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-rw-r--r--kernel/marker.c80
-rw-r--r--kernel/sysctl.c10
-rw-r--r--kernel/trace/Kconfig2
-rw-r--r--kernel/trace/trace.c119
4 files changed, 128 insertions, 83 deletions
diff --git a/kernel/marker.c b/kernel/marker.c
index e9c6b2bc9400..2898b647d415 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -43,6 +43,7 @@ static DEFINE_MUTEX(markers_mutex);
*/
#define MARKER_HASH_BITS 6
#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS)
+static struct hlist_head marker_table[MARKER_TABLE_SIZE];
/*
* Note about RCU :
@@ -64,11 +65,10 @@ struct marker_entry {
void *oldptr;
int rcu_pending;
unsigned char ptype:1;
+ unsigned char format_allocated:1;
char name[0]; /* Contains name'\0'format'\0' */
};
-static struct hlist_head marker_table[MARKER_TABLE_SIZE];
-
/**
* __mark_empty_function - Empty probe callback
* @probe_private: probe private data
@@ -157,7 +157,7 @@ EXPORT_SYMBOL_GPL(marker_probe_cb);
*
* Should be connected to markers "MARK_NOARGS".
*/
-void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
+static void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
{
va_list args; /* not initialized */
char ptype;
@@ -197,7 +197,6 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
}
rcu_read_unlock_sched();
}
-EXPORT_SYMBOL_GPL(marker_probe_cb_noarg);
static void free_old_closure(struct rcu_head *head)
{
@@ -416,6 +415,7 @@ static struct marker_entry *add_marker(const char *name, const char *format)
e->single.probe_private = NULL;
e->multi = NULL;
e->ptype = 0;
+ e->format_allocated = 0;
e->refcount = 0;
e->rcu_pending = 0;
hlist_add_head(&e->hlist, head);
@@ -447,6 +447,8 @@ static int remove_marker(const char *name)
if (e->single.func != __mark_empty_function)
return -EBUSY;
hlist_del(&e->hlist);
+ if (e->format_allocated)
+ kfree(e->format);
/* Make sure the call_rcu has been executed */
if (e->rcu_pending)
rcu_barrier_sched();
@@ -457,57 +459,34 @@ static int remove_marker(const char *name)
/*
* Set the mark_entry format to the format found in the element.
*/
-static int marker_set_format(struct marker_entry **entry, const char *format)
+static int marker_set_format(struct marker_entry *entry, const char *format)
{
- struct marker_entry *e;
- size_t name_len = strlen((*entry)->name) + 1;
- size_t format_len = strlen(format) + 1;
-
-
- e = kmalloc(sizeof(struct marker_entry) + name_len + format_len,
- GFP_KERNEL);
- if (!e)
+ entry->format = kstrdup(format, GFP_KERNEL);
+ if (!entry->format)
return -ENOMEM;
- memcpy(&e->name[0], (*entry)->name, name_len);
- e->format = &e->name[name_len];
- memcpy(e->format, format, format_len);
- if (strcmp(e->format, MARK_NOARGS) == 0)
- e->call = marker_probe_cb_noarg;
- else
- e->call = marker_probe_cb;
- e->single = (*entry)->single;
- e->multi = (*entry)->multi;
- e->ptype = (*entry)->ptype;
- e->refcount = (*entry)->refcount;
- e->rcu_pending = 0;
- hlist_add_before(&e->hlist, &(*entry)->hlist);
- hlist_del(&(*entry)->hlist);
- /* Make sure the call_rcu has been executed */
- if ((*entry)->rcu_pending)
- rcu_barrier_sched();
- kfree(*entry);
- *entry = e;
+ entry->format_allocated = 1;
+
trace_mark(core_marker_format, "name %s format %s",
- e->name, e->format);
+ entry->name, entry->format);
return 0;
}
/*
* Sets the probe callback corresponding to one marker.
*/
-static int set_marker(struct marker_entry **entry, struct marker *elem,
+static int set_marker(struct marker_entry *entry, struct marker *elem,
int active)
{
int ret;
- WARN_ON(strcmp((*entry)->name, elem->name) != 0);
+ WARN_ON(strcmp(entry->name, elem->name) != 0);
- if ((*entry)->format) {
- if (strcmp((*entry)->format, elem->format) != 0) {
+ if (entry->format) {
+ if (strcmp(entry->format, elem->format) != 0) {
printk(KERN_NOTICE
"Format mismatch for probe %s "
"(%s), marker (%s)\n",
- (*entry)->name,
- (*entry)->format,
+ entry->name,
+ entry->format,
elem->format);
return -EPERM;
}
@@ -523,34 +502,33 @@ static int set_marker(struct marker_entry **entry, struct marker *elem,
* pass from a "safe" callback (with argument) to an "unsafe"
* callback (does not set arguments).
