DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
+/*
+ * Normally, functions that we'd want to prohibit kprobes in, are marked
+ * __kprobes. But, there are cases where such functions already belong to
+ * a different section (__sched for preempt_schedule)
+ *
+ * For such cases, we now have a blacklist
+ */
+struct kprobe_blackpoint kprobe_blacklist[] = {
+ {"preempt_schedule",},
+ {NULL} /* Terminator */
+};
+
#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
/*
* kprobe->ainsn.insn points to the copy of the instruction to be
}
}
+static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
+{
+ unsigned long flags;
+ struct kretprobe_instance *ri;
+ struct hlist_node *pos, *next;
+ /* 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);
+ }
+ spin_unlock_irqrestore(&kretprobe_lock, flags);
+ free_rp_inst(rp);
+}
+
/*
* Keep all fields in the kprobe consistent
*/
static int __kprobes in_kprobes_functions(unsigned long addr)
{
+ struct kprobe_blackpoint *kb;
+
if (addr >= (unsigned long)__kprobes_text_start &&
addr < (unsigned long)__kprobes_text_end)
return -EINVAL;
+ /*
+ * If there exists a kprobe_blacklist, verify and
+ * fail any probe registration in the prohibited area
+ */
+ for (kb = kprobe_blacklist; kb->name != NULL; kb++) {
+ if (kb->start_addr) {
+ if (addr >= kb->start_addr &&
+ addr < (kb->start_addr + kb->range))
+ return -EINVAL;
+ }
+ }
return 0;
}
}
p->nmissed = 0;
+ INIT_LIST_HEAD(&p->list);
mutex_lock(&kprobe_mutex);
old_p = get_kprobe(p->addr);
if (old_p) {
return ret;
}
-int __kprobes register_kprobe(struct kprobe *p)
-{
- return __register_kprobe(p, (unsigned long)__builtin_return_address(0));
-}
-
-void __kprobes unregister_kprobe(struct kprobe *p)
+/*
+ * Unregister a kprobe without a scheduler synchronization.
+ */
+static int __kprobes __unregister_kprobe_top(struct kprobe *p)
{
- struct module *mod;
struct kprobe *old_p, *list_p;
- int cleanup_p;
- mutex_lock(&kprobe_mutex);
old_p = get_kprobe(p->addr);
- if (unlikely(!old_p)) {
- mutex_unlock(&kprobe_mutex);
- return;
- }
+ if (unlikely(!old_p))
+ 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;
- mutex_unlock(&kprobe_mutex);
- return;
+ return -EINVAL;
}
valid_p:
if (old_p == p ||
(old_p->pre_handler == aggr_pre_handler &&
- p->list.next == &old_p->list && p->list.prev == &old_p->list)) {
+ list_is_singular(&old_p->list))) {
/*
* Only probe on the hash list. Disarm only if kprobes are
* enabled - otherwise, the breakpoint would already have
if (kprobe_enabled)
arch_disarm_kprobe(p);
hlist_del_rcu(&old_p->hlist);
- cleanup_p = 1;
} else {
+ if (p->break_handler)
+ old_p->break_handler = NULL;
+ if (p->post_handler) {
+ list_for_each_entry_rcu(list_p, &old_p->list, list) {
+ if ((list_p != p) && (list_p->post_handler))
+ goto noclean;
+ }
+ old_p->post_handler = NULL;
+ }
+noclean:
list_del_rcu(&p->list);
- cleanup_p = 0;
}
+ return 0;
+}
- mutex_unlock(&kprobe_mutex);
+static void __kprobes __unregister_kprobe_bottom(struct kprobe *p)
+{
+ struct module *mod;
+ struct kprobe *old_p;
- synchronize_sched();
if (p->mod_refcounted) {
mod = module_text_address((unsigned long)p->addr);
if (mod)
module_put(mod);
}
- if (cleanup_p) {
- if (p != old_p) {
- list_del_rcu(&p->list);
+ 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);
}
arch_remove_kprobe(p);
- } else {
- mutex_lock(&kprobe_mutex);
- if (p->break_handler)
- old_p->break_handler = NULL;
- if (p->post_handler){
- list_for_each_entry_rcu(list_p, &old_p->list, list){
- if (list_p->post_handler){
- cleanup_p = 2;
- break;
- }
- }
- if (cleanup_p == 0)
- old_p->post_handler = NULL;
+ }
+}
+
+static int __register_kprobes(struct kprobe **kps, int num,
+ unsigned long called_from)
+{
+ 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);
+ break;
}
- mutex_unlock(&kprobe_mutex);
}
+ 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));
+}
+
+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));
+}
+
+void __kprobes unregister_kprobes(struct kprobe **kps, int num)
+{
+ int i;
+
+ if (num <= 0)
+ return;
+ mutex_lock(&kprobe_mutex);
+ for (i = 0; i < num; i++)
+ if (__unregister_kprobe_top(kps[i]) < 0)
+ kps[i]->addr = NULL;
+ mutex_unlock(&kprobe_mutex);
+
+ synchronize_sched();
+ for (i = 0; i < num; i++)
+ if (kps[i]->addr)
+ __unregister_kprobe_bottom(kps[i]);
}
static struct notifier_block kprobe_exceptions_nb = {
