On 27.03.20 10:23, Christian Borntraeger wrote:
> If a signal is pending we might return -ENOMEM instead of -EINTR.
> We should propagate the proper error during KSM unsharing.
>
> Fixes: 3ac8e38015d4 ("s390/mm: disable KSM for storage key enabled pages")
> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/mm/gmap.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 27926a06df32..1ef864c252e6 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -2552,12 +2552,13 @@ int gmap_mark_unmergeable(void)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> + int ret;
>
> for (vma = mm->mmap; vma; vma = vma->vm_next) {
> - if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
> - MADV_UNMERGEABLE, &vma->vm_flags)) {
> - return -ENOMEM;
> - }
> + ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
> + MADV_UNMERGEABLE, &vma->vm_flags);
> + if (ret)
> + return ret;
> }
> mm->def_flags &= ~VM_MERGEABLE;
> return 0;
After the qemu patch discussion I would add
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 0e268b3d1591..ba8f9cbe4376 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -4680,6 +4680,12 @@ KVM_PV_ENABLE
command has succeeded, any CPU added via hotplug will become
protected during its creation as well.
+ Errors:
+
+ ===== =============================
+ EINTR an unmasked signal is pending
+ ===== =============================
+
KVM_PV_DISABLE
Deregister the VM from the Ultravisor and reclaim the memory that
and change the patch description to something like
s390/gmap: return proper error code on ksm unsharing
If a signal is pending we might return -ENOMEM instead of -EINTR.
We should propagate the proper error during KSM unsharing.
unmerge_ksm_pages returns -ERESTARTSYS on signal_pending. This gets
translated by entry.S to -EINTR. It is important to get this error
code so that userspace can retry.
Fixes: 3ac8e38015d4 ("s390/mm: disable KSM for storage key enabled pages")
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
Reported-by: Marc Hartmayer <mhartmay@xxxxxxxxxxxxx>
Tested-by: Marc Hartmayer <mhartmay@xxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
