mm: change anon_vma linking to fix multi-process server scalability issue

[cascardo/linux.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index ea78617..5910307 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -246,6 +246,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
        vma->vm_start = vma->vm_end - PAGE_SIZE;
        vma->vm_flags = VM_STACK_FLAGS;
        vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+       INIT_LIST_HEAD(&vma->anon_vma_chain);
        err = insert_vm_struct(mm, vma);
        if (err)
                goto err;
@@ -516,7 +517,8 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
        /*
         * cover the whole range: [new_start, old_end)
         */
-       vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL);
+       if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL))
+               return -ENOMEM;
 
        /*
         * move the page tables downwards, on failure we rely on
@@ -547,7 +549,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
        tlb_finish_mmu(tlb, new_end, old_end);
 
        /*
-        * shrink the vma to just the new range.
+        * Shrink the vma to just the new range.  Always succeeds.
         */
        vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL);