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(vma->vm_start - address) >> PAGE_SHIFT--- linux-2.6.9/mm/mmap.c 2005-03-16 21:06:42.000000000 +0000
+++ linux-2.6.9-plasmaroo/mm/mmap.c 2005-03-16 21:09:26.000000000 +0000
@@ -1316,13 +1316,57 @@ out:
return prev ? prev->vm_next : vma;
}
+/*
+ * Verify that the stack growth is acceptable and
+ * update accounting. This is shared with both the
+ * grow-up and grow-down cases.
+ */
+static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, unsigned long grow)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ struct rlimit *rlim = current->rlim;
+
+ /* address space limit tests */
+ rlim = current->rlim;
+ if (mm->total_vm + grow > rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT)
+ return -ENOMEM;
+
+ /* Stack limit test */
+ if (size > rlim[RLIMIT_STACK].rlim_cur)
+ return -ENOMEM;
+
+ /* mlock limit tests */
+ if (vma->vm_flags & VM_LOCKED) {
+ unsigned long locked;
+ unsigned long limit;
+ locked = mm->locked_vm + grow;
+ limit = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+ if (locked > limit && !capable(CAP_IPC_LOCK))
+ return -ENOMEM;
+ }
+
+ /*
+ * Overcommit.. This must be the final test, as it will
+ * update security statistics.
+ */
+ if (security_vm_enough_memory(grow))
+ return -ENOMEM;
+
+ /* Ok, everything looks good - let it rip */
+ mm->total_vm += grow;
+ if (vma->vm_flags & VM_LOCKED)
+ mm->locked_vm += grow;
+ __vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow);
+ return 0;
+}
+
#ifdef CONFIG_STACK_GROWSUP
/*
* vma is the first one with address > vma->vm_end. Have to extend vma.
*/
int expand_stack(struct vm_area_struct * vma, unsigned long address)
{
- unsigned long grow;
+ int error;
if (!(vma->vm_flags & VM_GROWSUP))
return -EFAULT;
@@ -1342,28 +1386,24 @@ int expand_stack(struct vm_area_struct *
*/
address += 4 + PAGE_SIZE - 1;
address &= PAGE_MASK;
- grow = (address - vma->vm_end) >> PAGE_SHIFT;
+ error = 0;
- /* Overcommit.. */
- if (security_vm_enough_memory(grow)) {
- anon_vma_unlock(vma);
- return -ENOMEM;
- }
-
- if (address - vma->vm_start > current->rlim[RLIMIT_STACK].rlim_cur ||
- ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
- current->rlim[RLIMIT_AS].rlim_cur) {
- anon_vma_unlock(vma);
- vm_unacct_memory(grow);
- return -ENOMEM;
+ /* Somebody else might have raced and expanded it already */
+ if (address > vma->vm_end) {
+ unsigned long size, grow;
+
+ size = address - vma->vm_start;
+ grow = (address - vma->vm_end) >> PAGE_SHIFT;
+
+ error = acct_stack_growth(vma, size, grow);
+ if (!error)
+ vma->vm_end = address;
}
- vma->vm_end = address;
- vma->vm_mm->total_vm += grow;
- if (vma->vm_flags & VM_LOCKED)
- vma->vm_mm->locked_vm += grow;
+ error = acct_stack_growth(vma, size, grow);
+ if (!error)
+ vma->vm_end = address;
- __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow);
anon_vma_unlock(vma);
- return 0;
+ return error;
}
struct vm_area_struct *
@@ -1395,7 +1436,7 @@ find_extend_vma(struct mm_struct *mm, un
*/
int expand_stack(struct vm_area_struct *vma, unsigned long address)
{
- unsigned long grow;
+ int error;
/*
* We must make sure the anon_vma is allocated
@@ -1411,29 +1452,23 @@ int expand_stack(struct vm_area_struct *
* anon_vma lock to serialize against concurrent expand_stacks.
*/
address &= PAGE_MASK;
- grow = (vma->vm_start - address) >> PAGE_SHIFT;
+ error = 0;
- /* Overcommit.. */
- if (security_vm_enough_memory(grow)) {
- anon_vma_unlock(vma);
- return -ENOMEM;
- }
-
- if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
- ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
- current->rlim[RLIMIT_AS].rlim_cur) {
- anon_vma_unlock(vma);
- vm_unacct_memory(grow);
- return -ENOMEM;
+ /* Somebody else might have raced and expanded it already */
+ if (address < vma->vm_start) {
+ unsigned long size, grow;
+
+ size = vma->vm_end - address;
+ grow = (vma->vm_start - address) >> PAGE_SHIFT;
+
+ error = acct_stack_growth(vma, size, grow);
+ if (!error) {
+ vma->vm_start = address;
+ vma->vm_pgoff -= grow;
+ }
}
- vma->vm_start = address;
- vma->vm_pgoff -= grow;
- vma->vm_mm->total_vm += grow;
- if (vma->vm_flags & VM_LOCKED)
- vma->vm_mm->locked_vm += grow;
- __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow);
anon_vma_unlock(vma);
- return 0;
+ return error;
}
struct vm_area_struct *
|
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