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/des_generic.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 crypto/des_generic.c (limited to 'crypto/des_generic.c') diff --git a/crypto/des_generic.c b/crypto/des_generic.c new file mode 100644 index 000000000..fce341400 --- /dev/null +++ b/crypto/des_generic.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Cryptographic API. + * + * DES & Triple DES EDE Cipher Algorithms. + * + * Copyright (c) 2005 Dag Arne Osvik + */ + +#include +#include +#include +#include +#include +#include + +#include + +static int des_setkey(struct crypto_tfm *tfm, const u8 *key, + unsigned int keylen) +{ + struct des_ctx *dctx = crypto_tfm_ctx(tfm); + int err; + + err = des_expand_key(dctx, key, keylen); + if (err == -ENOKEY) { + if (crypto_tfm_get_flags(tfm) & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS) + err = -EINVAL; + else + err = 0; + } + if (err) + memset(dctx, 0, sizeof(*dctx)); + return err; +} + +static void crypto_des_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) +{ + const struct des_ctx *dctx = crypto_tfm_ctx(tfm); + + des_encrypt(dctx, dst, src); +} + +static void crypto_des_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) +{ + const struct des_ctx *dctx = crypto_tfm_ctx(tfm); + + des_decrypt(dctx, dst, src); +} + +static int des3_ede_setkey(struct crypto_tfm *tfm, const u8 *key, + unsigned int keylen) +{ + struct des3_ede_ctx *dctx = crypto_tfm_ctx(tfm); + int err; + + err = des3_ede_expand_key(dctx, key, keylen); + if (err == -ENOKEY) { + if (crypto_tfm_get_flags(tfm) & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS) + err = -EINVAL; + else + err = 0; + } + if (err) + memset(dctx, 0, sizeof(*dctx)); + return err; +} + +static void crypto_des3_ede_encrypt(struct crypto_tfm *tfm, u8 *dst, + const u8 *src) +{ + const struct des3_ede_ctx *dctx = crypto_tfm_ctx(tfm); + + des3_ede_encrypt(dctx, dst, src); +} + +static void crypto_des3_ede_decrypt(struct crypto_tfm *tfm, u8 *dst, + const u8 *src) +{ + const struct des3_ede_ctx *dctx = crypto_tfm_ctx(tfm); + + des3_ede_decrypt(dctx, dst, src); +} + +static struct crypto_alg des_algs[2] = { { + .cra_name = "des", + .cra_driver_name = "des-generic", + .cra_priority = 100, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = DES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct des_ctx), + .cra_module = THIS_MODULE, + .cra_u = { .cipher = { + .cia_min_keysize = DES_KEY_SIZE, + .cia_max_keysize = DES_KEY_SIZE, + .cia_setkey = des_setkey, + .cia_encrypt = crypto_des_encrypt, + .cia_decrypt = crypto_des_decrypt } } +}, { + .cra_name = "des3_ede", + .cra_driver_name = "des3_ede-generic", + .cra_priority = 100, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = DES3_EDE_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct des3_ede_ctx), + .cra_module = THIS_MODULE, + .cra_u = { .cipher = { + .cia_min_keysize = DES3_EDE_KEY_SIZE, + .cia_max_keysize = DES3_EDE_KEY_SIZE, + .cia_setkey = des3_ede_setkey, + .cia_encrypt = crypto_des3_ede_encrypt, + .cia_decrypt = crypto_des3_ede_decrypt } } +} }; + +static int __init des_generic_mod_init(void) +{ + return crypto_register_algs(des_algs, ARRAY_SIZE(des_algs)); +} + +static void __exit des_generic_mod_fini(void) +{ + crypto_unregister_algs(des_algs, ARRAY_SIZE(des_algs)); +} + +module_init(des_generic_mod_init); +module_exit(des_generic_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("DES & Triple DES EDE Cipher Algorithms"); +MODULE_AUTHOR("Dag Arne Osvik "); +MODULE_ALIAS_CRYPTO("des"); +MODULE_ALIAS_CRYPTO("des-generic"); +MODULE_ALIAS_CRYPTO("des3_ede"); +MODULE_ALIAS_CRYPTO("des3_ede-generic"); -- cgit v1.3.1