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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c197
1 files changed, 146 insertions, 51 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 24c1f2382557..737b0efa1a62 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -73,7 +73,8 @@ static struct tracer_flags dummy_tracer_flags = {
.opts = dummy_tracer_opt
};
-static int dummy_set_flag(u32 old_flags, u32 bit, int set)
+static int
+dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
{
return 0;
}
@@ -118,7 +119,7 @@ enum ftrace_dump_mode ftrace_dump_on_oops;
/* When set, tracing will stop when a WARN*() is hit */
int __disable_trace_on_warning;
-static int tracing_set_tracer(const char *buf);
+static int tracing_set_tracer(struct trace_array *tr, const char *buf);
#define MAX_TRACER_SIZE 100
static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
@@ -180,6 +181,17 @@ static int __init set_trace_boot_options(char *str)
}
__setup("trace_options=", set_trace_boot_options);
+static char trace_boot_clock_buf[MAX_TRACER_SIZE] __initdata;
+static char *trace_boot_clock __initdata;
+
+static int __init set_trace_boot_clock(char *str)
+{
+ strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
+ trace_boot_clock = trace_boot_clock_buf;
+ return 0;
+}
+__setup("trace_clock=", set_trace_boot_clock);
+
unsigned long long ns2usecs(cycle_t nsec)
{
@@ -1230,7 +1242,7 @@ int register_tracer(struct tracer *type)
printk(KERN_INFO "Starting tracer '%s'\n", type->name);
/* Do we want this tracer to start on bootup? */
- tracing_set_tracer(type->name);
+ tracing_set_tracer(&global_trace, type->name);
default_bootup_tracer = NULL;
/* disable other selftests, since this will break it. */
tracing_selftest_disabled = true;
@@ -3137,27 +3149,52 @@ static int tracing_open(struct inode *inode, struct file *file)
return ret;
}
+/*
+ * Some tracers are not suitable for instance buffers.
+ * A tracer is always available for the global array (toplevel)
+ * or if it explicitly states that it is.
+ */
+static bool
+trace_ok_for_array(struct tracer *t, struct trace_array *tr)
+{
+ return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances;
+}
+
+/* Find the next tracer that this trace array may use */
+static struct tracer *
+get_tracer_for_array(struct trace_array *tr, struct tracer *t)
+{
+ while (t && !trace_ok_for_array(t, tr))
+ t = t->next;
+
+ return t;
+}
+
static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
+ struct trace_array *tr = m->private;
struct tracer *t = v;
(*pos)++;
if (t)
- t = t->next;
+ t = get_tracer_for_array(tr, t->next);
return t;
}
static void *t_start(struct seq_file *m, loff_t *pos)
{
+ struct trace_array *tr = m->private;
struct tracer *t;
loff_t l = 0;
mutex_lock(&trace_types_lock);
- for (t = trace_types; t && l < *pos; t = t_next(m, t, &l))
- ;
+
+ t = get_tracer_for_array(tr, trace_types);
+ for (; t && l < *pos; t = t_next(m, t, &l))
+ ;
return t;
}
@@ -3192,10 +3229,21 @@ static const struct seq_operations show_traces_seq_ops = {
static int show_traces_open(struct inode *inode, struct file *file)
{
+ struct trace_array *tr = inode->i_private;
+ struct seq_file *m;
+ int ret;
+
if (tracing_disabled)
return -ENODEV;
- return seq_open(file, &show_traces_seq_ops);
+ ret = seq_open(file, &show_traces_seq_ops);
+ if (ret)
+ return ret;
+
+ m = file->private_data;
+ m->private = tr;
+
+ return 0;
}
static ssize_t
@@ -3355,13 +3403,14 @@ static int tracing_trace_options_show(struct seq_file *m, void *v)
return 0;
}
-static int __set_tracer_option(struct tracer *trace,
+static int __set_tracer_option(struct trace_array *tr,
struct tracer_flags *tracer_flags,
struct tracer_opt *opts, int neg)
{
+ struct tracer *trace = tr->current_trace;
int ret;
- ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
+ ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg);
if (ret)
return ret;
@@ -3373,8 +3422,9 @@ static int __set_tracer_option(struct tracer *trace,
}
/* Try to assign a tracer specific option */
-static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
+static int set_tracer_option(struct trace_array *tr, char *cmp, int neg)
