From 9157f90f08f7db3188cd06971f41cb2ba5646e57 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 4 Feb 2008 22:30:52 -0800 Subject: uml: move um_virt_to_phys This patchset makes UML build and run with three-level page tables on 32-bit hosts. This is an uncommon use case, but the code here needed fixing and cleaning up, so 32-bit three-level pages tables were tested to make sure the changes are good. Patch 1 - code movement Patch 2 - header untangling Patch 3 - style fixups in files affected so far Patch 4 - clean up use of current.h Patch 5 - fix sizes of types that are different between 2 and 3-level page tables - three-level page table support should build at this point Patch 6 - tidy (i.e. eliminate much of) the code that figures out how big the address space is Patch 7 - change um_virt_to_phys into virt_to_pte, clean its interface, and clean its (so far) one caller Patch 8 - the stub pages are covered with a VMA, allowing some nasty code to be thrown out - three-level page tables now work This patch: um_virt_to_phys only has one user, so it can be moved to the same file and made static. Its declarations in pgtable.h and ksyms.c are also gone. current_cmd was another apparent user, but it itself isn't used, so it is deleted. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/kernel/skas/uaccess.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) (limited to 'arch/um/kernel/skas') diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c index 1d8b119f2d0..302425b03d4 100644 --- a/arch/um/kernel/skas/uaccess.c +++ b/arch/um/kernel/skas/uaccess.c @@ -12,8 +12,38 @@ #include "kern_util.h" #include "os.h" -extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr, - pte_t *pte_out); +static void *um_virt_to_phys(struct task_struct *task, unsigned long addr, + pte_t *pte_out) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + pte_t ptent; + + if (task->mm == NULL) + return ERR_PTR(-EINVAL); + pgd = pgd_offset(task->mm, addr); + if (!pgd_present(*pgd)) + return ERR_PTR(-EINVAL); + + pud = pud_offset(pgd, addr); + if (!pud_present(*pud)) + return ERR_PTR(-EINVAL); + + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) + return ERR_PTR(-EINVAL); + + pte = pte_offset_kernel(pmd, addr); + ptent = *pte; + if (!pte_present(ptent)) + return ERR_PTR(-EINVAL); + + if (pte_out != NULL) + *pte_out = ptent; + return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK); +} static unsigned long maybe_map(unsigned long virt, int is_write) { -- cgit v1.2.3