diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 7 | ||||
| -rw-r--r-- | lib/flex_array.c | 25 | ||||
| -rw-r--r-- | lib/iommu-helper.c | 9 | ||||
| -rw-r--r-- | lib/list_debug.c | 6 | ||||
| -rw-r--r-- | lib/percpu_counter.c | 27 | ||||
| -rw-r--r-- | lib/radix-tree.c | 94 | ||||
| -rw-r--r-- | lib/rwsem.c | 150 | ||||
| -rw-r--r-- | lib/scatterlist.c | 23 | ||||
| -rw-r--r-- | lib/vsprintf.c | 14 |
9 files changed, 268 insertions, 87 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 79e0dff1cdcb..9e06b7f5ecf1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -410,6 +410,13 @@ config DEBUG_KMEMLEAK_TEST If unsure, say N. +config DEBUG_KMEMLEAK_DEFAULT_OFF + bool "Default kmemleak to off" + depends on DEBUG_KMEMLEAK + help + Say Y here to disable kmemleak by default. It can then be enabled + on the command line via kmemleak=on. + config DEBUG_PREEMPT bool "Debug preemptible kernel" depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT diff --git a/lib/flex_array.c b/lib/flex_array.c index 41b1804fa728..77a6fea7481e 100644 --- a/lib/flex_array.c +++ b/lib/flex_array.c @@ -171,6 +171,8 @@ __fa_get_part(struct flex_array *fa, int part_nr, gfp_t flags) * Note that this *copies* the contents of @src into * the array. If you are trying to store an array of * pointers, make sure to pass in &ptr instead of ptr. + * You may instead wish to use the flex_array_put_ptr() + * helper function. * * Locking must be provided by the caller. */ @@ -265,7 +267,8 @@ int flex_array_prealloc(struct flex_array *fa, unsigned int start, * * Returns a pointer to the data at index @element_nr. Note * that this is a copy of the data that was passed in. If you - * are using this to store pointers, you'll get back &ptr. + * are using this to store pointers, you'll get back &ptr. You + * may instead wish to use the flex_array_get_ptr helper. * * Locking must be provided by the caller. */ @@ -286,6 +289,26 @@ void *flex_array_get(struct flex_array *fa, unsigned int element_nr) return &part->elements[index_inside_part(fa, element_nr)]; } +/** + * flex_array_get_ptr - pull a ptr back out of the array + * @fa: the flex array from which to extract data + * @element_nr: index of the element to fetch from the array + * + * Returns the pointer placed in the flex array at element_nr using + * flex_array_put_ptr(). This function should not be called if the + * element in question was not set using the _put_ptr() helper. + */ +void *flex_array_get_ptr(struct flex_array *fa, unsigned int element_nr) +{ + void **tmp; + + tmp = flex_array_get(fa, element_nr); + if (!tmp) + return NULL; + + return *tmp; +} + static int part_is_free(struct flex_array_part *part) { int i; diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c index c0251f4ad08b..da053313ee5c 100644 --- a/lib/iommu-helper.c +++ b/lib/iommu-helper.c @@ -38,12 +38,3 @@ again: return -1; } EXPORT_SYMBOL(iommu_area_alloc); - -unsigned long iommu_num_pages(unsigned long addr, unsigned long len, - unsigned long io_page_size) -{ - unsigned long size = (addr & (io_page_size - 1)) + len; - - return DIV_ROUND_UP(size, io_page_size); -} -EXPORT_SYMBOL(iommu_num_pages); diff --git a/lib/list_debug.c b/lib/list_debug.c index 1a39f4e3ae1f..344c710d16ca 100644 --- a/lib/list_debug.c +++ b/lib/list_debug.c @@ -43,6 +43,12 @@ EXPORT_SYMBOL(__list_add); */ void list_del(struct list_head *entry) { + WARN(entry->next == LIST_POISON1, + "list_del corruption, next is LIST_POISON1 (%p)\n", + LIST_POISON1); + WARN(entry->next != LIST_POISON1 && entry->prev == LIST_POISON2, + "list_del corruption, prev is LIST_POISON2 (%p)\n", + LIST_POISON2); WARN(entry->prev->next != entry, "list_del corruption. prev->next should be %p, " "but was %p\n", entry, entry->prev->next); diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index aeaa6d734447..ec9048e74f44 