#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/kdebug.h>
+#include <linux/memory.h>
#include <asm-generic/sections.h>
#include <asm/cacheflush.h>
addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name)))
#endif
+static int kprobes_initialized;
static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
/* NOTE: change this value only with kprobe_mutex held */
-static bool kprobe_enabled;
+static bool kprobes_all_disarmed;
-DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */
-DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */
+static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
+static struct {
+ spinlock_t lock ____cacheline_aligned_in_smp;
+} kretprobe_table_locks[KPROBE_TABLE_SIZE];
+
+static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
+{
+ return &(kretprobe_table_locks[hash].lock);
+}
/*
* Normally, functions that we'd want to prohibit kprobes in, are marked
*
* For such cases, we now have a blacklist
*/
-struct kprobe_blackpoint kprobe_blacklist[] = {
+static struct kprobe_blackpoint kprobe_blacklist[] = {
{"preempt_schedule",},
+ {"native_get_debugreg",},
+ {"irq_entries_start",},
+ {"common_interrupt",},
{NULL} /* Terminator */
};
#define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
struct kprobe_insn_page {
- struct hlist_node hlist;
+ struct list_head list;
kprobe_opcode_t *insns; /* Page of instruction slots */
char slot_used[INSNS_PER_PAGE];
int nused;
SLOT_USED = 2,
};
-static struct hlist_head kprobe_insn_pages;
+static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */
+static LIST_HEAD(kprobe_insn_pages);
static int kprobe_garbage_slots;
static int collect_garbage_slots(void);
static int __kprobes check_safety(void)
{
int ret = 0;
-#if defined(CONFIG_PREEMPT) && defined(CONFIG_PM)
+#if defined(CONFIG_PREEMPT) && defined(CONFIG_FREEZER)
ret = freeze_processes();
if (ret == 0) {
struct task_struct *p, *q;
}
/**
- * get_insn_slot() - Find a slot on an executable page for an instruction.
+ * __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.
*/
-kprobe_opcode_t __kprobes *get_insn_slot(void)
+static kprobe_opcode_t __kprobes *__get_insn_slot(void)
{
struct kprobe_insn_page *kip;
- struct hlist_node *pos;
retry:
- hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+ list_for_each_entry(kip, &kprobe_insn_pages, list) {
if (kip->nused < INSNS_PER_PAGE) {
int i;
for (i = 0; i < INSNS_PER_PAGE; i++) {
kfree(kip);
return NULL;
}
- INIT_HLIST_NODE(&kip->hlist);
- hlist_add_head(&kip->hlist, &kprobe_insn_pages);
+ INIT_LIST_HEAD(&kip->list);
+ list_add(&kip->list, &kprobe_insn_pages);
memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
kip->slot_used[0] = SLOT_USED;
kip->nused = 1;
return kip->insns;
}
+kprobe_opcode_t __kprobes *get_insn_slot(void)
+{
+ kprobe_opcode_t *ret;
+ mutex_lock(&kprobe_insn_mutex);
+ ret = __get_insn_slot();
+ mutex_unlock(&kprobe_insn_mutex);
+ return ret;
+}
+
/* Return 1 if all garbages are collected, otherwise 0. */
static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
{
* so as not to have to set it up again the
* next time somebody inserts a probe.
*/
- hlist_del(&kip->hlist);
- if (hlist_empty(&kprobe_insn_pages)) {
- INIT_HLIST_NODE(&kip->hlist);
- hlist_add_head(&kip->hlist,
- &kprobe_insn_pages);
- } else {
+ if (!list_is_singular(&kprobe_insn_pages)) {
+ list_del(&kip->list);
module_free(NULL, kip->insns);
kfree(kip);
}
static int __kprobes collect_garbage_slots(void)
{
- struct kprobe_insn_page *kip;
- struct hlist_node *pos, *next;
+ struct kprobe_insn_page *kip, *next;
/* Ensure no-one is preepmted on the garbages */
- if (check_safety() != 0)
+ if (check_safety())
return -EAGAIN;
- hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {
+ list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) {
int i;
if (kip->ngarbage == 0)
continue;
void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
{
struct kprobe_insn_page *kip;
- struct hlist_node *pos;
- hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+ mutex_lock(&kprobe_insn_mutex);
