| Message ID | 20230517022115.3033604-2-pcc@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: Fix bug affecting swapping in MTE tagged pages | expand |
Peter Collingbourne <pcc@google.com> writes: > Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved > the call to swap_free() before the call to set_pte_at(), which meant that > the MTE tags could end up being freed before set_pte_at() had a chance > to restore them. Fix it by adding a call to the arch_swap_restore() hook > before the call to swap_free(). > > Signed-off-by: Peter Collingbourne <pcc@google.com> > Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965 > Cc: <stable@vger.kernel.org> # 6.1 > Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") > Reported-by: Qun-wei Lin (林群崴) <Qun-wei.Lin@mediatek.com> > Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/ > --- > v2: > - Call arch_swap_restore() directly instead of via arch_do_swap_page() > > mm/memory.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/memory.c b/mm/memory.c > index f69fbc251198..fc25764016b3 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3932,6 +3932,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > } > } > > + /* > + * Some architectures may have to restore extra metadata to the page > + * when reading from swap. This metadata may be indexed by swap entry > + * so this must be called before swap_free(). > + */ > + arch_swap_restore(entry, folio); > + > /* > * Remove the swap entry and conditionally try to free up the swapcache. > * We're already holding a reference on the page but haven't mapped it Should you add Suggested-by: David Hildenbrand <david@redhat.com> for 1/3 and 2/3. It looks good for me for swap code related part. Feel free to add Acked-by: "Huang, Ying" <ying.huang@intel.com> to 1/3 and 2/3. Best Regards, Huang, Ying
On 17.05.23 05:40, Huang, Ying wrote: > Peter Collingbourne <pcc@google.com> writes: > >> Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved >> the call to swap_free() before the call to set_pte_at(), which meant that >> the MTE tags could end up being freed before set_pte_at() had a chance >> to restore them. Fix it by adding a call to the arch_swap_restore() hook >> before the call to swap_free(). >> >> Signed-off-by: Peter Collingbourne <pcc@google.com> >> Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965 >> Cc: <stable@vger.kernel.org> # 6.1 >> Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") >> Reported-by: Qun-wei Lin (林群崴) <Qun-wei.Lin@mediatek.com> >> Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/ >> --- >> v2: >> - Call arch_swap_restore() directly instead of via arch_do_swap_page() >> >> mm/memory.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/mm/memory.c b/mm/memory.c >> index f69fbc251198..fc25764016b3 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -3932,6 +3932,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) >> } >> } >> >> + /* >> + * Some architectures may have to restore extra metadata to the page >> + * when reading from swap. This metadata may be indexed by swap entry >> + * so this must be called before swap_free(). >> + */ >> + arch_swap_restore(entry, folio); >> + >> /* >> * Remove the swap entry and conditionally try to free up the swapcache. >> * We're already holding a reference on the page but haven't mapped it > > Should you add > > Suggested-by: David Hildenbrand <david@redhat.com> > > for 1/3 and 2/3. For 1/3, I think I rather only explained the problem in the first patch and didn't really suggest this. Acked-by: David Hildenbrand <david@redhat.com>
On 17/05/2023 03:21, Peter Collingbourne wrote: > Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved > the call to swap_free() before the call to set_pte_at(), which meant that > the MTE tags could end up being freed before set_pte_at() had a chance > to restore them. Fix it by adding a call to the arch_swap_restore() hook > before the call to swap_free(). > > Signed-off-by: Peter Collingbourne <pcc@google.com> > Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965 > Cc: <stable@vger.kernel.org> # 6.1 > Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") > Reported-by: Qun-wei Lin (林群崴) <Qun-wei.Lin@mediatek.com> > Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/ Reviewed-by: Steven Price <steven.price@arm.com> > --- > v2: > - Call arch_swap_restore() directly instead of via arch_do_swap_page() > > mm/memory.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/memory.c b/mm/memory.c > index f69fbc251198..fc25764016b3 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3932,6 +3932,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > } > } > > + /* > + * Some architectures may have to restore extra metadata to the page > + * when reading from swap. This metadata may be indexed by swap entry > + * so this must be called before swap_free(). > + */ > + arch_swap_restore(entry, folio); > + > /* > * Remove the swap entry and conditionally try to free up the swapcache. > * We're already holding a reference on the page but haven't mapped it
On Tue, May 16, 2023 at 07:21:11PM -0700, Peter Collingbourne wrote: > Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved > the call to swap_free() before the call to set_pte_at(), which meant that > the MTE tags could end up being freed before set_pte_at() had a chance > to restore them. Fix it by adding a call to the arch_swap_restore() hook > before the call to swap_free(). > > Signed-off-by: Peter Collingbourne <pcc@google.com> > Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965 > Cc: <stable@vger.kernel.org> # 6.1 > Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") > Reported-by: Qun-wei Lin (林群崴) <Qun-wei.Lin@mediatek.com> > Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/ Acked-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/mm/memory.c b/mm/memory.c index f69fbc251198..fc25764016b3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3932,6 +3932,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) } } + /* + * Some architectures may have to restore extra metadata to the page + * when reading from swap. This metadata may be indexed by swap entry + * so this must be called before swap_free(). + */ + arch_swap_restore(entry, folio); + /* * Remove the swap entry and conditionally try to free up the swapcache. * We're already holding a reference on the page but haven't mapped it
Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved the call to swap_free() before the call to set_pte_at(), which meant that the MTE tags could end up being freed before set_pte_at() had a chance to restore them. Fix it by adding a call to the arch_swap_restore() hook before the call to swap_free(). Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965 Cc: <stable@vger.kernel.org> # 6.1 Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") Reported-by: Qun-wei Lin (林群崴) <Qun-wei.Lin@mediatek.com> Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/ --- v2: - Call arch_swap_restore() directly instead of via arch_do_swap_page() mm/memory.c | 7 +++++++ 1 file changed, 7 insertions(+)