#include <linux/freezer.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
+#include <linux/sysctl.h>
#include <linux/kdebug.h>
+#include <linux/memory.h>
+#include <linux/ftrace.h>
+#include <linux/cpu.h>
#include <asm-generic/sections.h>
#include <asm/cacheflush.h>
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;
static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
*/
static struct kprobe_blackpoint kprobe_blacklist[] = {
{"preempt_schedule",},
+ {"native_get_debugreg",},
+ {"irq_entries_start",},
+ {"common_interrupt",},
+ {"mcount",}, /* mcount can be called from everywhere */
{NULL} /* Terminator */
};
* stepping on the instruction on a vmalloced/kmalloced/data page
* is a recipe for disaster
*/
-#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;
int ngarbage;
+ char slot_used[];
+};
+
+#define KPROBE_INSN_PAGE_SIZE(slots) \
+ (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));
+}
+
enum kprobe_slot_state {
SLOT_CLEAN = 0,
SLOT_DIRTY = 1,
SLOT_USED = 2,
};
-static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */
-static struct hlist_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)
- ret = freeze_processes();
- if (ret == 0) {
- struct task_struct *p, *q;
- do_each_thread(p, q) {
- if (p != current && p->state == TASK_RUNNING &&
- p->pid != 0) {
- printk("Check failed: %s is running\n",p->comm);
- ret = -1;
- goto loop_end;
- }
- } while_each_thread(p, q);
- }
-loop_end:
- thaw_processes();
-#else
- synchronize_sched();
-#endif
- return ret;
-}
+static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_slots */
+static struct kprobe_insn_cache kprobe_insn_slots = {
+ .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages),
+ .insn_size = MAX_INSN_SIZE,
+ .nr_garbage = 0,
+};
+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(void)
+static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
{
struct kprobe_insn_page *kip;
- struct hlist_node *pos;
retry:
- hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
- if (kip->nused < INSNS_PER_PAGE) {
+ list_for_each_entry(kip, &c->pages, list) {
+ if (kip->nused < slots_per_page(c)) {
int i;
- for (i = 0; i < INSNS_PER_PAGE; i++) {
+ for (i = 0; i < slots_per_page(c); i++) {
if (kip->slot_used[i] == SLOT_CLEAN) {
kip->slot_used[i] = SLOT_USED;
kip->nused++;
- return kip->insns + (i * MAX_INSN_SIZE);
+ return kip->insns + (i * c->insn_size);
}
}
- /* Surprise! No unused slots. Fix kip->nused. */
- kip->nused = INSNS_PER_PAGE;
+ /* kip->nused is broken. Fix it. */
+ kip->nused = slots_per_page(c);
+ WARN_ON(1);
}
}
/* If there are any garbage slots, collect it and try again. */
- if (kprobe_garbage_slots && collect_garbage_slots() == 0) {
+ if (c->nr_garbage && collect_garbage_slots(c) == 0)
goto retry;
- }
- /* All out of space. Need to allocate a new page. Use slot 0. */
- kip = kmalloc(sizeof(struct kprobe_insn_page), GFP_KERNEL);
+
+ /* 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;
kfree(kip);
return NULL;
}
- INIT_HLIST_NODE(&kip->hlist);
- hlist_add_head(&kip->hlist, &kprobe_insn_pages);
- memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
+ INIT_LIST_HEAD(&kip->list);
+ memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c));
kip->slot_used[0] = SLOT_USED;
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;
+ kprobe_opcode_t *ret = NULL;
+
mutex_lock(&kprobe_insn_mutex);
- ret = __get_insn_slot();
+ ret = __get_insn_slot(&kprobe_insn_slots);
mutex_unlock(&kprobe_insn_mutex);
+
return ret;
}
* 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(&kip->list)) {
+ list_del(&kip->list);
module_free(NULL, kip->insns);
kfree(kip);
}
return 0;
}
-static int __kprobes collect_garbage_slots(void)
+static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c)
{
- struct kprobe_insn_page *kip;
- struct hlist_node *pos, *next;
- int safety;
+ struct kprobe_insn_page *kip, *next;
- /* Ensure no-one is preepmted on the garbages */
- mutex_unlock(&kprobe_insn_mutex);
- safety = check_safety();
- mutex_lock(&kprobe_insn_mutex);
- if (safety != 0)
- return -EAGAIN;
+ /* Ensure no-one is interrupted on the garbages */
+ synchronize_sched();
- hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {
+ list_for_each_entry_safe(kip, next, &c->pages, list) {
int i;
if (kip->ngarbage == 0)
continue;
kip->ngarbage = 0; /* we will collect all garbages */