+ list_for_each_entry(kip, &kprobe_insn_pages, list) {
if (kip->insns <= slot &&
slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
int i = (slot - kip->insns) / MAX_INSN_SIZE;
if (dirty) {
kip->slot_used[i] = SLOT_DIRTY;
kip->ngarbage++;
- } else {
+ } else
collect_one_slot(kip, i);
- }
break;
}
}
if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE)
collect_garbage_slots();
+
+ mutex_unlock(&kprobe_insn_mutex);
}
#endif
return NULL;
}
+/* Arm a kprobe with text_mutex */
+static void __kprobes arm_kprobe(struct kprobe *kp)
+{
+ mutex_lock(&text_mutex);
+ arch_arm_kprobe(kp);
+ mutex_unlock(&text_mutex);
+}
+
+/* Disarm a kprobe with text_mutex */
+static void __kprobes disarm_kprobe(struct kprobe *kp)
+{
+ mutex_lock(&text_mutex);
+ arch_disarm_kprobe(kp);
+ mutex_unlock(&text_mutex);
+}
+
/*
* Aggregate handlers for multiple kprobes support - these handlers
* take care of invoking the individual kprobe handlers on p->list
struct kprobe *kp;
list_for_each_entry_rcu(kp, &p->list, list) {
- if (kp->pre_handler) {
+ if (kp->pre_handler && likely(!kprobe_disabled(kp))) {
set_kprobe_instance(kp);
if (kp->pre_handler(kp, regs))
return 1;
struct kprobe *kp;
list_for_each_entry_rcu(kp, &p->list, list) {
- if (kp->post_handler) {
+ if (kp->post_handler && likely(!kprobe_disabled(kp))) {
set_kprobe_instance(kp);
kp->post_handler(kp, regs, flags);
reset_kprobe_instance();
return;
}
-/* Called with kretprobe_lock held */
void __kprobes recycle_rp_inst(struct kretprobe_instance *ri,
struct hlist_head *head)
{
+ struct kretprobe *rp = ri->rp;
+
/* remove rp inst off the rprobe_inst_table */
hlist_del(&ri->hlist);
- if (ri->rp) {
- /* remove rp inst off the used list */
- hlist_del(&ri->uflist);
- /* put rp inst back onto the free list */
- INIT_HLIST_NODE(&ri->uflist);
- hlist_add_head(&ri->uflist, &ri->rp->free_instances);
+ INIT_HLIST_NODE(&ri->hlist);
+ if (likely(rp)) {
+ spin_lock(&rp->lock);
+ hlist_add_head(&ri->hlist, &rp->free_instances);
+ spin_unlock(&rp->lock);
} else
/* Unregistering */
hlist_add_head(&ri->hlist, head);
}
-struct hlist_head __kprobes *kretprobe_inst_table_head(struct task_struct *tsk)
+void __kprobes kretprobe_hash_lock(struct task_struct *tsk,
+ struct hlist_head **head, unsigned long *flags)
{
- return &kretprobe_inst_table[hash_ptr(tsk, KPROBE_HASH_BITS)];
+ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
+ spinlock_t *hlist_lock;
+
+ *head = &kretprobe_inst_table[hash];
+ hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_lock_irqsave(hlist_lock, *flags);
+}
+
+static void __kprobes kretprobe_table_lock(unsigned long hash,
+ unsigned long *flags)
+{
+ spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_lock_irqsave(hlist_lock, *flags);
+}
+
+void __kprobes kretprobe_hash_unlock(struct task_struct *tsk,
+ unsigned long *flags)
+{
+ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
+ spinlock_t *hlist_lock;
+
+ hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_unlock_irqrestore(hlist_lock, *flags);
+}
+
+void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags)
+{
+ spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_unlock_irqrestore(hlist_lock, *flags);
}
/*
struct kretprobe_instance *ri;
struct hlist_head *head, empty_rp;
struct hlist_node *node, *tmp;
- unsigned long flags = 0;
+ unsigned long hash, flags = 0;
- INIT_HLIST_HEAD(&empty_rp);
- spin_lock_irqsave(&kretprobe_lock, flags);
- head = kretprobe_inst_table_head(tk);
+ if (unlikely(!kprobes_initialized))
+ /* Early boot. kretprobe_table_locks not yet initialized. */
+ return;
+
+ hash = hash_ptr(tk, KPROBE_HASH_BITS);
+ head = &kretprobe_inst_table[hash];
+ kretprobe_table_lock(hash, &flags);
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
if (ri->task == tk)
recycle_rp_inst(ri, &empty_rp);
}
- spin_unlock_irqrestore(&kretprobe_lock, flags);
-
+ kretprobe_table_unlock(hash, &flags);
+ INIT_HLIST_HEAD(&empty_rp);
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
struct kretprobe_instance *ri;
