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 <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c
index 7c7142ba3bd7d4c4980b07df559d3524d0fd78be..f0ced9840a27fee1619a9f8d6318f4f5e41f09eb 100644 (file)
--- a/arch/um/kernel/ksyms.c
+++ b/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 --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 62a4e0e12c9c223010cdd042ede959d027d1eea4..541a2bf331c527c80f581a32f0d2139a7c0f1938 100644 (file)
--- a/arch/um/kernel/process.c
+++ b/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 --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index 1d8b119f2d0e12f9930b5f3092df793f8d5c1803..302425b03d49d6978012e904b74b9e37fb938ca1 100644 (file)
--- 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)
 {

diff --git a/include/asm-um/pgtable.h b/include/asm-um/pgtable.h
index 1e7fc008559686c1618bfcf1d0c0327c42c963b0..e268506f322a048f8950a728ac09458341644035 100644 (file)
--- a/include/asm-um/pgtable.h
+++ b/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;