Re: [PATCH seccomp 0/8] seccomp: add bitmap cache support on remaining arches and report cache in procfs

On Tue, Nov 03, 2020 at 07:42:56AM -0600, YiFei Zhu wrote:

From: YiFei Zhu <redacted>

This patch series enables bitmap cache for the remaining arches with
SECCOMP_FILTER, other than MIPS.

I was unable to find any of the arches having subarch-specific NR_syscalls
macros, so generic NR_syscalls is used. SH's syscall_get_arch seems to
only have the 32-bit subarch implementation. I'm not sure if this is
expected.

This series has not been tested; I have not built all the cross compilers
necessary to build test, let alone run the kernel or benchmark the
performance, so help on making sure the bitmap cache works as expected
would be appreciated. The series applies on top of Kees's for-next/seccomp
branch.

Thank you! This looks good. I wonder if the different handling of little
endian is worth solving -- I'm suspicious about powerpc's use of
__LITTLE_ENDIAN__ vs a CONFIG, but I guess the compiler would match the
target endian-ness. Regardless, it captures what the architectures are
doing, and gets things standardized.

YiFei Zhu (8):
  csky: Enable seccomp architecture tracking
  parisc: Enable seccomp architecture tracking

I don't have compilers for these.

  powerpc: Enable seccomp architecture tracking
  riscv: Enable seccomp architecture tracking
  s390: Enable seccomp architecture tracking

These I can build-test immediately.

  sh: Enable seccomp architecture tracking
  xtensa: Enable seccomp architecture tracking

These two are available in Ubuntu's cross compiler set, so I'll get them
added to my cross-builders.

  seccomp/cache: Report cache data through /proc/pid/seccomp_cache

In the meantime, I'll wait a bit to see if we can get some Acks/Reviews
from arch maintainers. :)

-Kees

 arch/Kconfig                       | 15 ++++++++
 arch/csky/include/asm/Kbuild       |  1 -
 arch/csky/include/asm/seccomp.h    | 11 ++++++
 arch/parisc/include/asm/Kbuild     |  1 -
 arch/parisc/include/asm/seccomp.h  | 22 +++++++++++
 arch/powerpc/include/asm/seccomp.h | 21 +++++++++++
 arch/riscv/include/asm/seccomp.h   | 10 +++++
 arch/s390/include/asm/seccomp.h    |  9 +++++
 arch/sh/include/asm/seccomp.h      | 10 +++++
 arch/xtensa/include/asm/Kbuild     |  1 -
 arch/xtensa/include/asm/seccomp.h  | 11 ++++++
 fs/proc/base.c                     |  6 +++
 include/linux/seccomp.h            |  7 ++++
 kernel/seccomp.c                   | 59 ++++++++++++++++++++++++++++++
 14 files changed, 181 insertions(+), 3 deletions(-)
 create mode 100644 arch/csky/include/asm/seccomp.h
 create mode 100644 arch/parisc/include/asm/seccomp.h
 create mode 100644 arch/xtensa/include/asm/seccomp.h


base-commit: 38c37e8fd3d2590c4234d8cfbc22158362f0eb04
--
2.29.2

-- 
Kees Cook