378b1e7a80
pmd_huge() will always return 0 on !HUGETLBFS, however we use that helper function when walking the kernel page tables to decide if we have a 1MB page frame or not. Since we create 1MB frames for the kernel 1:1 mapping independently of HUGETLBFS this can lead to incorrect storage accesses since the code can assume that we have a pointer to a page table instead of a pointer to a 1MB frame. Fix this by adding a pmd_large() primitive like other architectures have it already and remove all references to HUGETLBFS/HUGETLBPAGE from the code that walks kernel page tables. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
63 lines
1.2 KiB
C
63 lines
1.2 KiB
C
/*
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* Copyright IBM Corp. 2011
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* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <asm/cacheflush.h>
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#include <asm/pgtable.h>
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static void change_page_attr(unsigned long addr, int numpages,
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pte_t (*set) (pte_t))
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{
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pte_t *ptep, pte;
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pmd_t *pmdp;
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pud_t *pudp;
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pgd_t *pgdp;
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int i;
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for (i = 0; i < numpages; i++) {
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pgdp = pgd_offset(&init_mm, addr);
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pudp = pud_offset(pgdp, addr);
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pmdp = pmd_offset(pudp, addr);
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if (pmd_large(*pmdp)) {
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WARN_ON_ONCE(1);
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continue;
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}
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ptep = pte_offset_kernel(pmdp, addr);
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pte = *ptep;
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pte = set(pte);
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__ptep_ipte(addr, ptep);
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*ptep = pte;
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addr += PAGE_SIZE;
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}
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}
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int set_memory_ro(unsigned long addr, int numpages)
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{
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change_page_attr(addr, numpages, pte_wrprotect);
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return 0;
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}
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EXPORT_SYMBOL_GPL(set_memory_ro);
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int set_memory_rw(unsigned long addr, int numpages)
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{
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change_page_attr(addr, numpages, pte_mkwrite);
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return 0;
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}
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EXPORT_SYMBOL_GPL(set_memory_rw);
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/* not possible */
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int set_memory_nx(unsigned long addr, int numpages)
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{
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return 0;
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}
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EXPORT_SYMBOL_GPL(set_memory_nx);
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int set_memory_x(unsigned long addr, int numpages)
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{
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return 0;
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}
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