Messages in this thread Patch in this message | | | Date | Fri, 15 Aug 2014 14:55:20 +0100 | From | Will Deacon <> | Subject | Re: [PATCH 2/2] asm-generic: add memfd_create system call to unistd.h |
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On Tue, Aug 12, 2014 at 01:37:36PM +0100, Vivek Goyal wrote: > On Tue, Aug 12, 2014 at 12:10:30PM +0100, Will Deacon wrote: > > Hmm, so whilst I can easily wire-up the new syscall, it's pretty useless for > > anybody other than x86 at the moment. There are a bunch of arch helpers: > > > > arch_kexec_kernel_image_probe > > arch_kexec_kernel_verify_sig > > arch_kexec_kernel_image_load > > arch_kimage_file_post_load_cleanup > > > > which are only implemented for x86 (arch/x86/kernel/machine_kexec_64.c), > > even though I don't really see what makes them arch-specific as opposed to > > file format specific. > > Yes, at this point of time, this system call will work only on x86. Agreed > that primarily it is file format details which are primarily in arch > specific section. > > I think that some of the code will become arch independent as other > arches start implementing this syscall. > > > > > So this syscall will always fail with -ENOEXEC at the moment. Is it still > > worth wiring it up? > > I thought that for other arches I have not even defined the syscall. So > it probably will fail with -ENOSYS.
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.
Will
--->8
commit a20104072c8faeeacb2857ce24cdb2818f51ff1a Author: Will Deacon <will.deacon@arm.com> Date: Mon Aug 11 14:24:47 2014 +0100
asm-generic: add kexec_file_load system call to unistd.h Commit cb1052581e2b ("kexec: implementation of new syscall kexec_file_load") added a new system call (kexec_file_load) but didn't update the asm-generic unistd header. This patch adds the new system call to the asm-generic version of unistd.h so that it can be used by architectures such as arm64. Note that without the arch_kexec hooks, all file formats will result in -ENOEXEC. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Vivek Goyal <vgoyal@redhat.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 11d11bc5c78f..92ae121fa055 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -705,9 +705,11 @@ __SYSCALL(__NR_seccomp, sys_seccomp) __SYSCALL(__NR_getrandom, sys_getrandom) #define __NR_memfd_create 279 __SYSCALL(__NR_memfd_create, sys_memfd_create) +#define __NR_kexec_file_load 280 +__SYSCALL(__NR_kexec_file_load, sys_kexec_file_load) #undef __NR_syscalls -#define __NR_syscalls 280 +#define __NR_syscalls 281 /* * All syscalls below here should go away really,
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