#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/init.h>
+#include <linux/panic_notifier.h>
#include <linux/poll.h>
#include <linux/nmi.h>
#include <linux/fs.h>
/* Pipe tracepoints to printk */
struct trace_iterator *tracepoint_print_iter;
int tracepoint_printk;
+static bool tracepoint_printk_stop_on_boot __initdata;
static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key);
/* For tracers that don't implement custom flags */
static int __init set_ftrace_dump_on_oops(char *str)
{
- if (*str++ != '=' || !*str) {
+ if (*str++ != '=' || !*str || !strcmp("1", str)) {
ftrace_dump_on_oops = DUMP_ALL;
return 1;
}
- if (!strcmp("orig_cpu", str)) {
+ if (!strcmp("orig_cpu", str) || !strcmp("2", str)) {
ftrace_dump_on_oops = DUMP_ORIG;
return 1;
}
}
__setup("tp_printk", set_tracepoint_printk);
+static int __init set_tracepoint_printk_stop(char *str)
+{
+ tracepoint_printk_stop_on_boot = true;
+ return 1;
+}
+__setup("tp_printk_stop_on_boot", set_tracepoint_printk_stop);
+
unsigned long long ns2usecs(u64 nsec)
{
nsec += 500;
unsigned long __read_mostly tracing_thresh;
static const struct file_operations tracing_max_lat_fops;
-#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
- defined(CONFIG_FSNOTIFY)
+#ifdef LATENCY_FS_NOTIFY
static struct workqueue_struct *fsnotify_wq;
}
}
+/*
+ * The tgid_map array maps from pid to tgid; i.e. the value stored at index i
+ * is the tgid last observed corresponding to pid=i.
+ */
static int *tgid_map;
+/* The maximum valid index into tgid_map. */
+static size_t tgid_map_max;
+
#define SAVED_CMDLINES_DEFAULT 128
#define NO_CMDLINE_MAP UINT_MAX
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
preempt_enable();
}
+static int *trace_find_tgid_ptr(int pid)
+{
+ /*
+ * Pairs with the smp_store_release in set_tracer_flag() to ensure that
+ * if we observe a non-NULL tgid_map then we also observe the correct
+ * tgid_map_max.
+ */
+ int *map = smp_load_acquire(&tgid_map);
+
+ if (unlikely(!map || pid > tgid_map_max))
+ return NULL;
+
+ return &map[pid];
+}
+
int trace_find_tgid(int pid)
{
- if (unlikely(!tgid_map || !pid || pid > PID_MAX_DEFAULT))
- return 0;
+ int *ptr = trace_find_tgid_ptr(pid);
- return tgid_map[pid];
+ return ptr ? *ptr : 0;
}
static int trace_save_tgid(struct task_struct *tsk)
{
+ int *ptr;
+
/* treat recording of idle task as a success */
if (!tsk->pid)
return 1;
- if (unlikely(!tgid_map || tsk->pid > PID_MAX_DEFAULT))
+ ptr = trace_find_tgid_ptr(tsk->pid);
+ if (!ptr)
return 0;
- tgid_map[tsk->pid] = tsk->tgid;
+ *ptr = tsk->tgid;
return 1;
}
if (!tr->no_filter_buffering_ref &&
(trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
(entry = this_cpu_read(trace_buffered_event))) {
- /* Try to use the per cpu buffer first */
+ /*
+ * Filtering is on, so try to use the per cpu buffer first.
+ * This buffer will simulate a ring_buffer_event,
+ * where the type_len is zero and the array[0] will
+ * hold the full length.
+ * (see include/linux/ring-buffer.h for details on
+ * how the ring_buffer_event is structured).
+ *
+ * Using a temp buffer during filtering and copying it
+ * on a matched filter is quicker than writing directly
+ * into the ring buffer and then discarding it when
+ * it doesn't match. That is because the discard
+ * requires several atomic operations to get right.
+ * Copying on match and doing nothing on a failed match
+ * is still quicker than no copy on match, but having
+ * to discard out of the ring buffer on a failed match.
+ */
+ int max_len = PAGE_SIZE - struct_size(entry, array, 1);
+
val = this_cpu_inc_return(trace_buffered_event_cnt);
- if ((len < (PAGE_SIZE - sizeof(*entry) - sizeof(entry->array[0]))) && val == 1) {
+
+ /*
+ * Preemption is disabled, but interrupts and NMIs
+ * can still come in now. If that happens after
+ * the above increment, then it will have to go
+ * back to the old method of allocating the event
+ * on the ring buffer, and if the filter fails, it
+ * will have to call ring_buffer_discard_commit()
+ * to remove it.
+ *
+ * Need to also check the unlikely case that the
+ * length is bigger than the temp buffer size.
+ * If that happens, then the reserve is pretty much
+ * guaranteed to fail, as the ring buffer currently
+ * only allows events less than a page. But that may
+ * change in the future, so let the ring buffer reserve
+ * handle the failure in that case.
+ */
+ if (val == 1 && likely(len <= max_len)) {
trace_event_setup(entry, type, trace_ctx);
entry->array[0] = len;
return entry;
int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
{
+ int *map;
+
if ((mask == TRACE_ITER_RECORD_TGID) ||
(mask == TRACE_ITER_RECORD_CMD))
lockdep_assert_held(&event_mutex);
trace_event_enable_cmd_record(enabled);
if (mask == TRACE_ITER_RECORD_TGID) {
- if (!tgid_map)
- tgid_map = kvcalloc(PID_MAX_DEFAULT + 1,
- sizeof(*tgid_map),
- GFP_KERNEL);
+ if (!tgid_map) {
+ tgid_map_max = pid_max;
+ map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),
+ GFP_KERNEL);
+
+ /*
+ * Pairs with smp_load_acquire() in
+ * trace_find_tgid_ptr() to ensure that if it observes
+ * the tgid_map we just allocated then it also observes
+ * the corresponding tgid_map_max value.
+ */
+ smp_store_release(&tgid_map, map);
+ }
if (!tgid_map) {
tr->trace_flags &= ~TRACE_ITER_RECORD_TGID;
return -ENOMEM;
"\t [:name=histname1]\n"
"\t [:<handler>.<action>]\n"
"\t [if <filter>]\n\n"
+ "\t Note, special fields can be used as well:\n"
+ "\t common_timestamp - to record current timestamp\n"
+ "\t common_cpu - to record the CPU the event happened on\n"
+ "\n"
"\t When a matching event is hit, an entry is added to a hash\n"
"\t table using the key(s) and value(s) named, and the value of a\n"
"\t sum called 'hitcount' is incremented. Keys and values\n"
static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
{
- int *ptr = v;
-
- if (*pos || m->count)
- ptr++;
-
- (*pos)++;
-
- for (; ptr <= &tgid_map[PID_MAX_DEFAULT]; ptr++) {
- if (trace_find_tgid(*ptr))
- return ptr;
- }
+ int pid = ++(*pos);
- return NULL;
+ return trace_find_tgid_ptr(pid);
}
static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
{
- void *v;
- loff_t l = 0;
-
- if (!tgid_map)
- return NULL;
+ int pid = *pos;
- v = &tgid_map[0];
- while (l <= *pos) {
- v = saved_tgids_next(m, v, &l);
- if (!v)
- return NULL;
- }
-
- return v;
+ return trace_find_tgid_ptr(pid);
}
static void saved_tgids_stop(struct seq_file *m, void *v)
static int saved_tgids_show(struct seq_file *m, void *v)
{
- int pid = (int *)v - tgid_map;
+ int *entry = (int *)v;
+ int pid = entry - tgid_map;
+ int tgid = *entry;
- seq_printf(m, "%d %d\n", pid, trace_find_tgid(pid));
+ if (tgid == 0)
+ return SEQ_SKIP;
+
+ seq_printf(m, "%d %d\n", pid, tgid);
return 0;
}
ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
unsigned long size, int cpu_id)
{
- int ret = size;
+ int ret;
mutex_lock(&trace_types_lock);
#endif /* CONFIG_TRACER_SNAPSHOT */
+/*
+ * trace_min_max_write - Write a u64 value to a trace_min_max_param struct
+ * @filp: The active open file structure
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function implements the write interface for a struct trace_min_max_param.
