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/*
* Copyright IBM Corp. 2011
* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <asm/pgtable.h>
static void change_page_attr(unsigned long addr, int numpages,
pte_t (*set) (pte_t))
{
pte_t *ptep, pte;
pmd_t *pmdp;
pud_t *pudp;
pgd_t *pgdp;
int i;
for (i = 0; i < numpages; i++) {
pgdp = pgd_offset(&init_mm, addr);
pudp = pud_offset(pgdp, addr);
pmdp = pmd_offset(pudp, addr);
if (pmd_huge(*pmdp)) {
WARN_ON_ONCE(1);
continue;
}
ptep = pte_offset_kernel(pmdp, addr);
pte = *ptep;
pte = set(pte);
ptep_invalidate(&init_mm, addr, ptep);
*ptep = pte;
addr += PAGE_SIZE;
}
}
int set_memory_ro(unsigned long addr, int numpages)
{
change_page_attr(addr, numpages, pte_wrprotect);
return 0;
}
EXPORT_SYMBOL_GPL(set_memory_ro);
int set_memory_rw(unsigned long addr, int numpages)
{
change_page_attr(addr, numpages, pte_mkwrite);
return 0;
}
EXPORT_SYMBOL_GPL(set_memory_rw);
/* not possible */
int set_memory_nx(unsigned long addr, int numpages)
{
return 0;
}
EXPORT_SYMBOL_GPL(set_memory_nx);
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