{
+ struct tracer *trace = tr->current_trace;
struct tracer_flags *tracer_flags = trace->flags;
struct tracer_opt *opts = NULL;
int i;
@@ -3383,8 +3433,7 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
opts = &tracer_flags->opts[i];
if (strcmp(cmp, opts->name) == 0)
- return __set_tracer_option(trace, trace->flags,
- opts, neg);
+ return __set_tracer_option(tr, trace->flags, opts, neg);
}
return -EINVAL;
@@ -3407,7 +3456,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
/* Give the tracer a chance to approve the change */
if (tr->current_trace->flag_changed)
- if (tr->current_trace->flag_changed(tr->current_trace, mask, !!enabled))
+ if (tr->current_trace->flag_changed(tr, mask, !!enabled))
return -EINVAL;
if (enabled)
@@ -3456,7 +3505,7 @@ static int trace_set_options(struct trace_array *tr, char *option)
/* If no option could be set, test the specific tracer options */
if (!trace_options[i])
- ret = set_tracer_option(tr->current_trace, cmp, neg);
+ ret = set_tracer_option(tr, cmp, neg);
mutex_unlock(&trace_types_lock);
@@ -3562,6 +3611,8 @@ static const char readme_msg[] =
#ifdef CONFIG_TRACER_SNAPSHOT
"\t\t snapshot\n"
#endif
+ "\t\t dump\n"
+ "\t\t cpudump\n"
"\t example: echo do_fault:traceoff > set_ftrace_filter\n"
"\t echo do_trap:traceoff:3 > set_ftrace_filter\n"
"\t The first one will disable tracing every time do_fault is hit\n"
@@ -3885,10 +3936,26 @@ create_trace_option_files(struct trace_array *tr, struct tracer *tracer);
static void
destroy_trace_option_files(struct trace_option_dentry *topts);
-static int tracing_set_tracer(const char *buf)
+/*
+ * Used to clear out the tracer before deletion of an instance.
+ * Must have trace_types_lock held.
+ */
+static void tracing_set_nop(struct trace_array *tr)
+{
+ if (tr->current_trace == &nop_trace)
+ return;
+
+ tr->current_trace->enabled--;
+
+ if (tr->current_trace->reset)
+ tr->current_trace->reset(tr);
+
+ tr->current_trace = &nop_trace;
+}
+
+static int tracing_set_tracer(struct trace_array *tr, const char *buf)
{
static struct trace_option_dentry *topts;
- struct trace_array *tr = &global_trace;
struct tracer *t;
#ifdef CONFIG_TRACER_MAX_TRACE
bool had_max_tr;
@@ -3916,9 +3983,15 @@ static int tracing_set_tracer(const char *buf)
if (t == tr->current_trace)
goto out;
+ /* Some tracers are only allowed for the top level buffer */
+ if (!trace_ok_for_array(t, tr)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
trace_branch_disable();
- tr->current_trace->enabled = false;
+ tr->current_trace->enabled--;
if (tr->current_trace->reset)
tr->current_trace->reset(tr);
@@ -3941,9 +4014,11 @@ static int tracing_set_tracer(const char *buf)
free_snapshot(tr);
}
#endif
- destroy_trace_option_files(topts);
-
- topts = create_trace_option_files(tr, t);
+ /* Currently, only the top instance has options */
+ if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
+ destroy_trace_option_files(topts);
+ topts = create_trace_option_files(tr, t);
+ }
#ifdef CONFIG_TRACER_MAX_TRACE
if (t->use_max_tr && !had_max_tr) {
@@ -3960,7 +4035,7 @@ static int tracing_set_tracer(const char *buf)
}
tr->current_trace = t;
- tr->current_trace->enabled = true;
+ tr->current_trace->enabled++;
trace_branch_enable(tr);
out:
mutex_unlock(&trace_types_lock);
@@ -3972,6 +4047,7 @@ static ssize_t
tracing_set_trace_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
+ struct trace_array *tr = filp->private_data;
char buf[MAX_TRACER_SIZE+1];
int i;
size_t ret;
@@ -3991,7 +4067,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
buf[i] = 0;
- err = tracing_set_tracer(buf);
+ err = tracing_set_tracer(tr, buf);
if (err)
return err;
@@ -4316,8 +4392,6 @@ static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
static const struct pipe_buf_operations tracing_pipe_buf_ops = {
.can_merge = 0,
- .map = generic_pipe_buf_map,
- .unmap = generic_pipe_buf_unmap,
.confirm = generic_pipe_buf_confirm,
.release = generic_pipe_buf_release,
.steal = generic_pipe_buf_steal,
@@ -4412,7 +4486,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
trace_access_lock(iter->cpu_file);
/* Fill as many pages as possible. */
