8 files changed, 42 insertions, 39 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index f20f49f7d244..2f9c0c8cb4c7 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -468,8 +468,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
          * ignore such a protection.
          */
         asm volatile(
-                "1: " _ASM_MOV " (%[parent_old]), %[old]\n"
-                "2: " _ASM_MOV " %[return_hooker], (%[parent_replaced])\n"
+                "1: " _ASM_MOV " (%[parent]), %[old]\n"
+                "2: " _ASM_MOV " %[return_hooker], (%[parent])\n"
                 "   movl $0, %[faulted]\n"
                 "3:\n"
 
@@ -481,9 +481,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
                 _ASM_EXTABLE(1b, 4b)
                 _ASM_EXTABLE(2b, 4b)
 
-                : [parent_replaced] "=r" (parent), [old] "=r" (old),
-                  [faulted] "=r" (faulted)
-                : [parent_old] "0" (parent), [return_hooker] "r" (return_hooker)
+                : [old] "=r" (old), [faulted] "=r" (faulted)
+                : [parent] "r" (parent), [return_hooker] "r" (return_hooker)
                 : "memory"
         );
 
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 3c103d636da3..8e6646a54acf 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -8,7 +8,7 @@ struct ring_buffer;
 struct ring_buffer_iter;
 
 /*
- * Don't reference this struct directly, use functions below.
+ * Don't refer to this struct directly, use functions below.
  */
 struct ring_buffer_event {
         u32             type:2, len:3, time_delta:27;
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 53ba3a6d16d0..fa64e1f003eb 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -91,7 +91,7 @@ EXPORT_SYMBOL_GPL(tracing_off);
  * tracing_off_permanent - permanently disable ring buffers
  *
  * This function, once called, will disable all ring buffers
- * permanenty.
+ * permanently.
  */
 void tracing_off_permanent(void)
 {
@@ -210,7 +210,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data);
 
 struct buffer_data_page {
         u64              time_stamp;    /* page time stamp */
-        local_t          commit;        /* write commited index */
+        local_t          commit;        /* write committed index */
         unsigned char    data[];        /* data of buffer page */
 };
 
@@ -260,7 +260,7 @@ struct ring_buffer_per_cpu {
         struct list_head                pages;
         struct buffer_page              *head_page;     /* read from head */
         struct buffer_page              *tail_page;     /* write to tail */
-        struct buffer_page              *commit_page;   /* commited pages */
+        struct buffer_page              *commit_page;   /* committed pages */
         struct buffer_page              *reader_page;
         unsigned long                   overrun;
         unsigned long                   entries;
@@ -303,7 +303,7 @@ struct ring_buffer_iter {
  * check_pages - integrity check of buffer pages
  * @cpu_buffer: CPU buffer with pages to test
  *
- * As a safty measure we check to make sure the data pages have not
+ * As a safety measure we check to make sure the data pages have not
  * been corrupted.
  */
 static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
@@ -2332,13 +2332,14 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
 EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
 
 static void rb_remove_entries(struct ring_buffer_per_cpu *cpu_buffer,
-                              struct buffer_data_page *bpage)
+                              struct buffer_data_page *bpage,
+                              unsigned int offset)
 {
         struct ring_buffer_event *event;
         unsigned long head;
 
         __raw_spin_lock(&cpu_buffer->lock);
-        for (head = 0; head < local_read(&bpage->commit);
+        for (head = offset; head < local_read(&bpage->commit);
              head += rb_event_length(event)) {
 
                 event = __rb_data_page_index(bpage, head);
@@ -2406,12 +2407,12 @@ void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data)
  * to swap with a page in the ring buffer.
  *
  * for example:
- *      rpage = ring_buffer_alloc_page(buffer);
+ *      rpage = ring_buffer_alloc_read_page(buffer);
  *      if (!rpage)
  *              return error;
  *      ret = ring_buffer_read_page(buffer, &rpage, cpu, 0);
- *      if (ret)
- *              process_page(rpage);
+ *      if (ret >= 0)
+ *              process_page(rpage, ret);
  *
  * When @full is set, the function will not return true unless
  * the writer is off the reader page.
@@ -2422,8 +2423,8 @@ void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data)
  *  responsible for that.
  *
  * Returns:
- *  1 if data has been transferred
- *  0 if no data has been transferred.
+ *  >=0 if data has been transferred, returns the offset of consumed data.
+ *  <0 if no data has been transferred.
  */
 int ring_buffer_read_page(struct ring_buffer *buffer,
                             void **data_page, int cpu, int full)
@@ -2432,7 +2433,8 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
         struct ring_buffer_event *event;
         struct buffer_data_page *bpage;
         unsigned long flags;
-        int ret = 0;
+        unsigned int read;
+        int ret = -1;
 