struct hlist_node *pos, *next;
- hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, uflist) {
- hlist_del(&ri->uflist);
+ hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) {
+ hlist_del(&ri->hlist);
kfree(ri);
}
}
static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
{
- unsigned long flags;
+ unsigned long flags, hash;
struct kretprobe_instance *ri;
struct hlist_node *pos, *next;
+ struct hlist_head *head;
+
/* No race here */
- spin_lock_irqsave(&kretprobe_lock, flags);
- hlist_for_each_entry_safe(ri, pos, next, &rp->used_instances, uflist) {
- ri->rp = NULL;
- hlist_del(&ri->uflist);
+ for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
+ kretprobe_table_lock(hash, &flags);
+ head = &kretprobe_inst_table[hash];
+ hlist_for_each_entry_safe(ri, pos, next, head, hlist) {
+ if (ri->rp == rp)
+ ri->rp = NULL;
+ }
+ kretprobe_table_unlock(hash, &flags);
}
- spin_unlock_irqrestore(&kretprobe_lock, flags);
free_rp_inst(rp);
}
}
/*
-* Add the new probe to old_p->list. Fail if this is the
+* Add the new probe to ap->list. Fail if this is the
* second jprobe at the address - two jprobes can't coexist
*/
-static int __kprobes add_new_kprobe(struct kprobe *old_p, struct kprobe *p)
+static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p)
{
+ BUG_ON(kprobe_gone(ap) || kprobe_gone(p));
if (p->break_handler) {
- if (old_p->break_handler)
+ if (ap->break_handler)
return -EEXIST;
- list_add_tail_rcu(&p->list, &old_p->list);
- old_p->break_handler = aggr_break_handler;
+ list_add_tail_rcu(&p->list, &ap->list);
+ ap->break_handler = aggr_break_handler;
} else
- list_add_rcu(&p->list, &old_p->list);
- if (p->post_handler && !old_p->post_handler)
- old_p->post_handler = aggr_post_handler;
+ list_add_rcu(&p->list, &ap->list);
+ if (p->post_handler && !ap->post_handler)
+ ap->post_handler = aggr_post_handler;
+
+ if (kprobe_disabled(ap) && !kprobe_disabled(p)) {
+ ap->flags &= ~KPROBE_FLAG_DISABLED;
+ if (!kprobes_all_disarmed)
+ /* Arm the breakpoint again. */
+ arm_kprobe(ap);
+ }
return 0;
}
copy_kprobe(p, ap);
flush_insn_slot(ap);
ap->addr = p->addr;
+ ap->flags = p->flags;
ap->pre_handler = aggr_pre_handler;
ap->fault_handler = aggr_fault_handler;
- if (p->post_handler)
+ /* We don't care the kprobe which has gone. */
+ if (p->post_handler && !kprobe_gone(p))
ap->post_handler = aggr_post_handler;
- if (p->break_handler)
+ if (p->break_handler && !kprobe_gone(p))
ap->break_handler = aggr_break_handler;
INIT_LIST_HEAD(&ap->list);
struct kprobe *p)
{
int ret = 0;
- struct kprobe *ap;
+ struct kprobe *ap = old_p;
- if (old_p->pre_handler == aggr_pre_handler) {
- copy_kprobe(old_p, p);
- ret = add_new_kprobe(old_p, p);
- } else {
+ if (old_p->pre_handler != aggr_pre_handler) {
+ /* If old_p is not an aggr_probe, create new aggr_kprobe. */
ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL);
if (!ap)
return -ENOMEM;
add_aggr_kprobe(ap, old_p);
- copy_kprobe(ap, p);
- ret = add_new_kprobe(ap, p);
}
- return ret;
+
+ if (kprobe_gone(ap)) {
+ /*
+ * Attempting to insert new probe at the same location that
+ * had a probe in the module vaddr area which already
+ * freed. So, the instruction slot has already been
+ * released. We need a new slot for the new probe.
+ */
+ ret = arch_prepare_kprobe(ap);
+ if (ret)
+ /*
+ * Even if fail to allocate new slot, don't need to
+ * free aggr_probe. It will be used next time, or
+ * freed by unregister_kprobe.
+ */
+ return ret;
+
+ /*
+ * Clear gone flag to prevent allocating new slot again, and
+ * set disabled flag because it is not armed yet.
+ */
+ ap->flags = (ap->flags & ~KPROBE_FLAG_GONE)
+ | KPROBE_FLAG_DISABLED;
+ }
+
+ copy_kprobe(ap, p);
+ return add_new_kprobe(ap, p);
+}
+
+/* Try to disable aggr_kprobe, and return 1 if succeeded.*/
+static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p)
+{
+ struct kprobe *kp;
+
+ list_for_each_entry_rcu(kp, &p->list, list) {
+ if (!kprobe_disabled(kp))
+ /*
+ * There is an active probe on the list.
+ * We can't disable aggr_kprobe.
+ */
+ return 0;
+ }
+ p->flags |= KPROBE_FLAG_DISABLED;
+ return 1;
}
static int __kprobes in_kprobes_functions(unsigned long addr)
return (kprobe_opcode_t *)(((char *)addr) + p->offset);
}
-static int __kprobes __register_kprobe(struct kprobe *p,
- unsigned long called_from)
+/* Check passed kprobe is valid and return kprobe in kprobe_table. */
+static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p)
+{
+ struct kprobe *old_p, *list_p;
+
+ old_p = get_kprobe(p->addr);
+ if (unlikely(!old_p))
+ return NULL;
+
+ if (p != old_p) {
+ list_for_each_entry_rcu(list_p, &old_p->list, list)
+ if (list_p == p)
+ /* kprobe p is a valid probe */
+ goto valid;
+ return NULL;
+ }
+valid:
+ return old_p;
+}
+
+/* Return error if the kprobe is being re-registered */
+static inline int check_kprobe_rereg(struct kprobe *p)
+{
+ int ret = 0;
+ struct kprobe *old_p;
+
+ mutex_lock(&kprobe_mutex);
+ old_p = __get_valid_kprobe(p);
+ if (old_p)
+ ret = -EINVAL;
+ mutex_unlock(&kprobe_mutex);
+ return ret;
+}
+
+int __kprobes register_kprobe(struct kprobe *p)
{
int ret = 0;
struct kprobe *old_p;
return -EINVAL;
p->addr = addr;
+ ret = check_kprobe_rereg(p);
+ if (ret)
+ return ret;
+
+ preempt_disable();
if (!kernel_text_address((unsigned long) p->addr) ||
- in_kprobes_functions((unsigned long) p->addr))
+ in_kprobes_functions((unsigned long) p->addr)) {
+ preempt_enable();
return -EINVAL;
+ }
- p->mod_refcounted = 0;
+ /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */
+ p->flags &= KPROBE_FLAG_DISABLED;
/*
* Check if are we probing a module.
*/
- probed_mod = module_text_address((unsigned long) p->addr);
+ probed_mod = __module_text_address((unsigned long) p->addr);
if (probed_mod) {
- struct module *calling_mod = module_text_address(called_from);
/*
- * We must allow modules to probe themself and in this case
- * avoid incrementing the module refcount, so as to allow
- * unloading of self probing modules.
+ * We must hold a refcount of the probed module while updating
+ * its code to prohibit unexpected unloading.
*/
- if (calling_mod && calling_mod != probed_mod) {
- if (unlikely(!try_module_get(probed_mod)))
- return -EINVAL;
- p->mod_refcounted = 1;
- } else
- probed_mod = NULL;
+ if (unlikely(!try_module_get(probed_mod))) {
+ preempt_enable();
+ return -EINVAL;
+ }
+ /*
+ * If the module freed .init.text, we couldn't insert
+ * kprobes in there.
+ */
+ if (within_module_init((unsigned long)p->addr, probed_mod) &&
+ probed_mod->state != MODULE_STATE_COMING) {
+ module_put(probed_mod);
+ preempt_enable();
+ return -EINVAL;
+ }
}
+ preempt_enable();
p->nmissed = 0;
INIT_LIST_HEAD(&p->list);
goto out;
}
+ mutex_lock(&text_mutex);
ret = arch_prepare_kprobe(p);
if (ret)
- goto out;
+ goto out_unlock_text;
INIT_HLIST_NODE(&p->hlist);
hlist_add_head_rcu(&p->hlist,
&kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]);
- if (kprobe_enabled)
+ if (!kprobes_all_disarmed && !kprobe_disabled(p))
arch_arm_kprobe(p);
+out_unlock_text:
+ mutex_unlock(&text_mutex);
out:
mutex_unlock(&kprobe_mutex);
- if (ret && probed_mod)
+ if (probed_mod)
module_put(probed_mod);
+
return ret;
}
+EXPORT_SYMBOL_GPL(register_kprobe);
/*
* Unregister a kprobe without a scheduler synchronization.
{
struct kprobe *old_p, *list_p;
- old_p = get_kprobe(p->addr);
- if (unlikely(!old_p))
+ old_p = __get_valid_kprobe(p);
+ if (old_p == NULL)
return -EINVAL;
- if (p != old_p) {
- list_for_each_entry_rcu(list_p, &old_p->list, list)
- if (list_p == p)
- /* kprobe p is a valid probe */
- goto valid_p;
- return -EINVAL;
- }
-valid_p:
if (old_p == p ||
(old_p->pre_handler == aggr_pre_handler &&
list_is_singular(&old_p->list))) {
/*
* Only probe on the hash list. Disarm only if kprobes are
- * enabled - otherwise, the breakpoint would already have
- * been removed. We save on flushing icache.
+ * enabled and not gone - otherwise, the breakpoint would
+ * already have been removed. We save on flushing icache.
