diff options
Diffstat (limited to 'drivers/char/random.c')
| -rw-r--r-- | drivers/char/random.c | 42 |
1 files changed, 33 insertions, 9 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 456be28ba67c..2581186fa61b 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) /* - * Copyright (C) 2017-2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * Copyright (C) 2017-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. * Copyright Matt Mackall <mpm@selenic.com>, 2003, 2004, 2005 * Copyright Theodore Ts'o, 1994, 1995, 1996, 1997, 1998, 1999. All rights reserved. * @@ -56,6 +56,11 @@ #include <linux/sched/isolation.h> #include <crypto/chacha.h> #include <crypto/blake2s.h> +#ifdef CONFIG_VDSO_GETRANDOM +#include <vdso/getrandom.h> +#include <vdso/datapage.h> +#include <vdso/vsyscall.h> +#endif #include <asm/archrandom.h> #include <asm/processor.h> #include <asm/irq.h> @@ -271,6 +276,22 @@ static void crng_reseed(struct work_struct *work) if (next_gen == ULONG_MAX) ++next_gen; WRITE_ONCE(base_crng.generation, next_gen); +#ifdef CONFIG_VDSO_GETRANDOM + /* base_crng.generation's invalid value is ULONG_MAX, while + * _vdso_rng_data.generation's invalid value is 0, so add one to the + * former to arrive at the latter. Use smp_store_release so that this + * is ordered with the write above to base_crng.generation. Pairs with + * the smp_rmb() before the syscall in the vDSO code. + * + * Cast to unsigned long for 32-bit architectures, since atomic 64-bit + * operations are not supported on those architectures. This is safe + * because base_crng.generation is a 32-bit value. On big-endian + * architectures it will be stored in the upper 32 bits, but that's okay + * because the vDSO side only checks whether the value changed, without + * actually using or interpreting the value. + */ + smp_store_release((unsigned long *)&__arch_get_k_vdso_rng_data()->generation, next_gen + 1); +#endif if (!static_branch_likely(&crng_is_ready)) crng_init = CRNG_READY; spin_unlock_irqrestore(&base_crng.lock, flags); @@ -702,7 +723,7 @@ static void extract_entropy(void *buf, size_t len) static void __cold _credit_init_bits(size_t bits) { - static struct execute_work set_ready; + static DECLARE_WORK(set_ready, crng_set_ready); unsigned int new, orig, add; unsigned long flags; @@ -718,9 +739,12 @@ static void __cold _credit_init_bits(size_t bits) if (orig < POOL_READY_BITS && new >= POOL_READY_BITS) { crng_reseed(NULL); /* Sets crng_init to CRNG_READY under base_crng.lock. */ - if (static_key_initialized) - execute_in_process_context(crng_set_ready, &set_ready); + if (static_key_initialized && system_unbound_wq) + queue_work(system_unbound_wq, &set_ready); atomic_notifier_call_chain(&random_ready_notifier, 0, NULL); +#ifdef CONFIG_VDSO_GETRANDOM + WRITE_ONCE(__arch_get_k_vdso_rng_data()->is_ready, true); +#endif wake_up_interruptible(&crng_init_wait); kill_fasync(&fasync, SIGIO, POLL_IN); pr_notice("crng init done\n"); @@ -890,8 +914,8 @@ void __init random_init(void) /* * If we were initialized by the cpu or bootloader before jump labels - * are initialized, then we should enable the static branch here, where - * it's guaranteed that jump labels have been initialized. + * or workqueues are initialized, then we should enable the static + * branch here, where it's guaranteed that these have been initialized. */ if (!static_branch_likely(&crng_is_ready) && crng_init >= CRNG_READY) crng_set_ready(NULL); @@ -1604,7 +1628,7 @@ static u8 sysctl_bootid[UUID_SIZE]; * UUID. The difference is in whether table->data is NULL; if it is, * then a new UUID is generated and returned to the user. */ -static int proc_do_uuid(struct ctl_table *table, int write, void *buf, +static int proc_do_uuid(const struct ctl_table *table, int write, void *buf, size_t *lenp, loff_t *ppos) { u8 tmp_uuid[UUID_SIZE], *uuid; @@ -1635,13 +1659,13 @@ static int proc_do_uuid(struct ctl_table *table, int write, void *buf, } /* The same as proc_dointvec, but writes don't change anything. */ -static int proc_do_rointvec(struct ctl_table *table, int write, void *buf, +static int proc_do_rointvec(const struct ctl_table *table, int write, void *buf, size_t *lenp, loff_t *ppos) { return write ? 0 : proc_dointvec(table, 0, buf, lenp, ppos); } -static struct ctl_table random_table[] = { +static const struct ctl_table random_table[] = { { .procname = "poolsize", .data = &sysctl_poolsize, |