From: Jeff Dike 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 --- arch/um/kernel/ksyms.c | 1 arch/um/kernel/process.c | 43 -------------------------------- arch/um/kernel/skas/uaccess.c | 34 +++++++++++++++++++++++-- include/asm-um/pgtable.h | 3 -- 4 files changed, 32 insertions(+), 49 deletions(-) diff -puN arch/um/kernel/ksyms.c~uml-move-um_virt_to_phys arch/um/kernel/ksyms.c --- a/arch/um/kernel/ksyms.c~uml-move-um_virt_to_phys +++ a/arch/um/kernel/ksyms.c @@ -26,7 +26,6 @@ EXPORT_SYMBOL(get_kmem_end); EXPORT_SYMBOL(high_physmem); EXPORT_SYMBOL(empty_zero_page); -EXPORT_SYMBOL(um_virt_to_phys); EXPORT_SYMBOL(handle_page_fault); EXPORT_SYMBOL(find_iomem); diff -puN arch/um/kernel/process.c~uml-move-um_virt_to_phys arch/um/kernel/process.c --- a/arch/um/kernel/process.c~uml-move-um_virt_to_phys +++ a/arch/um/kernel/process.c @@ -255,49 +255,6 @@ void cpu_idle(void) default_idle(); } -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); -} - -char *current_cmd(void) -{ -#if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM) - return "(Unknown)"; -#else - void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL); - return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr); -#endif -} - void dump_thread(struct pt_regs *regs, struct user *u) { } diff -puN arch/um/kernel/skas/uaccess.c~uml-move-um_virt_to_phys arch/um/kernel/skas/uaccess.c --- a/arch/um/kernel/skas/uaccess.c~uml-move-um_virt_to_phys +++ a/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) { diff -puN include/asm-um/pgtable.h~uml-move-um_virt_to_phys include/asm-um/pgtable.h --- a/include/asm-um/pgtable.h~uml-move-um_virt_to_phys +++ a/include/asm-um/pgtable.h @@ -31,9 +31,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; -extern void *um_virt_to_phys(struct task_struct *task, unsigned long virt, - pte_t *pte_out); - /* zero page used for uninitialized stuff */ extern unsigned long *empty_zero_page; _