Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755009Ab3IMUoG (ORCPT ); Fri, 13 Sep 2013 16:44:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23907 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752516Ab3IMUoF (ORCPT ); Fri, 13 Sep 2013 16:44:05 -0400 Date: Fri, 13 Sep 2013 16:43:54 -0400 From: Dave Jones To: Linux Kernel Mailing List Cc: nab@daterainc.com Subject: Re: target: Add support for EXTENDED_COPY copy offload emulation Message-ID: <20130913204354.GA20782@redhat.com> Mail-Followup-To: Dave Jones , Linux Kernel Mailing List , nab@daterainc.com References: <20130913000121.C53A6660D4A@gitolite.kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130913000121.C53A6660D4A@gitolite.kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2241 Lines: 68 On Fri, Sep 13, 2013 at 12:01:21AM +0000, Linux Kernel wrote: > Gitweb: http://git.kernel.org/linus/;a=commit;h=cbf031f425fd0b30ff10ba83b612753189a6bbbf > Commit: cbf031f425fd0b30ff10ba83b612753189a6bbbf > Parent: 89c12cc925a7d0982dc53b743a42108acc76aef4 > Author: Nicholas Bellinger > AuthorDate: Tue Aug 20 15:38:55 2013 -0700 > Committer: Nicholas Bellinger > CommitDate: Tue Sep 10 16:48:43 2013 -0700 > > target: Add support for EXTENDED_COPY copy offload emulation ... > +static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop, > + unsigned char *p) > +{ > + unsigned char *desc = p; > + int dc = (desc[1] & 0x02); > + unsigned short desc_len; > + > + desc_len = get_unaligned_be16(&desc[2]); > + if (desc_len != 0x18) { > + pr_err("XCOPY segment desc 0x02: Illegal desc_len:" > + " %hu\n", desc_len); > + return -EINVAL; > + } > + > + xop->stdi = get_unaligned_be16(&desc[4]); > + xop->dtdi = get_unaligned_be16(&desc[6]); > + pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n", > + desc_len, xop->stdi, xop->dtdi, dc); > + > + xop->nolb = get_unaligned_be16(&desc[10]); > + xop->src_lba = get_unaligned_be64(&desc[12]); > + xop->dst_lba = get_unaligned_be64(&desc[20]); > + pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n", > + xop->nolb, (unsigned long long)xop->src_lba, > + (unsigned long long)xop->dst_lba); > + > + if (dc != 0) { > + xop->dbl = (desc[29] << 16) & 0xff; > + xop->dbl |= (desc[30] << 8) & 0xff; > + xop->dbl |= desc[31] & 0xff; > + > + pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl); > + } > + return 0; > +} Coverity picked up a new warning in this code. It notes that (desc[30] << 8) & 0xff is always zero. Did you want xop->dbl = (desc[29] >> 16) & 0xff; instead maybe ? The << 16 looks suspect too, though it didn't warn on that. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/