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.
To make this clearer we also add -EINTR to the documentation of the
PV_ENABLE call, which calls unmerge_ksm_pages.
Fixes: 3ac8e38015
("s390/mm: disable KSM for storage key enabled pages")
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
parent
f3dd18d444
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@ -4677,6 +4677,12 @@ KVM_PV_ENABLE
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command has succeeded, any CPU added via hotplug will become
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protected during its creation as well.
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Errors:
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===== =============================
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EINTR an unmasked signal is pending
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===== =============================
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KVM_PV_DISABLE
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Deregister the VM from the Ultravisor and reclaim the memory that
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@ -2552,12 +2552,13 @@ int gmap_mark_unmergeable(void)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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int ret;
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for (vma = mm->mmap; vma; vma = vma->vm_next) {
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if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
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MADV_UNMERGEABLE, &vma->vm_flags)) {
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return -ENOMEM;
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}
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ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
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MADV_UNMERGEABLE, &vma->vm_flags);
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if (ret)
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return ret;
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}
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mm->def_flags &= ~VM_MERGEABLE;
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return 0;
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