Messages in this thread | | | Date | Thu, 26 Jul 2018 18:08:55 +0800 | From | Wei Wang <> | Subject | Re: [PATCH] linux/bitmap.h: fix BITMAP_LAST_WORD_MASK |
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On 07/26/2018 04:48 PM, Andy Shevchenko wrote: > On Thu, Jul 26, 2018 at 11:07 AM, Wei Wang <wei.w.wang@intel.com> wrote: >> The existing BITMAP_LAST_WORD_MASK macro returns 0xffffffff if nbits is >> 0. This patch changes the macro to return 0 when there is no bit needs to >> be masked. >> > Can you provide a practical example of what's going wrong before this > patch applied? >
The reason of making this patch is that I saw some other software which ports this function and has possibilities to fall into bugs with usages which pass 0 to the macro. So I wonder if it would be necessary to make such changes in case we would get a similar bug. Or adding something to explain that "0" is not applicable to this macro as a reminder to people who would use it.
Best, Wei
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