*/
- if (kprobe_enabled)
- arch_disarm_kprobe(p);
+ if (!kprobes_all_disarmed && !kprobe_disabled(old_p))
+ disarm_kprobe(p);
hlist_del_rcu(&old_p->hlist);
} else {
- if (p->break_handler)
+ if (p->break_handler && !kprobe_gone(p))
old_p->break_handler = NULL;
- if (p->post_handler) {
+ if (p->post_handler && !kprobe_gone(p)) {
list_for_each_entry_rcu(list_p, &old_p->list, list) {
if ((list_p != p) && (list_p->post_handler))
goto noclean;
}
noclean:
list_del_rcu(&p->list);
+ if (!kprobe_disabled(old_p)) {
+ try_to_disable_aggr_kprobe(old_p);
+ if (!kprobes_all_disarmed && kprobe_disabled(old_p))
+ disarm_kprobe(old_p);
+ }
}
return 0;
}
static void __kprobes __unregister_kprobe_bottom(struct kprobe *p)
{
- struct module *mod;
struct kprobe *old_p;
- if (p->mod_refcounted) {
- mod = module_text_address((unsigned long)p->addr);
- if (mod)
- module_put(mod);
- }
-
- if (list_empty(&p->list) || list_is_singular(&p->list)) {
- if (!list_empty(&p->list)) {
- /* "p" is the last child of an aggr_kprobe */
- old_p = list_entry(p->list.next, struct kprobe, list);
- list_del(&p->list);
- kfree(old_p);
- }
+ if (list_empty(&p->list))
arch_remove_kprobe(p);
+ else if (list_is_singular(&p->list)) {
+ /* "p" is the last child of an aggr_kprobe */
+ old_p = list_entry(p->list.next, struct kprobe, list);
+ list_del(&p->list);
+ arch_remove_kprobe(old_p);
+ kfree(old_p);
}
}
-static int __register_kprobes(struct kprobe **kps, int num,
- unsigned long called_from)
+int __kprobes register_kprobes(struct kprobe **kps, int num)
{
int i, ret = 0;
if (num <= 0)
return -EINVAL;
for (i = 0; i < num; i++) {
- ret = __register_kprobe(kps[i], called_from);
- if (ret < 0 && i > 0) {
- unregister_kprobes(kps, i);
+ ret = register_kprobe(kps[i]);
+ if (ret < 0) {
+ if (i > 0)
+ unregister_kprobes(kps, i);
break;
}
}
return ret;
}
-
-/*
- * Registration and unregistration functions for kprobe.
- */
-int __kprobes register_kprobe(struct kprobe *p)
-{
- return __register_kprobes(&p, 1,
- (unsigned long)__builtin_return_address(0));
-}
+EXPORT_SYMBOL_GPL(register_kprobes);
void __kprobes unregister_kprobe(struct kprobe *p)
{
unregister_kprobes(&p, 1);
}
-
-int __kprobes register_kprobes(struct kprobe **kps, int num)
-{
- return __register_kprobes(kps, num,
- (unsigned long)__builtin_return_address(0));
-}
+EXPORT_SYMBOL_GPL(unregister_kprobe);
void __kprobes unregister_kprobes(struct kprobe **kps, int num)
{
if (kps[i]->addr)
__unregister_kprobe_bottom(kps[i]);
}
+EXPORT_SYMBOL_GPL(unregister_kprobes);
static struct notifier_block kprobe_exceptions_nb = {
.notifier_call = kprobe_exceptions_notify,
return (unsigned long)entry;
}
-int __kprobes register_jprobe(struct jprobe *jp)
+int __kprobes register_jprobes(struct jprobe **jps, int num)
{
- unsigned long addr = arch_deref_entry_point(jp->entry);
+ struct jprobe *jp;
+ int ret = 0, i;
- if (!kernel_text_address(addr))
+ if (num <= 0)
return -EINVAL;
+ for (i = 0; i < num; i++) {
+ unsigned long addr;
+ jp = jps[i];
+ addr = arch_deref_entry_point(jp->entry);
+
+ if (!kernel_text_address(addr))
+ ret = -EINVAL;
+ else {
+ /* Todo: Verify probepoint is a function entry point */
+ jp->kp.pre_handler = setjmp_pre_handler;
+ jp->kp.break_handler = longjmp_break_handler;
+ ret = register_kprobe(&jp->kp);
+ }
+ if (ret < 0) {
+ if (i > 0)
+ unregister_jprobes(jps, i);
+ break;
+ }
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_jprobes);
- /* Todo: Verify probepoint is a function entry point */
- jp->kp.pre_handler = setjmp_pre_handler;
- jp->kp.break_handler = longjmp_break_handler;
-
- return __register_kprobe(&jp->kp,
- (unsigned long)__builtin_return_address(0));
+int __kprobes register_jprobe(struct jprobe *jp)
+{
+ return register_jprobes(&jp, 1);
}
+EXPORT_SYMBOL_GPL(register_jprobe);
void __kprobes unregister_jprobe(struct jprobe *jp)
{
- unregister_kprobe(&jp->kp);
+ unregister_jprobes(&jp, 1);
+}
+EXPORT_SYMBOL_GPL(unregister_jprobe);
+
+void __kprobes unregister_jprobes(struct jprobe **jps, int num)
+{
+ int i;
+
+ if (num <= 0)
+ return;
+ mutex_lock(&kprobe_mutex);
+ for (i = 0; i < num; i++)
+ if (__unregister_kprobe_top(&jps[i]->kp) < 0)
+ jps[i]->kp.addr = NULL;
+ mutex_unlock(&kprobe_mutex);
+
+ synchronize_sched();
+ for (i = 0; i < num; i++) {
+ if (jps[i]->kp.addr)
+ __unregister_kprobe_bottom(&jps[i]->kp);
+ }
}
+EXPORT_SYMBOL_GPL(unregister_jprobes);
#ifdef CONFIG_KRETPROBES
/*
struct pt_regs *regs)
{
struct kretprobe *rp = container_of(p, struct kretprobe, kp);
