Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull random changes from Ted Ts'o:
 "Change /dev/random so that it uses the CRNG and only blocking if the
  CRNG hasn't initialized, instead of the old blocking pool. Also clean
  up archrandom.h, and some other miscellaneous cleanups"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (24 commits)
  s390x: Mark archrandom.h functions __must_check
  powerpc: Mark archrandom.h functions __must_check
  powerpc: Use bool in archrandom.h
  x86: Mark archrandom.h functions __must_check
  linux/random.h: Mark CONFIG_ARCH_RANDOM functions __must_check
  linux/random.h: Use false with bool
  linux/random.h: Remove arch_has_random, arch_has_random_seed
  s390: Remove arch_has_random, arch_has_random_seed
  powerpc: Remove arch_has_random, arch_has_random_seed
  x86: Remove arch_has_random, arch_has_random_seed
  random: remove some dead code of poolinfo
  random: fix typo in add_timer_randomness()
  random: Add and use pr_fmt()
  random: convert to ENTROPY_BITS for better code readability
  random: remove unnecessary unlikely()
  random: remove kernel.random.read_wakeup_threshold
  random: delete code to pull data into pools
  random: remove the blocking pool
  random: make /dev/random be almost like /dev/urandom
  random: ignore GRND_RANDOM in getentropy(2)
  ...

arch/powerpc/include/asm/archrandom.h

@@ -6,27 +6,28 @@
 
 #include <asm/machdep.h>
 
-static inline int arch_get_random_long(unsigned long *v)
+static inline bool __must_check arch_get_random_long(unsigned long *v)
 {
-	return 0;
+	return false;
 }
 
-static inline int arch_get_random_int(unsigned int *v)
+static inline bool __must_check arch_get_random_int(unsigned int *v)
 {
-	return 0;
+	return false;
 }
 
-static inline int arch_get_random_seed_long(unsigned long *v)
+static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
 {
 	if (ppc_md.get_random_seed)
 		return ppc_md.get_random_seed(v);
 
-	return 0;
+	return false;
 }
-static inline int arch_get_random_seed_int(unsigned int *v)
+
+static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
 {
 	unsigned long val;
-	int rc;
+	bool rc;
 
 	rc = arch_get_random_seed_long(&val);
 	if (rc)
@@ -34,16 +35,6 @@ static inline int arch_get_random_seed_int(unsigned int *v)
 
 	return rc;
 }
-
-static inline int arch_has_random(void)
-{
-	return 0;
-}
-
-static inline int arch_has_random_seed(void)
-{
-	return !!ppc_md.get_random_seed;
-}
 #endif /* CONFIG_ARCH_RANDOM */
 
 #ifdef CONFIG_PPC_POWERNV

arch/s390/include/asm/archrandom.h

@@ -21,29 +21,17 @@ extern atomic64_t s390_arch_random_counter;
 
 bool s390_arch_random_generate(u8 *buf, unsigned int nbytes);
 
-static inline bool arch_has_random(void)
+static inline bool __must_check arch_get_random_long(unsigned long *v)
 {
 	return false;
 }
 
-static inline bool arch_has_random_seed(void)
+static inline bool __must_check arch_get_random_int(unsigned int *v)
 {
-	if (static_branch_likely(&s390_arch_random_available))
-		return true;
 	return false;
 }
 
-static inline bool arch_get_random_long(unsigned long *v)
-{
-	return false;
-}
-
-static inline bool arch_get_random_int(unsigned int *v)
-{
-	return false;
-}
-
-static inline bool arch_get_random_seed_long(unsigned long *v)
+static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
 {
 	if (static_branch_likely(&s390_arch_random_available)) {
 		return s390_arch_random_generate((u8 *)v, sizeof(*v));
@@ -51,7 +39,7 @@ static inline bool arch_get_random_seed_long(unsigned long *v)
 	return false;
 }
 
-static inline bool arch_get_random_seed_int(unsigned int *v)
+static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
 {
 	if (static_branch_likely(&s390_arch_random_available)) {
 		return s390_arch_random_generate((u8 *)v, sizeof(*v));

arch/x86/include/asm/archrandom.h

@@ -27,7 +27,7 @@
 
 /* Unconditional execution of RDRAND and RDSEED */
 
-static inline bool rdrand_long(unsigned long *v)
+static inline bool __must_check rdrand_long(unsigned long *v)
 {
 	bool ok;
 	unsigned int retry = RDRAND_RETRY_LOOPS;
@@ -41,7 +41,7 @@ static inline bool rdrand_long(unsigned long *v)
 	return false;
 }
 
