct boot_trace_ret *init_ret; u64 ts; unsigned long nsec_rem; int ret; trace_assign_type(field, entry); init_ret = &field->boot_ret; ts = iter->ts; nsec_rem = do_div(ts, 1000000000); ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s " "returned %d after %llu msecs\n", (unsigned long) ts, nsec_rem, init_ret->func, init_ret->result, init_ret->duration); if (!ret) return TRACE_TYPE_PARTIAL_LINE; else return TRACE_TYPE_HANDLED; } static enum print_line_t initcall_print_line(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; switch (entry->type) { case TRACE_BOOT_CALL: return initcall_call_print_line(iter); case TRACE_BOOT_RET: return initcall_ret_print_line(iter); default: return TRACE_TYPE_UNHANDLED; } } struct tracer boot_tracer __read_mostly = { .name = "initcall", .init = boot_trace_init, .reset = tracing_reset_online_cpus, .print_line = initcall_print_line, }; void trace_boot_call(struct boot_trace_call *bt, initcall_t fn) { struct ring_buffer_event *event; struct trace_boot_call *entry; unsigned long irq_flags; struct trace_array *tr = boot_trace; if (!pre_initcalls_finished) return; /* Get its name now since this function could * disappear because it is in the .init section. */ sprint_symbol(bt->func, (unsigned long)fn); preempt_disable(); event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq_flags); if (!event) goto out; entry = ring_buffer_event_data(event); tracing_generic_entry_update(&entry->ent, 0, 0); entry->ent.type = TRACE_BOOT_CALL; entry->boot_call = *bt; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); out: preempt_enable(); } void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn) { struct ring_buffer_event *event; struct trace_boot_ret *entry; unsigned long irq_flags; struct trace_array *tr = boot_trace; if (!pre_initcalls_finished) return; sprint_symbol(bt->func, (unsigned long)fn); preempt_disable(); event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq_flags); if (!event) goto out; entry = ring_buffer_event_data(event); tracing_generic_entry_update(&entry->ent, 0, 0); entry->ent.type = TRACE_BOOT_RET; entry->boot_ret = *bt; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); out: preempt_enable(); } |