aboutsummaryrefslogtreecommitdiff
path: root/kernel/trace/trace_functions_graph.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
-rw-r--r--kernel/trace/trace_functions_graph.c158
1 files changed, 101 insertions, 57 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 8388bc99f2e..4de3e57f723 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -38,15 +38,6 @@ struct fgraph_data {
#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
-#define TRACE_GRAPH_PRINT_IRQS 0x40
-
static unsigned int max_depth;
static struct tracer_opt trace_opts[] = {
@@ -64,11 +55,13 @@ static struct tracer_opt trace_opts[] = {
{ 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) },
{ } /* Empty entry */
};
static struct tracer_flags tracer_flags = {
- /* Don't display overruns and proc by default */
+ /* 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,
.opts = trace_opts
@@ -82,9 +75,9 @@ static struct trace_array *graph_array;
* to fill in space into DURATION column.
*/
enum {
- DURATION_FILL_FULL = -1,
- DURATION_FILL_START = -2,
- DURATION_FILL_END = -3,
+ 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 enum print_line_t
@@ -114,16 +107,37 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
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 debugfs 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;
current->ret_stack[index].subtime = 0;
current->ret_stack[index].fp = frame_pointer;
- *depth = index;
+ *depth = current->curr_ret_stack;
return 0;
}
@@ -137,7 +151,17 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
index = current->curr_ret_stack;
- if (unlikely(index < 0)) {
+ /*
+ * 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 */
@@ -193,6 +217,15 @@ unsigned long ftrace_return_to_handler(unsigned long 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
@@ -230,7 +263,7 @@ int __trace_graph_entry(struct trace_array *tr,
return 0;
entry = ring_buffer_event_data(event);
entry->graph_ent = *trace;
- if (!filter_current_check_discard(buffer, call, entry, event))
+ if (!call_filter_check_discard(call, entry, buffer, event))
__buffer_unlock_commit(buffer, event);
return 1;
@@ -259,10 +292,20 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
/* trace it when it is-nested-in or is a function enabled. */
if ((!(trace->depth || ftrace_graph_addr(trace->func)) ||
- ftrace_graph_ignore_irqs()) ||
+ 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;
+
local_irq_save(flags);
cpu = raw_smp_processor_id();
data = per_cpu_ptr(tr->trace_buffer.data, cpu);
@@ -335,7 +378,7 @@ void __trace_graph_return(struct trace_array *tr,
return;
entry = ring_buffer_event_data(event);
entry->ret = *trace;
- if (!filter_current_check_discard(buffer, call, entry, event))
+ if (!call_filter_check_discard(call, entry, buffer, event))
__buffer_unlock_commit(buffer, event);
}
@@ -446,7 +489,7 @@ print_graph_proc(struct trace_seq *s, pid_t pid)
/* First spaces to align center */
for (i = 0; i < spaces / 2; i++) {
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_putc(s, ' ');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
@@ -457,7 +500,7 @@ print_graph_proc(struct trace_seq *s, pid_t pid)
/* Last spaces to align center */
for (i = 0; i < spaces - (spaces / 2); i++) {
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_putc(s, ' ');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
@@ -503,7 +546,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
------------------------------------------
*/
- ret = trace_seq_printf(s,
+ ret = trace_seq_puts(s,
" ------------------------------------------\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -516,7 +559,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, " => ");
+ ret = trace_seq_puts(s, " => ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -524,7 +567,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s,
+ ret = trace_seq_puts(s,
"\n ------------------------------------------\n\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -645,30 +688,30 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
ret = print_graph_proc(s, pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, " | ");
+ ret = trace_seq_puts(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
}
/* No overhead */
- ret = print_graph_duration(DURATION_FILL_START, s, flags);
+ ret = print_graph_duration(0, s, flags | FLAGS_FILL_START);
if (ret != TRACE_TYPE_HANDLED)
return ret;
if (type == TRACE_GRAPH_ENT)
- ret = trace_seq_printf(s, "==========>");
+ ret = trace_seq_puts(s, "==========>");
else
- ret = trace_seq_printf(s, "<==========");
+ ret = trace_seq_puts(s, "<==========");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = print_graph_duration(DURATION_FILL_END, s, flags);
+ ret = print_graph_duration(0, s, flags | FLAGS_FILL_END);
if (ret != TRACE_TYPE_HANDLED)
return ret;
- ret = trace_seq_printf(s, "\n");
+ ret = trace_seq_putc(s, '\n');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -705,13 +748,13 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