return (unsigned long)entry;
}
-int __kprobes register_jprobe(struct jprobe *jp)
+static int __register_jprobes(struct jprobe **jps, int num,
+ unsigned long called_from)
{
- 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, called_from);
+ }
+ if (ret < 0 && i > 0) {
+ unregister_jprobes(jps, i);
+ break;
+ }
+ }
+ return ret;
+}
- /* 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,
+int __kprobes register_jprobe(struct jprobe *jp)
+{
+ return __register_jprobes(&jp, 1,
(unsigned long)__builtin_return_address(0));
}
void __kprobes unregister_jprobe(struct jprobe *jp)
{
- unregister_kprobe(&jp->kp);
+ unregister_jprobes(&jp, 1);
+}
+
+int __kprobes register_jprobes(struct jprobe **jps, int num)
+{
+ return __register_jprobes(jps, num,
+ (unsigned long)__builtin_return_address(0));
+}
+
+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);
+ }
}
#ifdef CONFIG_KRETPROBES
return 0;
}
-int __kprobes register_kretprobe(struct kretprobe *rp)
+static int __kprobes __register_kretprobe(struct kretprobe *rp,
+ unsigned long called_from)
{
int ret = 0;
struct kretprobe_instance *inst;
rp->nmissed = 0;
/* Establish function entry probe point */
- if ((ret = __register_kprobe(&rp->kp,
- (unsigned long)__builtin_return_address(0))) != 0)
+ ret = __register_kprobe(&rp->kp, called_from);
+ if (ret != 0)
free_rp_inst(rp);
return ret;
}
+static int __register_kretprobes(struct kretprobe **rps, int num,
+ unsigned long called_from)
+{
+ 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);
+ break;
+ }
+ }
+ return ret;
+}
+
+int __kprobes register_kretprobe(struct kretprobe *rp)
+{
+ return __register_kretprobes(&rp, 1,
+ (unsigned long)__builtin_return_address(0));
+}
+
+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));
+}
+
+void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
+{
+ int i;
+
+ if (num <= 0)
+ return;
+ mutex_lock(&kprobe_mutex);
+ for (i = 0; i < num; i++)
+ if (__unregister_kprobe_top(&rps[i]->kp) < 0)
+ rps[i]->kp.addr = NULL;
+ mutex_unlock(&kprobe_mutex);
+
+ synchronize_sched();
+ for (i = 0; i < num; i++) {
+ if (rps[i]->kp.addr) {
+ __unregister_kprobe_bottom(&rps[i]->kp);
+ cleanup_rp_inst(rps[i]);
+ }
+ }
+}
+
#else /* CONFIG_KRETPROBES */
int __kprobes register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
}
-static int __kprobes pre_handler_kretprobe(struct kprobe *p,
- struct pt_regs *regs)
+int __kprobes register_kretprobes(struct kretprobe **rps, int num)
{
- return 0;
+ return -ENOSYS;
}
-#endif /* CONFIG_KRETPROBES */
-
void __kprobes unregister_kretprobe(struct kretprobe *rp)
{
- unsigned long flags;
- struct kretprobe_instance *ri;
- struct hlist_node *pos, *next;
+}
- unregister_kprobe(&rp->kp);
+void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
+{
+}
- /* 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);
- }
- spin_unlock_irqrestore(&kretprobe_lock, flags);
- free_rp_inst(rp);
+static int __kprobes pre_handler_kretprobe(struct kprobe *p,
+ struct pt_regs *regs)
+{
+ return 0;
}
+#endif /* CONFIG_KRETPROBES */
+
static int __init init_kprobes(void)
{
int i, err = 0;
+ unsigned long offset = 0, size = 0;
+ char *modname, namebuf[128];
+ const char *symbol_name;
+ void *addr;
+ struct kprobe_blackpoint *kb;
/* FIXME allocate the probe table, currently defined statically */
/* initialize all list heads */
INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
}
+ /*
+ * Lookup and populate the kprobe_blacklist.
+ *
+ * Unlike the kretprobe blacklist, we'll need to determine
+ * the range of addresses that belong to the said functions,
+ * since a kprobe need not necessarily be at the beginning
+ * of a function.
+ */
+ for (kb = kprobe_blacklist; kb->name != NULL; kb++) {
+ kprobe_lookup_name(kb->name, addr);
+ if (!addr)
+ continue;
+
+ kb->start_addr = (unsigned long)addr;
+ symbol_name = kallsyms_lookup(kb->start_addr,
+ &size, &offset, &modname, namebuf);
+ if (!symbol_name)
+ kb->range = 0;
+ else
+ kb->range = size;
+ }
+
if (kretprobe_blacklist_size) {
/* lookup the function address from its name */
for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
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);
+EXPORT_SYMBOL_GPL(register_jprobes);
+EXPORT_SYMBOL_GPL(unregister_jprobes);
#ifdef CONFIG_KPROBES
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.openpandora.org / pandora-kernel.git / blobdiff