- for (i = 0; i < INSNS_PER_PAGE; i++) {
+ for (i = 0; i < slots_per_page(c); i++) {
if (kip->slot_used[i] == SLOT_DIRTY &&
collect_one_slot(kip, i))
break;
}
}
- kprobe_garbage_slots = 0;
+ c->nr_garbage = 0;
return 0;
}
-void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
+static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c,
+ kprobe_opcode_t *slot, int dirty)
{
struct kprobe_insn_page *kip;
- struct hlist_node *pos;
- mutex_lock(&kprobe_insn_mutex);
- hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
- if (kip->insns <= slot &&
- slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
- int i = (slot - kip->insns) / MAX_INSN_SIZE;
+ list_for_each_entry(kip, &c->pages, list) {
+ long idx = ((long)slot - (long)kip->insns) / c->insn_size;
+ if (idx >= 0 && idx < slots_per_page(c)) {
+ WARN_ON(kip->slot_used[idx] != SLOT_USED);
if (dirty) {
- kip->slot_used[i] = SLOT_DIRTY;
+ kip->slot_used[idx] = SLOT_DIRTY;
kip->ngarbage++;
- } else {
- collect_one_slot(kip, i);
- }
- break;
+ if (++c->nr_garbage > slots_per_page(c))
+ collect_garbage_slots(c);
+ } else
+ collect_one_slot(kip, idx);
+ return;
}
}
+ /* Could not free this slot. */
+ WARN_ON(1);
+}
- if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE)
- collect_garbage_slots();
-
+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 = {
+ .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
/* We have preemption disabled.. so it is safe to use __ versions */
if (p->addr == addr)
return p;
}
+
return NULL;
}
+static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs);
+
+/* Return true if the kprobe is an aggregator */
+static inline int kprobe_aggrprobe(struct kprobe *p)
+{
+ return p->pre_handler == aggr_pre_handler;
+}
+
+/*
+ * Keep all fields in the kprobe consistent
+ */
+static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p)
+{
+ memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t));
+ memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn));
+}
+
+#ifdef CONFIG_OPTPROBES
+/* NOTE: change this value only with kprobe_mutex held */
+static bool kprobes_allow_optimization;
+
+/*
+ * Call all pre_handler on the list, but ignores its return value.
+ * This must be called from arch-dep optimized caller.
+ */
+void __kprobes opt_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct kprobe *kp;
+
+ list_for_each_entry_rcu(kp, &p->list, list) {
+ if (kp->pre_handler && likely(!kprobe_disabled(kp))) {
+ set_kprobe_instance(kp);
+ kp->pre_handler(kp, regs);
+ }
+ reset_kprobe_instance();
+ }
+}
+
+/* Return true(!0) if the kprobe is ready for optimization. */
+static inline int kprobe_optready(struct kprobe *p)
+{
+ struct optimized_kprobe *op;
+
+ if (kprobe_aggrprobe(p)) {
+ op = container_of(p, struct optimized_kprobe, kp);
+ return arch_prepared_optinsn(&op->optinsn);
+ }
+
+ return 0;
+}
+
+/*
+ * Return an optimized kprobe whose optimizing code replaces
+ * instructions including addr (exclude breakpoint).
+ */
+struct kprobe *__kprobes get_optimized_kprobe(unsigned long addr)
+{
+ int i;
+ struct kprobe *p = NULL;
+ struct optimized_kprobe *op;
+
+ /* Don't check i == 0, since that is a breakpoint case. */
+ for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++)
+ p = get_kprobe((void *)(addr - i));
+
+ if (p && kprobe_optready(p)) {
+ op = container_of(p, struct optimized_kprobe, kp);
+ if (arch_within_optimized_kprobe(op, addr))
+ return p;
+ }
+
+ return NULL;
+}
+
+/* Optimization staging list, protected by kprobe_mutex */
+static LIST_HEAD(optimizing_list);
+
+static void kprobe_optimizer(struct work_struct *work);
+static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
+#define OPTIMIZE_DELAY 5
+
+/* Kprobe jump optimizer */
+static __kprobes void kprobe_optimizer(struct work_struct *work)
+{
+ struct optimized_kprobe *op, *tmp;
+
+ /* Lock modules while optimizing kprobes */
+ mutex_lock(&module_mutex);
+ mutex_lock(&kprobe_mutex);
+ if (kprobes_all_disarmed || !kprobes_allow_optimization)
+ goto end;
+
+ /*
+ * Wait for quiesence period to ensure all running interrupts
+ * are done. Because optprobe may modify multiple instructions
+ * there is a chance that Nth instruction is interrupted. In that
+ * case, running interrupt can return to 2nd-Nth byte of jump
+ * instruction. This wait is for avoiding it.