- unsigned long flags = 0;
+ unsigned long hash, flags = 0;
+ struct kretprobe_instance *ri;
/*TODO: consider to only swap the RA after the last pre_handler fired */
- spin_lock_irqsave(&kretprobe_lock, flags);
+ hash = hash_ptr(current, KPROBE_HASH_BITS);
+ spin_lock_irqsave(&rp->lock, flags);
if (!hlist_empty(&rp->free_instances)) {
- struct kretprobe_instance *ri;
-
ri = hlist_entry(rp->free_instances.first,
- struct kretprobe_instance, uflist);
+ struct kretprobe_instance, hlist);
+ hlist_del(&ri->hlist);
+ spin_unlock_irqrestore(&rp->lock, flags);
+
ri->rp = rp;
ri->task = current;
- if (rp->entry_handler && rp->entry_handler(ri, regs)) {
- spin_unlock_irqrestore(&kretprobe_lock, flags);
+ if (rp->entry_handler && rp->entry_handler(ri, regs))
return 0;
- }
arch_prepare_kretprobe(ri, regs);
/* XXX(hch): why is there no hlist_move_head? */
- hlist_del(&ri->uflist);
- hlist_add_head(&ri->uflist, &ri->rp->used_instances);
- hlist_add_head(&ri->hlist, kretprobe_inst_table_head(ri->task));
- } else
+ INIT_HLIST_NODE(&ri->hlist);
+ kretprobe_table_lock(hash, &flags);
+ hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]);
+ kretprobe_table_unlock(hash, &flags);
+ } else {
rp->nmissed++;
- spin_unlock_irqrestore(&kretprobe_lock, flags);
+ spin_unlock_irqrestore(&rp->lock, flags);
+ }
return 0;
}
-static int __kprobes __register_kretprobe(struct kretprobe *rp,
- unsigned long called_from)
+int __kprobes register_kretprobe(struct kretprobe *rp)
{
int ret = 0;
struct kretprobe_instance *inst;
/* Pre-allocate memory for max kretprobe instances */
if (rp->maxactive <= 0) {
#ifdef CONFIG_PREEMPT
- rp->maxactive = max(10, 2 * NR_CPUS);
+ rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus());
#else
- rp->maxactive = NR_CPUS;
+ rp->maxactive = num_possible_cpus();
#endif
}
- INIT_HLIST_HEAD(&rp->used_instances);
+ spin_lock_init(&rp->lock);
INIT_HLIST_HEAD(&rp->free_instances);
for (i = 0; i < rp->maxactive; i++) {
inst = kmalloc(sizeof(struct kretprobe_instance) +
free_rp_inst(rp);
return -ENOMEM;
}
- INIT_HLIST_NODE(&inst->uflist);
- hlist_add_head(&inst->uflist, &rp->free_instances);
+ INIT_HLIST_NODE(&inst->hlist);
+ hlist_add_head(&inst->hlist, &rp->free_instances);
}
rp->nmissed = 0;
/* Establish function entry probe point */
- ret = __register_kprobe(&rp->kp, called_from);
+ ret = register_kprobe(&rp->kp);
if (ret != 0)
free_rp_inst(rp);
return ret;
}
+EXPORT_SYMBOL_GPL(register_kretprobe);
-static int __register_kretprobes(struct kretprobe **rps, int num,
- unsigned long called_from)
+int __kprobes register_kretprobes(struct kretprobe **rps, int num)
{
int ret = 0, i;
if (num <= 0)
return -EINVAL;
for (i = 0; i < num; i++) {
- ret = __register_kretprobe(rps[i], called_from);
- if (ret < 0 && i > 0) {
- unregister_kretprobes(rps, i);
+ ret = register_kretprobe(rps[i]);
+ if (ret < 0) {
+ if (i > 0)
+ unregister_kretprobes(rps, i);
break;
}
}
return ret;
}
-
-int __kprobes register_kretprobe(struct kretprobe *rp)
-{
- return __register_kretprobes(&rp, 1,
- (unsigned long)__builtin_return_address(0));
-}
+EXPORT_SYMBOL_GPL(register_kretprobes);
void __kprobes unregister_kretprobe(struct kretprobe *rp)
{
unregister_kretprobes(&rp, 1);
}
-
-int __kprobes register_kretprobes(struct kretprobe **rps, int num)
-{
- return __register_kretprobes(rps, num,
- (unsigned long)__builtin_return_address(0));
-}
+EXPORT_SYMBOL_GPL(unregister_kretprobe);
void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
{
}
}
}
+EXPORT_SYMBOL_GPL(unregister_kretprobes);
#else /* CONFIG_KRETPROBES */
int __kprobes register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
}
+EXPORT_SYMBOL_GPL(register_kretprobe);
int __kprobes register_kretprobes(struct kretprobe **rps, int num)
{
return -ENOSYS;
}
+EXPORT_SYMBOL_GPL(register_kretprobes);
+
void __kprobes unregister_kretprobe(struct kretprobe *rp)
{
}
+EXPORT_SYMBOL_GPL(unregister_kretprobe);
void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
{
}
+EXPORT_SYMBOL_GPL(unregister_kretprobes);
static int __kprobes pre_handler_kretprobe(struct kprobe *p,
struct pt_regs *regs)
#endif /* CONFIG_KRETPROBES */
+/* Set the kprobe gone and remove its instruction buffer. */
+static void __kprobes kill_kprobe(struct kprobe *p)
+{
+ struct kprobe *kp;
+
+ p->flags |= KPROBE_FLAG_GONE;
+ if (p->pre_handler == aggr_pre_handler) {
+ /*
+ * If this is an aggr_kprobe, we have to list all the
+ * chained probes and mark them GONE.