*/
- elem->call = (*entry)->call;
+ elem->call = entry->call;
/*
* Sanity check :
* We only update the single probe private data when the ptr is
* set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1)
*/
WARN_ON(elem->single.func != __mark_empty_function
- && elem->single.probe_private
- != (*entry)->single.probe_private &&
- !elem->ptype);
- elem->single.probe_private = (*entry)->single.probe_private;
+ && elem->single.probe_private != entry->single.probe_private
+ && !elem->ptype);
+ elem->single.probe_private = entry->single.probe_private;
/*
* Make sure the private data is valid when we update the
* single probe ptr.
*/
smp_wmb();
- elem->single.func = (*entry)->single.func;
+ elem->single.func = entry->single.func;
/*
* We also make sure that the new probe callbacks array is consistent
* before setting a pointer to it.
*/
- rcu_assign_pointer(elem->multi, (*entry)->multi);
+ rcu_assign_pointer(elem->multi, entry->multi);
/*
* Update the function or multi probe array pointer before setting the
* ptype.
*/
smp_wmb();
- elem->ptype = (*entry)->ptype;
+ elem->ptype = entry->ptype;
elem->state = active;
return 0;
@@ -594,8 +572,7 @@ void marker_update_probe_range(struct marker *begin,
for (iter = begin; iter < end; iter++) {
mark_entry = get_marker(iter->name);
if (mark_entry) {
- set_marker(&mark_entry, iter,
- !!mark_entry->refcount);
+ set_marker(mark_entry, iter, !!mark_entry->refcount);
/*
* ignore error, continue
*/
@@ -657,7 +634,7 @@ int marker_probe_register(const char *name, const char *format,
ret = PTR_ERR(entry);
} else if (format) {
if (!entry->format)
- ret = marker_set_format(&entry, format);
+ ret = marker_set_format(entry, format);
else if (strcmp(entry->format, format))
ret = -EPERM;
}
@@ -848,8 +825,6 @@ void *marker_get_private_data(const char *name, marker_probe_func *probe,
if (!e->ptype) {
if (num == 0 && e->single.func == probe)
return e->single.probe_private;
- else
- break;
} else {
struct marker_probe_closure *closure;
int match = 0;
@@ -861,6 +836,7 @@ void *marker_get_private_data(const char *name, marker_probe_func *probe,
return closure[i].probe_private;
}
}
+ break;
}
}
return ERR_PTR(-ENOENT);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9d048fa2d902..6b6b727258b5 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -484,6 +484,16 @@ static struct ctl_table kern_table[] = {
.proc_handler = &ftrace_enable_sysctl,
},
#endif
+#ifdef CONFIG_TRACING
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "ftrace_dump_on_opps",
+ .data = &ftrace_dump_on_oops,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+#endif
#ifdef CONFIG_MODULES
{
.ctl_name = KERN_MODPROBE,
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index b58f43bec363..33dbefd471e8 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -25,7 +25,7 @@ config TRACING
bool
select DEBUG_FS
select RING_BUFFER
- select STACKTRACE
+ select STACKTRACE if STACKTRACE_SUPPORT
select TRACEPOINTS
select NOP_TRACER
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8a499e2adaec..e4c40c868d67 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -64,6 +64,37 @@ static cpumask_t __read_mostly tracing_buffer_mask;
static int tracing_disabled = 1;
+/*
+ * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
+ *
+ * If there is an oops (or kernel panic) and the ftrace_dump_on_oops
+ * is set, then ftrace_dump is called. This will output the contents
+ * of the ftrace buffers to the console. This is very useful for
+ * capturing traces that lead to crashes and outputing it to a
+ * serial console.
+ *
+ * It is default off, but you can enable it with either specifying
+ * "ftrace_dump_on_oops" in the kernel command line, or setting
+ * /proc/sys/kernel/ftrace_dump_on_oops to true.