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -137,6 +137,33 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb, return NOTIFY_OK; } +/* + * Compare counter against given value. + * Return 1 if greater, 0 if equal and -1 if less + */ +int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs) +{ + s64 count; + + count = percpu_counter_read(fbc); + /* Check to see if rough count will be sufficient for comparison */ + if (abs(count - rhs) > (percpu_counter_batch*num_online_cpus())) { + if (count > rhs) + return 1; + else + return -1; + } + /* Need to use precise count */ + count = percpu_counter_sum(fbc); + if (count > rhs) + return 1; + else if (count < rhs) + return -1; + else + return 0; +} +EXPORT_SYMBOL(percpu_counter_compare); + static int __init percpu_counter_startup(void) { compute_batch_value(); diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 05da38bcc298..e907858498a6 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -609,6 +609,100 @@ int radix_tree_tag_get(struct radix_tree_root *root, EXPORT_SYMBOL(radix_tree_tag_get); /** + * radix_tree_range_tag_if_tagged - for each item in given range set given + * tag if item has another tag set + * @root: radix tree root + * @first_indexp: pointer to a starting index of a range to scan + * @last_index: last index of a range to scan + * @nr_to_tag: maximum number items to tag + * @iftag: tag index to test + * @settag: tag index to set if tested tag is set + * + * This function scans range of radix tree from first_index to last_index + * (inclusive). For each item in the range if iftag is set, the function sets + * also settag. The function stops either after tagging nr_to_tag items or + * after reaching last_index. + * + * The function returns number of leaves where the tag was set and sets + * *first_indexp to the first unscanned index. + */ +unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, + unsigned long *first_indexp, unsigned long last_index, + unsigned long nr_to_tag, + unsigned int iftag, unsigned int settag) +{ + unsigned int height = root->height, shift; + unsigned long tagged = 0, index = *first_indexp; + struct radix_tree_node *open_slots[height], *slot; + + last_index = min(last_index, radix_tree_maxindex(height)); + if (index > last_index) + return 0; + if (!nr_to_tag) + return 0; + if (!root_tag_get(root, iftag)) { + *first_indexp = last_index + 1; + return 0; + } + if (height == 0) { + *first_indexp = last_index + 1; + root_tag_set(root, settag); + return 1; + } + + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + slot = radix_tree_indirect_to_ptr(root->rnode); + + for (;;) { + int offset; + + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + if (!slot->slots[offset]) + goto next; + if (!tag_get(slot, iftag, offset)) + goto next; + tag_set(slot, settag, offset); + if (height == 1) { + tagged++; + goto next; + } + /* Go down one level */ + height--; + shift -= RADIX_TREE_MAP_SHIFT; + open_slots[height] = slot; + slot = slot->slots[offset]; + continue; +next: + /* Go to next item at level determined by 'shift' */ + index = ((index >> shift) + 1) << shift; + if (index > last_index) + break; + if (tagged >= nr_to_tag) + break; + while (((index >> shift) & RADIX_TREE_MAP_MASK) == 0) { + /* + * We've fully scanned this node. Go up. Because + * last_index is guaranteed to be in the tree, what + * we do below cannot wander astray. + */ + slot = open_slots[height]; + height++; + shift += RADIX_TREE_MAP_SHIFT; + } + } + /* + * The iftag must have been set somewhere because otherwise + * we would return immediated at the beginning of the function + */ + root_tag_set(root, settag); + *first_indexp = index; + + return tagged; +} +EXPORT_SYMBOL(radix_tree_range_tag_if_tagged); + + +/** * radix_tree_next_hole - find the next hole (not-present entry) * @root: tree root * @index: index key diff --git a/lib/rwsem.c b/lib/rwsem.c index ceba8e28807a..f236d7cd5cf3 100644 --- a/lib/rwsem.c +++ b/lib/rwsem.c @@ -36,45 +36,56 @@ struct rwsem_waiter { #define RWSEM_WAITING_FOR_WRITE 0x00000002 }; +/* Wake types for __rwsem_do_wake(). Note that RWSEM_WAKE_NO_ACTIVE and + * RWSEM_WAKE_READ_OWNED imply that the spinlock must have been kept held + * since the rwsem value was observed. + */ +#define RWSEM_WAKE_ANY 0 /* Wake whatever's at head of wait list */ +#define RWSEM_WAKE_NO_ACTIVE 1 /* rwsem was observed with no active thread */ +#define RWSEM_WAKE_READ_OWNED 2 /* rwsem was observed to be read owned */ + /* * handle the lock release when processes blocked on it that can now run * - if we come here from up_xxxx(), then: * - the 'active part' of count (&0x0000ffff) reached 0 (but may have changed) * - the 'waiting part' of count (&0xffff0000) is -ve (and will still be so) - * - there must be someone on the queue + * - there must be someone on the queue * - the spinlock must be held by the caller * - woken process blocks are discarded from the list after having task zeroed * - writers are only woken if downgrading is false */ -static inline struct rw_semaphore * -__rwsem_do_wake(struct rw_semaphore *sem, int downgrading) +static struct rw_semaphore * +__rwsem_do_wake(struct rw_semaphore *sem, int wake_type) { struct rwsem_waiter *waiter; struct task_struct *tsk; struct list_head *next; - signed long oldcount, woken, loop; - - if (downgrading) - goto dont_wake_writers; - - /* if we came through an up_xxxx() call, we only only wake someone up - * if we can transition the active part of the count from 0 -> 1 - */ - try_again: - oldcount = rwsem_atomic_update(RWSEM_ACTIVE_BIAS, sem) - - RWSEM_ACTIVE_BIAS; - if (oldcount & RWSEM_ACTIVE_MASK) - goto undo; + signed long oldcount, woken, loop, adjustment; waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list); - - /* try to grant a single write lock if there's a writer at the front - * of the queue - note we leave the 'active part' of the count - * incremented by 1 and the waiting part incremented by 0x00010000 - */ if (!(waiter->flags & RWSEM_WAITING_FOR_WRITE)) goto readers_only; + if (wake_type == RWSEM_WAKE_READ_OWNED) + /* Another active reader was observed, so wakeup is not + * likely to succeed. Save the atomic op. + */ + goto out; + + /* There's a writer at the front of the queue - try to grant it the + * write lock. However, we only wake this writer if we can transition + * the active part of the count from 0 -> 1 + */ + adjustment = RWSEM_ACTIVE_WRITE_BIAS; + if (waiter->list.next == &sem->wait_list) + adjustment -= RWSEM_WAITING_BIAS; + + try_again_write: + oldcount = rwsem_atomic_update(adjustment, sem) - adjustment; + if (oldcount & RWSEM_ACTIVE_MASK) + /* Someone grabbed the sem already */ + goto undo_write; + /* We must be careful not to touch 'waiter' after we set ->task = NULL. * It is an allocated on the waiter's stack and may become invalid at * any time after that point (due to a wakeup from another source). @@ -87,18 +98,30 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading) put_task_struct(tsk); goto out; - /* don't want to wake any writers */ - dont_wake_writers: - waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list); - if (waiter->flags & RWSEM_WAITING_FOR_WRITE) + readers_only: + /* If we come here from up_xxxx(), another thread might have reached + * rwsem_down_failed_common() before we acquired the spinlock and + * woken up a waiter, making it now active. We prefer to check for + * this first in order to not spend too much time with the spinlock + * held if we're not going to be able to wake up readers in the end. + * + * Note that we do not need to update the rwsem count: any writer + * trying to acquire rwsem will run