latent_entropy: Mark functions with __latent_entropy

The __latent_entropy gcc attribute can be used only on functions and
variables.  If it is on a function then the plugin will instrument it for
gathering control-flow entropy. If the attribute is on a variable then
the plugin will initialize it with random contents.  The variable must
be an integer, an integer array type or a structure with integer fields.

These specific functions have been selected because they are init
functions (to help gather boot-time entropy), are called at unpredictable
times, or they have variable loops, each of which provide some level of
latent entropy.

Signed-off-by: Emese Revfy <re.emese@gmail.com>
[kees: expanded commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Emese Revfy 2016-06-20 20:42:34 +02:00 committed by Kees Cook
parent 38addce8b6
commit 0766f788eb
19 changed files with 37 additions and 22 deletions

View file

@ -39,7 +39,7 @@
/* These are for everybody (although not all archs will actually
discard it in modules) */
#define __init __section(.init.text) __cold notrace
#define __init __section(.init.text) __cold notrace __latent_entropy
#define __initdata __section(.init.data)
#define __initconst __constsection(.init.rodata)
#define __exitdata __section(.exit.data)
@ -86,7 +86,8 @@
#define __exit __section(.exit.text) __exitused __cold notrace
/* Used for MEMORY_HOTPLUG */
#define __meminit __section(.meminit.text) __cold notrace
#define __meminit __section(.meminit.text) __cold notrace \
__latent_entropy
#define __meminitdata __section(.meminit.data)
#define __meminitconst __constsection(.meminit.rodata)
#define __memexit __section(.memexit.text) __exitused __cold notrace