Messages in this thread | | | Date | Thu, 14 Aug 2014 19:53:46 +0200 | From | Frantisek Hrbata <> | Subject | Re: [PATCH 1/1] x86: add phys addr validity check for /dev/mem mmap |
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On Thu, Aug 14, 2014 at 10:20:53AM -0700, H. Peter Anvin wrote: > On 08/14/2014 09:36 AM, Dave Hansen wrote: > > Thanks for dredging this back up! > > > > On 08/14/2014 07:18 AM, Frantisek Hrbata wrote: > >> +int valid_phys_addr_range(phys_addr_t addr, size_t count) > >> +{ > >> + return addr + count <= __pa(high_memory); > >> +} > > > > Is this correct on 32-bit? It would limit /dev/mem to memory below 896MB. > > > > Last I checked, /dev/mem was already broken for highmem... which is > actually a problem. I would prefer to see it fixed. > > -hpa >
Hi Peter,
thank you for jumping in again. I'm not going to pretent I fully understand this code, as proven by Dave :), but wouldn't it help just to move the high_memory check directly to the xlate_dev_mem_ptr. Meaning no high_memory check in valid_phys_addr_range for x86. I sent more info in my reply to Dave's mail.
Again many thanks.
-- Frantisek Hrbata
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