1 files changed, 146 insertions, 42 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5c75deeefe30..6c0f6a8a22eb 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -125,13 +125,13 @@ int ftrace_dump_on_oops;
 
 static int tracing_set_tracer(const char *buf);
 
-#define BOOTUP_TRACER_SIZE              100
-static char bootup_tracer_buf[BOOTUP_TRACER_SIZE] __initdata;
+#define MAX_TRACER_SIZE         100
+static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
 static int __init set_ftrace(char *str)
 {
-        strncpy(bootup_tracer_buf, str, BOOTUP_TRACER_SIZE);
+        strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
         default_bootup_tracer = bootup_tracer_buf;
         /* We are using ftrace early, expand it */
         ring_buffer_expanded = 1;
@@ -242,13 +242,6 @@ static struct tracer		*trace_types __read_mostly;
 static struct tracer            *current_trace __read_mostly;
 
 /*
- * max_tracer_type_len is used to simplify the allocating of
- * buffers to read userspace tracer names. We keep track of
- * the longest tracer name registered.
- */
-static int                      max_tracer_type_len;
-
-/*
  * trace_types_lock is used to protect the trace_types list.
  * This lock is also used to keep user access serialized.
  * Accesses from userspace will grab this lock while userspace
@@ -275,12 +268,18 @@ static DEFINE_SPINLOCK(tracing_start_lock);
  */
 void trace_wake_up(void)
 {
+        int cpu;
+
+        if (trace_flags & TRACE_ITER_BLOCK)
+                return;
         /*
          * The runqueue_is_locked() can fail, but this is the best we
          * have for now:
          */
-        if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
+        cpu = get_cpu();
+        if (!runqueue_is_locked(cpu))
                 wake_up(&trace_wait);
+        put_cpu();
 }
 
 static int __init set_buf_size(char *str)
@@ -339,6 +338,112 @@ static struct {
 
 int trace_clock_id;
 
+/*
+ * trace_parser_get_init - gets the buffer for trace parser
+ */
+int trace_parser_get_init(struct trace_parser *parser, int size)
+{
+        memset(parser, 0, sizeof(*parser));
+
+        parser->buffer = kmalloc(size, GFP_KERNEL);
+        if (!parser->buffer)
+                return 1;
+
+        parser->size = size;
+        return 0;
+}
+
+/*
+ * trace_parser_put - frees the buffer for trace parser
+ */
+void trace_parser_put(struct trace_parser *parser)
+{
+        kfree(parser->buffer);
+}
+
+/*
+ * trace_get_user - reads the user input string separated by  space
+ * (matched by isspace(ch))
+ *
+ * For each string found the 'struct trace_parser' is updated,
+ * and the function returns.
+ *
+ * Returns number of bytes read.
+ *
+ * See kernel/trace/trace.h for 'struct trace_parser' details.
+ */
+int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
+        size_t cnt, loff_t *ppos)
+{
+        char ch;
+        size_t read = 0;
+        ssize_t ret;
+
+        if (!*ppos)
+                trace_parser_clear(parser);
+
+        ret = get_user(ch, ubuf++);
+        if (ret)
+                goto out;
+
+        read++;
+        cnt--;
+
+        /*
+         * The parser is not finished with the last write,
+         * continue reading the user input without skipping spaces.
+         */
+        if (!parser->cont) {
+                /* skip white space */
+                while (cnt && isspace(ch)) {
+                        ret = get_user(ch, ubuf++);
+                        if (ret)
+                                goto out;
+                        read++;
+                        cnt--;
+                }
+
+                /* only spaces were written */
+                if (isspace(ch)) {
+                        *ppos += read;
+                        ret = read;
+                        goto out;
+                }
+
+                parser->idx = 0;
+        }
+
+        /* read the non-space input */
+        while (cnt && !isspace(ch)) {
+                if (parser->idx < parser->size)
+                        parser->buffer[parser->idx++] = ch;
+                else {
+                        ret = -EINVAL;
+                        goto out;
+                }
+                ret = get_user(ch, ubuf++);
+                if (ret)
+                        goto out;
+                read++;
+                cnt--;
+        }
+
+        /* We either got finished input or we have to wait for another call. */
+        if (isspace(ch)) {
+                parser->buffer[parser->idx] = 0;
+                parser->cont = false;
+        } else {
+                parser->cont = true;
+                parser->buffer[parser->idx++] = ch;
+        }
+
+        *ppos += read;
+        ret = read;
+
+out:
+        return ret;
+}
+
 ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
 {
         int len;
@@ -513,7 +618,6 @@ __releases(kernel_lock)
 __acquires(kernel_lock)
 {
         struct tracer *t;
-        int len;
         int ret = 0;
 
         if (!type->name) {
@@ -521,6 +625,11 @@ __acquires(kernel_lock)
                 return -1;
         }
 
+        if (strlen(type->name) > MAX_TRACER_SIZE) {
+                pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
+                return -1;
+        }
+
         /*
          * When this gets called we hold the BKL which means that
          * preemption is disabled. Various trace selftests however
@@ -535,7 +644,7 @@ __acquires(kernel_lock)
         for (t = trace_types; t; t = t->next) {
                 if (strcmp(type->name, t->name) == 0) {
                         /* already found */
-                        pr_info("Trace %s already registered\n",
+                        pr_info("Tracer %s already registered\n",
                                 type->name);
                         ret = -1;
                         goto out;
@@ -586,9 +695,6 @@ __acquires(kernel_lock)
 
         type->next = trace_types;
         trace_types = type;
-        len = strlen(type->name);
-        if (len > max_tracer_type_len)
-                max_tracer_type_len = len;
 
  out:
         tracing_selftest_running = false;
@@ -597,7 +703,7 @@ __acquires(kernel_lock)
         if (ret || !default_bootup_tracer)
                 goto out_unlock;
 