-static inline bool rdrand_int(unsigned int *v)
+static inline bool __must_check rdrand_int(unsigned int *v)
 {
 	bool ok;
 	unsigned int retry = RDRAND_RETRY_LOOPS;
@@ -55,7 +55,7 @@ static inline bool rdrand_int(unsigned int *v)
 	return false;
 }
 
-static inline bool rdseed_long(unsigned long *v)
+static inline bool __must_check rdseed_long(unsigned long *v)
 {
 	bool ok;
 	asm volatile(RDSEED_LONG
@@ -64,7 +64,7 @@ static inline bool rdseed_long(unsigned long *v)
 	return ok;
 }
 
-static inline bool rdseed_int(unsigned int *v)
+static inline bool __must_check rdseed_int(unsigned int *v)
 {
 	bool ok;
 	asm volatile(RDSEED_INT
@@ -73,10 +73,6 @@ static inline bool rdseed_int(unsigned int *v)
 	return ok;
 }
 
-/* Conditional execution based on CPU type */
-#define arch_has_random()	static_cpu_has(X86_FEATURE_RDRAND)
-#define arch_has_random_seed()	static_cpu_has(X86_FEATURE_RDSEED)
-
 /*
  * These are the generic interfaces; they must not be declared if the
  * stubs in <linux/random.h> are to be invoked,
@@ -84,24 +80,24 @@ static inline bool rdseed_int(unsigned int *v)
  */
 #ifdef CONFIG_ARCH_RANDOM
 
-static inline bool arch_get_random_long(unsigned long *v)
+static inline bool __must_check arch_get_random_long(unsigned long *v)
 {
-	return arch_has_random() ? rdrand_long(v) : false;
+	return static_cpu_has(X86_FEATURE_RDRAND) ? rdrand_long(v) : false;
 }
 
-static inline bool arch_get_random_int(unsigned int *v)
+static inline bool __must_check arch_get_random_int(unsigned int *v)
 {
-	return arch_has_random() ? rdrand_int(v) : false;
+	return static_cpu_has(X86_FEATURE_RDRAND) ? rdrand_int(v) : false;
 }
 
-static inline bool arch_get_random_seed_long(unsigned long *v)
+static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
 {
-	return arch_has_random_seed() ? rdseed_long(v) : false;
+	return static_cpu_has(X86_FEATURE_RDSEED) ? rdseed_long(v) : false;
 }
 
-static inline bool arch_get_random_seed_int(unsigned int *v)
+static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
 {
-	return arch_has_random_seed() ? rdseed_int(v) : false;
+	return static_cpu_has(X86_FEATURE_RDSEED) ? rdseed_int(v) : false;
 }
 
 extern void x86_init_rdrand(struct cpuinfo_x86 *c);

include/linux/random.h

@@ -167,29 +167,21 @@ static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
 #ifdef CONFIG_ARCH_RANDOM
 # include <asm/archrandom.h>
 #else
-static inline bool arch_get_random_long(unsigned long *v)
+static inline bool __must_check arch_get_random_long(unsigned long *v)
 {
-	return 0;
+	return false;
 }
-static inline bool arch_get_random_int(unsigned int *v)
+static inline bool __must_check arch_get_random_int(unsigned int *v)
 {
-	return 0;
+	return false;
 }
-static inline bool arch_has_random(void)
+static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
 {
-	return 0;
+	return false;
 }
-static inline bool arch_get_random_seed_long(unsigned long *v)
+static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
 {
-	return 0;
-}
-static inline bool arch_get_random_seed_int(unsigned int *v)
-{
-	return 0;
-}
-static inline bool arch_has_random_seed(void)
-{
-	return 0;
+	return false;
 }
 #endif
 

include/uapi/linux/random.h

@@ -48,9 +48,11 @@ struct rand_pool_info {
  * Flags for getrandom(2)
  *
  * GRND_NONBLOCK	Don't block and return EAGAIN instead
- * GRND_RANDOM		Use the /dev/random pool instead of /dev/urandom
+ * GRND_RANDOM		No effect
+ * GRND_INSECURE	Return non-cryptographic random bytes
  */
 #define GRND_NONBLOCK	0x0001
 #define GRND_RANDOM	0x0002
+#define GRND_INSECURE	0x0004
 
 #endif /* _UAPI_LINUX_RANDOM_H */