| Message ID | 20221114115537.727371-1-apopple@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/memory: Return vm_fault_t result from migrate_to_ram() callback | expand |
On 14.11.22 12:55, Alistair Popple wrote: > The migrate_to_ram() callback should always succeed, but in rare cases > can fail usually returning VM_FAULT_SIGBUS. Commit 16ce101db85d > ("mm/memory.c: fix race when faulting a device private page") > incorrectly stopped passing the return code up the stack. Fix this by > setting the ret variable, restoring the previous behaviour on > migrate_to_ram() failure. > > Fixes: 16ce101db85d ("mm/memory.c: fix race when faulting a device private page") > Signed-off-by: Alistair Popple <apopple@nvidia.com> > Cc: Ralph Campbell <rcampbell@nvidia.com> > Cc: John Hubbard <jhubbard@nvidia.com> > Cc: Alex Sierra <alex.sierra@amd.com> > Cc: Ben Skeggs <bskeggs@redhat.com> > Cc: Felix Kuehling <Felix.Kuehling@amd.com> > Cc: Lyude Paul <lyude@redhat.com> > Cc: Jason Gunthorpe <jgg@nvidia.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > > --- > > Hi Andrew, I noticed my series needs another small fix which I'm > hoping you can apply for v6.1-rcX. Thanks (and sorry for not catching > this sooner). > --- > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memory.c b/mm/memory.c > index f88c351aecd4..8a6d5c823f91 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3763,7 +3763,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > */ > get_page(vmf->page); > pte_unmap_unlock(vmf->pte, vmf->ptl); > - vmf->page->pgmap->ops->migrate_to_ram(vmf); > + ret = vmf->page->pgmap->ops->migrate_to_ram(vmf); > put_page(vmf->page); > } else if (is_hwpoison_entry(entry)) { > ret = VM_FAULT_HWPOISON; Acked-by: David Hildenbrand <david@redhat.com>
Am 2022-11-14 um 11:41 schrieb David Hildenbrand: > On 14.11.22 12:55, Alistair Popple wrote: >> The migrate_to_ram() callback should always succeed, but in rare cases >> can fail usually returning VM_FAULT_SIGBUS. Commit 16ce101db85d >> ("mm/memory.c: fix race when faulting a device private page") >> incorrectly stopped passing the return code up the stack. Fix this by >> setting the ret variable, restoring the previous behaviour on >> migrate_to_ram() failure. >> >> Fixes: 16ce101db85d ("mm/memory.c: fix race when faulting a device >> private page") >> Signed-off-by: Alistair Popple <apopple@nvidia.com> >> Cc: Ralph Campbell <rcampbell@nvidia.com> >> Cc: John Hubbard <jhubbard@nvidia.com> >> Cc: Alex Sierra <alex.sierra@amd.com> >> Cc: Ben Skeggs <bskeggs@redhat.com> >> Cc: Felix Kuehling <Felix.Kuehling@amd.com> >> Cc: Lyude Paul <lyude@redhat.com> >> Cc: Jason Gunthorpe <jgg@nvidia.com> >> Cc: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> >> >> --- >> >> Hi Andrew, I noticed my series needs another small fix which I'm >> hoping you can apply for v6.1-rcX. Thanks (and sorry for not catching >> this sooner). >> --- >> mm/memory.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/mm/memory.c b/mm/memory.c >> index f88c351aecd4..8a6d5c823f91 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -3763,7 +3763,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) >> */ >> get_page(vmf->page); >> pte_unmap_unlock(vmf->pte, vmf->ptl); >> - vmf->page->pgmap->ops->migrate_to_ram(vmf); >> + ret = vmf->page->pgmap->ops->migrate_to_ram(vmf); >> put_page(vmf->page); >> } else if (is_hwpoison_entry(entry)) { >> ret = VM_FAULT_HWPOISON; > > > Acked-by: David Hildenbrand <david@redhat.com> >
diff --git a/mm/memory.c b/mm/memory.c index f88c351aecd4..8a6d5c823f91 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3763,7 +3763,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) */ get_page(vmf->page); pte_unmap_unlock(vmf->pte, vmf->ptl); - vmf->page->pgmap->ops->migrate_to_ram(vmf); + ret = vmf->page->pgmap->ops->migrate_to_ram(vmf); put_page(vmf->page); } else if (is_hwpoison_entry(entry)) { ret = VM_FAULT_HWPOISON;
The migrate_to_ram() callback should always succeed, but in rare cases can fail usually returning VM_FAULT_SIGBUS. Commit 16ce101db85d ("mm/memory.c: fix race when faulting a device private page") incorrectly stopped passing the return code up the stack. Fix this by setting the ret variable, restoring the previous behaviour on migrate_to_ram() failure. Fixes: 16ce101db85d ("mm/memory.c: fix race when faulting a device private page") Signed-off-by: Alistair Popple <apopple@nvidia.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Alex Sierra <alex.sierra@amd.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Lyude Paul <lyude@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> --- Hi Andrew, I noticed my series needs another small fix which I'm hoping you can apply for v6.1-rcX. Thanks (and sorry for not catching this sooner). --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)