/* * KASAN quarantine. * * Author: Alexander Potapenko * Copyright (C) 2016 Google, Inc. * * Based on code by Dmitry Chernenkov. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * */ #include #include #include #include #include #include #include #include #include #include #include "../slab.h" #include "kasan.h" /* Data structure and operations for quarantine queues. */ /* * Each queue is a signle-linked list, which also stores the total size of * objects inside of it. */ struct qlist_head { struct qlist_node *head; struct qlist_node *tail; size_t bytes; }; #define QLIST_INIT { NULL, NULL, 0 } static bool qlist_empty(struct qlist_head *q) { return !q->head; } static void qlist_init(struct qlist_head *q) { q->head = q->tail = NULL; q->bytes = 0; } static void qlist_put(struct qlist_head *q, struct qlist_node *qlink, size_t size) { if (unlikely(qlist_empty(q))) q->head = qlink; else q->tail->next = qlink; q->tail = qlink; qlink->next = NULL; q->bytes += size; } static void qlist_move_all(struct qlist_head *from, struct qlist_head *to) { if (unlikely(qlist_empty(from))) return; if (qlist_empty(to)) { *to = *from; qlist_init(from); return; } to->tail->next = from->head; to->tail = from->tail; to->bytes += from->bytes; qlist_init(from); } #define QUARANTINE_PERCPU_SIZE (1 << 20) #define QUARANTINE_BATCHES \ (1024 > 4 * CONFIG_NR_CPUS ? 1024 : 4 * CONFIG_NR_CPUS) /* * The object quarantine consists of per-cpu queues and a global queue, * guarded by quarantine_lock. */ static DEFINE_PER_CPU(struct qlist_head, cpu_quarantine); /* Round-robin FIFO array of batches. */ static struct qlist_head global_quarantine[QUARANTINE_BATCHES]; static int quarantine_head; static int quarantine_tail; /* Total size of all objects in global_quarantine across all batches. */ static unsigned long quarantine_size; static DEFINE_SPINLOCK(quarantine_lock); /* Maximum size of the global queue. */ static unsigned long quarantine_max_size; /* * Target size of a batch in global_quarantine. * Usually equal to QUARANTINE_PERCPU_SIZE unless we have too much RAM. */ static unsigned long quarantine_batch_size; /* * The fraction of physical memory the quarantine is allowed to occupy. * Quarantine doesn't support memory shrinker with SLAB allocator, so we keep * the ratio low to avoid OOM. */ #define QUARANTINE_FRACTION 32 static struct kmem_cache *qlink_to_cache(struct qlist_node *qlink) { return virt_to_head_page(qlink)->slab_cache; } static void *qlink_to_object(struct qlist_node *qlink, struct kmem_cache *cache) { struct kasan_free_meta *free_info = container_of(qlink, struct kasan_free_meta, quarantine_link); return ((void *)free_info) - cache->kasan_info.free_meta_offset; } static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache) { void *object = qlink_to_object(qlink, cache); unsigned long flags; if (IS_ENABLED(CONFIG_SLAB)) local_irq_save(flags); ___cache_free(cache, object, _THIS_IP_); if (IS_ENABLED(CONFIG_SLAB)) local_irq_restore(flags); } static void qlist_free_all(struct qlist_head *q, struct kmem_cache *cache) { struct qlist_node *qlink; if (unlikely(qlist_empty(q))) return; qlink = q->head; while (qlink) { struct kmem_cache *obj_cache = cache ? cache : qlink_to_cache(qlink); struct qlist_node *next = qlink->next; qlink_free(qlink, obj_cache); qlink = next; } qlist_init(q); } void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache) { unsigned long flags; struct qlist_head *q; struct qlist_head temp = QLIST_INIT; local_irq_save(flags); q = this_cpu_ptr(&cpu_quarantine); qlist_put(q, &info->quarantine_link, cache->size); if (unlikely(q->bytes > QUARANTINE_PERCPU_SIZE)) qlist_move_all(q, &temp); local_irq_restore(flags); if (unlikely(!qlist_empty(&temp))) { spin_lock_irqsave(&quarantine_lock, flags); WRITE_ONCE(quarantine_size, quarantine_size + temp.bytes); qlist_move_all(&temp, &global_quarantine[quarantine_tail]); if (global_quarantine[quarantine_tail].bytes >= READ_ONCE(quarantine_batch_size)) { int new_tail; new_tail = quarantine_tail + 1; if (new_tail == QUARANTINE_BATCHES) new_tail = 0; if (new_tail != quarantine_head) quarantine_tail = new_tail; } spin_unlock_irqrestore(&quarantine_lock, flags); } } void quarantine_reduce(void) { size_t total_size, new_quarantine_size, percpu_quarantines; unsigned long flags; struct qlist_head to_free = QLIST_INIT; if (likely(READ_ONCE(quarantine_size) <= READ_ONCE(quarantine_max_size))) return; spin_lock_irqsave(&quarantine_lock, flags); /* * Update quarantine size in case of hotplug. Allocate a fraction of * the installed memory to quarantine minus per-cpu queue limits. */ total_size = (READ_ONCE(totalram_pages) << PAGE_SHIFT) / QUARANTINE_FRACTION; percpu_quarantines = QUARANTINE_PERCPU_SIZE * num_online_cpus(); new_quarantine_size = (total_size < percpu_quarantines) ? 0 : total_size - percpu_quarantines; WRITE_ONCE(quarantine_max_size, new_quarantine_size); /* Aim at consuming at most 1/2 of slots in quarantine. */ WRITE_ONCE(quarantine_batch_size, max((size_t)QUARANTINE_PERCPU_SIZE, 2 * total_size / QUARANTINE_BATCHES)); if (likely(quarantine_size > quarantine_max_size)) { qlist_move_all(&global_quarantine[quarantine_head], &to_free); WRITE_ONCE(quarantine_size, quarantine_size - to_free.bytes); quarantine_head++; if (quarantine_head == QUARANTINE_BATCHES) quarantine_head = 0; } spin_unlock_irqrestore(&quarantine_lock, flags); qlist_free_all(&to_free, NULL); } static void qlist_move_cache(struct qlist_head *from, struct qlist_head *to, struct kmem_cache *cache) { struct qlist_node *curr; if (unlikely(qlist_empty(from))) return; curr = from->head; qlist_init(from); while (curr) { struct qlist_node *next = curr->next; struct kmem_cache *obj_cache = qlink_to_cache(curr); if (obj_cache == cache) qlist_put(to, curr, obj_cache->size); else qlist_put(from, curr, obj_cache->size); curr = next; } } static void per_cpu_remove_cache(void *arg) { struct kmem_cache *cache = arg; struct qlist_head to_free = QLIST_INIT; struct qlist_head *q; q = this_cpu_ptr(&cpu_quarantine); qlist_move_cache(q, &to_free, cache); qlist_free_all(&to_free, cache); } void quarantine_remove_cache(struct kmem_cache *cache) { unsigned long flags, i; struct qlist_head to_free = QLIST_INIT; on_each_cpu(per_cpu_remove_cache, cache, 1); spin_lock_irqsave(&quarantine_lock, flags); for (i = 0; i < QUARANTINE_BATCHES; i++) qlist_move_cache(&global_quarantine[i], &to_free, cache); spin_unlock_irqrestore(&quarantine_lock, flags); qlist_free_all(&to_free, cache); } c_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'sound/soc/codecs/es8328.h')