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authorTörök Edwin <edwintorok@gmail.com>2008-11-22 06:28:47 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-23 03:25:15 -0500
commit02b67518e2b1c490787dac7f35e1204e74fe21ba (patch)
treea3d92846e1a09a829f300ab15726ee9c288cb49e /kernel/trace/trace.c
parenta0a70c735ef714fe1b6777b571630c3d50c7b008 (diff)
tracing: add support for userspace stacktraces in tracing/iter_ctrl
Impact: add new (default-off) tracing visualization feature Usage example: mount -t debugfs nodev /sys/kernel/debug cd /sys/kernel/debug/tracing echo userstacktrace >iter_ctrl echo sched_switch >current_tracer echo 1 >tracing_enabled .... run application ... echo 0 >tracing_enabled Then read one of 'trace','latency_trace','trace_pipe'. To get the best output you can compile your userspace programs with frame pointers (at least glibc + the app you are tracing). Signed-off-by: Török Edwin <edwintorok@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4ee6f0375222..ced8b4fa9f51 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -275,6 +275,7 @@ static const char *trace_options[] = {
275 "ftrace_preempt", 275 "ftrace_preempt",
276 "branch", 276 "branch",
277 "annotate", 277 "annotate",
278 "userstacktrace",
278 NULL 279 NULL
279}; 280};
280 281
@@ -918,6 +919,44 @@ void __trace_stack(struct trace_array *tr,
918 ftrace_trace_stack(tr, data, flags, skip, preempt_count()); 919 ftrace_trace_stack(tr, data, flags, skip, preempt_count());
919} 920}
920 921
922static void ftrace_trace_userstack(struct trace_array *tr,
923 struct trace_array_cpu *data,
924 unsigned long flags, int pc)
925{
926 struct userstack_entry *entry;
927 struct stack_trace trace;
928 struct ring_buffer_event *event;
929 unsigned long irq_flags;
930
931 if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
932 return;
933
934 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
935 &irq_flags);
936 if (!event)
937 return;
938 entry = ring_buffer_event_data(event);
939 tracing_generic_entry_update(&entry->ent, flags, pc);
940 entry->ent.type = TRACE_USER_STACK;
941
942 memset(&entry->caller, 0, sizeof(entry->caller));
943
944 trace.nr_entries = 0;
945 trace.max_entries = FTRACE_STACK_ENTRIES;
946 trace.skip = 0;
947 trace.entries = entry->caller;
948
949 save_stack_trace_user(&trace);
950 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
951}
952
953void __trace_userstack(struct trace_array *tr,
954 struct trace_array_cpu *data,
955 unsigned long flags)
956{
957 ftrace_trace_userstack(tr, data, flags, preempt_count());
958}
959
921static void 960static void
922ftrace_trace_special(void *__tr, void *__data, 961ftrace_trace_special(void *__tr, void *__data,
923 unsigned long arg1, unsigned long arg2, unsigned long arg3, 962 unsigned long arg1, unsigned long arg2, unsigned long arg3,
@@ -941,6 +980,7 @@ ftrace_trace_special(void *__tr, void *__data,
941 entry->arg3 = arg3; 980 entry->arg3 = arg3;
942 ring_buffer_unlock_commit(tr->buffer, event, irq_flags); 981 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
943 ftrace_trace_stack(tr, data, irq_flags, 4, pc); 982 ftrace_trace_stack(tr, data, irq_flags, 4, pc);
983 ftrace_trace_userstack(tr, data, irq_flags, pc);
944 984
945 trace_wake_up(); 985 trace_wake_up();
946} 986}
@@ -979,6 +1019,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
979 entry->next_cpu = task_cpu(next); 1019 entry->next_cpu = task_cpu(next);
980 ring_buffer_unlock_commit(tr->buffer, event, irq_flags); 1020 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
981 ftrace_trace_stack(tr, data, flags, 5, pc); 1021 ftrace_trace_stack(tr, data, flags, 5, pc);
