diff options
| author | Waiman Long <longman@redhat.com> | 2020-08-06 23:18:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 11:33:22 -0700 |
| commit | 453431a54934d917153c65211b2dabf45562ca88 (patch) | |
| tree | e9672e7fb28f59331ff00fe6197360d703cbd9c3 /lib | |
| parent | 57c720d4144a9c2b88105c3e8f7b0e97e4b5cc93 (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.c | 6 | ||||
| -rw-r--r-- | lib/test_kasan.c | 6 |
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 |