Here is a re-spin of the first set of patches which reduce the number of
syscall invocations from within the kernel; the RFC may be found at
The rationale for this change is described in patch 1 as follows:
The syscall entry points to the kernel defined by SYSCALL_DEFINEx()
and COMPAT_SYSCALL_DEFINEx() should only be called from userspace
through kernel entry points, but not from the kernel itself. This
will allow cleanups and optimizations to the entry paths *and* to
the parts of the kernel code which currently need to pretend to be
userspace in order to make use of syscalls.
The whole series can be found at
https://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux.git
syscalls-next
and will be submitted for merging for the v4.17-rc1 cycle, probably together
with another batch of related patches I hope to send out tomorrow as a RFC.
Changes since the RFC / v1:
- rebase to v4.15-rc5; sys_ioperm already got its SYSCALL_DEFINE3
- add ACKs
- CC: -> Cc: (suggested by Ingo Molnar)
- update comment in include/linux/syscalls.h (suggested by Ingo Molnar and
Andy Lutomirski)
- separate declarations from definitions with newlines in
include/linux/syscalls.h; add comment on ksys_close() (suggested by
Ingo Molnar)
- expand commit messages (suggested by Christoph Hellwig)
- include patch 36:
fs: add ksys_open() wrapper; remove in-kernel calls to sys_open()
- do not worry about the following archs, as they are going away:
cris, frv, metag, mn10300, score, tile
(solving conflicts in -next)
- fix builds with CONFIG_FUTEX=n, CONFIG_ADVISE_SYSCALLS=n (solving issues
found by Stephen Rothwell)
Thanks,
Dominik
Dominik Brodowski (36):
syscalls: define goal to not call sys_xyzzy() from within the kernel
kernel: use kernel_wait4() instead of sys_wait4()
mm: use do_futex() instead of sys_futex() in mm_release()
kernel: add do_getpgid() helper; remove internal call to sys_getpgid()
fs: add do_readlinkat() helper; remove internal call to
sys_readlinkat()
fs: add do_pipe2() helper; remove internal call to sys_pipe2()
fs: add do_renameat2() helper; remove internal call to sys_renameat2()
fs: add do_futimesat() helper; remove internal call to sys_futimesat()
syscalls: add do_epoll_*() helpers; remove internal calls to
sys_epoll_*()
fs: add do_signalfd4() helper; remove internal calls to
sys_signalfd4()
fs: add do_eventfd() helper; remove internal call to sys_eventfd()
kernel: open-code sys_rt_sigpending() in sys_sigpending()
x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to
sys_ioperm()
fs: add ksys_mount() helper; remove in-kernel calls to sys_mount()
fs: add ksys_umount() helper; remove in-kernel call to sys_umount()
fs: add ksys_dup{,3}() helper; remove in-kernel calls to sys_dup{,3}()
fs: add ksys_chroot() helper; remove-in kernel calls to sys_chroot()
fs: add ksys_write() helper; remove in-kernel calls to sys_write()
kernel: add ksys_unshare() helper; remove in-kernel calls to
sys_unshare()
mm: add ksys_fadvise64_64() helper; remove in-kernel call to
sys_fadvise64_64()
mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to
sys_mmap_pgoff()
fs: add ksys_chdir() helper; remove in-kernel calls to sys_chdir()
