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[PATCH] Fix pte_exec/mkexec and use it in change_page_attr()

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Fix the pte_exec/mkexec page table accessor functions to really
use the NX bit. Previously they only checked the USER bit, but
weren't actually used for anything.

Then use them in change_page_attr() to manipulate the NX bit
properly.

Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Andi Kleen 2006-09-26 10:52:37 +02:00 committed by Andi Kleen
parent d3cf7f0615
commit df992848f5
2 changed files with 7 additions and 5 deletions
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8
arch/x86_64/mm/pageattr.c
View file

@ -190,10 +190,12 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
* lowmem */
if (__pa(address) < KERNEL_TEXT_SIZE) {
unsigned long addr2;
pgprot_t prot2 = prot;
pgprot_t prot2;
addr2 = __START_KERNEL_map + __pa(address);
pgprot_val(prot2) &= ~_PAGE_NX;
err = __change_page_attr(addr2, pfn, prot2, PAGE_KERNEL_EXEC);
/* Make sure the kernel mappings stay executable */
prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot)));
err = __change_page_attr(addr2, pfn, prot2,
PAGE_KERNEL_EXEC);
}
}
up_write(&init_mm.mmap_sem);

4
include/asm-x86_64/pgtable.h
View file

@ -265,7 +265,7 @@ static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
#define __LARGE_PTE (_PAGE_PSE|_PAGE_PRESENT)
static inline int pte_user(pte_t pte) { return pte_val(pte) & _PAGE_USER; }
static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_USER; }
static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_USER; }
static inline int pte_exec(pte_t pte) { return !(pte_val(pte) & _PAGE_NX); }
static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW; }
@ -278,7 +278,7 @@ static inline pte_t pte_mkclean(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) &
static inline pte_t pte_mkold(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_ACCESSED)); return pte; }
static inline pte_t pte_wrprotect(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_RW)); return pte; }
static inline pte_t pte_mkread(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_USER)); return pte; }
static inline pte_t pte_mkexec(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_USER)); return pte; }
static inline pte_t pte_mkexec(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_NX)); return pte; }
static inline pte_t pte_mkdirty(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_DIRTY)); return pte; }
static inline pte_t pte_mkyoung(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_ACCESSED)); return pte; }
static inline pte_t pte_mkwrite(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_RW)); return pte; }