From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [PATCH v5 2/4] kernel hacking: new config NO_AUTO_INLINE to disable compiler auto-inline optimizations Date: Fri, 8 Jun 2018 16:03:55 -0400 Message-ID: <20180608160355.67712eb8@vmware.local.home> References: <1528186420-6615-3-git-send-email-changbin.du@intel.com> <201806060501.btF3aJMZ%fengguang.wu@intel.com> <20180606095714.1d3c2def@vmware.local.home> <20180606142600.GN13775@localhost> <20180606142622.2338abf6@vmware.local.home> <20180607041718.qpqucjzlvcm5h3gn@vireshk-i7> <20180607074628.kd3iyxevwj3ypzbr@intel.com> <20180607083856.ealw62v3wx43zeqz@vireshk-i7> <1303b1abf9f9229a8d3ccbb68a3e413266b360d7.camel@petrovitsch.priv.at> <20180607091025.m7dfix3e2xbwx4cs@vireshk-i7> <20180607091816.GT13775@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180607091816.GT13775@localhost> Sender: linux-kernel-owner@vger.kernel.org To: Johan Hovold Cc: Viresh Kumar , Bernd Petrovitsch , "Du, Changbin" , gregkh@linuxfoundation.org, alex.elder@linaro.org, kbuild test robot , linux-arch@vger.kernel.org, michal.lkml@markovi.net, linux-kernel@vger.kernel.org, arnd@arndb.de, yamada.masahiro@socionext.com, lgirdwood@gmail.com, broonie@kernel.org, rdunlap@infradead.org, x86@kernel.org, linux@armlinux.org.uk, linux-sparse@vger.kernel.org, mingo@redhat.com, kbuild-all@01.org, akpm@linux-foundation.org, changbin.du@gmail.com, tglx@linutronix.de, linux-kbuild@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-arch.vger.kernel.org On Thu, 7 Jun 2018 11:18:16 +0200 Johan Hovold wrote: > If you want to work around the warning and think you can do it in some > non-contrived way, then go for it. > > Clearing the request buffer, checking for termination using strnlen, and > then using memcpy might not be too bad. > > But after all, it is a false positive, so leaving things as they stand > is fine too. Not sure how contrived you think this is, but it solves the warning without adding extra work in the normal case. -- Steve diff --git a/drivers/staging/greybus/fw-management.c b/drivers/staging/greybus/fw-management.c index 71aec14f8181..4fb9f1dff47d 100644 --- a/drivers/staging/greybus/fw-management.c +++ b/drivers/staging/greybus/fw-management.c @@ -150,15 +150,18 @@ static int fw_mgmt_load_and_validate_operation(struct fw_mgmt *fw_mgmt, } request.load_method = load_method; - strncpy(request.firmware_tag, tag, GB_FIRMWARE_TAG_MAX_SIZE); + strncpy(request.firmware_tag, tag, GB_FIRMWARE_TAG_MAX_SIZE - 1); /* * The firmware-tag should be NULL terminated, otherwise throw error and * fail. */ - if (request.firmware_tag[GB_FIRMWARE_TAG_MAX_SIZE - 1] != '\0') { - dev_err(fw_mgmt->parent, "load-and-validate: firmware-tag is not NULL terminated\n"); - return -EINVAL; + if (request.firmware_tag[GB_FIRMWARE_TAG_MAX_SIZE - 2] != '\0') { + if (tag[GB_FIRMWARE_TAG_MAX_SIZE - 1] != '\0') { + dev_err(fw_mgmt->parent, "load-and-validate: firmware-tag is not NULL terminated\n"); + return -EINVAL; + } + request.firmware_tag[GB_FIRMWARE_TAG_MAX_SIZE - 1] = '\0'; } /* Allocate ids from 1 to 255 (u8-max), 0 is an invalid id */ From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:48426 