Messages in this thread Patch in this message | | | Date | Sun, 11 May 2003 10:08:41 +0200 | From | Andi Kleen <> | Subject | [PATCH] Use correct page protection for put_dirty_page |
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put_page_dirty must use the page protection of the stack VMA, not hardcoded PAGE_COPY. They can be different e.g. when the stack is set non executable via VM_STACK_FLAGS.
I added an fallback path for now because I'm not sure if the stack VMA is always predowngrowed here, if the printk better it may be also needed to add an stack extension here.
-Andi
--- linux-2.5.69-amd64/fs/exec.c-o 2003-04-20 21:21:50.000000000 +0200 +++ linux-2.5.69-amd64/fs/exec.c 2003-05-11 08:38:35.000000000 +0200 @@ -292,7 +292,9 @@ pgd_t * pgd; pmd_t * pmd; pte_t * pte; + pgprot_t prot; struct pte_chain *pte_chain; + struct vm_area_struct *vma; if (page_count(page) != 1) printk(KERN_ERR "mem_map disagrees with %p at %08lx\n", page, address); @@ -314,7 +316,13 @@ } lru_cache_add_active(page); flush_dcache_page(page); - set_pte(pte, pte_mkdirty(pte_mkwrite(mk_pte(page, PAGE_COPY)))); + vma = find_vma(tsk->mm, address); + if (!vma) { + printk("put_dirty_page: stack vma not extended yet %lx?\n",address); + prot = PAGE_COPY; + } else + prot = vma->vm_page_prot; + set_pte(pte, pte_mkdirty(pte_mkwrite(mk_pte(page, prot)))); pte_chain = page_add_rmap(page, pte, pte_chain); pte_unmap(pte); tsk->mm->rss++; - 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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