[PATCH 4/4] mm: replace set_pte_at_notify() with just set_pte_at()

From: Paolo Bonzini
Date: Fri Apr 05 2024 - 07:59:50 EST


With the demise of the .change_pte() MMU notifier callback, there is no
notification happening in set_pte_at_notify(). It is a synonym of
set_pte_at() and can be replaced with it.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
include/linux/mmu_notifier.h | 2 --
kernel/events/uprobes.c | 5 ++---
mm/ksm.c | 4 ++--
mm/memory.c | 7 +------
mm/migrate_device.c | 8 ++------
5 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 8c72bf651606..d39ebb10caeb 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -657,6 +657,4 @@ static inline void mmu_notifier_synchronize(void)

#endif /* CONFIG_MMU_NOTIFIER */

-#define set_pte_at_notify set_pte_at
-
#endif /* _LINUX_MMU_NOTIFIER_H */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index e4834d23e1d1..f4523b95c945 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -18,7 +18,6 @@
#include <linux/sched/coredump.h>
#include <linux/export.h>
#include <linux/rmap.h> /* anon_vma_prepare */
-#include <linux/mmu_notifier.h> /* set_pte_at_notify */
#include <linux/swap.h> /* folio_free_swap */
#include <linux/ptrace.h> /* user_enable_single_step */
#include <linux/kdebug.h> /* notifier mechanism */
@@ -195,8 +194,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
flush_cache_page(vma, addr, pte_pfn(ptep_get(pvmw.pte)));
ptep_clear_flush(vma, addr, pvmw.pte);
if (new_page)
- set_pte_at_notify(mm, addr, pvmw.pte,
- mk_pte(new_page, vma->vm_page_prot));
+ set_pte_at(mm, addr, pvmw.pte,
+ mk_pte(new_page, vma->vm_page_prot));

folio_remove_rmap_pte(old_folio, old_page, vma);
if (!folio_mapped(old_folio))
diff --git a/mm/ksm.c b/mm/ksm.c
index 8c001819cf10..108a4d167824 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1345,7 +1345,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
if (pte_write(entry))
entry = pte_wrprotect(entry);

- set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry);
+ set_pte_at(mm, pvmw.address, pvmw.pte, entry);
}
*orig_pte = entry;
err = 0;
@@ -1447,7 +1447,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
* See Documentation/mm/mmu_notifier.rst
*/
ptep_clear_flush(vma, addr, ptep);
- set_pte_at_notify(mm, addr, ptep, newpte);
+ set_pte_at(mm, addr, ptep, newpte);

folio = page_folio(page);
folio_remove_rmap_pte(folio, page, vma);
diff --git a/mm/memory.c b/mm/memory.c
index f2bc6dd15eb8..9a6f4d8aa379 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3327,13 +3327,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
ptep_clear_flush(vma, vmf->address, vmf->pte);
folio_add_new_anon_rmap(new_folio, vma, vmf->address);
folio_add_lru_vma(new_folio, vma);
- /*
- * We call the notify macro here because, when using secondary
- * mmu page tables (such as kvm shadow page tables), we want the
- * new page to be mapped directly into the secondary page table.
- */
BUG_ON(unshare && pte_write(entry));
- set_pte_at_notify(mm, vmf->address, vmf->pte, entry);
+ set_pte_at(mm, vmf->address, vmf->pte, entry);
update_mmu_cache_range(vmf, vma, vmf->address, vmf->pte, 1);
if (old_folio) {
/*
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index b6c27c76e1a0..66206734b1b9 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -664,13 +664,9 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
if (flush) {
flush_cache_page(vma, addr, pte_pfn(orig_pte));
ptep_clear_flush(vma, addr, ptep);
- set_pte_at_notify(mm, addr, ptep, entry);
- update_mmu_cache(vma, addr, ptep);
- } else {
- /* No need to invalidate - it was non-present before */
- set_pte_at(mm, addr, ptep, entry);
- update_mmu_cache(vma, addr, ptep);
}
+ set_pte_at(mm, addr, ptep, entry);
+ update_mmu_cache(vma, addr, ptep);

pte_unmap_unlock(ptep, ptl);
*src = MIGRATE_PFN_MIGRATE;
--
2.43.0