diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-06-07 12:22:15 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-06-07 12:22:15 +0200 |
commit | 5f4457a4f62cc9d78e04c0eb12ff0540899aad89 (patch) | |
tree | 0b973d527ea6b2ae31e08da0746b4965a3c5a6d8 /kernel/trace/trace.c | |
parent | 9b94b3a19b13e094c10f65f24bc358f6ffe4eacd (diff) | |
parent | b87297fb405ef13cac375f202d114323b076a56d (diff) |
Merge branch 'linus' into x86/cpu
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r-- | kernel/trace/trace.c | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9d28476a985..cda81ec58d9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2380,7 +2380,7 @@ static const char readme_msg[] = "# echo print-parent > /debug/tracing/trace_options\n" "# echo 1 > /debug/tracing/tracing_enabled\n" "# cat /debug/tracing/trace > /tmp/trace.txt\n" - "echo 0 > /debug/tracing/tracing_enabled\n" + "# echo 0 > /debug/tracing/tracing_enabled\n" ; static ssize_t @@ -3277,19 +3277,13 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) info->tr = &global_trace; info->cpu = cpu; - info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + info->spare = NULL; /* Force reading ring buffer for first read */ info->read = (unsigned int)-1; - if (!info->spare) - goto out; filp->private_data = info; - return 0; - - out: - kfree(info); - return -ENOMEM; + return nonseekable_open(inode, filp); } static ssize_t @@ -3304,6 +3298,11 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, if (!count) return 0; + if (!info->spare) + info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + if (!info->spare) + return -ENOMEM; + /* Do we have previous read data to read? */ if (info->read < PAGE_SIZE) goto read; @@ -3342,7 +3341,8 @@ static int tracing_buffers_release(struct inode *inode, struct file *file) { struct ftrace_buffer_info *info = file->private_data; - ring_buffer_free_read_page(info->tr->buffer, info->spare); + if (info->spare) + ring_buffer_free_read_page(info->tr->buffer, info->spare); kfree(info); return 0; @@ -3428,14 +3428,19 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, int size, i; size_t ret; - /* - * We can't seek on a buffer input - */ - if (unlikely(*ppos)) - return -ESPIPE; + if (*ppos & (PAGE_SIZE - 1)) { + WARN_ONCE(1, "Ftrace: previous read must page-align\n"); + return -EINVAL; + } + if (len & (PAGE_SIZE - 1)) { + WARN_ONCE(1, "Ftrace: splice_read should page-align\n"); + if (len < PAGE_SIZE) + return -EINVAL; + len &= PAGE_MASK; + } - for (i = 0; i < PIPE_BUFFERS && len; i++, len -= size) { + for (i = 0; i < PIPE_BUFFERS && len; i++, len -= PAGE_SIZE) { struct page *page; int r; @@ -3443,6 +3448,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, if (!ref) break; + ref->ref = 1; ref->buffer = info->tr->buffer; ref->page = ring_buffer_alloc_read_page(ref->buffer); if (!ref->page) { @@ -3474,6 +3480,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, spd.partial[i].offset = 0; spd.partial[i].private = (unsigned long)ref; spd.nr_pages++; + *ppos += PAGE_SIZE; } spd.nr_pages = i; |