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752478AbeFHUEL (ORCPT ); Fri, 8 Jun 2018 16:04:11 -0400 Date: Fri, 8 Jun 2018 16:03:55 -0400 From: Steven Rostedt Subject: Re: [PATCH v5 2/4] kernel hacking: new config NO_AUTO_INLINE to disable compiler auto-inline optimizations Message-ID: <20180608160355.67712eb8@vmware.local.home> In-Reply-To: <20180607091816.GT13775@localhost> References: <1528186420-6615-3-git-send-email-changbin.du@intel.com> <201806060501.btF3aJMZ%fengguang.wu@intel.com> <20180606095714.1d3c2def@vmware.local.home> <20180606142600.GN13775@localhost> <20180606142622.2338abf6@vmware.local.home> <20180607041718.qpqucjzlvcm5h3gn@vireshk-i7> <20180607074628.kd3iyxevwj3ypzbr@intel.com> <20180607083856.ealw62v3wx43zeqz@vireshk-i7> <1303b1abf9f9229a8d3ccbb68a3e413266b360d7.camel@petrovitsch.priv.at> <20180607091025.m7dfix3e2xbwx4cs@vireshk-i7> <20180607091816.GT13775@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Johan Hovold Cc: Viresh Kumar , Bernd Petrovitsch , "Du, Changbin" , gregkh@linuxfoundation.org, alex.elder@linaro.org, kbuild test robot , linux-arch@vger.kernel.org, michal.lkml@markovi.net, linux-kernel@vger.kernel.org, arnd@arndb.de, yamada.masahiro@socionext.com, lgirdwood@gmail.com, broonie@kernel.org, rdunlap@infradead.org, x86@kernel.org, linux@armlinux.org.uk, linux-sparse@vger.kernel.org, mingo@redhat.com, kbuild-all@01.org, akpm@linux-foundation.org, changbin.du@gmail.com, tglx@linutronix.de, linux-kbuild@vger.kernel.org, linux-arm-kernel@lists.infradead.org Message-ID: <20180608200355.zouvqxzaQLO4nT9k7XPZxbg5VmEKJsb-i4HO5kmMj9M@z> On Thu, 7 Jun 2018 11:18:16 +0200 Johan Hovold wrote: > If you want to work around the warning and think you can do it in some > non-contrived way, then go for it. > > Clearing the request buffer, checking for termination using strnlen, and > then using memcpy might not be too bad. > > But after all, it is a false positive, so leaving things as they stand > is fine too. Not sure how contrived you think this is, but it solves the warning without adding extra work in the normal case. -- Steve diff --git a/drivers/staging/greybus/fw-management.c b/drivers/staging/greybus/fw-management.c index 71aec14f8181..4fb9f1dff47d 100644 --- a/drivers/staging/greybus/fw-management.c +++ b/drivers/staging/greybus/fw-management.c @@ -150,15 +150,18 @@ static int fw_mgmt_load_and_validate_operation(struct fw_mgmt *fw_mgmt, } request.load_method = load_method; - strncpy(request.firmware_tag, tag, GB_FIRMWARE_TAG_MAX_SIZE); + strncpy(request.firmware_tag, tag, GB_FIRMWARE_TAG_MAX_SIZE - 1); /* * The firmware-tag should be NULL terminated, otherwise throw error and * fail. */ - if (request.firmware_tag[GB_FIRMWARE_TAG_MAX_SIZE - 1] != '\0') { - dev_err(fw_mgmt->parent, "load-and-validate: firmware-tag is not NULL terminated\n"); - return -EINVAL; + if (request.firmware_tag[GB_FIRMWARE_TAG_MAX_SIZE - 2] != '\0') { + if (tag[GB_FIRMWARE_TAG_MAX_SIZE - 1] != '\0') { + dev_err(fw_mgmt->parent, "load-and-validate: firmware-tag is not NULL terminated\n"); + return -EINVAL; + } + request.firmware_tag[GB_FIRMWARE_TAG_MAX_SIZE - 1] = '\0'; } /* Allocate ids from 1 to 255 (u8-max), 0 is an invalid id */