- for (i = 0, rem = len; i < pipe->buffers && rem; i++) {
+ for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) {
spd.pages[i] = alloc_page(GFP_KERNEL);
if (!spd.pages[i])
break;
@@ -4699,25 +4773,10 @@ static int tracing_clock_show(struct seq_file *m, void *v)
return 0;
}
-static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *fpos)
+static int tracing_set_clock(struct trace_array *tr, const char *clockstr)
{
- struct seq_file *m = filp->private_data;
- struct trace_array *tr = m->private;
- char buf[64];
- const char *clockstr;
int i;
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- clockstr = strstrip(buf);
-
for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
if (strcmp(trace_clocks[i].name, clockstr) == 0)
break;
@@ -4745,6 +4804,32 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
mutex_unlock(&trace_types_lock);
+ return 0;
+}
+
+static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *fpos)
+{
+ struct seq_file *m = filp->private_data;
+ struct trace_array *tr = m->private;
+ char buf[64];
+ const char *clockstr;
+ int ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ clockstr = strstrip(buf);
+
+ ret = tracing_set_clock(tr, clockstr);
+ if (ret)
+ return ret;
+
*fpos += cnt;
return cnt;
@@ -5194,8 +5279,6 @@ static void buffer_pipe_buf_get(struct pipe_inode_info *pipe,
/* Pipe buffer operations for a buffer. */
static const struct pipe_buf_operations buffer_pipe_buf_ops = {
.can_merge = 0,
- .map = generic_pipe_buf_map,
- .unmap = generic_pipe_buf_unmap,
.confirm = generic_pipe_buf_confirm,
.release = buffer_pipe_buf_release,
.steal = generic_pipe_buf_steal,
@@ -5271,7 +5354,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
trace_access_lock(iter->cpu_file);
entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
- for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) {
+ for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) {
struct page *page;
int r;
@@ -5705,7 +5788,7 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
if (!!(topt->flags->val & topt->opt->bit) != val) {
mutex_lock(&trace_types_lock);
- ret = __set_tracer_option(topt->tr->current_trace, topt->flags,
+ ret = __set_tracer_option(topt->tr, topt->flags,
topt->opt, !val);
mutex_unlock(&trace_types_lock);
if (ret)
@@ -6112,7 +6195,9 @@ static int instance_delete(const char *name)
list_del(&tr->list);
+ tracing_set_nop(tr);
event_trace_del_tracer(tr);
+ ftrace_destroy_function_files(tr);
debugfs_remove_recursive(tr->dir);
free_percpu(tr->trace_buffer.data);
ring_buffer_free(tr->trace_buffer.buffer);
@@ -6207,6 +6292,12 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
{
int cpu;
+ trace_create_file("available_tracers", 0444, d_tracer,
+ tr, &show_traces_fops);
+
+ trace_create_file("current_tracer", 0644, d_tracer,
+ tr, &set_tracer_fops);
+
trace_create_file("tracing_cpumask", 0644, d_tracer,
tr, &tracing_cpumask_fops);
@@ -6237,6 +6328,9 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("tracing_on", 0644, d_tracer,
tr, &rb_simple_fops);
+ if (ftrace_create_function_files(tr, d_tracer))
+ WARN(1, "Could not allocate function filter files");
+
#ifdef CONFIG_TRACER_SNAPSHOT
trace_create_file("snapshot", 0644, d_tracer,
tr, &snapshot_fops);
@@ -6259,12 +6353,6 @@ static __init int tracer_init_debugfs(void)
init_tracer_debugfs(&global_trace, d_tracer);
- trace_create_file("available_tracers", 0444, d_tracer,
- &global_trace, &show_traces_fops);
-
- trace_create_file("current_tracer", 0644, d_tracer,
- &global_trace, &set_tracer_fops);
-
#ifdef CONFIG_TRACER_MAX_TRACE
trace_create_file("tracing_max_latency", 0644, d_tracer,
&tracing_max_latency, &tracing_max_lat_fops);
@@ -6527,6 +6615,13 @@ __init static int tracer_alloc_buffers(void)
trace_init_cmdlines();
+ if (trace_boot_clock) {
+ ret = tracing_set_clock(&global_trace, trace_boot_clock);
+ if (ret < 0)
+ pr_warning("Trace clock %s not defined, going back to default\n",
+ trace_boot_clock);
+ }
+
/*
* register_tracer() might reference current_trace, so it
* needs to be set before we register anything. This is
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 12:02:12 +0000