rwsem_down_write_failed() due + * to the waiting threads and block trying to acquire the spinlock. + * + * We use a dummy atomic update in order to acquire the cache line + * exclusively since we expect to succeed and run the final rwsem + * count adjustment pretty soon. + */ + if (wake_type == RWSEM_WAKE_ANY && + rwsem_atomic_update(0, sem) < RWSEM_WAITING_BIAS) + /* Someone grabbed the sem for write already */ goto out; - /* grant an infinite number of read locks to the readers at the front - * of the queue - * - note we increment the 'active part' of the count by the number of - * readers before waking any processes up + /* Grant an infinite number of read locks to the readers at the front + * of the queue. Note we increment the 'active part' of the count by + * the number of readers before waking any processes up. */ - readers_only: woken = 0; do { woken++; @@ -111,16 +134,15 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading) } while (waiter->flags & RWSEM_WAITING_FOR_READ); - loop = woken; - woken *= RWSEM_ACTIVE_BIAS - RWSEM_WAITING_BIAS; - if (!downgrading) - /* we'd already done one increment earlier */ - woken -= RWSEM_ACTIVE_BIAS; + adjustment = woken * RWSEM_ACTIVE_READ_BIAS; + if (waiter->flags & RWSEM_WAITING_FOR_READ) + /* hit end of list above */ + adjustment -= RWSEM_WAITING_BIAS; - rwsem_atomic_add(woken, sem); + rwsem_atomic_add(adjustment, sem); next = sem->wait_list.next; - for (; loop > 0; loop--) { + for (loop = woken; loop > 0; loop--) { waiter = list_entry(next, struct rwsem_waiter, list); next = waiter->list.next; tsk = waiter->task; @@ -138,10 +160,10 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading) /* undo the change to the active count, but check for a transition * 1->0 */ - undo: - if (rwsem_atomic_update(-RWSEM_ACTIVE_BIAS, sem) & RWSEM_ACTIVE_MASK) + undo_write: + if (rwsem_atomic_update(-adjustment, sem) & RWSEM_ACTIVE_MASK) goto out; - goto try_again; + goto try_again_write; } /* @@ -149,8 +171,9 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading) */ static struct rw_semaphore __sched * rwsem_down_failed_common(struct rw_semaphore *sem, - struct rwsem_waiter *waiter, signed long adjustment) + unsigned int flags, signed long adjustment) { + struct rwsem_waiter waiter; struct task_struct *tsk = current; signed long count; @@ -158,23 +181,34 @@ rwsem_down_failed_common(struct rw_semaphore *sem, /* set up my own style of waitqueue */ spin_lock_irq(&sem->wait_lock); - waiter->task = tsk; + waiter.task = tsk; + waiter.flags = flags; get_task_struct(tsk); - list_add_tail(&waiter->list, &sem->wait_list); + if (list_empty(&sem->wait_list)) + adjustment += RWSEM_WAITING_BIAS; + list_add_tail(&waiter.list, &sem->wait_list); - /* we're now waiting on the lock, but no longer actively read-locking */ + /* we're now waiting on the lock, but no longer actively locking */ count = rwsem_atomic_update(adjustment, sem); - /* if there are no active locks, wake the front queued process(es) up */ - if (!(count & RWSEM_ACTIVE_MASK)) - sem = __rwsem_do_wake(sem, 0); + /* If there are no active locks, wake the front queued process(es) up. + * + * Alternatively, if we're called from a failed down_write(), there + * were already threads queued before us and there are no active + * writers, the lock must be read owned; so we try to wake any read + * locks that were queued ahead of us. */ + if (count == RWSEM_WAITING_BIAS) + sem = __rwsem_do_wake(sem, RWSEM_WAKE_NO_ACTIVE); + else if (count > RWSEM_WAITING_BIAS && + adjustment == -RWSEM_ACTIVE_WRITE_BIAS) + sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED); spin_unlock_irq(&sem->wait_lock); /* wait to be given the lock */ for (;;) { - if (!waiter->task) + if (!waiter.task) break; schedule(); set_task_state(tsk, TASK_UNINTERRUPTIBLE); @@ -191,12 +225,8 @@ rwsem_down_failed_common(struct