+ */
+ synchronize_sched();
+
+ /*
+ * The optimization/unoptimization refers online_cpus via
+ * stop_machine() and cpu-hotplug modifies online_cpus.
+ * And same time, text_mutex will be held in cpu-hotplug and here.
+ * This combination can cause a deadlock (cpu-hotplug try to lock
+ * text_mutex but stop_machine can not be done because online_cpus
+ * has been changed)
+ * To avoid this deadlock, we need to call get_online_cpus()
+ * for preventing cpu-hotplug outside of text_mutex locking.
+ */
+ get_online_cpus();
+ mutex_lock(&text_mutex);
+ list_for_each_entry_safe(op, tmp, &optimizing_list, list) {
+ WARN_ON(kprobe_disabled(&op->kp));
+ if (arch_optimize_kprobe(op) < 0)
+ op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
+ list_del_init(&op->list);
+ }
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
+end:
+ mutex_unlock(&kprobe_mutex);
+ mutex_unlock(&module_mutex);
+}
+
+/* Optimize kprobe if p is ready to be optimized */
+static __kprobes void optimize_kprobe(struct kprobe *p)
+{
+ struct optimized_kprobe *op;
+
+ /* Check if the kprobe is disabled or not ready for optimization. */
+ if (!kprobe_optready(p) || !kprobes_allow_optimization ||
+ (kprobe_disabled(p) || kprobes_all_disarmed))
+ return;
+
+ /* Both of break_handler and post_handler are not supported. */
+ if (p->break_handler || p->post_handler)
+ return;
+
+ op = container_of(p, struct optimized_kprobe, kp);
+
+ /* Check there is no other kprobes at the optimized instructions */
+ if (arch_check_optimized_kprobe(op) < 0)
+ return;
+
+ /* Check if it is already optimized. */
+ if (op->kp.flags & KPROBE_FLAG_OPTIMIZED)
+ return;
+
+ op->kp.flags |= KPROBE_FLAG_OPTIMIZED;
+ list_add(&op->list, &optimizing_list);
+ if (!delayed_work_pending(&optimizing_work))
+ schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY);
+}
+
+/* Unoptimize a kprobe if p is optimized */
+static __kprobes void unoptimize_kprobe(struct kprobe *p)
+{
+ struct optimized_kprobe *op;
+
+ if ((p->flags & KPROBE_FLAG_OPTIMIZED) && kprobe_aggrprobe(p)) {
+ op = container_of(p, struct optimized_kprobe, kp);
+ if (!list_empty(&op->list))
+ /* Dequeue from the optimization queue */
+ list_del_init(&op->list);
+ else
+ /* Replace jump with break */
+ arch_unoptimize_kprobe(op);
+ op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
+ }
+}
+
+/* Remove optimized instructions */
+static void __kprobes kill_optimized_kprobe(struct kprobe *p)
+{
+ struct optimized_kprobe *op;
+
+ op = container_of(p, struct optimized_kprobe, kp);
+ if (!list_empty(&op->list)) {
+ /* Dequeue from the optimization queue */
+ list_del_init(&op->list);
+ op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
+ }
+ /* Don't unoptimize, because the target code will be freed. */
+ arch_remove_optimized_kprobe(op);
+}
+
+/* Try to prepare optimized instructions */
+static __kprobes void prepare_optimized_kprobe(struct kprobe *p)
+{
+ struct optimized_kprobe *op;
+
+ op = container_of(p, struct optimized_kprobe, kp);
+ arch_prepare_optimized_kprobe(op);
+}
+
+/* Free optimized instructions and optimized_kprobe */
+static __kprobes void free_aggr_kprobe(struct kprobe *p)
+{
+ struct optimized_kprobe *op;
+
+ op = container_of(p, struct optimized_kprobe, kp);
+ arch_remove_optimized_kprobe(op);
+ kfree(op);
+}
+
+/* Allocate new optimized_kprobe and try to prepare optimized instructions */
+static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
+{
+ struct optimized_kprobe *op;
+
+ op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL);
+ if (!op)
+ return NULL;
+
+ INIT_LIST_HEAD(&op->list);
+ op->kp.addr = p->addr;
+ arch_prepare_optimized_kprobe(op);
+
+ return &op->kp;
+}
+
