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| 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 | |
| parent | [PATCH] i386: rationalize paravirt wrappers (diff) | |
| download | linux-dev-d01ad8dd56527be72947b4b9997bb2c05783c3ed.tar.xz linux-dev-d01ad8dd56527be72947b4b9997bb2c05783c3ed.zip | |
[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')
| -rw-r--r-- | arch/i386/mm/pageattr.c | 4 | ||||
| -rw-r--r-- | arch/x86_64/mm/pageattr.c | 16 |
2 files changed, 14 insertions, 6 deletions
diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c index 412ebbd8adb0..ea6b6d4a0a2a 100644 --- a/arch/i386/mm/pageattr.c +++ b/arch/i386/mm/pageattr.c @@ -142,7 +142,7 @@ __change_page_attr(struct page *page, pgprot_t prot) return -EINVAL; kpte_page = virt_to_page(kpte); if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) { - if ((pte_val(*kpte) & _PAGE_PSE) == 0) { + if (!pte_huge(*kpte)) { set_pte_atomic(kpte, mk_pte(page, prot)); } else { pgprot_t ref_prot; @@ -158,7 +158,7 @@ __change_page_attr(struct page *page, pgprot_t prot) kpte_page = split; } page_private(kpte_page)++; - } else if ((pte_val(*kpte) & _PAGE_PSE) == 0) { + } else if (!pte_huge(*kpte)) { set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL)); BUG_ON(page_private(kpte_page) == 0); page_private(kpte_page)--; diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c index 76ee90a5abe0..bf4aa8dd4254 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) && |