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Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
-rw-r--r--kernel/trace/trace_functions_graph.c247
1 files changed, 178 insertions, 69 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index a7d2a4c653d..4de3e57f723 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -38,14 +38,7 @@ 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[] = {
/* Display overruns? (for self-debug purpose) */
@@ -62,11 +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
@@ -80,9 +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
@@ -112,16 +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;
}
@@ -135,7 +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 */
@@ -143,7 +169,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
return;
}
-#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
+#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
/*
* The arch may choose to record the frame pointer used
* and check it here to make sure that it is what we expect it
@@ -154,6 +180,9 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
*
* Currently, x86_32 with optimize for size (-Os) makes the latest
* gcc do the above.
+ *
+ * Note, -mfentry does not use frame pointers, and this test
+ * is not needed if CC_USING_FENTRY is set.
*/
if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
ftrace_graph_stop();
@@ -186,9 +215,24 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
ftrace_pop_return_trace(&trace, &ret, frame_pointer);
trace.rettime = trace_clock_local();
- ftrace_graph_return(&trace);
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
+ * in case an interrupt were to come in. We don't want to
+ * lose the interrupt if max_depth is set.
+ */
+ ftrace_graph_return(&trace);
if (unlikely(!ret)) {
ftrace_graph_stop();
@@ -207,7 +251,7 @@ int __trace_graph_entry(struct trace_array *tr,
{
struct ftrace_event_call *call = &event_funcgraph_entry;
struct ring_buffer_event *event;
- struct ring_buffer *buffer = tr->buffer;
+ struct ring_buffer *buffer = tr->trace_buffer.buffer;
struct ftrace_graph_ent_entry *entry;
if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
@@ -219,8 +263,8 @@ 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))
- ring_buffer_unlock_commit(buffer, event);
+ if (!call_filter_check_discard(call, entry, buffer, event))
+ __buffer_unlock_commit(buffer, event);
return 1;
}
@@ -247,13 +291,24 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
return 0;
/* trace it when it is-nested-in or is a function enabled. */
- if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
- ftrace_graph_ignore_irqs())
+ if ((!(trace->depth || ftrace_graph_addr(trace->func)) ||
+ 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 = tr->data[cpu];
+ data = per_cpu_ptr(tr->trace_buffer.data, cpu);
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1)) {
pc = preempt_count();
@@ -311,7 +366,7 @@ void __trace_graph_return(struct trace_array *tr,
{
struct ftrace_event_call *call = &event_funcgraph_exit;
struct ring_buffer_event *event;
- struct ring_buffer *buffer = tr->buffer;
+ struct ring_buffer *buffer = tr->trace_buffer.buffer;
struct ftrace_graph_ret_entry *entry;
if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
@@ -323,8 +378,8 @@ 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))
- ring_buffer_unlock_commit(buffer, event);
+ if (!call_filter_check_discard(call, entry, buffer, event))
+ __buffer_unlock_commit(buffer, event);
}
void trace_graph_return(struct ftrace_graph_ret *trace)
@@ -338,7 +393,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
local_irq_save(flags);
cpu = raw_smp_processor_id();
- data = tr->data[cpu];
+ data = per_cpu_ptr(tr->trace_buffer.data, cpu);
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1)) {
pc = preempt_count();
@@ -434,7 +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;
}
@@ -445,7 +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;
}
@@ -491,7 +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;
@@ -504,7 +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;
@@ -512,7 +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;
@@ -538,7 +593,7 @@ get_return_for_leaf(struct trace_iterator *iter,
next = &data->ret;
} else {
- ring_iter = iter->buffer_iter[iter->cpu];
+ ring_iter = trace_buffer_iter(iter, iter->cpu);
/* First peek to compare current entry and the next one */
if (ring_iter)
@@ -548,9 +603,9 @@ get_return_for_leaf(struct trace_iterator *iter,
* We need to consume the current entry to see
* the next one.
*/
- ring_buffer_consume(iter->tr->buffer, iter->cpu,
+ ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,
NULL, NULL);
- event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
+ event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,
NULL, NULL);
}
@@ -633,30 +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;
@@ -693,13 +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;
}
@@ -717,15 +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;
}
@@ -733,10 +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, "+ ");
}
/*
@@ -745,7 +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)
@@ -755,7 +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;
@@ -805,7 +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;
}
@@ -840,13 +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;
}
@@ -905,7 +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;
}
@@ -1105,7 +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;
}
@@ -1114,10 +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 {
@@ -1160,20 +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;
@@ -1204,7 +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;
@@ -1414,7 +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;
@@ -1436,13 +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,
@@ -1454,6 +1510,59 @@ static struct tracer graph_trace __read_mostly = {
#endif
};
+
+static ssize_t
+graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ max_depth = val;
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static ssize_t
+graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
+ int n;
+
+ n = sprintf(buf, "%d\n", max_depth);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
+}
+
+static const struct file_operations graph_depth_fops = {
+ .open = tracing_open_generic,
+ .write = graph_depth_write,
+ .read = graph_depth_read,
+ .llseek = generic_file_llseek,
+};
+
+static __init int init_graph_debugfs(void)
+{
+ struct dentry *d_tracer;
+
+ d_tracer = tracing_init_dentry();
+ if (!d_tracer)
+ return 0;
+
+ trace_create_file("max_graph_depth", 0644, d_tracer,
+ NULL, &graph_depth_fops);
+
+ return 0;
+}
+fs_initcall(init_graph_debugfs);
+
static __init int init_graph_trace(void)
{
max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
@@ -1471,4 +1580,4 @@ static __init int init_graph_trace(void)
return register_tracer(&graph_trace);
}
-device_initcall(init_graph_trace);
+core_initcall(init_graph_trace);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 20:40:36 +0000