+static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p);
+
+/*
+ * Prepare an optimized_kprobe and optimize it
+ * NOTE: p must be a normal registered kprobe
+ */
+static __kprobes void try_to_optimize_kprobe(struct kprobe *p)
+{
+ struct kprobe *ap;
+ struct optimized_kprobe *op;
+
+ ap = alloc_aggr_kprobe(p);
+ if (!ap)
+ return;
+
+ op = container_of(ap, struct optimized_kprobe, kp);
+ if (!arch_prepared_optinsn(&op->optinsn)) {
+ /* If failed to setup optimizing, fallback to kprobe */
+ free_aggr_kprobe(ap);
+ return;
+ }
+
+ init_aggr_kprobe(ap, p);
+ optimize_kprobe(ap);
+}
+
+#ifdef CONFIG_SYSCTL
+static void __kprobes optimize_all_kprobes(void)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct kprobe *p;
+ unsigned int i;
+
+ /* If optimization is already allowed, just return */
+ if (kprobes_allow_optimization)
+ return;
+
+ kprobes_allow_optimization = true;
+ 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 (!kprobe_disabled(p))
+ optimize_kprobe(p);
+ }
+ mutex_unlock(&text_mutex);
+ printk(KERN_INFO "Kprobes globally optimized\n");
+}
+
+static void __kprobes unoptimize_all_kprobes(void)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct kprobe *p;
+ unsigned int i;
+
+ /* If optimization is already prohibited, just return */
+ if (!kprobes_allow_optimization)
+ return;
+
+ kprobes_allow_optimization = false;
+ printk(KERN_INFO "Kprobes globally unoptimized\n");
+ get_online_cpus(); /* For avoiding text_mutex deadlock */
+ 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 (!kprobe_disabled(p))
+ unoptimize_kprobe(p);
+ }
+ }
+
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
+ /* Allow all currently running kprobes to complete */
+ synchronize_sched();
+}
+
+int sysctl_kprobes_optimization;
+int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length,
+ loff_t *ppos)
+{
+ int ret;
+
+ mutex_lock(&kprobe_mutex);
+ sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0;
+ ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
+
+ if (sysctl_kprobes_optimization)
+ optimize_all_kprobes();
+ else
+ unoptimize_all_kprobes();
+ mutex_unlock(&kprobe_mutex);
+
+ return ret;
+}
+#endif /* CONFIG_SYSCTL */
+
+static void __kprobes __arm_kprobe(struct kprobe *p)
+{
+ struct kprobe *old_p;
+
+ /* Check collision with other optimized kprobes */
+ old_p = get_optimized_kprobe((unsigned long)p->addr);
+ if (unlikely(old_p))
+ unoptimize_kprobe(old_p); /* Fallback to unoptimized kprobe */
+
+ arch_arm_kprobe(p);
+ optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */
+}
+
+static void __kprobes __disarm_kprobe(struct kprobe *p)
+{
+ struct kprobe *old_p;
+
+ unoptimize_kprobe(p); /* Try to unoptimize */
+ arch_disarm_kprobe(p);
+
+ /* If another kprobe was blocked, optimize it. */
+ old_p = get_optimized_kprobe((unsigned long)p->addr);
+ if (unlikely(old_p))
+ optimize_kprobe(old_p);
+}
+
+#else /* !CONFIG_OPTPROBES */
+
+#define optimize_kprobe(p) do {} while (0)
+#define unoptimize_kprobe(p) do {} while (0)
+#define kill_optimized_kprobe(p) do {} while (0)
+#define prepare_optimized_kprobe(p) do {} while (0)
+#define try_to_optimize_kprobe(p) do {} while (0)
+#define __arm_kprobe(p) arch_arm_kprobe(p)
+#define __disarm_kprobe(p) arch_disarm_kprobe(p)
+
+static __kprobes void free_aggr_kprobe(struct kprobe *p)
+{
+ kfree(p);
+}
+
+static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
+{
+ return kzalloc(sizeof(struct kprobe), GFP_KERNEL);
+}
+#endif /* CONFIG_OPTPROBES */
+
+/* Arm a kprobe with text_mutex */
+static void __kprobes arm_kprobe(struct kprobe *kp)
+{
+ /*
+ * Here, since __arm_kprobe() doesn't use stop_machine(),
+ * this doesn't cause deadlock on text_mutex. So, we don't
+ * need get_online_cpus().
