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authorLinus Torvalds <torvalds@linux-foundation.org>2008-06-11 10:35:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-06-11 10:35:44 -0700
commita4df1ac12dd2d2812713a5fdd56af954d1bc251d (patch)
tree1cf0a68f8960892d8ff83fdb233e79013b954858 /arch/s390/mm
parent2a212f699671c967dd0fad133f62e6f3e721c73d (diff)
parent3c9155106d589584f67b026ec444e69c4a68d7dc (diff)
downloadop-kernel-dev-a4df1ac12dd2d2812713a5fdd56af954d1bc251d.zip
op-kernel-dev-a4df1ac12dd2d2812713a5fdd56af954d1bc251d.tar.gz
Merge branch 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
* 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: KVM: MMU: Fix is_empty_shadow_page() check KVM: MMU: Fix printk() format string KVM: IOAPIC: only set remote_irr if interrupt was injected KVM: MMU: reschedule during shadow teardown KVM: VMX: Clear CR4.VMXE in hardware_disable KVM: migrate PIT timer KVM: ppc: Report bad GFNs KVM: ppc: Use a read lock around MMU operations, and release it on error KVM: ppc: Remove unmatched kunmap() call KVM: ppc: add lwzx/stwz emulation KVM: ppc: Remove duplicate function KVM: s390: Fix race condition in kvm_s390_handle_wait KVM: s390: Send program check on access error KVM: s390: fix interrupt delivery KVM: s390: handle machine checks when guest is running KVM: s390: fix locking order problem in enable_sie KVM: s390: use yield instead of schedule to implement diag 0x44 KVM: x86 emulator: fix hypercall return value on AMD KVM: ia64: fix zero extending for mmio ld1/2/4 emulation in KVM
Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/pgtable.c44
1 files changed, 27 insertions, 17 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 5c1aea9..3d98ba8 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -254,36 +254,46 @@ void disable_noexec(struct mm_struct *mm, struct task_struct *tsk)
int s390_enable_sie(void)
{
struct task_struct *tsk = current;
- struct mm_struct *mm;
- int rc;
+ struct mm_struct *mm, *old_mm;
- task_lock(tsk);
-
- rc = 0;
+ /* Do we have pgstes? if yes, we are done */
if (tsk->mm->context.pgstes)
- goto unlock;
+ return 0;
- rc = -EINVAL;
+ /* lets check if we are allowed to replace the mm */
+ task_lock(tsk);
if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
- tsk->mm != tsk->active_mm || tsk->mm->ioctx_list)
- goto unlock;
+ tsk->mm != tsk->active_mm || tsk->mm->ioctx_list) {
+ task_unlock(tsk);
+ return -EINVAL;
+ }
+ task_unlock(tsk);
- tsk->mm->context.pgstes = 1; /* dirty little tricks .. */
+ /* we copy the mm with pgstes enabled */
+ tsk->mm->context.pgstes = 1;
mm = dup_mm(tsk);
tsk->mm->context.pgstes = 0;
-
- rc = -ENOMEM;
if (!mm)
- goto unlock;
- mmput(tsk->mm);
+ return -ENOMEM;
+
+ /* Now lets check again if somebody attached ptrace etc */
+ task_lock(tsk);
+ if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
+ tsk->mm != tsk->active_mm || tsk->mm->ioctx_list) {
+ mmput(mm);
+ task_unlock(tsk);
+ return -EINVAL;
+ }
+
+ /* ok, we are alone. No ptrace, no threads, etc. */
+ old_mm = tsk->mm;
tsk->mm = tsk->active_mm = mm;
preempt_disable();
update_mm(mm, tsk);
cpu_set(smp_processor_id(), mm->cpu_vm_mask);
preempt_enable();
- rc = 0;
-unlock:
task_unlock(tsk);
- return rc;
+ mmput(old_mm);
+ return 0;
}
EXPORT_SYMBOL_GPL(s390_enable_sie);
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