| Message ID | 20180620065830.6612-2-johannes@sipsolutions.net (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e7d4a95da86e0b048702765bbdcdc968aaf312e7 |
| Delegated to: | Kalle Valo |
| Headers | show |
Johannes Berg <johannes@sipsolutions.net> wrote: > There's a bug in *_encode_bits() in using ~field_multiplier() for > the check whether or not the constant value fits into the field, > this is wrong and clearly ~field_mask() was intended. This was > triggering for me for both constant and non-constant values. > > Additionally, make this case actually into an compile error. > Declaring the extern function that will never exist with just a > warning is pointless as then later we'll just get a link error. > > While at it, also fix the indentation in those lines I'm touching. > > Finally, as suggested by Andy Shevchenko, add some tests and for > that introduce also u8 helpers. The tests don't compile without > the fix, showing that it's necessary. > > Fixes: 00b0c9b82663 ("Add primitives for manipulating bitfields both in host- and fixed-endian.") > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Signed-off-by: Johannes Berg <johannes@sipsolutions.net> 3 patches applied to wireless-drivers-next.git, thanks. e7d4a95da86e bitfield: fix *_encode_bits() 37a3862e1238 bitfield: add u8 helpers 0e2dc70e3d0d bitfield: add tests
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index cf2588d81148..147a7bb341dd 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -104,7 +104,7 @@ (typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \ }) -extern void __compiletime_warning("value doesn't fit into mask") +extern void __compiletime_error("value doesn't fit into mask") __field_overflow(void); extern void __compiletime_error("bad bitfield mask") __bad_mask(void); @@ -121,8 +121,8 @@ static __always_inline u64 field_mask(u64 field) #define ____MAKE_OP(type,base,to,from) \ static __always_inline __##type type##_encode_bits(base v, base field) \ { \ - if (__builtin_constant_p(v) && (v & ~field_multiplier(field))) \ - __field_overflow(); \ + if (__builtin_constant_p(v) && (v & ~field_mask(field))) \ + __field_overflow(); \ return to((v & field_mask(field)) * field_multiplier(field)); \ } \ static __always_inline __##type type##_replace_bits(__##type old, \
There's a bug in *_encode_bits() in using ~field_multiplier() for the check whether or not the constant value fits into the field, this is wrong and clearly ~field_mask() was intended. This was triggering for me for both constant and non-constant values. Additionally, make this case actually into an compile error. Declaring the extern function that will never exist with just a warning is pointless as then later we'll just get a link error. While at it, also fix the indentation in those lines I'm touching. Finally, as suggested by Andy Shevchenko, add some tests and for that introduce also u8 helpers. The tests don't compile without the fix, showing that it's necessary. Fixes: 00b0c9b82663 ("Add primitives for manipulating bitfields both in host- and fixed-endian.") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Johannes Berg <johannes@sipsolutions.net> --- v2: replace stray tab by space v3: u8 helpers, tests v4: minor cleanup (Andy) split into two patches (Andy) --- include/linux/bitfield.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)