Messages in this thread | | | Date | Tue, 15 Dec 2015 11:35:24 +0100 | From | Joerg Roedel <> | Subject | Re: [for-4.4-rc6 PATCH] scatterlist: fix sg_phys() masking |
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On Mon, Dec 14, 2015 at 03:17:39PM -0800, Dan Williams wrote: > commit db0fa0cb0157 "scatterlist: use sg_phys()" did replacements of the > form: > > phys_addr_t phys = page_to_phys(sg_page(s)); > phys_addr_t phys = sg_phys(s) & PAGE_MASK; > > However, this breaks platforms where sizeof(phys_addr_t) > > sizeof(unsigned long). Since PAGE_MASK is an unsigned long this > inadvertently masks the high bits returned by sg_phys(). Convert to > PHYSICAL_PAGE_MASK in these cases which will do the proper sign > extension. > > As caught by the kbuild robot, a generic fallback definition of > PHYSICAL_PAGE_MASK is needed for several archs.
It is getting late in the cycle already, isn't it better to revert db0fa0cb0157 for now and queue a fixed version for the next round? Then you can also replace all the 'sg_phys() & MASK' parts by a new sg helper which just returns the page-aligned physical address. This would not only be cleaner than your original patch but also leaves just one place where you need to fix things if necessary.
Joerg
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