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authorIngo Molnar <mingo@elte.hu>2008-05-12 21:20:51 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-23 21:04:20 +0200
commit86387f7ee5d3273ff4859e2c64ce656639b6ca65 (patch)
treed2080c680e9e9415dfa99bb8408302584035e664
parent57422797dc009fc83766bcf230d29dbe6e08e21e (diff)
ftrace: add stack tracing
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/ftrace.h2
-rw-r--r--kernel/trace/Kconfig1
-rw-r--r--kernel/trace/trace.c103
-rw-r--r--kernel/trace/trace.h11
4 files changed, 99 insertions, 18 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 08fbef1744c..0d3714e7110 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -93,6 +93,7 @@ static inline void tracer_disable(void)
# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
+# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
#else
# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
# define CALLER_ADDR1 0UL
@@ -100,6 +101,7 @@ static inline void tracer_disable(void)
# define CALLER_ADDR3 0UL
# define CALLER_ADDR4 0UL
# define CALLER_ADDR5 0UL
+# define CALLER_ADDR6 0UL
#endif
#ifdef CONFIG_IRQSOFF_TRACER
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 3f73a171024..eb1988ed84b 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -10,6 +10,7 @@ config TRACER_MAX_TRACE
config TRACING
bool
select DEBUG_FS
+ select STACKTRACE
config FTRACE
bool "Kernel Function Tracer"
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 192c1354a7e..b4b1b4fe99f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -28,6 +28,8 @@
#include <linux/gfp.h>
#include <linux/fs.h>
+#include <linux/stacktrace.h>
+
#include "trace.h"
unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
@@ -88,6 +90,7 @@ enum trace_type {
TRACE_FN,
TRACE_CTX,
TRACE_WAKE,
+ TRACE_STACK,
TRACE_SPECIAL,
__TRACE_LAST_TYPE
@@ -109,6 +112,7 @@ enum trace_iterator_flags {
TRACE_ITER_HEX = 0x20,
TRACE_ITER_BIN = 0x40,
TRACE_ITER_BLOCK = 0x80,
+ TRACE_ITER_STACKTRACE = 0x100,
};
#define TRACE_ITER_SYM_MASK \
@@ -124,10 +128,11 @@ static const char *trace_options[] = {
"hex",
"bin",
"block",
+ "stacktrace",
NULL
};
-static unsigned trace_flags;
+static unsigned trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_STACKTRACE;
static DEFINE_SPINLOCK(ftrace_max_lock);
@@ -657,7 +662,7 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
spin_unlock_irqrestore(&data->lock, irq_flags);
if (!(trace_flags & TRACE_ITER_BLOCK))
- wake_up (&trace_wait);
+ wake_up(&trace_wait);
}
void
@@ -685,13 +690,39 @@ trace_special(struct trace_array *tr, struct trace_array_cpu *data,
spin_unlock_irqrestore(&data->lock, irq_flags);
if (!(trace_flags & TRACE_ITER_BLOCK))
- wake_up (&trace_wait);
+ wake_up(&trace_wait);
+}
+
+void __trace_stack(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long flags,
+ int skip)
+{
+ struct trace_entry *entry;
+ struct stack_trace trace;
+
+ if (!(trace_flags & TRACE_ITER_STACKTRACE))
+ return;
+
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, flags);
+ entry->type = TRACE_STACK;
+
+ memset(&entry->stack, 0, sizeof(entry->stack));
+
+ trace.nr_entries = 0;
+ trace.max_entries = FTRACE_STACK_ENTRIES;
+ trace.skip = skip;
+ trace.entries = entry->stack.caller;
+
+ save_stack_trace(&trace);
}
void
tracing_sched_switch_trace(struct trace_array *tr,
struct trace_array_cpu *data,
- struct task_struct *prev, struct task_struct *next,
+ struct task_struct *prev,
+ struct task_struct *next,
unsigned long flags)
{
struct trace_entry *entry;
@@ -706,16 +737,18 @@ tracing_sched_switch_trace(struct trace_array *tr,
entry->ctx.prev_state = prev->state;
entry->ctx.next_pid = next->pid;
entry->ctx.next_prio = next->prio;
+ __trace_stack(tr, data, flags, 4);
spin_unlock_irqrestore(&data->lock, irq_flags);
if (!(trace_flags & TRACE_ITER_BLOCK))
- wake_up (&trace_wait);
+ wake_up(&trace_wait);
}
void
tracing_sched_wakeup_trace(struct trace_array *tr,
struct trace_array_cpu *data,
- struct task_struct *wakee, struct task_struct *curr,
+ struct task_struct *wakee,
+ struct task_struct *curr,
unsigned long flags)
{
