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

@ -30,8 +30,8 @@ static inline void add_latent_entropy(void) {}
#endif
extern void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value);
extern void add_interrupt_randomness(int irq, int irq_flags);
unsigned int value) __latent_entropy;
extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
extern void get_random_bytes(void *buf, int nbytes);
extern int add_random_ready_callback(struct random_ready_callback *rdy);