JFIF$        dd7 

Viewing File: /usr/src/kernels/5.14.0-570.32.1.el9_6.x86_64/include/linux/random.h

/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _LINUX_RANDOM_H
#define _LINUX_RANDOM_H

#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/list.h>

#include <uapi/linux/random.h>

struct iov_iter;
struct random_extrng {
	ssize_t (*extrng_read_iter)(struct iov_iter *, bool reseed);
	struct module *owner;
};

struct notifier_block;

void add_device_randomness(const void *buf, size_t len);
void __init add_bootloader_randomness(const void *buf, size_t len);
void add_input_randomness(unsigned int type, unsigned int code,
			  unsigned int value) __latent_entropy;
void add_interrupt_randomness(int irq) __latent_entropy;
void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy, bool sleep_after);

static inline void add_latent_entropy(void)
{
#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
	add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
#else
	add_device_randomness(NULL, 0);
#endif
}

#if IS_ENABLED(CONFIG_VMGENID)
void add_vmfork_randomness(const void *unique_vm_id, size_t len);
int register_random_vmfork_notifier(struct notifier_block *nb);
int unregister_random_vmfork_notifier(struct notifier_block *nb);
#else
static inline int register_random_vmfork_notifier(struct notifier_block *nb) { return 0; }
static inline int unregister_random_vmfork_notifier(struct notifier_block *nb) { return 0; }
#endif

void random_register_extrng(const struct random_extrng *rng);
void random_unregister_extrng(void);

void get_random_bytes(void *buf, size_t len);
u8 get_random_u8(void);
u16 get_random_u16(void);
u32 get_random_u32(void);
u64 get_random_u64(void);
static inline unsigned int get_random_int(void)
{
	return get_random_u32();
}
static inline unsigned long get_random_long(void)
{
#if BITS_PER_LONG == 64
	return get_random_u64();
#else
	return get_random_u32();
#endif
}

u32 __get_random_u32_below(u32 ceil);

/*
 * Returns a random integer in the interval [0, ceil), with uniform
 * distribution, suitable for all uses. Fastest when ceil is a constant, but
 * still fast for variable ceil as well.
 */
static inline u32 get_random_u32_below(u32 ceil)
{
	if (!__builtin_constant_p(ceil))
		return __get_random_u32_below(ceil);

	/*
	 * For the fast path, below, all operations on ceil are precomputed by
	 * the compiler, so this incurs no overhead for checking pow2, doing
	 * divisions, or branching based on integer size. The resultant
	 * algorithm does traditional reciprocal multiplication (typically
	 * optimized by the compiler into shifts and adds), rejecting samples
	 * whose lower half would indicate a range indivisible by ceil.
	 */
	BUILD_BUG_ON_MSG(!ceil, "get_random_u32_below() must take ceil > 0");
	if (ceil <= 1)
		return 0;
	for (;;) {
		if (ceil <= 1U << 8) {
			u32 mult = ceil * get_random_u8();
			if (likely(is_power_of_2(ceil) || (u8)mult >= (1U << 8) % ceil))
				return mult >> 8;
		} else if (ceil <= 1U << 16) {
			u32 mult = ceil * get_random_u16();
			if (likely(is_power_of_2(ceil) || (u16)mult >= (1U << 16) % ceil))
				return mult >> 16;
		} else {
			u64 mult = (u64)ceil * get_random_u32();
			if (likely(is_power_of_2(ceil) || (u32)mult >= -ceil % ceil))
				return mult >> 32;
		}
	}
}

/*
 * Returns a random integer in the interval (floor, U32_MAX], with uniform
 * distribution, suitable for all uses. Fastest when floor is a constant, but
 * still fast for variable floor as well.
 */
static inline u32 get_random_u32_above(u32 floor)
{
	BUILD_BUG_ON_MSG(__builtin_constant_p(floor) && floor == U32_MAX,
			 "get_random_u32_above() must take floor < U32_MAX");
	return floor + 1 + get_random_u32_below(U32_MAX - floor);
}

/*
 * Returns a random integer in the interval [floor, ceil], with uniform
 * distribution, suitable for all uses. Fastest when floor and ceil are
 * constant, but still fast for variable floor and ceil as well.
 */
static inline u32 get_random_u32_inclusive(u32 floor, u32 ceil)
{
	BUILD_BUG_ON_MSG(__builtin_constant_p(floor) && __builtin_constant_p(ceil) &&
			 (floor > ceil || ceil - floor == U32_MAX),
			 "get_random_u32_inclusive() must take floor <= ceil");
	return floor + get_random_u32_below(ceil - floor + 1);
}

void __init random_init_early(const char *command_line);
void __init random_init(void);
bool rng_is_initialized(void);
int wait_for_random_bytes(void);
int execute_with_initialized_rng(struct notifier_block *nb);

/* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes).
 * Returns the result of the call to wait_for_random_bytes. */
static inline int get_random_bytes_wait(void *buf, size_t nbytes)
{
	int ret = wait_for_random_bytes();
	get_random_bytes(buf, nbytes);
	return ret;
}

#define declare_get_random_var_wait(name, ret_type) \
	static inline int get_random_ ## name ## _wait(ret_type *out) { \
		int ret = wait_for_random_bytes(); \
		if (unlikely(ret)) \
			return ret; \
		*out = get_random_ ## name(); \
		return 0; \
	}
declare_get_random_var_wait(u8, u8)
declare_get_random_var_wait(u16, u16)
declare_get_random_var_wait(u32, u32)
declare_get_random_var_wait(u64, u32)
declare_get_random_var_wait(int, unsigned int)
declare_get_random_var_wait(long, unsigned long)
#undef declare_get_random_var

/*
 * This is designed to be standalone for just prandom
 * users, but for now we include it from <linux/random.h>
 * for legacy reasons.
 */
#include <linux/prandom.h>

#ifdef CONFIG_SMP
int random_prepare_cpu(unsigned int cpu);
int random_online_cpu(unsigned int cpu);
#endif

#ifndef MODULE
extern const struct file_operations random_fops, urandom_fops;
#endif

#endif /* _LINUX_RANDOM_H */
Back to Directory  nL+D550H?Mx ,D"v]qv;6*Zqn)ZP0!1 A "#a$2Qr D8 a Ri[f\mIykIw0cuFcRı?lO7к_f˓[C$殷WF<_W ԣsKcëIzyQy/_LKℂ;C",pFA:/]=H  ~,ls/9ć:[=/#f;)x{ٛEQ )~ =𘙲r*2~ a _V=' kumFD}KYYC)({ *g&f`툪ry`=^cJ.I](*`wq1dđ#̩͑0;H]u搂@:~וKL Nsh}OIR*8:2 !lDJVo(3=M(zȰ+i*NAr6KnSl)!JJӁ* %݉?|D}d5:eP0R;{$X'xF@.ÊB {,WJuQɲRI;9QE琯62fT.DUJ;*cP A\ILNj!J۱+O\͔]ޒS߼Jȧc%ANolՎprULZԛerE2=XDXgVQeӓk yP7U*omQIs,K`)6\G3t?pgjrmۛجwluGtfh9uyP0D;Uڽ"OXlif$)&|ML0Zrm1[HXPlPR0'G=i2N+0e2]]9VTPO׮7h(F*癈'=QVZDF,d߬~TX G[`le69CR(!S2!P <0x<!1AQ "Raq02Br#SCTb ?Ζ"]mH5WR7k.ۛ!}Q~+yԏz|@T20S~Kek *zFf^2X*(@8r?CIuI|֓>^ExLgNUY+{.RѪ τV׸YTD I62'8Y27'\TP.6d&˦@Vqi|8-OΕ]ʔ U=TL8=;6c| !qfF3aů&~$l}'NWUs$Uk^SV:U# 6w++s&r+nڐ{@29 gL u"TÙM=6(^"7r}=6YݾlCuhquympǦ GjhsǜNlɻ}o7#S6aw4!OSrD57%|?x>L |/nD6?/8w#[)L7+6〼T ATg!%5MmZ/c-{1_Je"|^$'O&ޱմTrb$w)R$& N1EtdU3Uȉ1pM"N*(DNyd96.(jQ)X 5cQɎMyW?Q*!R>6=7)Xj5`J]e8%t!+'!1Q5 !1 AQaqё#2"0BRb?Gt^## .llQT $v,,m㵜5ubV =sY+@d{N! dnO<.-B;_wJt6;QJd.Qc%p{ 1,sNDdFHI0ГoXшe黅XۢF:)[FGXƹ/w_cMeD,ʡcc.WDtA$j@:) -# u c1<@ۗ9F)KJ-hpP]_x[qBlbpʖw q"LFGdƶ*s+ډ_Zc"?%t[IP 6J]#=ɺVvvCGsGh1 >)6|ey?Lӣm,4GWUi`]uJVoVDG< SB6ϏQ@ TiUlyOU0kfV~~}SZ@*WUUi##; s/[=!7}"WN]'(L! ~y5g9T̅JkbM' +s:S +B)v@Mj e Cf jE 0Y\QnzG1д~Wo{T9?`Rmyhsy3!HAD]mc1~2LSu7xT;j$`}4->L#vzŏILS ֭T{rjGKC;bpU=-`BsK.SFw4Mq]ZdHS0)tLg