um: embed ->stub_pages[] into mmu_context

seriously, kmalloc() for two-element array of pointers?

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 18 deletions

diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 1aee587e9c5..db2ef422c1b 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -92,8 +92,6 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
                 goto out_free;
         }
 
-        to_mm->stub_pages = NULL;
-
         return 0;
 
  out_free:
@@ -120,29 +118,20 @@ void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
         if (ret)
                 goto out;
 
-        pages = kmalloc(2 * sizeof(struct page *), GFP_KERNEL);
-        if (pages == NULL) {
-                printk(KERN_ERR "arch_dup_mmap failed to allocate 2 page "
-                       "pointers\n");
-                goto out;
-        }
-
-        pages[0] = virt_to_page(&__syscall_stub_start);
-        pages[1] = virt_to_page(mm->context.id.stack);
-        mm->context.stub_pages = pages;
+        mm->context.stub_pages[0] = virt_to_page(&__syscall_stub_start);
+        mm->context.stub_pages[1] = virt_to_page(mm->context.id.stack);
 
         /* dup_mmap already holds mmap_sem */
         err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
                                       VM_READ | VM_MAYREAD | VM_EXEC |
-                                      VM_MAYEXEC | VM_DONTCOPY, pages);
+                                      VM_MAYEXEC | VM_DONTCOPY,
+                                      mm->context.stub_pages);
         if (err) {
                 printk(KERN_ERR "install_special_mapping returned %d\n", err);
-                goto out_free;
+                goto out;
         }
         return;
 
-out_free:
-        kfree(pages);
 out:
         force_sigsegv(SIGSEGV, current);
 }
@@ -151,8 +140,6 @@ void arch_exit_mmap(struct mm_struct *mm)
 {
         pte_t *pte;
 
-        if (mm->context.stub_pages != NULL)
-                kfree(mm->context.stub_pages);
         pte = virt_to_pte(mm, STUB_CODE);
         if (pte != NULL)
                 pte_clear(mm, STUB_CODE, pte);