+ */
+ list_for_each_entry_rcu(kp, &p->list, list)
+ kp->flags |= KPROBE_FLAG_GONE;
+ p->post_handler = NULL;
+ p->break_handler = NULL;
+ }
+ /*
+ * Here, we can remove insn_slot safely, because no thread calls
+ * the original probed function (which will be freed soon) any more.
+ */
+ arch_remove_kprobe(p);
+}
+
+void __kprobes dump_kprobe(struct kprobe *kp)
+{
+ printk(KERN_WARNING "Dumping kprobe:\n");
+ printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n",
+ kp->symbol_name, kp->addr, kp->offset);
+}
+
+/* Module notifier call back, checking kprobes on the module */
+static int __kprobes kprobes_module_callback(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct module *mod = data;
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct kprobe *p;
+ unsigned int i;
+ int checkcore = (val == MODULE_STATE_GOING);
+
+ if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE)
+ return NOTIFY_DONE;
+
+ /*
+ * When MODULE_STATE_GOING was notified, both of module .text and
+ * .init.text sections would be freed. When MODULE_STATE_LIVE was
+ * notified, only .init.text section would be freed. We need to
+ * disable kprobes which have been inserted in the sections.
+ */
+ mutex_lock(&kprobe_mutex);
+ for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
+ head = &kprobe_table[i];
+ hlist_for_each_entry_rcu(p, node, head, hlist)
+ if (within_module_init((unsigned long)p->addr, mod) ||
+ (checkcore &&
+ within_module_core((unsigned long)p->addr, mod))) {
+ /*
+ * The vaddr this probe is installed will soon
+ * be vfreed buy not synced to disk. Hence,
+ * disarming the breakpoint isn't needed.
+ */
+ kill_kprobe(p);
+ }
+ }
+ mutex_unlock(&kprobe_mutex);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block kprobe_module_nb = {
+ .notifier_call = kprobes_module_callback,
+ .priority = 0
+};
+
static int __init init_kprobes(void)
{
int i, err = 0;
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
INIT_HLIST_HEAD(&kprobe_table[i]);
INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
+ spin_lock_init(&(kretprobe_table_locks[i].lock));
}
/*
}
}
- /* By default, kprobes are enabled */
- kprobe_enabled = true;
+ /* By default, kprobes are armed */
+ kprobes_all_disarmed = false;
err = arch_init_kprobes();
if (!err)
err = register_die_notifier(&kprobe_exceptions_nb);
+ if (!err)
+ err = register_module_notifier(&kprobe_module_nb);
+
+ kprobes_initialized = (err == 0);
if (!err)
init_test_probes();
else
kprobe_type = "k";
if (sym)
- seq_printf(pi, "%p %s %s+0x%x %s\n", p->addr, kprobe_type,
- sym, offset, (modname ? modname : " "));
+ seq_printf(pi, "%p %s %s+0x%x %s %s%s\n",
+ p->addr, kprobe_type, sym, offset,
+ (modname ? modname : " "),
+ (kprobe_gone(p) ? "[GONE]" : ""),
+ ((kprobe_disabled(p) && !kprobe_gone(p)) ?
+ "[DISABLED]" : ""));
else
- seq_printf(pi, "%p %s %p\n", p->addr, kprobe_type, p->addr);
+ seq_printf(pi, "%p %s %p %s%s\n",
+ p->addr, kprobe_type, p->addr,
+ (kprobe_gone(p) ? "[GONE]" : ""),
+ ((kprobe_disabled(p) && !kprobe_gone(p)) ?
