Commit 9157f90f authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

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: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b8bec829
......@@ -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);
......
......@@ -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)
{
}
......
......@@ -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)
{
......
......@@ -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;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment