[PATCH 00/18] uaccess: fix sparse warning on get_user for bitwise types

Michael S. Tsirkin
2014-12-14T16:52:06Z

At the moment, if p and x are both tagged as bitwise types,
get_user(x, p) produces a sparse warning on many architectures.
This is because *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.

Specificlly, vhost wants to read bitwise types from userspace using get_user.
At the moment this triggers sparse errors, since the value is passed through an
integer.

For now, I worked around this by converting vhost code to access_ok +
__get_user, but that's not robust, I'd like to switch to get_user for 3.19.

I tested this on x86 only so far. Since it's just adding __force, should be
trivially safe everywhere?

Please review, and consider for 3.19.

Who can merge this? Arnd?

Michael S. Tsirkin (18):
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
microblaze/uaccess: fix sparse errors
openrisc/uaccess: fix sparse errors
parisc/uaccess: fix sparse errors
powerpc/uaccess: fix sparse errors
sh/uaccess: fix sparse errors
sparc/uaccess: fix sparse errors
sparc/uaccess: fix sparse errors
xtensa/uaccess: fix sparse errors
m68k/uaccess: fix sparse errors

arch/alpha/include/asm/uaccess.h | 4 ++--
arch/arm64/include/asm/uaccess.h | 2 +-
arch/avr32/include/asm/uaccess.h | 4 ++--
arch/blackfin/include/asm/uaccess.h | 2 +-
arch/cris/include/asm/uaccess.h | 4 ++--
arch/ia64/include/asm/uaccess.h | 2 +-
arch/m32r/include/asm/uaccess.h | 4 ++--
arch/m68k/include/asm/uaccess_mm.h | 4 ++--
arch/metag/include/asm/uaccess.h | 4 ++--
arch/microblaze/include/asm/uaccess.h | 4 ++--
arch/openrisc/include/asm/uaccess.h | 4 ++--
arch/parisc/include/asm/uaccess.h | 2 +-
arch/powerpc/include/asm/uaccess.h | 6 +++---
arch/sh/include/asm/uaccess.h | 4 ++--
arch/sparc/include/asm/uaccess_32.h | 8 ++++----
arch/sparc/include/asm/uaccess_64.h | 4 ++--
arch/x86/include/asm/uaccess.h | 2 +-
arch/xtensa/include/asm/uaccess.h | 4 ++--
18 files changed, 34 insertions(+), 34 deletions(-)

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