Here is another series of patches which reduce the number of syscall
invocations from within the kernel. This series is focused solely on
the net/ part of the kernel and get rids of syscall and compat_syscall
invocations from within the kernel completely. It is also available at
https://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux.git
syscalls-net-next
The rationale of this change is described in patch 1 of part 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.
At present, these patches are based on v4.16-rc5; there is one trivial
conflict against net-next. Dave, I presume that you prefer to take them
through net-next? If you want to, I can re-base them against net-next.
If you prefer otherwise, though, I can route them as part of my whole
syscall series.
Thanks,
Dominik
[*] The cover letter for v2 is available at
http://lkml.kernel.org/r/20180315190529.20943-1-li...@dominikbrodowski.net ;
the whole patchset -- in its current, slightly modified form -- is
available at
at https://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux.git
syscalls-next
Dominik Brodowski (22):
net: socket: add __sys_recvfrom() helper; remove in-kernel call to
syscall
net: socket: add __sys_sendto() helper; remove in-kernel call to
syscall
net: socket: add __sys_accept4() helper; remove in-kernel call to
syscall
net: socket: add __sys_socket() helper; remove in-kernel call to
syscall
net: socket: add __sys_bind() helper; remove in-kernel call to syscall
net: socket: add __sys_connect() helper; remove in-kernel call to
syscall
net: socket: add __sys_listen() helper; remove in-kernel call to
syscall
net: socket: add __sys_getsockname() helper; remove in-kernel call to
syscall
net: socket: add __sys_getpeername() helper; remove in-kernel call to
syscall
net: socket: add __sys_socketpair() helper; remove in-kernel call to
syscall
net: socket: add __sys_shutdown() helper; remove in-kernel call to
syscall
net: socket: add __sys_setsockopt() helper; remove in-kernel call to
syscall
net: socket: add __sys_getsockopt() helper; remove in-kernel call to
syscall
net: socket: add do_sys_recvmmsg() helper; remove in-kernel call to
syscall
net: socket: move check for forbid_cmsg_compat to __sys_...msg()
net: socket: replace calls to sys_send() with __sys_sendto()
net: socket: replace call to sys_recv() with __sys_recvfrom()
net: socket: add __compat_sys_recvfrom() helper; remove in-kernel call
to compat syscall
net: socket: add __compat_sys_setsockopt() helper; remove in-kernel
call to compat syscall
net: socket: add __compat_sys_getsockopt() helper; remove in-kernel
call to compat syscall
net: socket: add __compat_sys_recvmmsg() helper; remove in-kernel call
to compat syscall
net: socket: add __compat_sys_...msg() helpers; remove in-kernel calls
to compat syscalls
include/linux/socket.h | 37 +++++++-
net/compat.c | 136 +++++++++++++++++++---------
net/socket.c | 234 ++++++++++++++++++++++++++++++++++---------------
3 files changed, 291 insertions(+), 116 deletions(-)
--
2.16.2