struct trace_entry *entry;
@@ -730,6 +763,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
entry->ctx.prev_state = curr->state;
entry->ctx.next_pid = wakee->pid;
entry->ctx.next_prio = wakee->prio;
+ __trace_stack(tr, data, flags, 5);
spin_unlock_irqrestore(&data->lock, irq_flags);
if (!(trace_flags & TRACE_ITER_BLOCK))
@@ -1179,6 +1213,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
unsigned long rel_usecs;
char *comm;
int S;
+ int i;
if (!next_entry)
next_entry = entry;
@@ -1197,8 +1232,10 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
abs_usecs % 1000, rel_usecs/1000,
rel_usecs % 1000);
} else {
- lat_print_generic(s, entry, cpu);
- lat_print_timestamp(s, abs_usecs, rel_usecs);
+ if (entry->type != TRACE_STACK) {
+ lat_print_generic(s, entry, cpu);
+ lat_print_timestamp(s, abs_usecs, rel_usecs);
+ }
}
switch (entry->type) {
case TRACE_FN:
@@ -1226,6 +1263,14 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
entry->special.arg2,
entry->special.arg3);
break;
+ case TRACE_STACK:
+ for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+ if (i)
+ trace_seq_puts(s, " <= ");
+ seq_print_ip_sym(s, entry->stack.caller[i], sym_flags);
+ }
+ trace_seq_puts(s, "\n");
+ break;
default:
trace_seq_printf(s, "Unknown type %d\n", entry->type);
}
@@ -1241,8 +1286,9 @@ static int print_trace_fmt(struct trace_iterator *iter)
unsigned long long t;
unsigned long secs;
char *comm;
- int S;
int ret;
+ int S;
+ int i;
entry = iter->ent;
@@ -1252,15 +1298,17 @@ static int print_trace_fmt(struct trace_iterator *iter)
usec_rem = do_div(t, 1000000ULL);
secs = (unsigned long)t;
- ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
- if (!ret)
- return 0;
- ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
- if (!ret)
- return 0;
- ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
- if (!ret)
- return 0;
+ if (entry->type != TRACE_STACK) {
+ ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
+ if (!ret)
+ return 0;
+ ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+ if (!ret)
+ return 0;
+ ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
+ if (!ret)
+ return 0;
+ }
switch (entry->type) {
case TRACE_FN:
@@ -1303,6 +1351,22 @@ static int print_trace_fmt(struct trace_iterator *iter)
if (!ret)
return 0;
break;
+ case TRACE_STACK:
+ for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+ if (i) {
+ ret = trace_seq_puts(s, " <= ");
+ if (!ret)
+ return 0;
+ }
+ ret = seq_print_ip_sym(s, entry->stack.caller[i],
+ sym_flags);
+ if (!ret)
+ return 0;
+ }
+ ret = trace_seq_puts(s, "\n");
+ if (!ret)
+ return 0;
+ break;
}
return 1;
}
@@ -1344,6 +1408,7 @@ static int print_raw_fmt(struct trace_iterator *iter)
return 0;
break;
case TRACE_SPECIAL:
+ case TRACE_STACK:
ret = trace_seq_printf(s, " %lx %lx %lx\n",
entry->special.arg1,
entry->special.arg2,
@@ -1399,6 +1464,7 @@ static int print_hex_fmt(struct trace_iterator *iter)
SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
break;
case TRACE_SPECIAL:
+ case TRACE_STACK:
SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1);
SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2);
SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3);
@@ -1433,6 +1499,7 @@ static int print_bin_fmt(struct trace_iterator *iter)
SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
break;
case TRACE_SPECIAL:
+ case TRACE_STACK:
SEQ_PUT_FIELD_RET(s, entry->special.arg1);
SEQ_PUT_FIELD_RET(s, entry->special.arg2);
SEQ_PUT_FIELD_RET(s, entry->special.arg3);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 90e0ba0f6eb..387bdcf45e2 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -35,6 +35,16 @@ struct special_entry {
};
/*
+ * Stack-trace entry:
+ */
+
+#define FTRACE_STACK_ENTRIES 5
+
+struct stack_entry {
+ unsigned long caller[FTRACE_STACK_ENTRIES];
+};
+
+/*
* The trace entry - the most basic unit of tracing. This is what
* is printed in the end as a single line in the trace output, such as:
*
@@ -51,6 +61,7 @@ struct trace_entry {
struct ftrace_entry fn;
struct ctx_switch_entry ctx;
struct special_entry special;
+ struct stack_entry stack;
};
};