+ mm-refactor-va_remove_mappings.patch added to mm-unstable branch

+ mm-refactor-va_remove_mappings.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: refactor va_remove_mappings
has been added to the -mm mm-unstable branch.  Its filename is
     mm-refactor-va_remove_mappings.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-refactor-va_remove_mappings.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: mm: refactor va_remove_mappings
Date: Sat, 21 Jan 2023 08:10:51 +0100

Move the VM_FLUSH_RESET_PERMS to the caller and rename the function to
better describe what it is doing.

Link: https://lkml.kernel.org/r/20230121071051.1143058-11-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/vmalloc.c~mm-refactor-va_remove_mappings
+++ a/mm/vmalloc.c
@@ -2617,35 +2617,23 @@ static inline void set_area_direct_map(c
 			set_direct_map(area->pages[i]);
 }
 
-/* Handle removing and resetting vm mappings related to the vm_struct. */
-static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
+/*
+ * Flush the vm mapping and reset the direct map.
+ */
+static void vm_reset_perms(struct vm_struct *area)
 {
 	unsigned long start = ULONG_MAX, end = 0;
 	unsigned int page_order = vm_area_page_order(area);
-	int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
 	int flush_dmap = 0;
 	int i;
 
-	/* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
-	if (!flush_reset)
-		return;
-
 	/*
-	 * If not deallocating pages, just do the flush of the VM area and
-	 * return.
-	 */
-	if (!deallocate_pages) {
-		vm_unmap_aliases();
-		return;
-	}
-
-	/*
-	 * If execution gets here, flush the vm mapping and reset the direct
-	 * map. Find the start and end range of the direct mappings to make sure
+	 * Find the start and end range of the direct mappings to make sure that
 	 * the vm_unmap_aliases() flush includes the direct map.
 	 */
 	for (i = 0; i < area->nr_pages; i += 1U << page_order) {
 		unsigned long addr = (unsigned long)page_address(area->pages[i]);
+
 		if (addr) {
 			unsigned long page_size;
 
@@ -2740,7 +2728,8 @@ void vfree(const void *addr)
 		return;
 	}
 
-	vm_remove_mappings(vm, true);
+	if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
+		vm_reset_perms(vm);
 	for (i = 0; i < vm->nr_pages; i++) {
 		struct page *page = vm->pages[i];
 
_

Patches currently in -mm which might be from hch@lst.de are

revert-remoteproc-qcom_q6v5_mss-map-unmap-metadata-region-before-after-use.patch
mm-reject-vmap-with-vm_flush_reset_perms.patch
mm-remove-__vfree.patch
mm-remove-__vfree_deferred.patch
mm-move-vmalloc_init-and-free_work-down-in-vmallocc.patch
mm-call-vfree-instead-of-__vunmap-from-delayed_vfree_work.patch
mm-move-__remove_vm_area-out-of-va_remove_mappings.patch
mm-use-remove_vm_area-in-__vunmap.patch
mm-move-debug-checks-from-__vunmap-to-remove_vm_area.patch
mm-split-__vunmap.patch
mm-refactor-va_remove_mappings.patch