Re: [PULL] uaccess: fix sparse warning on get/put_user for bitwise types

2015-01-14 Thread Arnd Bergmann
On Wednesday 14 January 2015 19:36:18 Michael S. Tsirkin wrote:
 As you asked, here's a pull request.
 This has been in linux-next apparently with no ill effects.
 
 The following changes since commit 99975cc6ada0d5f2675e83abecae05aba5f437d2:
 
   vhost/net: length miscalculation (2015-01-07 12:22:00 +0200)
 
 are available in the git repository at:
 
   git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git 
 tags/uaccess_for_upstream
 
 for you to fetch changes up to 0795cb1b46e7938ed679ccd48f933e75272b30e3:
 

Pulled into my asm-generic now, thanks!

Arnd
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[PULL] uaccess: fix sparse warning on get/put_user for bitwise types

2015-01-14 Thread Michael S. Tsirkin
Hello, Arnd,
As you asked, here's a pull request.
This has been in linux-next apparently with no ill effects.

The following changes since commit 99975cc6ada0d5f2675e83abecae05aba5f437d2:

  vhost/net: length miscalculation (2015-01-07 12:22:00 +0200)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git 
tags/uaccess_for_upstream

for you to fetch changes up to 0795cb1b46e7938ed679ccd48f933e75272b30e3:

  sparc32: nocheck uaccess coding style tweaks (2015-01-13 15:24:14 +0200)


uaccess: fix sparse warning on get/put_user for bitwise types

At the moment, if p and x are both tagged as bitwise types,
some of get_user(x, p), put_user(x, p), __get_user(x, p), __put_user(x, p)
might produce a sparse warning on many architectures.
This is a false positive: *p on these architectures is loaded into long
(typically using asm), then cast back to typeof(*p).

When typeof(*p) is a bitwise type (which is uncommon), such a cast needs
__force, otherwise sparse produces a warning.

Some architectures already have the __force tag, add it
where it's missing.

I verified that adding these __force casts does not supress any useful warnings.

Specifically, vhost wants to read/write bitwise types in userspace memory
using get_user/put_user.
At the moment this triggers sparse errors, since the value is passed through an
integer.

For example:
__le32 __user *p;
__u32 x;

both
put_user(x, p);
and
get_user(x, p);
should be safe, but produce warnings on some architectures.

While there, I noticed that a bunch of architectures violated
coding style rules within uaccess macros.
Included patches to fix them up.

Signed-off-by: Michael S. Tsirkin m...@redhat.com


Michael S. Tsirkin (37):
  x86/uaccess: fix sparse errors
  alpha/uaccess: fix sparse errors
  arm64/uaccess: fix sparse errors
  avr32/uaccess: fix sparse errors
  blackfin/uaccess: fix sparse errors
  cris/uaccess: fix sparse errors
  ia64/uaccess: fix sparse errors
  m32r/uaccess: fix sparse errors
  metag/uaccess: fix sparse errors
  openrisc/uaccess: fix sparse errors
  parisc/uaccess: fix sparse errors
  sh/uaccess: fix sparse errors
  sparc32/uaccess: fix sparse errors
  sparc64/uaccess: fix sparse errors
  m68k/uaccess: fix sparse errors
  arm: fix put_user sparse errors
  blackfin: fix put_user sparse errors
  ia64: fix put_user sparse errors
  metag: fix put_user sparse errors
  sh: fix put_user sparse errors
  avr32: whitespace fix
  sparc32: uaccess_32 macro whitespace fixes
  sparc64: uaccess_64 macro whitespace fixes
  blackfin: macro whitespace fixes
  alpha: macro whitespace fixes
  arm: macro whitespace fixes
  arm64: macro whitespace fixes
  avr32: macro whitespace fixes
  cris: macro whitespace fixes
  frv: macro whitespace fixes
  m32r: macro whitespace fixes
  m68k: macro whitespace fixes
  parisc: macro whitespace fixes
  sh: macro whitespace fixes
  xtensa: macro whitespace fixes
  sparc64: nocheck uaccess coding style tweaks
  sparc32: nocheck uaccess coding style tweaks

 arch/alpha/include/asm/uaccess.h|  86 -
 arch/arm/include/asm/uaccess.h  |  96 +-
 arch/arm64/include/asm/uaccess.h|   4 +-
 arch/avr32/include/asm/uaccess.h|  24 +--
 arch/blackfin/include/asm/uaccess.h |  32 ++--
 arch/cris/include/asm/uaccess.h | 117 +++--
 arch/frv/include/asm/segment.h  |   2 +-
 arch/ia64/include/asm/uaccess.h |  11 +-
 arch/m32r/include/asm/uaccess.h |  88 +-
 arch/m68k/include/asm/segment.h |   2 +-
 arch/m68k/include/asm/uaccess_mm.h  |  40 ++---
 arch/metag/include/asm/uaccess.h|  25 +--
 arch/openrisc/include/asm/uaccess.h |   4 +-
 arch/parisc/include/asm/uaccess.h   | 116 ++--
 arch/sh/include/asm/segment.h   |   2 +-
 arch/sh/include/asm/uaccess.h   |   4 +-
 arch/sh/include/asm/uaccess_64.h|   8 +-
 arch/sparc/include/asm/uaccess_32.h | 339 +---
 arch/sparc/include/asm/uaccess_64.h | 222 ---
 arch/x86/include/asm/uaccess.h  |   2 +-
 arch/xtensa/include/asm/uaccess.h   |  90 +-
 21 files changed, 700 insertions(+), 614 deletions(-)
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