Messages in this thread | | | Subject | Re: [PATCH] mm: fix incorrect behavior when process virtual address space limit is exceeded | From | Chris Metcalf <> | Date | Tue, 17 Nov 2015 12:38:13 -0500 |
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On 11/17/2015 11:19 AM, Oleg Nesterov wrote: > On 11/16, Piotr Kwapulinski wrote: >> @@ -1551,7 +1552,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, >> * MAP_FIXED may remove pages of mappings that intersects with >> * requested mapping. Account for the pages it would unmap. >> */ >> - if (!(vm_flags & MAP_FIXED)) >> + if (!(flags & MAP_FIXED)) >> return -ENOMEM; > And afaics arch/tile/mm/elf.c can use do_mmap(MAP_FIXED ...) rather than > mmap_region(), it can be changed by a separate patch. In this case we can > unexport mmap_region().
The problem is that we are mapping a region of virtual address space that the chip provides for setting up interrupt handlers (at 0xfc000000) but that is above the TASK_SIZE cutoff, so do_mmap() would fail the call in get_unmapped_area().
-- Chris Metcalf, EZChip Semiconductor http://www.ezchip.com
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