+ */
+ mutex_lock(&text_mutex);
+ __arm_kprobe(kp);
+ mutex_unlock(&text_mutex);
+}
+
+/* Disarm a kprobe with text_mutex */
+static void __kprobes disarm_kprobe(struct kprobe *kp)
+{
+ get_online_cpus(); /* For avoiding text_mutex deadlock */
+ mutex_lock(&text_mutex);
+ __disarm_kprobe(kp);
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
+}
+
/*
* 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();
void __kprobes kprobes_inc_nmissed_count(struct kprobe *p)
{
struct kprobe *kp;
- if (p->pre_handler != aggr_pre_handler) {
+ if (!kprobe_aggrprobe(p)) {
p->nmissed++;
} else {
list_for_each_entry_rcu(kp, &p->list, list)
}
/*
- * Keep all fields in the kprobe consistent
- */
-static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p)
-{
- memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t));
- memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn));
-}
-
-/*
-* 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 || p->post_handler)
+ unoptimize_kprobe(ap); /* Fall back to normal kprobe */
+
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;
}
* Fill in the required fields of the "manager kprobe". Replace the
* earlier kprobe in the hlist with the manager kprobe
*/
-static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
+static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
{
+ /* Copy p's insn slot to ap */
copy_kprobe(p, ap);
flush_insn_slot(ap);
ap->addr = p->addr;
+ ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED;
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);
- list_add_rcu(&p->list, &ap->list);
+ INIT_HLIST_NODE(&ap->hlist);
+ list_add_rcu(&p->list, &ap->list);
hlist_replace_rcu(&p->hlist, &ap->hlist);
}
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 {
- ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL);
+ if (!kprobe_aggrprobe(old_p)) {
+ /* If old_p is not an aggr_kprobe, create new aggr_kprobe. */
+ ap = alloc_aggr_kprobe(old_p);
if (!ap)
return -ENOMEM;
- add_aggr_kprobe(ap, old_p);
- copy_kprobe(ap, p);
- ret = add_new_kprobe(ap, p);
+ init_aggr_kprobe(ap, old_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;
+
+ /* Prepare optimized instructions if possible. */
+ prepare_optimized_kprobe(ap);
+
+ /*
+ * 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 ap's insn slot to p */
+ 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)) {
+ if (!kernel_text_address((unsigned long) p->addr) ||
+ in_kprobes_functions((unsigned long) p->addr) ||
+ ftrace_text_reserved(p->addr, 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);
if (probed_mod) {
- struct module *calling_mod;
- 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 != probed_mod) {
- if (unlikely(!try_module_get(probed_mod))) {
- preempt_enable();
- 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);
mutex_lock(&kprobe_mutex);
+
+ get_online_cpus(); /* For avoiding text_mutex deadlock. */
+ mutex_lock(&text_mutex);
+
old_p = get_kprobe(p->addr);
if (old_p) {
+ /* Since this may unoptimize old_p, locking text_mutex. */
ret = register_aggr_kprobe(old_p, p);
goto out;
}
hlist_add_head_rcu(&p->hlist,
&kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]);
- if (kprobe_enabled)
- arch_arm_kprobe(p);
+ if (!kprobes_all_disarmed && !kprobe_disabled(p))
+ __arm_kprobe(p);
+
+ /* Try to optimize kprobe */
+ try_to_optimize_kprobe(p);
out:
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
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 &&
+ (kprobe_aggrprobe(old_p) &&
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(old_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) {
+ if (kprobe_disabled(old_p))
+ disarm_kprobe(old_p);
+ else
+ /* Try to optimize this probe again */
+ optimize_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) {
- /*
- * Since we've already incremented refcount,
- * we don't need to disable preemption.