rw_semaphore *sem, asmregparm struct rw_semaphore __sched * rwsem_down_read_failed(struct rw_semaphore *sem) { - struct rwsem_waiter waiter; - - waiter.flags = RWSEM_WAITING_FOR_READ; - rwsem_down_failed_common(sem, &waiter, - RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS); - return sem; + return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_READ, + -RWSEM_ACTIVE_READ_BIAS); } /* @@ -205,12 +235,8 @@ rwsem_down_read_failed(struct rw_semaphore *sem) asmregparm struct rw_semaphore __sched * rwsem_down_write_failed(struct rw_semaphore *sem) { - struct rwsem_waiter waiter; - - waiter.flags = RWSEM_WAITING_FOR_WRITE; - rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS); - - return sem; + return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_WRITE, + -RWSEM_ACTIVE_WRITE_BIAS); } /* @@ -225,7 +251,7 @@ asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem) /* do nothing if list empty */ if (!list_empty(&sem->wait_list)) - sem = __rwsem_do_wake(sem, 0); + sem = __rwsem_do_wake(sem, RWSEM_WAKE_ANY); spin_unlock_irqrestore(&sem->wait_lock, flags); @@ -245,7 +271,7 @@ asmregparm struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem) /* do nothing if list empty */ if (!list_empty(&sem->wait_list)) - sem = __rwsem_do_wake(sem, 1); + sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED); spin_unlock_irqrestore(&sem->wait_lock, flags); diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 9afa25b52a83..a5ec42868f99 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -10,6 +10,7 @@ #include <linux/slab.h> #include <linux/scatterlist.h> #include <linux/highmem.h> +#include <linux/kmemleak.h> /** * sg_next - return the next scatterlist entry in a list @@ -115,17 +116,29 @@ EXPORT_SYMBOL(sg_init_one); */ static struct scatterlist *sg_kmalloc(unsigned int nents, gfp_t gfp_mask) { - if (nents == SG_MAX_SINGLE_ALLOC) - return (struct scatterlist *) __get_free_page(gfp_mask); - else + if (nents == SG_MAX_SINGLE_ALLOC) { + /* + * Kmemleak doesn't track page allocations as they are not + * commonly used (in a raw form) for kernel data structures. + * As we chain together a list of pages and then a normal + * kmalloc (tracked by kmemleak), in order to for that last + * allocation not to become decoupled (and thus a + * false-positive) we need to inform kmemleak of all the + * intermediate allocations. + */ + void *ptr = (void *) __get_free_page(gfp_mask); + kmemleak_alloc(ptr, PAGE_SIZE, 1, gfp_mask); + return ptr; + } else return kmalloc(nents * sizeof(struct scatterlist), gfp_mask); } static void sg_kfree(struct scatterlist *sg, unsigned int nents) { - if (nents == SG_MAX_SINGLE_ALLOC) + if (nents == SG_MAX_SINGLE_ALLOC) { + kmemleak_free(sg); free_page((unsigned long) sg); - else + } else kfree(sg); } diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 4ee19d0d3910..7af9d841c43b 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -146,19 +146,16 @@ int strict_strtoul(const char *cp, unsigned int base, unsigned long *res) { char *tail; unsigned long val; - size_t len; *res = 0; - len = strlen(cp); - if (len == 0) + if (!*cp) return -EINVAL; val = simple_strtoul(cp, &tail, base); if (tail == cp) return -EINVAL; - if ((*tail == '\0') || - ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) { + if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) { *res = val; return 0; } @@ -220,18 +217,15 @@ int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res) { char *tail; unsigned long long val; - size_t len; *res = 0; - len = strlen(cp); - if (len == 0) + if (!*cp) return -EINVAL; val = simple_strtoull(cp, &tail, base); if (tail == cp) return -EINVAL; - if ((*tail == '\0') || - ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) { + if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) { *res = val; return 0; } |