14.09.2017 16:49, Eric Blake wrote: > When using bit-wise operations that exploit the power-of-two > nature of the second argument of ROUND_UP(), we still need to > ensure that the mask is as wide as the first argument (done > by using a ternary to force proper arithmetic promotion). > Unpatched, ROUND_UP(2ULL*1024*1024*1024*1024, 512U) produces 0, > instead of the intended 2TiB, because negation of an unsigned > 32-bit quantity followed by widening to 64-bits does not > sign-extend the mask. > > Broken since its introduction in commit 292c8e50 (v1.5.0). > Callers that passed the same width type to both macro parameters, > or that had other code to ensure the first parameter's maximum > runtime value did not exceed the second parameter's width, are > unaffected, but I did not audit to see which (if any) existing > clients of the macro could trigger incorrect behavior (I found > the bug while adding a new use of the macro). > > While preparing the patch, checkpatch complained about poor > spacing, so I also fixed that here and in the nearby DIV_ROUND_UP.
Applied to -trivial, thanks! /mjt
