From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nathan Chancellor Subject: Re: [PATCH] scsi: qla4xxx: avoid freeing unallocated dma memory Date: Fri, 22 Mar 2019 08:25:04 -0700 Message-ID: <20190322152504.GA21978@archlinux-ryzen> References: <20190322142530.904080-1-arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190322142530.904080-1-arnd@arndb.de> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann Cc: QLogic-Storage-Upstream@qlogic.com, "James E.J. Bottomley" , "Martin K. Petersen" , clang-built-linux@googlegroups.com, Nick Desaulniers , Manish Rangankar , Chengguang Xu , Johannes Thumshirn , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-scsi@vger.kernel.org On Fri, Mar 22, 2019 at 03:25:03PM +0100, Arnd Bergmann wrote: > Clang -Wuninitialized notices that on is_qla40XX we never allocate > any DMA memory in get_fw_boot_info() but attempt to free it anyway: > > drivers/scsi/qla4xxx/ql4_os.c:5915:7: error: variable 'buf_dma' is used uninitialized whenever 'if' condition is false > [-Werror,-Wsometimes-uninitialized] > if (!(val & 0x07)) { > ^~~~~~~~~~~~~ > drivers/scsi/qla4xxx/ql4_os.c:5985:47: note: uninitialized use occurs here > dma_free_coherent(&ha->pdev->dev, size, buf, buf_dma); > ^~~~~~~ > drivers/scsi/qla4xxx/ql4_os.c:5915:3: note: remove the 'if' if its condition is always true > if (!(val & 0x07)) { > ^~~~~~~~~~~~~~~~~~~ > drivers/scsi/qla4xxx/ql4_os.c:5885:20: note: initialize the variable 'buf_dma' to silence this warning > dma_addr_t buf_dma; > ^ > = 0 > > Skip the call to dma_free_coherent() here. > > Fixes: 2a991c215978 ("[SCSI] qla4xxx: Boot from SAN support for open-iscsi") > Signed-off-by: Arnd Bergmann This is what I initially had but I guess I cared too much about that debug print firing properly :) I like this better personally. Reviewed-by: Nathan Chancellor > --- > drivers/scsi/qla4xxx/ql4_os.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c > index 16a18d5d856f..daa884fa43f4 100644 > --- a/drivers/scsi/qla4xxx/ql4_os.c > +++ b/drivers/scsi/qla4xxx/ql4_os.c > @@ -5928,7 +5928,7 @@ static int get_fw_boot_info(struct scsi_qla_host *ha, uint16_t ddb_index[]) > val = rd_nvram_byte(ha, sec_addr); > if (val & BIT_7) > ddb_index[1] = (val & 0x7f); > - > + goto exit_boot_info; > } else if (is_qla80XX(ha)) { > buf = dma_alloc_coherent(&ha->pdev->dev, size, > &buf_dma, GFP_KERNEL); > -- > 2.20.0 >