+ "[DISABLED]" : ""));
}
static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos)
return 0;
}
-static struct seq_operations kprobes_seq_ops = {
+static const struct seq_operations kprobes_seq_ops = {
.start = kprobe_seq_start,
.next = kprobe_seq_next,
.stop = kprobe_seq_stop,
return seq_open(filp, &kprobes_seq_ops);
}
-static struct file_operations debugfs_kprobes_operations = {
+static const struct file_operations debugfs_kprobes_operations = {
.open = kprobes_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
-static void __kprobes enable_all_kprobes(void)
+/* Disable one kprobe */
+int __kprobes disable_kprobe(struct kprobe *kp)
+{
+ int ret = 0;
+ struct kprobe *p;
+
+ mutex_lock(&kprobe_mutex);
+
+ /* Check whether specified probe is valid. */
+ p = __get_valid_kprobe(kp);
+ if (unlikely(p == NULL)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* If the probe is already disabled (or gone), just return */
+ if (kprobe_disabled(kp))
+ goto out;
+
+ kp->flags |= KPROBE_FLAG_DISABLED;
+ if (p != kp)
+ /* When kp != p, p is always enabled. */
+ try_to_disable_aggr_kprobe(p);
+
+ if (!kprobes_all_disarmed && kprobe_disabled(p))
+ disarm_kprobe(p);
+out:
+ mutex_unlock(&kprobe_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(disable_kprobe);
+
+/* Enable one kprobe */
+int __kprobes enable_kprobe(struct kprobe *kp)
+{
+ int ret = 0;
+ struct kprobe *p;
+
+ mutex_lock(&kprobe_mutex);
+
+ /* Check whether specified probe is valid. */
+ p = __get_valid_kprobe(kp);
+ if (unlikely(p == NULL)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (kprobe_gone(kp)) {
+ /* This kprobe has gone, we couldn't enable it. */
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!kprobes_all_disarmed && kprobe_disabled(p))
+ arm_kprobe(p);
+
+ p->flags &= ~KPROBE_FLAG_DISABLED;
+ if (p != kp)
+ kp->flags &= ~KPROBE_FLAG_DISABLED;
+out:
+ mutex_unlock(&kprobe_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(enable_kprobe);
+
+static void __kprobes arm_all_kprobes(void)
{
struct hlist_head *head;
struct hlist_node *node;
mutex_lock(&kprobe_mutex);
- /* If kprobes are already enabled, just return */
- if (kprobe_enabled)
+ /* If kprobes are armed, just return */
+ if (!kprobes_all_disarmed)
goto already_enabled;
+ mutex_lock(&text_mutex);
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist)
- arch_arm_kprobe(p);
+ if (!kprobe_disabled(p))
+ arch_arm_kprobe(p);
}
+ mutex_unlock(&text_mutex);
- kprobe_enabled = true;
+ kprobes_all_disarmed = false;
printk(KERN_INFO "Kprobes globally enabled\n");
already_enabled:
return;
}
-static void __kprobes disable_all_kprobes(void)
+static void __kprobes disarm_all_kprobes(void)
{
struct hlist_head *head;
struct hlist_node *node;
mutex_lock(&kprobe_mutex);
- /* If kprobes are already disabled, just return */
- if (!kprobe_enabled)
+ /* If kprobes are already disarmed, just return */
+ if (kprobes_all_disarmed)
goto already_disabled;
- kprobe_enabled = false;
+ kprobes_all_disarmed = true;
printk(KERN_INFO "Kprobes globally disabled\n");
+ mutex_lock(&text_mutex);
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist) {
- if (!arch_trampoline_kprobe(p))
+ if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p))
arch_disarm_kprobe(p);
}
}
+ mutex_unlock(&text_mutex);
mutex_unlock(&kprobe_mutex);
/* Allow all currently running kprobes to complete */
synchronize_sched();
{
char buf[3];
- if (kprobe_enabled)
+ if (!kprobes_all_disarmed)
buf[0] = '1';
else
buf[0] = '0';
case 'y':
case 'Y':
case '1':
- enable_all_kprobes();
+ arm_all_kprobes();
break;
case 'n':
case 'N':
case '0':
- disable_all_kprobes();
+ disarm_all_kprobes();
break;
}
return count;
}
-static struct file_operations fops_kp = {
+static const struct file_operations fops_kp = {
.read = read_enabled_file_bool,
.write = write_enabled_file_bool,
};
module_init(init_kprobes);
-EXPORT_SYMBOL_GPL(register_kprobe);
-EXPORT_SYMBOL_GPL(unregister_kprobe);
-EXPORT_SYMBOL_GPL(register_kprobes);
-EXPORT_SYMBOL_GPL(unregister_kprobes);
-EXPORT_SYMBOL_GPL(register_jprobe);
-EXPORT_SYMBOL_GPL(unregister_jprobe);
-#ifdef CONFIG_KPROBES
+/* defined in arch/.../kernel/kprobes.c */
EXPORT_SYMBOL_GPL(jprobe_return);
-#endif
-
-#ifdef CONFIG_KPROBES
-EXPORT_SYMBOL_GPL(register_kretprobe);
-EXPORT_SYMBOL_GPL(unregister_kretprobe);
-EXPORT_SYMBOL_GPL(register_kretprobes);
-EXPORT_SYMBOL_GPL(unregister_kretprobes);
-#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff