On Mon, Aug 18, 2014 at 01:15:40PM -0400, Vivek Goyal wrote: > On Fri, Aug 15, 2014 at 02:55:20PM +0100, Will Deacon wrote: > > What I meant was, if I wire it into asm-generic/unistd.h then it will return > > -ENOEXEC for architectures using that file (e.g. arm64). > > > > Patch below, but I don't think it's very useful. > > > > Hi Will, > > I have not even defined a syscall number for other arches. IIUC, this > patch will forcibly introduce a syscall number for the new syscall for > arches which use asm-generic/unistd.h. > > So question I have is that why should we do it now. One can do it once > somebody enables kexec_file_load() on arm64. > > Right now I see that kexec_file_load() gets compiled if CONFIG_KEXEC=y. So > even on arm64 it must be getting compiled in. But it is not being hooked > up using system call table. So there should not be any way to invoke > syscalll definition. So my understand is that in current form, one can > not invoke kexec_file_load() on arm64. Is that right. > > Now I have put one more patch to make compilation of kexec_file_load() > conditional on config option CONFIG_KEXEC_FILE. And this option can > be enabled only on x86_64. That means kexec_file_load() will not even > be compiled in on arm64 (once the patch gets merged). Right now patch > is sitting in andrew's tree. > > http://ozlabs.org/~akpm/mmotm/broken-out/kexec-create-a-new-config-option-config_kexec_file-for-new-syscall.patch > > Can you please help me understand that why do we need this patch if at > this point of time we are not even fixing a system call number for > kexec_file_load() for arches except x86_64.
>From what I read, the only arch which supports this call is x86_64, and it requires arch code make work. So simply wiring up the syscall is not enough. What is probably worth doing is reserving the syscall number _if_ it's going to be useful on architectures - by that, I mean inserting the syscall number with a comment in the unistd.h file, rather than defining a constant. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
