From mboxrd@z Thu Jan  1 00:00:00 1970
From: dan.carpenter@oracle.com (Dan Carpenter)
Date: Wed, 30 Nov 2011 11:44:49 +0300
Subject: [lttng-dev] lttng lib: ring buffer
Message-ID: <20111130084448.GE6268@elgon.mountain>

Hello Mathieu Desnoyers,

This is a semi-automatic email about new static checker warnings.

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 +33 lib_ring_buffer_fault()
	 warn: variable dereferenced before check 'buf' (see line 26)

drivers/staging/lttng/lib/ringbuffer/ring_buffer_mmap.c
    25		struct lib_ring_buffer *buf = vma->vm_private_data;
    26		struct channel *chan = buf->backend.chan;
                                       ^^^^^^^^^^^^^^^^^
Dereference.

    27		const struct lib_ring_buffer_config *config = chan->backend.config;
    28		pgoff_t pgoff = vmf->pgoff;
    29		struct page **page;
    30		void **virt;
    31		unsigned long offset, sb_bindex;
    32	
    33		if (!buf)
                    ^^^^
Check.

    34			return VM_FAULT_OOM;
    35	

regards,
dan carpenter