diff options
| -rw-r--r-- | kernel/trace/ring_buffer.c | 19 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 6 |
2 files changed, 17 insertions, 8 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 7f6059c5aa9..1da7b6ea8b8 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1768,6 +1768,14 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer, * must fill the old tail_page with padding. */ if (tail >= BUF_PAGE_SIZE) { + /* + * If the page was filled, then we still need + * to update the real_end. Reset it to zero + * and the reader will ignore it. + */ + if (tail == BUF_PAGE_SIZE) + tail_page->real_end = 0; + local_sub(length, &tail_page->write); return; } @@ -3894,12 +3902,12 @@ int ring_buffer_read_page(struct ring_buffer *buffer, ret = read; cpu_buffer->lost_events = 0; + + commit = local_read(&bpage->commit); /* * Set a flag in the commit field if we lost events */ if (missed_events) { - commit = local_read(&bpage->commit); - /* If there is room at the end of the page to save the * missed events, then record it there. */ @@ -3907,10 +3915,17 @@ int ring_buffer_read_page(struct ring_buffer *buffer, memcpy(&bpage->data[commit], &missed_events, sizeof(missed_events)); local_add(RB_MISSED_STORED, &bpage->commit); + commit += sizeof(missed_events); } local_add(RB_MISSED_EVENTS, &bpage->commit); } + /* + * This page may be off to user land. Zero it out here. + */ + if (commit < BUF_PAGE_SIZE) + memset(&bpage->data[commit], 0, BUF_PAGE_SIZE - commit); + out_unlock: spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ba0ec81158b..95d0b1a28f9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3661,7 +3661,6 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) { struct ftrace_buffer_info *info = filp->private_data; - unsigned int pos; ssize_t ret; size_t size; @@ -3688,11 +3687,6 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, if (ret < 0) return 0; - pos = ring_buffer_page_len(info->spare); - - if (pos < PAGE_SIZE) - memset(info->spare + pos, 0, PAGE_SIZE - pos); - read: size = PAGE_SIZE - info->read; if (size > count) |