diff options
| -rw-r--r-- | include/linux/list.h | 15 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 9 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/list_debug.c | 77 |
4 files changed, 102 insertions, 0 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index 65a5b5ceda49..a9c90287c0ff 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -39,6 +39,7 @@ static inline void INIT_LIST_HEAD(struct list_head *list) * This is only for internal list manipulation where we know * the prev/next entries already! */ +#ifndef CONFIG_DEBUG_LIST static inline void __list_add(struct list_head *new, struct list_head *prev, struct list_head *next) @@ -48,6 +49,11 @@ static inline void __list_add(struct list_head *new, new->prev = prev; prev->next = new; } +#else +extern void __list_add(struct list_head *new, + struct list_head *prev, + struct list_head *next); +#endif /** * list_add - add a new entry @@ -57,10 +63,15 @@ static inline void __list_add(struct list_head *new, * Insert a new entry after the specified head. * This is good for implementing stacks. */ +#ifndef CONFIG_DEBUG_LIST static inline void list_add(struct list_head *new, struct list_head *head) { __list_add(new, head, head->next); } +#else +extern void list_add(struct list_head *new, struct list_head *head); +#endif + /** * list_add_tail - add a new entry @@ -153,12 +164,16 @@ static inline void __list_del(struct list_head * prev, struct list_head * next) * Note: list_empty on entry does not return true after this, the entry is * in an undefined state. */ +#ifndef CONFIG_DEBUG_LIST static inline void list_del(struct list_head *entry) { __list_del(entry->prev, entry->next); entry->next = LIST_POISON1; entry->prev = LIST_POISON2; } +#else +extern void list_del(struct list_head *entry); +#endif /** * list_del_rcu - deletes entry from list without re-initialization diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index b0f5ca72599f..f9ae75cc0145 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -320,6 +320,15 @@ config DEBUG_VM If unsure, say N. +config DEBUG_LIST + bool "Debug linked list manipulation" + depends on DEBUG_KERNEL + help + Enable this to turn on extended checks in the linked-list + walking routines. + + If unsure, say N. + config FRAME_POINTER bool "Compile the kernel with frame pointers" depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || AVR32 || SUPERH) diff --git a/lib/Makefile b/lib/Makefile index ef1d37afbbb6..402762fead70 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -28,6 +28,7 @@ lib-$(CONFIG_GENERIC_HWEIGHT) += hweight.o obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o obj-$(CONFIG_PLIST) += plist.o obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o +obj-$(CONFIG_DEBUG_LIST) += list_debug.o ifneq ($(CONFIG_HAVE_DEC_LOCK),y) lib-y += dec_and_lock.o diff --git a/lib/list_debug.c b/lib/list_debug.c new file mode 100644 index 000000000000..1aae85cef92c --- /dev/null +++ b/lib/list_debug.c @@ -0,0 +1,77 @@ +/* + * Copyright 2006, Red Hat, Inc., Dave Jones + * Released under the General Public License (GPL). + * + * This file contains the linked list implementations for + * DEBUG_LIST. + */ + +#include <linux/module.h> +#include <linux/list.h> + +/* + * Insert a new entry between two known consecutive entries. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ + +void __list_add(struct list_head *new, + struct list_head *prev, + struct list_head *next) +{ + if (unlikely(next->prev != prev)) { + printk(KERN_ERR "list_add corruption. next->prev should be %p, but was %p\n", + prev, next->prev); + BUG(); + } + if (unlikely(prev->next != next)) { + printk(KERN_ERR "list_add corruption. prev->next should be %p, but was %p\n", + next, prev->next); + BUG(); + } + next->prev = new; + new->next = next; + new->prev = prev; + prev->next = new; +} +EXPORT_SYMBOL(__list_add); + +/** + * list_add - add a new entry + * @new: new entry to be added + * @head: list head to add it after + * + * Insert a new entry after the specified head. + * This is good for implementing stacks. + */ +void list_add(struct list_head *new, struct list_head *head) +{ + __list_add(new, head, head->next); +} +EXPORT_SYMBOL(list_add); + +/** + * list_del - deletes entry from list. + * @entry: the element to delete from the list. + * Note: list_empty on entry does not return true after this, the entry is + * in an undefined state. + */ +void list_del(struct list_head *entry) +{ + if (unlikely(entry->prev->next != entry)) { + printk(KERN_ERR "list_del corruption. prev->next should be %p, but was %p\n", + entry, entry->prev->next); + BUG(); + } + if (unlikely(entry->next->prev != entry)) { + printk(KERN_ERR "list_del corruption. next->prev should be %p, but was %p\n", + entry, entry->next->prev); + BUG(); + } + __list_del(entry->prev, entry->next); + entry->next = LIST_POISON1; + entry->prev = LIST_POISON2; +} +EXPORT_SYMBOL(list_del); + |