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Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c75
1 files changed, 21 insertions, 54 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 6e33498d665c..9e4912dc5559 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -121,12 +121,6 @@ struct kprobe_insn_page {
(offsetof(struct kprobe_insn_page, slot_used) + \
(sizeof(char) * (slots)))
-struct kprobe_insn_cache {
- struct list_head pages; /* list of kprobe_insn_page */
- size_t insn_size; /* size of instruction slot */
- int nr_garbage;
-};
-
static int slots_per_page(struct kprobe_insn_cache *c)
{
return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t));
@@ -138,8 +132,8 @@ enum kprobe_slot_state {
SLOT_USED = 2,
};
-static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_slots */
-static struct kprobe_insn_cache kprobe_insn_slots = {
+struct kprobe_insn_cache kprobe_insn_slots = {
+ .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex),
.pages = LIST_HEAD_INIT(kprobe_insn_slots.pages),
.insn_size = MAX_INSN_SIZE,
.nr_garbage = 0,
@@ -150,10 +144,12 @@ static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c);
* __get_insn_slot() - Find a slot on an executable page for an instruction.
* We allocate an executable page if there's no room on existing ones.
*/
-static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
+kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
{
struct kprobe_insn_page *kip;
+ kprobe_opcode_t *slot = NULL;
+ mutex_lock(&c->mutex);
retry:
list_for_each_entry(kip, &c->pages, list) {
if (kip->nused < slots_per_page(c)) {
@@ -162,7 +158,8 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
if (kip->slot_used[i] == SLOT_CLEAN) {
kip->slot_used[i] = SLOT_USED;
kip->nused++;
- return kip->insns + (i * c->insn_size);
+ slot = kip->insns + (i * c->insn_size);
+ goto out;
}
}
/* kip->nused is broken. Fix it. */
@@ -178,7 +175,7 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
/* All out of space. Need to allocate a new page. */
kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL);
if (!kip)
- return NULL;
+ goto out;
/*
* Use module_alloc so this page is within +/- 2GB of where the
@@ -188,7 +185,7 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
kip->insns = module_alloc(PAGE_SIZE);
if (!kip->insns) {
kfree(kip);
- return NULL;
+ goto out;
}
INIT_LIST_HEAD(&kip->list);
memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c));
@@ -196,19 +193,10 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
kip->nused = 1;
kip->ngarbage = 0;
list_add(&kip->list, &c->pages);
- return kip->insns;
-}
-
-
-kprobe_opcode_t __kprobes *get_insn_slot(void)
-{
- kprobe_opcode_t *ret = NULL;
-
- mutex_lock(&kprobe_insn_mutex);
- ret = __get_insn_slot(&kprobe_insn_slots);
- mutex_unlock(&kprobe_insn_mutex);
-
- return ret;
+ slot = kip->insns;
+out:
+ mutex_unlock(&c->mutex);
+ return slot;
}
/* Return 1 if all garbages are collected, otherwise 0. */
@@ -255,11 +243,12 @@ static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c)
return 0;
}
-static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c,
- kprobe_opcode_t *slot, int dirty)
+void __kprobes __free_insn_slot(struct kprobe_insn_cache *c,
+ kprobe_opcode_t *slot, int dirty)
{
struct kprobe_insn_page *kip;
+ mutex_lock(&c->mutex);
list_for_each_entry(kip, &c->pages, list) {
long idx = ((long)slot - (long)kip->insns) /
(c->insn_size * sizeof(kprobe_opcode_t));
@@ -272,45 +261,23 @@ static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c,
collect_garbage_slots(c);
} else
collect_one_slot(kip, idx);
- return;
+ goto out;
}
}
/* Could not free this slot. */
WARN_ON(1);
+out:
+ mutex_unlock(&c->mutex);
}
-void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
-{
- mutex_lock(&kprobe_insn_mutex);
- __free_insn_slot(&kprobe_insn_slots, slot, dirty);
- mutex_unlock(&kprobe_insn_mutex);
-}
#ifdef CONFIG_OPTPROBES
/* For optimized_kprobe buffer */
-static DEFINE_MUTEX(kprobe_optinsn_mutex); /* Protects kprobe_optinsn_slots */
-static struct kprobe_insn_cache kprobe_optinsn_slots = {
+struct kprobe_insn_cache kprobe_optinsn_slots = {
+ .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex),
.pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages),
/* .insn_size is initialized later */
.nr_garbage = 0,
};
-/* Get a slot for optimized_kprobe buffer */
-kprobe_opcode_t __kprobes *get_optinsn_slot(void)
-{
- kprobe_opcode_t *ret = NULL;
-
- mutex_lock(&kprobe_optinsn_mutex);
- ret = __get_insn_slot(&kprobe_optinsn_slots);
- mutex_unlock(&kprobe_optinsn_mutex);
-
- return ret;
-}
-
-void __kprobes free_optinsn_slot(kprobe_opcode_t * slot, int dirty)
-{
- mutex_lock(&kprobe_optinsn_mutex);
- __free_insn_slot(&kprobe_optinsn_slots, slot, dirty);
- mutex_unlock(&kprobe_optinsn_mutex);
-}
#endif
#endif