latent_entropy: Mark functions with __latent_entropy

The __latent_entropy gcc attribute can be only on functions and variables.
If it is on a function then the plugin will instrument it. If the
attribute is on a variable then the plugin will initialize it with a
random value.  The variable must be an integer, an integer array type or a
structure with integer fields.

These functions have been selected because they are init functions, are
called at random times, or they have variable loops, each of which provide
some level of latent entropy.

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index 53b1737e978d584878f3dae13352e17a8aed1f06..489eab825a8aee7efa68ba222e015195cb8c8932 100644 (file)
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -18,7 +18,7 @@ static DEFINE_PER_CPU(struct list_head, blk_cpu_done);
  * Softirq action handler - move entries to local list and loop over them
  * while passing them to the queue registered handler.
  */
-static void blk_done_softirq(struct softirq_action *h)
+static __latent_entropy void blk_done_softirq(struct softirq_action *h)
 {
        struct list_head *cpu_list, local_list;
 

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 3efb3bf0ab839578156e33907eb20c741c08155f..7274ae89ddb39f3450ac9f56ef64db6384330497 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -479,8 +479,8 @@ static ssize_t _extract_entropy(struct entropy_store *r, void *buf,
 
 static void crng_reseed(struct crng_state *crng, struct entropy_store *r);
 static void push_to_pool(struct work_struct *work);
-static __u32 input_pool_data[INPUT_POOL_WORDS];
-static __u32 blocking_pool_data[OUTPUT_POOL_WORDS];
+static __u32 input_pool_data[INPUT_POOL_WORDS] __latent_entropy;
+static __u32 blocking_pool_data[OUTPUT_POOL_WORDS] __latent_entropy;
 
 static struct entropy_store input_pool = {
        .poolinfo = &poolinfo_table[0],

diff --git a/fs/namespace.c b/fs/namespace.c
index 7bb2cda3bfef50b27f9bb8b3b478cc7aeb3d1049..4a9568b81138f7bd16cfd8b8987c3d8638cdcae7 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2759,6 +2759,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
        return new_ns;
 }
 
+__latent_entropy
 struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
                struct user_namespace *user_ns, struct fs_struct *new_fs)
 {

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index e2949397c19b0d58bbebf84d37028ae9b969546c..0ef8329f95c283642611fbee17b82292f5f197e3 100644 (file)
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -188,6 +188,13 @@
 #endif /* GCC_VERSION >= 40300 */
 
 #if GCC_VERSION >= 40500
+
+#ifndef __CHECKER__
+#ifdef LATENT_ENTROPY_PLUGIN
+#define __latent_entropy __attribute__((latent_entropy))
+#endif
+#endif
+
 /*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 1bb95484272501bbc8d0603da489f56b4f87714a..d7a0b579442c9064a933ce6e7219031562ad9807 100644 (file)
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -406,6 +406,10 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 # define __attribute_const__   /* unimplemented */
 #endif
 
+#ifndef __latent_entropy
+# define __latent_entropy
+#endif
+
 /*
  * Tell gcc if a function is cold. The compiler will assume any path
  * directly leading to the call is unlikely.

diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index 5295535b60c60768ccb91034b3ba290dc1a57f1a..9852c7e334660e8314c66e8017a9405592197f06 100644 (file)
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -105,7 +105,7 @@ struct files_struct *get_files_struct(struct task_struct *);
 void put_files_struct(struct files_struct *fs);
 void reset_files_struct(struct files_struct *);
 int unshare_files(struct files_struct **);
-struct files_struct *dup_fd(struct files_struct *, int *);
+struct files_struct *dup_fd(struct files_struct *, int *) __latent_entropy;
 void do_close_on_exec(struct files_struct *);
 int iterate_fd(struct files_struct *, unsigned,
                int (*)(const void *, struct file *, unsigned),

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 1dbf52f9c24b88a0f4a299bae5ec3bfdcea1e566..e0341af6950e2116a43b3b0281f57fea8099c06f 100644 (file)
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -437,7 +437,7 @@ extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 
 /* drivers/char/random.c */
-extern void add_disk_randomness(struct gendisk *disk);
+extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
 extern void rand_initialize_disk(struct gendisk *disk);
 
 static inline sector_t get_start_sect(struct block_device *bdev)

diff --git a/include/linux/init.h b/include/linux/init.h
index 6935d02474aae623e5277a5733642fabb8754577..1e5c131d5c9a12c513b33b021be26ac21fee8df8 100644 (file)
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -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

diff --git a/include/linux/random.h b/include/linux/random.h
index a59c74cdb1eb0f88a6ea6c4952f6574bbfd58bc7..d80a4388a4fd793b0113675c1f8b42cb86b5506e 100644 (file)
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -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);

diff --git a/kernel/fork.c b/kernel/fork.c
index 6aa9b8b5c5529e9d4dcc4d236964b81cc2ae4f0e..5baf957f1bcdbd7c20c28de2379d60855d20b56e 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -404,7 +404,8 @@ free_tsk:
 }
 
 #ifdef CONFIG_MMU
-static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
+static __latent_entropy int dup_mmap(struct mm_struct *mm,
+                                       struct mm_struct *oldmm)
 {
        struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
        struct rb_node **rb_link, *rb_parent;
@@ -1275,7 +1276,8 @@ init_task_pid(struct task_struct *task, enum pid_type type, struct pid *pid)
  * parts of the process environment (as per the clone
  * flags). The actual kick-off is left to the caller.
  */
-static struct task_struct *copy_process(unsigned long clone_flags,
+static __latent_entropy struct task_struct *copy_process(
+                                       unsigned long clone_flags,
                                        unsigned long stack_start,
                                        unsigned long stack_size,
                                        int __user *child_tidptr,

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 944b1b491ed84b3d2d1cf977a9838a30cf405121..1898559e6b60ddc52884f6977fca21e57c6f1f90 100644 (file)
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -170,7 +170,7 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
                                      false));
 }
 
-static void rcu_process_callbacks(struct softirq_action *unused)
+static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
 {
        __rcu_process_callbacks(&rcu_sched_ctrlblk);
        __rcu_process_callbacks(&rcu_bh_ctrlblk);

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 5d80925e7fc8638fda26465273dcf78fbc015a0a..e5164deb51e1e2e7f8079e41fed5cc2678ea4b4b 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3013,7 +3013,7 @@ __rcu_process_callbacks(struct rcu_state *rsp)
 /*
  * Do RCU core processing for the current CPU.
  */
-static void rcu_process_callbacks(struct softirq_action *unused)
+static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
 {
        struct rcu_state *rsp;
 

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4088eedea7637859844c777dfa56dfb23136c142..24d9602c8a8556a1503e1baeadf87bad814ea929 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8283,7 +8283,7 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { }
  * run_rebalance_domains is triggered when needed from the scheduler tick.
  * Also triggered for nohz idle balancing (with nohz_balancing_kick set).
  */
-static void run_rebalance_domains(struct softirq_action *h)
+static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
 {
        struct rq *this_rq = this_rq();
        enum cpu_idle_type idle = this_rq->idle_balance ?

diff --git a/kernel/softirq.c b/kernel/softirq.c
index 17caf4b63342d7839528f367b283a386413b0362..34033fd09c8c66ffe1249db174a3db780e28df94 100644 (file)
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -482,7 +482,7 @@ void __tasklet_hi_schedule_first(struct tasklet_struct *t)
 }
 EXPORT_SYMBOL(__tasklet_hi_schedule_first);
 
-static void tasklet_action(struct softirq_action *a)
+static __latent_entropy void tasklet_action(struct softirq_action *a)
 {
        struct tasklet_struct *list;
 
@@ -518,7 +518,7 @@ static void tasklet_action(struct softirq_action *a)
        }
 }
 
-static void tasklet_hi_action(struct softirq_action *a)
+static __latent_entropy void tasklet_hi_action(struct softirq_action *a)
 {
        struct tasklet_struct *list;
 

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 555670a5143c61bed5e7015f4f13849240be37b9..5f58fd2c220e723058d2c19d762013e2a5022287 100644 (file)
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1630,7 +1630,7 @@ static inline void __run_timers(struct timer_base *base)
 /*
  * This function runs timers and the timer-tq in bottom half context.
  */
-static void run_timer_softirq(struct softirq_action *h)
+static __latent_entropy void run_timer_softirq(struct softirq_action *h)
 {
        struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
 

diff --git a/lib/irq_poll.c b/lib/irq_poll.c
index 836f7db4e548e8142b09f8b6d147d926d42a3f99..63be7495dbb250fac3c3a4f92abb7d17a4cbdd2e 100644 (file)
--- a/lib/irq_poll.c
+++ b/lib/irq_poll.c
@@ -74,7 +74,7 @@ void irq_poll_complete(struct irq_poll *iop)
 }
 EXPORT_SYMBOL(irq_poll_complete);
 
-static void irq_poll_softirq(struct softirq_action *h)
+static void __latent_entropy irq_poll_softirq(struct softirq_action *h)
 {
        struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll);
        int rearm = 0, budget = irq_poll_budget;

diff --git a/lib/random32.c b/lib/random32.c
index 69ed593aab07315d90c4b2dc2e2fcbb9931211fd..a30923573676ec77f0defe9d4f43eb02f4b8e771 100644 (file)
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -47,7 +47,7 @@ static inline void prandom_state_selftest(void)
 }
 #endif
 
-static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
+static DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy;
 
 /**
  *     prandom_u32_state - seeded pseudo-random number generator.

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2bde86fd677243d4f944c1d7b066734ce8d48a26..194ba70faaeff877ddc9c3bf138812c2d305596e 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -93,7 +93,7 @@ int _node_numa_mem_[MAX_NUMNODES];
 #endif
 
 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
-volatile u64 latent_entropy;
+volatile u64 latent_entropy __latent_entropy;
 EXPORT_SYMBOL(latent_entropy);
 #endif
 

diff --git a/net/core/dev.c b/net/core/dev.c
index 4ce07dc25573ed3d20f181f5b36327cb0f407fe3..a38319b0c19794a937792124c61ac1c651542d5c 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3855,7 +3855,7 @@ int netif_rx_ni(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(netif_rx_ni);
 
-static void net_tx_action(struct softirq_action *h)
+static __latent_entropy void net_tx_action(struct softirq_action *h)
 {
        struct softnet_data *sd = this_cpu_ptr(&softnet_data);
 
@@ -5171,7 +5171,7 @@ out_unlock:
        return work;
 }
 
-static void net_rx_action(struct softirq_action *h)
+static __latent_entropy void net_rx_action(struct softirq_action *h)
 {
        struct softnet_data *sd = this_cpu_ptr(&softnet_data);
        unsigned long time_limit = jiffies + 2;