fs: add ksys_sync_file_range helper(); remove in-kernel calls to
syscall
fs: add ksys_unlink() wrapper; remove in-kernel calls to sys_unlink()
hostfs: rename do_rmdir() to hostfs_do_rmdir()
fs: add ksys_rmdir() wrapper; remove in-kernel calls to sys_rmdir()
fs: add do_mkdirat() helper and ksys_mkdir() wrapper; remove in-kernel
calls to syscall
fs: add do_symlinkat() helper and ksys_symlink() wrapper; remove
in-kernel calls to syscall
fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel
calls to syscall
fs: add do_linkat() helper and ksys_link() wrapper; remove in-kernel
calls to syscall
fs: add ksys_fchmod() and do_fchmodat() helpers and ksys_chmod()
wrapper; remove in-kernel calls to syscall
fs: add do_faccessat() helper and ksys_access() wrapper; remove
in-kernel calls to syscall
fs: add ksys_ftruncate() wrapper; remove in-kernel calls to
sys_ftruncate()
fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown()
wrappers
fs: add ksys_close() wrapper; remove in-kernel calls to sys_close()
fs: add ksys_open() wrapper; remove in-kernel calls to sys_open()
Documentation/process/adding-syscalls.rst | 14 ---
arch/alpha/kernel/osf_sys.c | 2 +-
arch/arm/kernel/sys_arm.c | 2 +-
arch/arm64/kernel/sys.c | 2 +-
arch/ia64/kernel/sys_ia64.c | 4 +-
arch/m68k/kernel/sys_m68k.c | 2 +-
arch/microblaze/kernel/sys_microblaze.c | 6 +-
arch/mips/kernel/linux32.c | 10 +-
arch/mips/kernel/syscall.c | 6 +-
arch/parisc/kernel/sys_parisc.c | 14 +--
arch/powerpc/kernel/sys_ppc32.c | 8 +-
arch/powerpc/kernel/syscalls.c | 6 +-
arch/riscv/kernel/sys_riscv.c | 4 +-
arch/s390/kernel/compat_linux.c | 23 ++---
arch/s390/kernel/sys_s390.c | 2 +-
arch/sh/kernel/sys_sh.c | 4 +-
arch/sh/kernel/sys_sh32.c | 8 +-
arch/sparc/kernel/sys_sparc32.c | 14 +--
arch/sparc/kernel/sys_sparc_32.c | 6 +-
arch/sparc/kernel/sys_sparc_64.c | 2 +-
arch/um/kernel/syscall.c | 2 +-
arch/x86/ia32/sys_ia32.c | 22 ++---
arch/x86/include/asm/syscalls.h | 1 +
arch/x86/kernel/ioport.c | 7 +-
arch/x86/kernel/sys_x86_64.c | 2 +-
arch/xtensa/kernel/syscall.c | 2 +-
drivers/base/devtmpfs.c | 11 ++-
drivers/tty/vt/vt_ioctl.c | 6 +-
fs/autofs4/dev-ioctl.c | 2 +-
fs/binfmt_misc.c | 2 +-
fs/eventfd.c | 9 +-
fs/eventpoll.c | 23 +++--
fs/file.c | 17 +++-
fs/hostfs/hostfs.h | 2 +-
fs/hostfs/hostfs_kern.c | 2 +-
fs/hostfs/hostfs_user.c | 2 +-
fs/internal.h | 14 +++
fs/namei.c | 61 +++++++++----
fs/namespace.c | 19 +++-
fs/open.c | 68 ++++++++++----
fs/pipe.c | 9 +-
fs/read_write.c | 9 +-
fs/signalfd.c | 14 ++-
fs/stat.c | 12 ++-
fs/sync.c | 12 ++-
fs/utimes.c | 13 ++-
include/linux/futex.h | 13 ++-
include/linux/syscalls.h | 146 +++++++++++++++++++++++++++++-
init/do_mounts.c | 16 ++--
init/do_mounts.h | 4 +-
init/do_mounts_initrd.c | 38 ++++----
init/do_mounts_md.c | 14 +--
init/do_mounts_rd.c | 18 ++--
init/initramfs.c | 48 +++++-----
init/main.c | 9 +-
init/noinitramfs.c | 6 +-
kernel/exit.c | 2 +-
kernel/fork.c | 11 ++-
kernel/pid_namespace.c | 6 +-
kernel/signal.c | 15 ++-
kernel/sys.c | 9 +-
kernel/uid16.c | 6 +-
kernel/umh.c | 2 +-
mm/fadvise.c | 10 +-
mm/mmap.c | 17 +++-
mm/nommu.c | 17 +++-
66 files changed, 614 insertions(+), 275 deletions(-)
--
2.16.2
