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authorWaiman Long <longman@redhat.com>2020-08-06 23:18:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 11:33:22 -0700
commit453431a54934d917153c65211b2dabf45562ca88 (patch)
treee9672e7fb28f59331ff00fe6197360d703cbd9c3 /lib
parent57c720d4144a9c2b88105c3e8f7b0e97e4b5cc93 (diff)
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 <joe@perches.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: "Jason A . Donenfeld" <Jason@zx2c4.com> Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/mpi/mpiutil.c6
-rw-r--r--lib/test_kasan.c6
2 files changed, 6 insertions, 6 deletions
diff --git a/lib/mpi/mpiutil.c b/lib/mpi/mpiutil.c
index 20ed0f766787..4cd2b335cb7f 100644
--- a/lib/mpi/mpiutil.c
+++ b/lib/mpi/mpiutil.c
@@ -69,7 +69,7 @@ void mpi_free_limb_space(mpi_ptr_t a)
if (!a)
return;
- kzfree(a);
+ kfree_sensitive(a);
}
void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
@@ -95,7 +95,7 @@ int mpi_resize(MPI a, unsigned nlimbs)
if (!p)
return -ENOMEM;
memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
- kzfree(a->d);
+ kfree_sensitive(a->d);
a->d = p;
} else {
a->d = kcalloc(nlimbs, sizeof(mpi_limb_t), GFP_KERNEL);
@@ -112,7 +112,7 @@ void mpi_free(MPI a)
return;
if (a->flags & 4)
- kzfree(a->d);
+ kfree_sensitive(a->d);
else
mpi_free_limb_space(a->d);
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