-        if (strncmp(default_bootup_tracer, type->name, BOOTUP_TRACER_SIZE))
+        if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
                 goto out_unlock;
 
         printk(KERN_INFO "Starting tracer '%s'\n", type->name);
@@ -619,14 +725,13 @@ __acquires(kernel_lock)
 void unregister_tracer(struct tracer *type)
 {
         struct tracer **t;
-        int len;
 
         mutex_lock(&trace_types_lock);
         for (t = &trace_types; *t; t = &(*t)->next) {
                 if (*t == type)
                         goto found;
         }
-        pr_info("Trace %s not registered\n", type->name);
+        pr_info("Tracer %s not registered\n", type->name);
         goto out;
 
  found:
@@ -639,17 +744,7 @@ void unregister_tracer(struct tracer *type)
                         current_trace->stop(&global_trace);
                 current_trace = &nop_trace;
         }
-
-        if (strlen(type->name) != max_tracer_type_len)
-                goto out;
-
-        max_tracer_type_len = 0;
-        for (t = &trace_types; *t; t = &(*t)->next) {
-                len = strlen((*t)->name);
-                if (len > max_tracer_type_len)
-                        max_tracer_type_len = len;
-        }
- out:
+out:
         mutex_unlock(&trace_types_lock);
 }
 
@@ -719,6 +814,11 @@ static void trace_init_cmdlines(void)
         cmdline_idx = 0;
 }
 
+int is_tracing_stopped(void)
+{
+        return trace_stop_count;
+}
+
 /**
  * ftrace_off_permanent - disable all ftrace code permanently
  *
@@ -886,7 +986,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 
         entry->preempt_count            = pc & 0xff;
         entry->pid                      = (tsk) ? tsk->pid : 0;
-        entry->tgid                     = (tsk) ? tsk->tgid : 0;
+        entry->lock_depth               = (tsk) ? tsk->lock_depth : 0;
         entry->flags =
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
                 (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
@@ -1068,6 +1168,7 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
                 return;
         entry   = ring_buffer_event_data(event);
 
+        entry->tgid             = current->tgid;
         memset(&entry->caller, 0, sizeof(entry->caller));
 
         trace.nr_entries        = 0;
@@ -1094,6 +1195,7 @@ ftrace_trace_special(void *__tr,
                      unsigned long arg1, unsigned long arg2, unsigned long arg3,
                      int pc)
 {
+        struct ftrace_event_call *call = &event_special;
         struct ring_buffer_event *event;
         struct trace_array *tr = __tr;
         struct ring_buffer *buffer = tr->buffer;
@@ -1107,7 +1209,9 @@ ftrace_trace_special(void *__tr,
         entry->arg1                     = arg1;
         entry->arg2                     = arg2;
         entry->arg3                     = arg3;
-        trace_buffer_unlock_commit(buffer, event, 0, pc);
+
+        if (!filter_check_discard(call, entry, buffer, event))
+                trace_buffer_unlock_commit(buffer, event, 0, pc);
 }
 
 void
@@ -1530,10 +1634,10 @@ static void print_lat_help_header(struct seq_file *m)
         seq_puts(m, "#                | / _----=> need-resched    \n");
         seq_puts(m, "#                || / _---=> hardirq/softirq \n");
         seq_puts(m, "#                ||| / _--=> preempt-depth   \n");
-        seq_puts(m, "#                |||| /                      \n");
-        seq_puts(m, "#                |||||     delay             \n");
-        seq_puts(m, "#  cmd     pid   ||||| time  |   caller      \n");
-        seq_puts(m, "#     \\   /      |||||   \\   |   /           \n");
+        seq_puts(m, "#                |||| /_--=> lock-depth       \n");
+        seq_puts(m, "#                |||||/     delay             \n");
+        seq_puts(m, "#  cmd     pid   |||||| time  |   caller      \n");
+        seq_puts(m, "#     \\   /      ||||||   \\   |   /           \n");
 }
 
 static void print_func_help_header(struct seq_file *m)
@@ -1845,7 +1949,7 @@ static int s_show(struct seq_file *m, void *v)
         return 0;
 }
 
-static struct seq_operations tracer_seq_ops = {
+static const struct seq_operations tracer_seq_ops = {
         .start          = s_start,
         .next           = s_next,
         .stop           = s_stop,
@@ -2059,7 +2163,7 @@ static int t_show(struct seq_file *m, void *v)
         return 0;
 }
 
-static struct seq_operations show_traces_seq_ops = {
+static const struct seq_operations show_traces_seq_ops = {
         .start          = t_start,
         .next           = t_next,
         .stop           = t_stop,
@@ -2489,7 +2593,7 @@ static ssize_t
 tracing_set_trace_read(struct file *filp, char __user *ubuf,
                        size_t cnt, loff_t *ppos)
 {
-        char buf[max_tracer_type_len+2];
+        char buf[MAX_TRACER_SIZE+2];
         int r;
 
         mutex_lock(&trace_types_lock);
@@ -2639,15 +2743,15 @@ 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];
+        char buf[MAX_TRACER_SIZE+1];
         int i;
         size_t ret;
         int err;
 
         ret = cnt;
 
-        if (cnt > max_tracer_type_len)
-                cnt = max_tracer_type_len;
+        if (cnt > MAX_TRACER_SIZE)
+                cnt = MAX_TRACER_SIZE;
 
         if (copy_from_user(&buf, ubuf, cnt))
                 return -EFAULT;