diff options
| author | Jan Beulich <jbeulich@novell.com> | 2007-05-02 19:27:10 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-05-02 19:27:10 +0200 |
| commit | d01ad8dd56527be72947b4b9997bb2c05783c3ed (patch) | |
| tree | 4bb9ad792fae974101d0baec755202eebc8181aa /arch/x86_64/mm/pageattr.c | |
| parent | 90a0a06aa81692028864c21f981905fda46b1208 (diff) | |
[PATCH] x86: Improve handling of kernel mappings in change_page_attr
Fix various broken corner cases in i386 and x86-64 change_page_attr.
AK: split off from tighten kernel image access rights
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/mm/pageattr.c')
| -rw-r--r-- | arch/x86_64/mm/pageattr.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c index 76ee90a5abe..bf4aa8dd425 100644 --- a/arch/x86_64/mm/pageattr.c +++ b/arch/x86_64/mm/pageattr.c @@ -179,16 +179,24 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) { unsigned long phys_base_pfn = __pa_symbol(__START_KERNEL_map) >> PAGE_SHIFT; - int err = 0; + int err = 0, kernel_map = 0; int i; + if (address >= __START_KERNEL_map + && address < __START_KERNEL_map + KERNEL_TEXT_SIZE) { + address = (unsigned long)__va(__pa(address)); + kernel_map = 1; + } + down_write(&init_mm.mmap_sem); for (i = 0; i < numpages; i++, address += PAGE_SIZE) { unsigned long pfn = __pa(address) >> PAGE_SHIFT; - err = __change_page_attr(address, pfn, prot, PAGE_KERNEL); - if (err) - break; + if (!kernel_map || pte_present(pfn_pte(0, prot))) { + err = __change_page_attr(address, pfn, prot, PAGE_KERNEL); + if (err) + break; + } /* Handle kernel mapping too which aliases part of the * lowmem */ if ((pfn >= phys_base_pfn) && |