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From: Julia Lawall <Julia.Lawall@lip6.fr>
To: linux-arm-kernel@lists.infradead.org
Cc: kernel-janitors@vger.kernel.org, linux-raid@vger.kernel.org,
        dm-devel@redhat.com, linux-kernel@vger.kernel.org,
        linux-crypto@vger.kernel.org, sparclinux@vger.kernel.org,
        linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
        linuxppc-dev@lists.ozlabs.org, linux-usb@vger.kernel.org
Subject: [PATCH 0/8] replace memset by memzero_explicit
Date: Sun, 30 Nov 2014 18:03:41 +0100
Message-Id: <1417367029-32762-1-git-send-email-Julia.Lawall@lip6.fr>
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Memset on a local variable may be removed when it is called just before the
variable goes out of scope.  Using memzero_explicit defeats this
optimization.  The complete semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
local idexpression e;
type T,T1;
@@

{
... when any
T x[...];
... when any
    when exists
(
e = (T1)x
|
e = (T1)&x[0]
)
... when any
    when exists
- memset
+ memzero_explicit
  (x,
-0,
  ...)
... when != x
    when != e
    when strict
}

@@
identifier i,x;
local idexpression e;
type T;
@@

{
... when any
struct i x;
... when any
    when exists
e = (T)&x
... when any
    when exists
- memset
+ memzero_explicit
  (&x,
-0,
  ...)
... when != x
    when != e
    when strict
}

// ------------------------------------------------------------------------

@@
identifier x;
type T,T1;
expression e;
@@

{
... when any
T x[...];
... when any
    when exists
    when != e = (T1)x
    when != e = (T1)&x[0]
- memset
+ memzero_explicit
  (x,
-0,
  ...)
... when != x
    when strict
}

@@
identifier i,x;
expression e;
type T;
@@

{
... when any
struct i x;
... when any
    when exists
    when != e = (T)&x
- memset
+ memzero_explicit
  (&x,
-0,
  ...)
... when != x
    when strict
}
// </smpl>

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