mm: refactor va_remove_mappings

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>
Reviewed-by: David Hildenbrand <david@redhat.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>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 11144a29665a32e7246a06910425a47e3dd39a7b..9b71ec3213cbb91b83a5d189b964ff81d9d1053a 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2602,35 +2602,23 @@ static inline void set_area_direct_map(const struct vm_struct *area,
                        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;
 
@@ -2725,7 +2713,8 @@ 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];