From 453431a54934d917153c65211b2dabf45562ca88 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Thu, 6 Aug 2020 23:18:13 -0700 Subject: mm, treewide: rename kzfree() to kfree_sensitive() As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches Signed-off-by: Waiman Long Signed-off-by: Andrew Morton Acked-by: David Howells Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Jarkko Sakkinen Cc: James Morris Cc: "Serge E. Hallyn" Cc: Joe Perches Cc: Matthew Wilcox Cc: David Rientjes Cc: Dan Carpenter Cc: "Jason A . Donenfeld" Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds --- lib/test_kasan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'lib/test_kasan.c') diff --git a/lib/test_kasan.c b/lib/test_kasan.c index dc2c6a51d11a..e4d9a86b174b 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -766,15 +766,15 @@ static noinline void __init kmalloc_double_kzfree(void) char *ptr; size_t size = 16; - pr_info("double-free (kzfree)\n"); + pr_info("double-free (kfree_sensitive)\n"); ptr = kmalloc(size, GFP_KERNEL); if (!ptr) { pr_err("Allocation failed\n"); return; } - kzfree(ptr); - kzfree(ptr); + kfree_sensitive(ptr); + kfree_sensitive(ptr); } #ifdef CONFIG_KASAN_VMALLOC -- cgit v1.2.3