From 0d6526f82c3cdefcca47f73f5fc08dc6f335eac6 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:22 -0700 Subject: sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug alb_break_llc() decides whether to break LLC preference during active load balance. It does so by testing that every runnable fair task on the source rq prefers its LLC: env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable But the two counters cover different sets. nr_pref_llc_running is updated in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued, so it follows queued tasks. h_nr_runnable is updated in set_delayed()/ clear_delayed() and drops delay-dequeued tasks. So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks, alb_break_llc() returns false, and active balance is free to pull a task off its preferred LLC. Active balance only moves runnable tasks, and this is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB skips the per-task test in can_migrate_task(). The runnable set is the one we want. Fix it on the counter side. A task should be counted in nr_pref_llc_running exactly while it is both queued on its preferred LLC (pref_llc_queued) and runnable (!sched_delayed). Define that membership once in task_pref_llc_runnable(), and adjust the counter only through pref_llc_running_inc()/pref_llc_running_dec() from the four sites that change either input: account_llc_enqueue(), account_llc_dequeue(), set_delayed() and clear_delayed(). Gating every update on the same predicate keeps the delay, wake and dequeue paths from double-counting or underflowing; see the comments at those sites for the ordering. nr_llc_running and sd->llc_counts are not touched and stay on queued semantics. Fixes: 714059f79ff0 ("sched/cache: Handle moving single tasks to/from their preferred LLC") Closes: https://lore.kernel.org/lkml/20260827135000.735138-1-zhanxusheng@xiaomi.com/ Reported-by: Zhan Xusheng Suggested-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Kayra Cizmeci Cc: # v7.2.x Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com --- crypto/blowfish_generic.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 crypto/blowfish_generic.c (limited to 'crypto/blowfish_generic.c') diff --git a/crypto/blowfish_generic.c b/crypto/blowfish_generic.c new file mode 100644 index 000000000..f3c5f9b09 --- /dev/null +++ b/crypto/blowfish_generic.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Cryptographic API. + * + * Blowfish Cipher Algorithm, by Bruce Schneier. + * http://www.counterpane.com/blowfish.html + * + * Adapted from Kerneli implementation. + * + * Copyright (c) Herbert Valerio Riedel + * Copyright (c) Kyle McMartin + * Copyright (c) 2002 James Morris + */ + +#include +#include +#include +#include +#include +#include +#include + +/* + * Round loop unrolling macros, S is a pointer to a S-Box array + * organized in 4 unsigned longs at a row. + */ +#define GET32_3(x) (((x) & 0xff)) +#define GET32_2(x) (((x) >> (8)) & (0xff)) +#define GET32_1(x) (((x) >> (16)) & (0xff)) +#define GET32_0(x) (((x) >> (24)) & (0xff)) + +#define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \ + S[512 + GET32_2(x)]) + S[768 + GET32_3(x)]) + +#define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); }) + +static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) +{ + struct bf_ctx *ctx = crypto_tfm_ctx(tfm); + const u32 *P = ctx->p; + const u32 *S = ctx->s; + u32 yl = get_unaligned_be32(src); + u32 yr = get_unaligned_be32(src + 4); + + ROUND(yr, yl, 0); + ROUND(yl, yr, 1); + ROUND(yr, yl, 2); + ROUND(yl, yr, 3); + ROUND(yr, yl, 4); + ROUND(yl, yr, 5); + ROUND(yr, yl, 6); + ROUND(yl, yr, 7); + ROUND(yr, yl, 8); + ROUND(yl, yr, 9); + ROUND(yr, yl, 10); + ROUND(yl, yr, 11); + ROUND(yr, yl, 12); + ROUND(yl, yr, 13); + ROUND(yr, yl, 14); + ROUND(yl, yr, 15); + + yl ^= P[16]; + yr ^= P[17]; + + put_unaligned_be32(yr, dst); + put_unaligned_be32(yl, dst + 4); +} + +static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) +{ + struct bf_ctx *ctx = crypto_tfm_ctx(tfm); + const u32 *P = ctx->p; + const u32 *S = ctx->s; + u32 yl = get_unaligned_be32(src); + u32 yr = get_unaligned_be32(src + 4); + + ROUND(yr, yl, 17); + ROUND(yl, yr, 16); + ROUND(yr, yl, 15); + ROUND(yl, yr, 14); + ROUND(yr, yl, 13); + ROUND(yl, yr, 12); + ROUND(yr, yl, 11); + ROUND(yl, yr, 10); + ROUND(yr, yl, 9); + ROUND(yl, yr, 8); + ROUND(yr, yl, 7); + ROUND(yl, yr, 6); + ROUND(yr, yl, 5); + ROUND(yl, yr, 4); + ROUND(yr, yl, 3); + ROUND(yl, yr, 2); + + yl ^= P[1]; + yr ^= P[0]; + + put_unaligned_be32(yr, dst); + put_unaligned_be32(yl, dst + 4); +} + +static struct crypto_alg alg = { + .cra_name = "blowfish", + .cra_driver_name = "blowfish-generic", + .cra_priority = 100, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = BF_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct bf_ctx), + .cra_module = THIS_MODULE, + .cra_u = { .cipher = { + .cia_min_keysize = BF_MIN_KEY_SIZE, + .cia_max_keysize = BF_MAX_KEY_SIZE, + .cia_setkey = blowfish_setkey, + .cia_encrypt = bf_encrypt, + .cia_decrypt = bf_decrypt } } +}; + +static int __init blowfish_mod_init(void) +{ + return crypto_register_alg(&alg); +} + +static void __exit blowfish_mod_fini(void) +{ + crypto_unregister_alg(&alg); +} + +module_init(blowfish_mod_init); +module_exit(blowfish_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Blowfish Cipher Algorithm"); +MODULE_ALIAS_CRYPTO("blowfish"); +MODULE_ALIAS_CRYPTO("blowfish-generic"); -- cgit v1.3.1