+ * The filp->private_data must point to a trace_min_max_param structure that
+ * defines where to write the value, the min and the max acceptable values,
+ * and a lock to protect the write.
+ */
+static ssize_t
+trace_min_max_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ struct trace_min_max_param *param = filp->private_data;
+ u64 val;
+ int err;
+
+ if (!param)
+ return -EFAULT;
+
+ err = kstrtoull_from_user(ubuf, cnt, 10, &val);
+ if (err)
+ return err;
+
+ if (param->lock)
+ mutex_lock(param->lock);
+
+ if (param->min && val < *param->min)
+ err = -EINVAL;
+
+ if (param->max && val > *param->max)
+ err = -EINVAL;
+
+ if (!err)
+ *param->val = val;
+
+ if (param->lock)
+ mutex_unlock(param->lock);
+
+ if (err)
+ return err;
+
+ return cnt;
+}
+
+/*
+ * trace_min_max_read - Read a u64 value from a trace_min_max_param struct
+ * @filp: The active open file structure
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function implements the read interface for a struct trace_min_max_param.
+ * The filp->private_data must point to a trace_min_max_param struct with valid
+ * data.
+ */
+static ssize_t
+trace_min_max_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ struct trace_min_max_param *param = filp->private_data;
+ char buf[U64_STR_SIZE];
+ int len;
+ u64 val;
+
+ if (!param)
+ return -EFAULT;
+
+ val = *param->val;
+
+ if (cnt > sizeof(buf))
+ cnt = sizeof(buf);
+
+ len = snprintf(buf, sizeof(buf), "%llu\n", val);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
+}
+
+const struct file_operations trace_min_max_fops = {
+ .open = tracing_open_generic,
+ .read = trace_min_max_read,
+ .write = trace_min_max_write,
+};
+
#define TRACING_LOG_ERRS_MAX 8
#define TRACING_LOG_LOC_MAX 128
return 0;
}
+fs_initcall(tracer_init_tracefs);
+
static int trace_panic_handler(struct notifier_block *this,
unsigned long event, void *unused)
{
trace_event_init();
}
-__init static int clear_boot_tracer(void)
+__init static void clear_boot_tracer(void)
{
/*
* The default tracer at boot buffer is an init section.
* about to be freed.
*/
if (!default_bootup_tracer)
- return 0;
+ return;
printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n",
default_bootup_tracer);
default_bootup_tracer = NULL;
-
- return 0;
}
-fs_initcall(tracer_init_tracefs);
-late_initcall_sync(clear_boot_tracer);
-
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
-__init static int tracing_set_default_clock(void)
+__init static void tracing_set_default_clock(void)
{
/* sched_clock_stable() is determined in late_initcall */
if (!trace_boot_clock && !sched_clock_stable()) {
if (security_locked_down(LOCKDOWN_TRACEFS)) {
pr_warn("Can not set tracing clock due to lockdown\n");
- return -EPERM;
+ return;
}
printk(KERN_WARNING
"on the kernel command line\n");
tracing_set_clock(&global_trace, "global");
}
+}
+#else
+static inline void tracing_set_default_clock(void) { }
+#endif
+
+__init static int late_trace_init(void)
+{
+ if (tracepoint_printk && tracepoint_printk_stop_on_boot) {
+ static_key_disable(&tracepoint_printk_key.key);
+ tracepoint_printk = 0;
+ }
+ tracing_set_default_clock();
+ clear_boot_tracer();
return 0;
}
-late_initcall_sync(tracing_set_default_clock);
-#endif
+
+late_initcall_sync(late_trace_init);
projects / linux-2.6-microblaze.git / blobdiff