Messages in this thread | | | Date | Thu, 18 Nov 2004 19:41:57 +0000 (GMT) | From | Hugh Dickins <> | Subject | Re: [PATCH 1/2] setup_arg_pages can insert overlapping vma |
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On Thu, 18 Nov 2004, Chris Wright wrote: > * Hugh Dickins (hugh@veritas.com) wrote: > > > > Chris, shouldn't your patch also cover the setup_arg_pages clones for > > 32-bit support on 64-bit architectures, with something - uncompiled, > > untested - like the below? I'm not sure how necessary the additional > > vma->vm_start < mpnt->vm_end test is, but suspect ia64 might need it. > > I expect other arches should need the fix as well, it would be nice > to test them.
ia64, s390 and x86_64 seem to be the only ones with their own code to insert_vm_struct for 32-bit setup_arg_pages.
> I'm not clear on that extra test. Wouldn't it imply vm_end < vm_start?
Whose vm_end and whose vm_start? Well, no need to answer...
Check the comment on find_vma in mm/mmap.c: /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ but perhaps you thought it returns NULL if addr is not covered by a vma?
If so, maybe your original fs/exec.c fix also needs that check added: it's usually the case that there cannot be a vma above the stack being set up here, but I don't know enough of all the architectures to say that's always so (and it looks like not the case for 32-bit on ia64).
Hugh
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