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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 292c8e5 (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. CC: qemu-trivial@nongnu.org CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> (cherry picked from commit 2098b07) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
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