From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- include/crypto/chacha.h | 102 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 include/crypto/chacha.h (limited to 'include/crypto/chacha.h') diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h new file mode 100644 index 000000000..1cc301a48 --- /dev/null +++ b/include/crypto/chacha.h @@ -0,0 +1,102 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values and helper functions for the ChaCha and XChaCha stream ciphers. + * + * XChaCha extends ChaCha's nonce to 192 bits, while provably retaining ChaCha's + * security. Here they share the same key size, tfm context, and setkey + * function; only their IV size and encrypt/decrypt function differ. + * + * The ChaCha paper specifies 20, 12, and 8-round variants. In general, it is + * recommended to use the 20-round variant ChaCha20. However, the other + * variants can be needed in some performance-sensitive scenarios. The generic + * ChaCha code currently allows only the 20 and 12-round variants. + */ + +#ifndef _CRYPTO_CHACHA_H +#define _CRYPTO_CHACHA_H + +#include +#include +#include + +/* 32-bit stream position, then 96-bit nonce (RFC7539 convention) */ +#define CHACHA_IV_SIZE 16 + +#define CHACHA_KEY_SIZE 32 +#define CHACHA_BLOCK_SIZE 64 +#define CHACHAPOLY_IV_SIZE 12 + +#define CHACHA_KEY_WORDS 8 +#define CHACHA_STATE_WORDS 16 +#define HCHACHA_OUT_WORDS 8 + +/* 192-bit nonce, then 64-bit stream position */ +#define XCHACHA_IV_SIZE 32 + +struct chacha_state { + u32 x[CHACHA_STATE_WORDS]; +}; + +void chacha_block_generic(struct chacha_state *state, + u8 out[at_least CHACHA_BLOCK_SIZE], int nrounds); +static inline void chacha20_block(struct chacha_state *state, + u8 out[at_least CHACHA_BLOCK_SIZE]) +{ + chacha_block_generic(state, out, 20); +} + +void hchacha_block_generic(const struct chacha_state *state, + u32 out[at_least HCHACHA_OUT_WORDS], int nrounds); + +void hchacha_block(const struct chacha_state *state, + u32 out[at_least HCHACHA_OUT_WORDS], int nrounds); + +enum chacha_constants { /* expand 32-byte k */ + CHACHA_CONSTANT_EXPA = 0x61707865U, + CHACHA_CONSTANT_ND_3 = 0x3320646eU, + CHACHA_CONSTANT_2_BY = 0x79622d32U, + CHACHA_CONSTANT_TE_K = 0x6b206574U +}; + +static inline void chacha_init_consts(struct chacha_state *state) +{ + state->x[0] = CHACHA_CONSTANT_EXPA; + state->x[1] = CHACHA_CONSTANT_ND_3; + state->x[2] = CHACHA_CONSTANT_2_BY; + state->x[3] = CHACHA_CONSTANT_TE_K; +} + +static inline void chacha_init(struct chacha_state *state, + const u32 key[at_least CHACHA_KEY_WORDS], + const u8 iv[at_least CHACHA_IV_SIZE]) +{ + chacha_init_consts(state); + state->x[4] = key[0]; + state->x[5] = key[1]; + state->x[6] = key[2]; + state->x[7] = key[3]; + state->x[8] = key[4]; + state->x[9] = key[5]; + state->x[10] = key[6]; + state->x[11] = key[7]; + state->x[12] = get_unaligned_le32(iv + 0); + state->x[13] = get_unaligned_le32(iv + 4); + state->x[14] = get_unaligned_le32(iv + 8); + state->x[15] = get_unaligned_le32(iv + 12); +} + +void chacha_crypt(struct chacha_state *state, u8 *dst, const u8 *src, + unsigned int bytes, int nrounds); + +static inline void chacha20_crypt(struct chacha_state *state, + u8 *dst, const u8 *src, unsigned int bytes) +{ + chacha_crypt(state, dst, src, bytes, 20); +} + +static inline void chacha_zeroize_state(struct chacha_state *state) +{ + memzero_explicit(state, sizeof(*state)); +} + +#endif /* _CRYPTO_CHACHA_H */ -- cgit v1.3.1