Commit 17c05f18 authored by Suren Baghdasaryan's avatar Suren Baghdasaryan Committed by Andrew Morton

mm: prevent do_swap_page from handling page faults under VMA lock

Due to the possibility of do_swap_page dropping mmap_lock, abort fault
handling under VMA lock and retry holding mmap_lock.  This can be handled
more gracefully in the future.

Link: https://lkml.kernel.org/r/20230227173632.3292573-27-surenb@google.comSigned-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
Reviewed-by: default avatarLaurent Dufour <laurent.dufour@fr.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 55324e46
...@@ -3697,6 +3697,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) ...@@ -3697,6 +3697,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
if (!pte_unmap_same(vmf)) if (!pte_unmap_same(vmf))
goto out; goto out;
if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
ret = VM_FAULT_RETRY;
goto out;
}
entry = pte_to_swp_entry(vmf->orig_pte); entry = pte_to_swp_entry(vmf->orig_pte);
if (unlikely(non_swap_entry(entry))) { if (unlikely(non_swap_entry(entry))) {
if (is_migration_entry(entry)) { if (is_migration_entry(entry)) {
......
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