On Thu, 29 Aug 2019 14:57:39 +0200 Arnd Bergmann <a...@arndb.de> wrote:
> On Thu, Aug 29, 2019 at 2:37 PM Michal Suchánek <msucha...@suse.de> wrote: > > On Thu, 29 Aug 2019 14:19:46 +0200 Arnd Bergmann <a...@arndb.de> wrote: > > > On Thu, Aug 29, 2019 at 12:23 PM Michal Suchanek <msucha...@suse.de> > > > wrote: > > > In particular, I don't see why you single out llseek here, but leave other > > > syscalls that are not needed on 64-bit machines such as pread64(). > > > > Because llseek is not built in fs/ when building 64bit only causing a > > link error. > > > > I initially posted patch to build it always but it was pointed out it > > is not needed, and the interface does not make sense on 64bit, and > > that platforms that don't have it on 64bit now don't want that useless > > code. > > Ok, please put that into the changeset description then. > > I looked at uses of __NR__llseek in debian code search and > found this one: > > https://codesearch.debian.net/show?file=umview_0.8.2-1.2%2Fxmview%2Fum_mmap.c&line=328 > > It looks like this application will try to use llseek instead of lseek > when built against kernel headers that define __NR_llseek. > The available documentation says this syscall is for 32bit only so using it on 64bit is undefined. The interface is not well-defined in that case either. Thanks Michal