Messages in this thread |  | | Date | Sat, 21 Jan 2023 19:26:56 +0000 | From | Al Viro <> | Subject | Re: [PATCH v3 4/4] fs/sysv: Replace kmap() with kmap_local_page() |
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On Sat, Jan 21, 2023 at 12:05:58AM -0800, Ira Weiny wrote:
> First, arn't PAGE_ALIGN_DOWN(addr) and PTR_ALIGN_DOWN(addr, PAGE_SIZE) the > same? > > align.h > #define PTR_ALIGN_DOWN(p, a) ((typeof(p))ALIGN_DOWN((unsigned long)(p), (a))) > > mm.h: > #define PAGE_ALIGN_DOWN(addr) ALIGN_DOWN(addr, PAGE_SIZE)
... and ALIGN_DOWN ends up with doing bitwise and on the first argument. Which doesn't work for pointers, thus the separate variant for those and typecast to unsigned long in it...
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