lttng lib: ring buffer move null pointer check to open
* Dan Carpenter <dan.carpenter@oracle.com> wrote:
> The patch c844b2f5cfea: "lttng lib: ring buffer" from Nov 28, 2011,
> leads to the following Smatch complaint:
>
> drivers/staging/lttng/lib/ringbuffer/ring_buffer_mmap.c +86
> +lib_ring_buffer_mmap_buf()
> warn: variable dereferenced before check 'buf' (see line 79)
>
> drivers/staging/lttng/lib/ringbuffer/ring_buffer_mmap.c
> 78 unsigned long length = vma->vm_end - vma->vm_start;
> 79 struct channel *chan = buf->backend.chan;
> ^^^^^^^^^^^^^^^^^
> Dereference.
>
> 80 const struct lib_ring_buffer_config *config = chan->backend.config;
> 81 unsigned long mmap_buf_len;
> 82
> 83 if (config->output != RING_BUFFER_MMAP)
> 84 return -EINVAL;
> 85
> 86 if (!buf)
> ^^^^
> Check.
>
> 87 return -EBADF;
> 88
Let's move the NULL buf check to the file "open", where it belongs. The
"open" file operation is the actual interface between lib ring buffer
and the modules using it.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2 files changed