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author | Arnd Bergmann <arnd@arndb.de> | 2015-01-14 23:17:49 +0100 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2015-01-14 23:17:49 +0100 |
commit | 643165c8bbc8617d8222cb50c89e34fe64d226cf (patch) | |
tree | e2a88de9b8efb0c9fa2436f53b0a3ab4948c4a55 /arch/x86/include | |
parent | eaa27f34e91a14cdceed26ed6c6793ec1d186115 (diff) | |
parent | 0795cb1b46e7938ed679ccd48f933e75272b30e3 (diff) | |
download | blackbird-op-linux-643165c8bbc8617d8222cb50c89e34fe64d226cf.tar.gz blackbird-op-linux-643165c8bbc8617d8222cb50c89e34fe64d226cf.zip |
Merge tag 'uaccess_for_upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost into asm-generic
Merge "uaccess: fix sparse warning on get/put_user for bitwise types" from Michael S. Tsirkin:
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 <mst@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* tag 'uaccess_for_upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (37 commits)
sparc32: nocheck uaccess coding style tweaks
sparc64: nocheck uaccess coding style tweaks
xtensa: macro whitespace fixes
sh: macro whitespace fixes
parisc: macro whitespace fixes
m68k: macro whitespace fixes
m32r: macro whitespace fixes
frv: macro whitespace fixes
cris: macro whitespace fixes
avr32: macro whitespace fixes
arm64: macro whitespace fixes
arm: macro whitespace fixes
alpha: macro whitespace fixes
blackfin: macro whitespace fixes
sparc64: uaccess_64 macro whitespace fixes
sparc32: uaccess_32 macro whitespace fixes
avr32: whitespace fix
sh: fix put_user sparse errors
metag: fix put_user sparse errors
ia64: fix put_user sparse errors
...
Diffstat (limited to 'arch/x86/include')
-rw-r--r-- | arch/x86/include/asm/uaccess.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 0d592e0a5b84..ace9dec050b1 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -179,7 +179,7 @@ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) asm volatile("call __get_user_%P3" \ : "=a" (__ret_gu), "=r" (__val_gu) \ : "0" (ptr), "i" (sizeof(*(ptr)))); \ - (x) = (__typeof__(*(ptr))) __val_gu; \ + (x) = (__force __typeof__(*(ptr))) __val_gu; \ __ret_gu; \ }) |