mm/vmalloc: separate put pages and flush VM flags

When VM_MAP_PUT_PAGES was added, it was defined with the same value as
VM_FLUSH_RESET_PERMS.  This doesn't seem like it will cause any big
functional problems other than some excess flushing for VM_MAP_PUT_PAGES
allocations.

Redefine VM_MAP_PUT_PAGES to have its own value.  Also, rearrange things
so flags are less likely to be missed in the future.

Link: https://lkml.kernel.org/r/20210122233706.9304-1-rick.p.edgecombe@intel.com
Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap")
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Axtens <dja@axtens.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 80c0181..cedcda6 100644 (file)
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -24,7 +24,8 @@ struct notifier_block;                /* in notifier.h */
 #define VM_UNINITIALIZED       0x00000020      /* vm_struct is not fully initialized */
 #define VM_NO_GUARD            0x00000040      /* don't add guard page */
 #define VM_KASAN               0x00000080      /* has allocated kasan shadow memory */
-#define VM_MAP_PUT_PAGES       0x00000100      /* put pages and free array in vfree */
+#define VM_FLUSH_RESET_PERMS   0x00000100      /* reset direct map and flush TLB on unmap, can't be freed in atomic context */
+#define VM_MAP_PUT_PAGES       0x00000200      /* put pages and free array in vfree */
 
 /*
  * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC.
@@ -37,12 +38,6 @@ struct notifier_block;               /* in notifier.h */
  * determine which allocations need the module shadow freed.
  */
 
-/*
- * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
- * vfree_atomic().
- */
-#define VM_FLUSH_RESET_PERMS   0x00000100      /* Reset direct map and flush TLB on unmap */
-
 /* bits [20..32] reserved for arch specific ioremap internals */
 
 /*