Messages in this thread Patch in this message | | | Date | Sat, 05 Oct 2002 04:00:10 +0400 | From | Oleg Nesterov <> | Subject | Re: [patch] futex-2.5.40-B5 |
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Hello.
Ingo Molnar wrote: > the new lookup code first does a lightweight follow_page(), then if no > page is present we do the get_user_pages() thing.
What if futex placed in VM_HUGETLB area? Then follow_page() return garbage.
I beleive in i386 case it can be fixed something like this:
--- mm/memory.c.orig Sat Oct 5 01:08:54 2002 +++ mm/memory.c Sat Oct 5 03:31:28 2002 @@ -480,6 +480,17 @@ follow_page(struct mm_struct *mm, unsign if (pmd_none(*pmd) || pmd_bad(*pmd)) goto out; +#ifdef CONFIG_HUGETLB_PAGE + if (pmd_large(pmd)) { + ptep = (pte_t *) pmd; + + if (write && !pte_write(*ptep)) + return NULL; + + return pte_page(*ptep) + ((address & ~HPAGE_MASK) >> PAGE_SHIFT); + } +#endif + ptep = pte_offset_map(pmd, address); if (!ptep) goto out;
Then follow_hugetlb_page() hook can be killed.
Oleg. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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