         if (!data_page)
                 return 0;
@@ -2454,25 +2456,29 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
         /* check for data */
         if (!local_read(&cpu_buffer->reader_page->page->commit))
                 goto out;
+
+        read = cpu_buffer->reader_page->read;
         /*
          * If the writer is already off of the read page, then simply
          * switch the read page with the given page. Otherwise
          * we need to copy the data from the reader to the writer.
          */
         if (cpu_buffer->reader_page == cpu_buffer->commit_page) {
-                unsigned int read = cpu_buffer->reader_page->read;
+                unsigned int commit = rb_page_commit(cpu_buffer->reader_page);
+                struct buffer_data_page *rpage = cpu_buffer->reader_page->page;
 
                 if (full)
                         goto out;
                 /* The writer is still on the reader page, we must copy */
-                bpage = cpu_buffer->reader_page->page;
-                memcpy(bpage->data,
-                       cpu_buffer->reader_page->page->data + read,
-                       local_read(&bpage->commit) - read);
+                memcpy(bpage->data + read, rpage->data + read, commit - read);
 
                 /* consume what was read */
-                cpu_buffer->reader_page += read;
+                cpu_buffer->reader_page->read = commit;
 
+                /* update bpage */
+                local_set(&bpage->commit, commit);
+                if (!read)
+                        bpage->time_stamp = rpage->time_stamp;
         } else {
                 /* swap the pages */
                 rb_init_page(bpage);
@@ -2481,10 +2487,10 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
                 cpu_buffer->reader_page->read = 0;
                 *data_page = bpage;
         }
-        ret = 1;
+        ret = read;
 
         /* update the entry counter */
-        rb_remove_entries(cpu_buffer, bpage);
+        rb_remove_entries(cpu_buffer, bpage, read);
  out:
         spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d89821283b47..d7c175a442df 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1963,7 +1963,7 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
         struct tracer_opt *trace_opts = current_trace->flags->opts;
 
 
-        /* calulate max size */
+        /* calculate max size */
         for (i = 0; trace_options[i]; i++) {
                 len += strlen(trace_options[i]);
                 len += 3; /* "no" and space */
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index f8ae2c50e01d..c2e68d440c4d 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -91,8 +91,6 @@ void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 
 int enable_branch_tracing(struct trace_array *tr)
 {
-        int ret = 0;
-
         mutex_lock(&branch_tracing_mutex);
         branch_tracer = tr;
         /*
@@ -103,7 +101,7 @@ int enable_branch_tracing(struct trace_array *tr)
         branch_tracing_enabled++;
         mutex_unlock(&branch_tracing_mutex);
 
-        return ret;
+        return 0;
 }
 
 void disable_branch_tracing(void)
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 782ec0fdf453..519a0cab1530 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -186,30 +186,30 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, pid_t *last_pids_cpu)
         ret = trace_seq_printf(s,
                 " ------------------------------------------\n");
         if (!ret)
-                TRACE_TYPE_PARTIAL_LINE;
+                return TRACE_TYPE_PARTIAL_LINE;
 
         ret = print_graph_cpu(s, cpu);
         if (ret == TRACE_TYPE_PARTIAL_LINE)
-                TRACE_TYPE_PARTIAL_LINE;
+                return TRACE_TYPE_PARTIAL_LINE;
 
         ret = print_graph_proc(s, prev_pid);
         if (ret == TRACE_TYPE_PARTIAL_LINE)
-                TRACE_TYPE_PARTIAL_LINE;
+                return TRACE_TYPE_PARTIAL_LINE;
 
         ret = trace_seq_printf(s, " => ");
         if (!ret)
-                TRACE_TYPE_PARTIAL_LINE;
+                return TRACE_TYPE_PARTIAL_LINE;
 
         ret = print_graph_proc(s, pid);
         if (ret == TRACE_TYPE_PARTIAL_LINE)
-                TRACE_TYPE_PARTIAL_LINE;
+                return TRACE_TYPE_PARTIAL_LINE;
 
         ret = trace_seq_printf(s,
                 "\n ------------------------------------------\n\n");
         if (!ret)
-                TRACE_TYPE_PARTIAL_LINE;
+                return TRACE_TYPE_PARTIAL_LINE;
 
-        return ret;
+        return TRACE_TYPE_HANDLED;
 }
 
 static struct ftrace_graph_ret_entry *
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
index e3e7db61c067..0794dd33f27b 100644
--- a/kernel/trace/trace_hw_branches.c
+++ b/kernel/trace/trace_hw_branches.c
@@ -75,7 +75,7 @@ static void bts_trace_start(struct trace_array *tr)
 }
 
 /*
- * Start tracing on the current cpu.
+ * Stop tracing on the current cpu.
  * The argument is ignored.
  *
  * pre: bts_tracer_mutex must be locked.
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 84ca9d81e74d..4e2de4de1d65 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -88,7 +88,7 @@ static void backtrace_address(void *data, unsigned long addr, int reliable)
         }
 }
 
-const static struct stacktrace_ops backtrace_ops = {
+static const struct stacktrace_ops backtrace_ops = {
         .warning                = backtrace_warning,
         .warning_symbol         = backtrace_warning_symbol,
         .stack                  = backtrace_stack,