1 files changed, 48 insertions, 20 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b20d3ec75de9..88bd9ae2a9ed 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -129,7 +129,7 @@ static int tracing_set_tracer(const char *buf);
 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
-static int __init set_ftrace(char *str)
+static int __init set_cmdline_ftrace(char *str)
 {
         strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
         default_bootup_tracer = bootup_tracer_buf;
@@ -137,7 +137,7 @@ static int __init set_ftrace(char *str)
         ring_buffer_expanded = 1;
         return 1;
 }
-__setup("ftrace=", set_ftrace);
+__setup("ftrace=", set_cmdline_ftrace);
 
 static int __init set_ftrace_dump_on_oops(char *str)
 {
@@ -1363,9 +1363,6 @@ int trace_array_vprintk(struct trace_array *tr,
         __raw_spin_lock(&trace_buf_lock);
         len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
-        len = min(len, TRACE_BUF_SIZE-1);
-        trace_buf[len] = 0;
-
         size = sizeof(*entry) + len + 1;
         buffer = tr->buffer;
         event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
@@ -1373,10 +1370,10 @@ int trace_array_vprintk(struct trace_array *tr,
         if (!event)
                 goto out_unlock;
         entry = ring_buffer_event_data(event);
-        entry->ip                       = ip;
+        entry->ip = ip;
 
         memcpy(&entry->buf, trace_buf, len);
-        entry->buf[len] = 0;
+        entry->buf[len] = '\0';
         if (!filter_check_discard(call, entry, buffer, event))
                 ring_buffer_unlock_commit(buffer, event);
 
@@ -1515,6 +1512,8 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos)
         int i = (int)*pos;
         void *ent;
 
+        WARN_ON_ONCE(iter->leftover);
+
         (*pos)++;
 
         /* can't go backwards */
@@ -1613,8 +1612,16 @@ static void *s_start(struct seq_file *m, loff_t *pos)
                         ;
 
         } else {
-                l = *pos - 1;
-                p = s_next(m, p, &l);
+                /*
+                 * If we overflowed the seq_file before, then we want
+                 * to just reuse the trace_seq buffer again.
+                 */
+                if (iter->leftover)
+                        p = iter;
+                else {
+                        l = *pos - 1;
+                        p = s_next(m, p, &l);
+                }
         }
 
         trace_event_read_lock();
@@ -1922,6 +1929,7 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
 static int s_show(struct seq_file *m, void *v)
 {
         struct trace_iterator *iter = v;
+        int ret;
 
         if (iter->ent == NULL) {
                 if (iter->tr) {
@@ -1941,9 +1949,27 @@ static int s_show(struct seq_file *m, void *v)
                         if (!(trace_flags & TRACE_ITER_VERBOSE))
                                 print_func_help_header(m);
                 }
+        } else if (iter->leftover) {
+                /*
+                 * If we filled the seq_file buffer earlier, we
+                 * want to just show it now.
+                 */
+                ret = trace_print_seq(m, &iter->seq);
+
+                /* ret should this time be zero, but you never know */
+                iter->leftover = ret;
+
         } else {
                 print_trace_line(iter);
-                trace_print_seq(m, &iter->seq);
+                ret = trace_print_seq(m, &iter->seq);
+                /*
+                 * If we overflow the seq_file buffer, then it will
+                 * ask us for this data again at start up.
+                 * Use that instead.
+                 *  ret is 0 if seq_file write succeeded.
+                 *        -1 otherwise.
+                 */
+                iter->leftover = ret;
         }
 
         return 0;
@@ -2897,6 +2923,10 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
         else
                 cpumask_clear_cpu(iter->cpu_file, tracing_reader_cpumask);
 
+
+        if (iter->trace->pipe_close)
+                iter->trace->pipe_close(iter);
+
         mutex_unlock(&trace_types_lock);
 
         free_cpumask_var(iter->started);
@@ -3334,7 +3364,6 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
                                         size_t cnt, loff_t *fpos)
 {
         char *buf;
-        char *end;
 
         if (tracing_disabled)
                 return -EINVAL;
@@ -3342,7 +3371,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
         if (cnt > TRACE_BUF_SIZE)
                 cnt = TRACE_BUF_SIZE;
 
-        buf = kmalloc(cnt + 1, GFP_KERNEL);
+        buf = kmalloc(cnt + 2, GFP_KERNEL);
         if (buf == NULL)
                 return -ENOMEM;
 
@@ -3350,14 +3379,13 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
                 kfree(buf);
                 return -EFAULT;
         }
+        if (buf[cnt-1] != '\n') {
+                buf[cnt] = '\n';
+                buf[cnt+1] = '\0';
+        } else
+                buf[cnt] = '\0';
 
-        /* Cut from the first nil or newline. */
-        buf[cnt] = '\0';
-        end = strchr(buf, '\n');
-        if (end)
-                *end = '\0';
-
-        cnt = mark_printk("%s\n", buf);
+        cnt = mark_printk("%s", buf);
         kfree(buf);
         *fpos += cnt;
 
@@ -3730,7 +3758,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 
         s = kmalloc(sizeof(*s), GFP_KERNEL);
         if (!s)
-                return ENOMEM;
+                return -ENOMEM;
 
         trace_seq_init(s);