From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by sourceware.org (Postfix) with ESMTP id 64D7F3858413 for ; Tue, 4 Oct 2022 09:10:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 64D7F3858413 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C33B812FC; Tue, 4 Oct 2022 02:10:33 -0700 (PDT) Received: from localhost (e121540-lin.manchester.arm.com [10.32.98.62]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 502C93F67D; Tue, 4 Oct 2022 02:10:26 -0700 (PDT) From: Richard Sandiford To: Philipp Tomsich Mail-Followup-To: Philipp Tomsich ,gcc-patches@gcc.gnu.org, Tamar Christina , Christoph Muellner , richard.sandiford@arm.com Cc: gcc-patches@gcc.gnu.org, Tamar Christina , Christoph Muellner Subject: Re: [PATCH] aarch64: fix off-by-one in reading cpuinfo References: <20221003212419.3337714-1-philipp.tomsich@vrull.eu> Date: Tue, 04 Oct 2022 10:10:25 +0100 In-Reply-To: <20221003212419.3337714-1-philipp.tomsich@vrull.eu> (Philipp Tomsich's message of "Mon, 3 Oct 2022 23:24:19 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-45.1 required=5.0 tests=BAYES_00,GIT_PATCH_0,KAM_DMARC_NONE,KAM_DMARC_STATUS,KAM_LAZY_DOMAIN_SECURITY,KAM_SHORT,RCVD_IN_DNSWL_LOW,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Philipp Tomsich writes: > Fixes: 341573406b39 > > Don't subtract one from the result of strnlen() when trying to point > to the first character after the current string. This issue would > cause individual characters (where the 128 byte buffers are stitched > together) to be lost. > > gcc/ChangeLog: > > * config/aarch64/driver-aarch64.cc (readline): Fix off-by-one. > > Signed-off-by: Philipp Tomsich Thanks for the patch. Would it be possible to create a testcase along the lines of gcc.target/aarch64/cpunative/native_cpu_15.c? Richard > --- > > gcc/config/aarch64/driver-aarch64.cc | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/gcc/config/aarch64/driver-aarch64.cc b/gcc/config/aarch64/driver-aarch64.cc > index 52ff537908e..48250e68034 100644 > --- a/gcc/config/aarch64/driver-aarch64.cc > +++ b/gcc/config/aarch64/driver-aarch64.cc > @@ -203,9 +203,9 @@ readline (FILE *f) > return std::string (); > /* If we're not at the end of the line then override the > \0 added by fgets. */ > - last = strnlen (buf, size) - 1; > + last = strnlen (buf, size); > } > - while (!feof (f) && buf[last] != '\n'); > + while (!feof (f) && (last > 0 && buf[last - 1] != '\n')); > > std::string result (buf); > free (buf);