+ */
+int ftrace_dump_on_oops;
+
+static int tracing_set_tracer(char *buf);
+
+static int __init set_ftrace(char *str)
+{
+ tracing_set_tracer(str);
+ return 1;
+}
+__setup("ftrace", set_ftrace);
+
+static int __init set_ftrace_dump_on_oops(char *str)
+{
+ ftrace_dump_on_oops = 1;
+ return 1;
+}
+__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
+
long
ns2usecs(cycle_t nsec)
{
@@ -705,6 +736,7 @@ static void ftrace_trace_stack(struct trace_array *tr,
unsigned long flags,
int skip, int pc)
{
+#ifdef CONFIG_STACKTRACE
struct ring_buffer_event *event;
struct stack_entry *entry;
struct stack_trace trace;
@@ -730,6 +762,7 @@ static void ftrace_trace_stack(struct trace_array *tr,
save_stack_trace(&trace);
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+#endif
}
void __trace_stack(struct trace_array *tr,
@@ -2372,29 +2405,11 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf,
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
-static ssize_t
-tracing_set_trace_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
+static int tracing_set_tracer(char *buf)
{
struct trace_array *tr = &global_trace;
struct tracer *t;
- char buf[max_tracer_type_len+1];
- int i;
- size_t ret;
-
- ret = cnt;
-
- if (cnt > max_tracer_type_len)
- cnt = max_tracer_type_len;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- /* strip ending whitespace. */
- for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
- buf[i] = 0;
+ int ret = 0;
mutex_lock(&trace_types_lock);
for (t = trace_types; t; t = t->next) {
@@ -2418,6 +2433,33 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
out:
mutex_unlock(&trace_types_lock);
+ return ret;
+}
+
+static ssize_t
+tracing_set_trace_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[max_tracer_type_len+1];
+ int i;
+ size_t ret;
+
+ if (cnt > max_tracer_type_len)
+ cnt = max_tracer_type_len;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ /* strip ending whitespace. */
+ for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
+ buf[i] = 0;
+
+ ret = tracing_set_tracer(buf);
+ if (!ret)
+ ret = cnt;
+
if (ret > 0)
filp->f_pos += ret;
@@ -2820,22 +2862,38 @@ static struct file_operations tracing_mark_fops = {
#ifdef CONFIG_DYNAMIC_FTRACE
+int __weak ftrace_arch_read_dyn_info(char *buf, int size)
+{
+ return 0;
+}
+
static ssize_t
-tracing_read_long(struct file *filp, char __user *ubuf,
+tracing_read_dyn_info(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
+ static char ftrace_dyn_info_buffer[1024];
+ static DEFINE_MUTEX(dyn_info_mutex);
unsigned long *p = filp->private_data;
- char buf[64];
+ char *buf = ftrace_dyn_info_buffer;
+ int size = ARRAY_SIZE(ftrace_dyn_info_buffer);
int r;
- r = sprintf(buf, "%ld\n", *p);
+ mutex_lock(&dyn_info_mutex);
+ r = sprintf(buf, "%ld ", *p);
- return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+ r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r);
+ buf[r++] = '\n';
+
+ r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+
+ mutex_unlock(&dyn_info_mutex);
+
+ return r;
}
-static struct file_operations tracing_read_long_fops = {
+static struct file_operations tracing_dyn_info_fops = {
.open = tracing_open_generic,
- .read = tracing_read_long,
+ .read = tracing_read_dyn_info,
};
#endif
@@ -2944,7 +3002,7 @@ static __init int tracer_init_debugfs(void)
#ifdef CONFIG_DYNAMIC_FTRACE
entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
&ftrace_update_tot_cnt,
- &tracing_read_long_fops);
+ &tracing_dyn_info_fops);
if (!entry)
pr_warning("Could not create debugfs "
"'dyn_ftrace_total_info' entry\n");
@@ -3025,7 +3083,8 @@ EXPORT_SYMBOL_GPL(__ftrace_printk);
static int trace_panic_handler(struct notifier_block *this,
unsigned long event, void *unused)
{
- ftrace_dump();
+ if (ftrace_dump_on_oops)
+ ftrace_dump();
return NOTIFY_OK;
}
@@ -3041,7 +3100,8 @@ static int trace_die_handler(struct notifier_block *self,
{
switch (val) {
case DIE_OOPS:
- ftrace_dump();
+ if (ftrace_dump_on_oops)
+ ftrace_dump();
break;
default:
break;
@@ -3082,7 +3142,6 @@ trace_printk_seq(struct trace_seq *s)
trace_seq_reset(s);
}
-
void ftrace_dump(void)
{
static DEFINE_SPINLOCK(ftrace_dump_lock);