len += strlen(nsecs_str);
}
- ret = trace_seq_printf(s, " us ");
+ ret = trace_seq_puts(s, " us ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Print remaining spaces to fit the row's width */
for (i = len; i < 7; i++) {
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_putc(s, ' ');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
@@ -729,15 +772,15 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
return TRACE_TYPE_HANDLED;
/* No real adata, just filling the column with spaces */
- switch (duration) {
- case DURATION_FILL_FULL:
- ret = trace_seq_printf(s, " | ");
+ switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
+ case FLAGS_FILL_FULL:
+ ret = trace_seq_puts(s, " | ");
return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
- case DURATION_FILL_START:
- ret = trace_seq_printf(s, " ");
+ case FLAGS_FILL_START:
+ ret = trace_seq_puts(s, " ");
return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
- case DURATION_FILL_END:
- ret = trace_seq_printf(s, " |");
+ case FLAGS_FILL_END:
+ ret = trace_seq_puts(s, " |");
return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
}
@@ -745,10 +788,10 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
/* Duration exceeded 100 msecs */
if (duration > 100000ULL)
- ret = trace_seq_printf(s, "! ");
+ ret = trace_seq_puts(s, "! ");
/* Duration exceeded 10 msecs */
else if (duration > 10000ULL)
- ret = trace_seq_printf(s, "+ ");
+ ret = trace_seq_puts(s, "+ ");
}
/*
@@ -757,7 +800,7 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
* to fill out the space.
*/
if (ret == -1)
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_puts(s, " ");
/* Catching here any failure happenned above */
if (!ret)
@@ -767,7 +810,7 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
if (ret != TRACE_TYPE_HANDLED)
return ret;
- ret = trace_seq_printf(s, "| ");
+ ret = trace_seq_puts(s, "| ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -817,7 +860,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
/* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_putc(s, ' ');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
@@ -852,13 +895,13 @@ print_graph_entry_nested(struct trace_iterator *iter,
}
/* No time */
- ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
+ ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
if (ret != TRACE_TYPE_HANDLED)
return ret;
/* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_putc(s, ' ');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
@@ -917,7 +960,7 @@ print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, " | ");
+ ret = trace_seq_puts(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
@@ -1117,7 +1160,7 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
/* Closing brace */
for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_putc(s, ' ');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
@@ -1126,10 +1169,11 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *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.
+ * belongs to, write out the function name. Always do
+ * that if the funcgraph-tail option is enabled.
*/
- if (func_match) {
- ret = trace_seq_printf(s, "}\n");
+ if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) {
+ ret = trace_seq_puts(s, "}\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
} else {
@@ -1172,20 +1216,20 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
return TRACE_TYPE_PARTIAL_LINE;
/* No time */
- ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
+ ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
if (ret != TRACE_TYPE_HANDLED)
return ret;
/* Indentation */
if (depth > 0)
for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
- ret = trace_seq_printf(s, " ");
+ ret = trace_seq_putc(s, ' ');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* The comment */
- ret = trace_seq_printf(s, "/* ");
+ ret = trace_seq_puts(s, "/* ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -1216,7 +1260,7 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
s->len--;
}
- ret = trace_seq_printf(s, " */\n");
+ ret = trace_seq_puts(s, " */\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -1426,7 +1470,8 @@ void graph_trace_close(struct trace_iterator *iter)
}
}
-static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
+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;
@@ -1448,13 +1493,12 @@ static struct trace_event graph_trace_ret_event = {
.funcs = &graph_functions
};
-static struct tracer graph_trace __read_mostly = {
+static struct tracer graph_trace __tracer_data = {
.name = "function_graph",
.open = graph_trace_open,
.pipe_open = graph_trace_open,
.close = graph_trace_close,
.pipe_close = graph_trace_close,
- .wait_pipe = poll_wait_pipe,
.init = graph_trace_init,
.reset = graph_trace_reset,
.print_line = print_graph_function,
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 05:53:09 +0000