1022 ftrace_trace_userstack(tr, data, flags, pc);
982} 1023}
983 1024
984void 1025void
@@ -1008,6 +1049,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
1008 entry->next_cpu = task_cpu(wakee); 1049 entry->next_cpu = task_cpu(wakee);
1009 ring_buffer_unlock_commit(tr->buffer, event, irq_flags); 1050 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
1010 ftrace_trace_stack(tr, data, flags, 6, pc); 1051 ftrace_trace_stack(tr, data, flags, 6, pc);
1052 ftrace_trace_userstack(tr, data, flags, pc);
1011 1053
1012 trace_wake_up(); 1054 trace_wake_up();
1013} 1055}
@@ -1387,6 +1429,31 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
1387 return ret; 1429 return ret;
1388} 1430}
1389 1431
1432static int
1433seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
1434 unsigned long sym_flags)
1435{
1436 int ret = 1;
1437 unsigned i;
1438
1439 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1440 unsigned long ip = entry->caller[i];
1441
1442 if (ip == ULONG_MAX || !ret)
1443 break;
1444 if (i)
1445 ret = trace_seq_puts(s, " <- ");
1446 if (!ip) {
1447 ret = trace_seq_puts(s, "??");
1448 continue;
1449 }
1450 if (ret /*&& (sym_flags & TRACE_ITER_SYM_ADDR)*/)
1451 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
1452 }
1453
1454 return ret;
1455}
1456
1390static void print_lat_help_header(struct seq_file *m) 1457static void print_lat_help_header(struct seq_file *m)
1391{ 1458{
1392 seq_puts(m, "# _------=> CPU# \n"); 1459 seq_puts(m, "# _------=> CPU# \n");
@@ -1702,6 +1769,16 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
1702 field->line); 1769 field->line);
1703 break; 1770 break;
1704 } 1771 }
1772 case TRACE_USER_STACK: {
1773 struct userstack_entry *field;
1774
1775 trace_assign_type(field, entry);
1776
1777 seq_print_userip_objs(field, s, sym_flags);
1778 if (entry->flags & TRACE_FLAG_CONT)
1779 trace_seq_print_cont(s, iter);
1780 break;
1781 }
1705 default: 1782 default:
1706 trace_seq_printf(s, "Unknown type %d\n", entry->type); 1783 trace_seq_printf(s, "Unknown type %d\n", entry->type);
1707 } 1784 }
@@ -1853,6 +1930,19 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
1853 field->line); 1930 field->line);
1854 break; 1931 break;
1855 } 1932 }
1933 case TRACE_USER_STACK: {
1934 struct userstack_entry *field;
1935
1936 trace_assign_type(field, entry);
1937
1938 ret = seq_print_userip_objs(field, s, sym_flags);
1939 if (!ret)
1940 return TRACE_TYPE_PARTIAL_LINE;
1941 ret = trace_seq_putc(s, '\n');
1942 if (!ret)
1943 return TRACE_TYPE_PARTIAL_LINE;
1944 break;
1945 }
1856 } 1946 }
1857 return TRACE_TYPE_HANDLED; 1947 return TRACE_TYPE_HANDLED;
1858} 1948}
@@ -1912,6 +2002,7 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
1912 break; 2002 break;
1913 } 2003 }
1914 case TRACE_SPECIAL: 2004 case TRACE_SPECIAL:
2005 case TRACE_USER_STACK:
1915 case TRACE_STACK: { 2006 case TRACE_STACK: {
1916 struct special_entry *field; 2007 struct special_entry *field;
1917 2008
@@ -2000,6 +2091,7 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
2000 break; 2091 break;
2001 } 2092 }
2002 case TRACE_SPECIAL: 2093 case TRACE_SPECIAL:
2094 case TRACE_USER_STACK:
2003 case TRACE_STACK: { 2095 case TRACE_STACK: {
2004 struct special_entry *field; 2096 struct special_entry *field;
2005 2097
@@ -2054,6 +2146,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
2054 break; 2146 break;
2055 } 2147 }
2056 case TRACE_SPECIAL: 2148 case TRACE_SPECIAL:
2149 case TRACE_USER_STACK:
2057 case TRACE_STACK: { 2150 case TRACE_STACK: {
2058 struct special_entry *field; 2151 struct special_entry *field;
2059 2152