[RFC PATCH v1 00/19] powerpc: Switch signal 32 to using user_access_begin() and friends

From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	 ldv@altlinux.org, viro@zeniv.linux.org.uk
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH v1 00/19] powerpc: Switch signal 32 to using user_access_begin() and friends
Date: Wed, 12 Aug 2020 12:05:51 +0000 (UTC)	[thread overview]
Message-ID: <cover.1597233555.git.christophe.leroy@csgroup.eu> (raw)

This series replaces copies to users by unsafe_put_user() and friends
with user_write_access_begin() dance in signal32.

The advantages are:
- No KUAP unlock/lock at every copy
- More readable code.
- Better generated code.

Copying Al Viro who did it on x86 and may have suggestions,
and Dmitry V. Levin who introduced put_compat_sigset()

Christophe Leroy (19):
  powerpc/signal: Move inline functions in signal.h
  powerpc/ptrace: Move declaration of ptrace_get_reg() and
    ptrace_set_reg()
  powerpc/ptrace: Consolidate reg index calculation
  powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()
  powerpc/signal: Don't manage floating point regs when no FPU
  powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x
  powerpc/signal: Move access_ok() out of get_sigframe()
  powerpc/signal: Remove get_clean_sp()
  powerpc/signal: Call get_tm_stackpointer() from get_sigframe()
  powerpc/signal: Refactor bad frame logging
  powerpc/signal32: Simplify logging in handle_rt_signal32()
  powerpc/signal32: Regroup copies in save_user_regs() and
    save_tm_user_regs()
  powerpc/signal32: Create 'unsafe' versions of
    copy_[ck][fpr/vsx]_to_user()
  powerpc/signal32: Switch save_user_regs() and save_tm_user_regs() to
    user_access_begin() logic
  powerpc/signal32: Switch handle_signal32() to user_access_begin()
    logic
  powerpc/signal32: Switch handle_rt_signal32() to user_access_begin()
    logic
  signal: Add unsafe_put_compat_sigset()
  powerpc/signal32: Add and use unsafe_put_sigset_t()
  powerpc/signal32: Switch swap_context() to user_access_begin() logic

 arch/powerpc/Kconfig                     |   1 +
 arch/powerpc/include/asm/processor.h     |  16 +-
 arch/powerpc/include/asm/ptrace.h        |   6 -
 arch/powerpc/kernel/asm-offsets.c        |   2 +
 arch/powerpc/kernel/process.c            |   4 +
 arch/powerpc/kernel/ptrace/Makefile      |   3 +-
 arch/powerpc/kernel/ptrace/ptrace-decl.h |  21 ++
 arch/powerpc/kernel/ptrace/ptrace-fpu.c  |  40 +++
 arch/powerpc/kernel/ptrace/ptrace-view.c |   2 +
 arch/powerpc/kernel/ptrace/ptrace.c      |  54 +---
 arch/powerpc/kernel/signal.c             |  59 ++--
 arch/powerpc/kernel/signal.h             | 109 ++++++-
 arch/powerpc/kernel/signal_32.c          | 386 ++++++++++++-----------
 arch/powerpc/kernel/signal_64.c          |  19 +-
 arch/powerpc/kernel/traps.c              |   2 +
 arch/powerpc/platforms/Kconfig.cputype   |  15 +-
 include/linux/compat.h                   |  32 ++
 17 files changed, 462 insertions(+), 309 deletions(-)
 create mode 100644 arch/powerpc/kernel/ptrace/ptrace-fpu.c

-- 
2.25.0