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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-06-11 17:35:44 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-06-11 17:35:44 (GMT) |
commit | a4df1ac12dd2d2812713a5fdd56af954d1bc251d (patch) | |
tree | 1cf0a68f8960892d8ff83fdb233e79013b954858 /arch/s390/mm | |
parent | 2a212f699671c967dd0fad133f62e6f3e721c73d (diff) | |
parent | 3c9155106d589584f67b026ec444e69c4a68d7dc (diff) | |
download | linux-fsl-qoriq-a4df1ac12dd2d2812713a5fdd56af954d1bc251d.tar.xz |
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.c | 44 |
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); |