From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 12 Dec 2019 02:41:05 +0300 From: "Dmitry V. Levin" To: ALT Devel discussion list Message-ID: <20191211234105.GA17949@altlinux.org> References: <20191210152343.33867-1-darktemplar@altlinux.org> <20191210152343.33867-27-darktemplar@altlinux.org> <20191210225754.GA32733@altlinux.org> <59355380-012f-3fdf-cf2f-32e6ca4e9d3e@altlinux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <59355380-012f-3fdf-cf2f-32e6ca4e9d3e@altlinux.org> Subject: Re: [devel] [PATCH for apt 26/38] Fix warning about truncation of value of pkgCache::Header::HeaderSz X-BeenThere: devel@lists.altlinux.org X-Mailman-Version: 2.1.12 Precedence: list Reply-To: ALT Linux Team development discussions List-Id: ALT Linux Team development discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Dec 2019 23:41:05 -0000 Archived-At: List-Archive: List-Post: On Wed, Dec 11, 2019 at 10:51:28AM +0300, Aleksei Nikiforov wrote: > 11.12.2019 1:58, Dmitry V. Levin пишет: > > On Tue, Dec 10, 2019 at 06:23:31PM +0300, Aleksei Nikiforov wrote: > >> Update types of other variables as well. > > > > What's the rationale for changing types of *all* these fields, > > and for choosing architecture-dependent "unsigned long" > > as the new type instead of "unsigned short"? > > Value of HeaderSz is truncated. IIRC, assigned value was around 270k. > Types of other variables were changed for uniformity and possible > mitigation of same overflow issues in future, but may be reverted for > now. Since type wasn't architecture-independent, similar > architecture-dependent type of bigger size was used. All of this may be > changed as needed, with only exception of keeping size of HeaderSz > increased. How many objects containing struct pkgCache::Header are created? If there are just a few of them, then we don't have to worry about the memory footprint and can make them all unsigned long (== size_t) as you did in your patch. > >> apt/apt-pkg/pkgcache.h | 14 +++++++------- > >> 1 file changed, 7 insertions(+), 7 deletions(-) > >> > >> diff --git a/apt/apt-pkg/pkgcache.h b/apt/apt-pkg/pkgcache.h > >> index 05a63bc..6b44522 100644 > >> --- a/apt/apt-pkg/pkgcache.h > >> +++ b/apt/apt-pkg/pkgcache.h > >> @@ -175,13 +175,13 @@ struct pkgCache::Header > >> unsigned long OptionsHash; > >> > >> // Size of structure values > >> - unsigned short HeaderSz; > >> - unsigned short PackageSz; > >> - unsigned short PackageFileSz; > >> - unsigned short VersionSz; > >> - unsigned short DependencySz; > >> - unsigned short ProvidesSz; > >> - unsigned short VerFileSz; > >> + unsigned long HeaderSz; > >> + unsigned long PackageSz; > >> + unsigned long PackageFileSz; > >> + unsigned long VersionSz; > >> + unsigned long DependencySz; > >> + unsigned long ProvidesSz; > >> + unsigned long VerFileSz; > >> > >> // Structure counts > >> unsigned long PackageCount; -- ldv