- */
- 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);
+ free_aggr_kprobe(old_p);
}
}
-static int __kprobes __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);
+ ret = register_kprobe(kps[i]);
if (ret < 0) {
if (i > 0)
unregister_kprobes(kps, i);
}
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;
}
-static int __kprobes __register_jprobes(struct jprobe **jps, int num,
- unsigned long called_from)
+int __kprobes register_jprobes(struct jprobe **jps, int num)
{
struct jprobe *jp;
int ret = 0, i;
/* 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);
+ ret = register_kprobe(&jp->kp);
}
if (ret < 0) {
if (i > 0)
}
return ret;
}
+EXPORT_SYMBOL_GPL(register_jprobes);
int __kprobes register_jprobe(struct jprobe *jp)
{
- return __register_jprobes(&jp, 1,
- (unsigned long)__builtin_return_address(0));
+ return register_jprobes(&jp, 1);
}
+EXPORT_SYMBOL_GPL(register_jprobe);
void __kprobes unregister_jprobe(struct jprobe *jp)
{
unregister_jprobes(&jp, 1);
}
-
-int __kprobes register_jprobes(struct jprobe **jps, int num)
-{
- return __register_jprobes(jps, num,
- (unsigned long)__builtin_return_address(0));
-}
+EXPORT_SYMBOL_GPL(unregister_jprobe);
void __kprobes unregister_jprobes(struct jprobe **jps, int num)
{
__unregister_kprobe_bottom(&jps[i]->kp);
}
}
+EXPORT_SYMBOL_GPL(unregister_jprobes);
#ifdef CONFIG_KRETPROBES
/*
ri->rp = rp;
ri->task = current;
- if (rp->entry_handler && rp->entry_handler(ri, regs)) {
- spin_unlock_irqrestore(&rp->lock, flags);
+ if (rp->entry_handler && rp->entry_handler(ri, regs))
return 0;
- }
arch_prepare_kretprobe(ri, regs);
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
}
spin_lock_init(&rp->lock);
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 __kprobes __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);
+ ret = register_kretprobe(rps[i]);
if (ret < 0) {
if (i > 0)
unregister_kretprobes(rps, i);
}
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 (kprobe_aggrprobe(p)) {
+ /*
+ * 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;
+ kill_optimized_kprobe(p);
+ }
+ /*
+ * 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;
}
}
- /* By default, kprobes are enabled */
- kprobe_enabled = true;
+#if defined(CONFIG_OPTPROBES)
+#if defined(__ARCH_WANT_KPROBES_INSN_SLOT)
+ /* Init kprobe_optinsn_slots */
+ kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE;
+#endif
+ /* By default, kprobes can be optimized */
+ kprobes_allow_optimization = true;
+#endif
+
+ /* 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)
#ifdef CONFIG_DEBUG_FS
static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p,
- const char *sym, int offset,char *modname)
+ const char *sym, int offset, char *modname, struct kprobe *pp)
{
char *kprobe_type;
kprobe_type = "j";
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 ",
+ p->addr, kprobe_type, sym, offset,
+ (modname ? modname : " "));
else
- seq_printf(pi, "%p %s %p\n", p->addr, kprobe_type, p->addr);
+ seq_printf(pi, "%p %s %p ",
+ p->addr, kprobe_type, p->addr);
+
+ if (!pp)
+ pp = p;
+ seq_printf(pi, "%s%s%s\n",
+ (kprobe_gone(p) ? "[GONE]" : ""),
+ ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""),
+ (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""));
}
static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos)
hlist_for_each_entry_rcu(p, node, head, hlist) {
sym = kallsyms_lookup((unsigned long)p->addr, NULL,
&offset, &modname, namebuf);
- if (p->pre_handler == aggr_pre_handler) {
+ if (kprobe_aggrprobe(p)) {
list_for_each_entry_rcu(kp, &p->list, list)
- report_probe(pi, kp, sym, offset, modname);
+ report_probe(pi, kp, sym, offset, modname, p);
} else
- report_probe(pi, p, sym, offset, modname);
+ report_probe(pi, p, sym, offset, modname, NULL);
}
preempt_enable();
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 (p != kp)
+ kp->flags &= ~KPROBE_FLAG_DISABLED;
+
+ if (!kprobes_all_disarmed && kprobe_disabled(p)) {
+ p->flags &= ~KPROBE_FLAG_DISABLED;
+ arm_kprobe(p);
+ }
+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;
+ /* Arming kprobes doesn't optimize kprobe itself */
+ 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))
+ __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");
+
+ /*
+ * Here we call get_online_cpus() for avoiding text_mutex deadlock,
+ * because disarming may also unoptimize kprobes.
+ */
+ get_online_cpus();
+ 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))
- arch_disarm_kprobe(p);
+ if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p))
+ __disarm_kprobe(p);
}
}
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
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);
-EXPORT_SYMBOL_GPL(register_jprobes);
-EXPORT_SYMBOL_GPL(unregister_jprobes);
+/* defined in arch/.../kernel/kprobes.c */
EXPORT_SYMBOL_GPL(jprobe_return);
-EXPORT_SYMBOL_GPL(register_kretprobe);
-EXPORT_SYMBOL_GPL(unregister_kretprobe);
-EXPORT_SYMBOL_GPL(register_kretprobes);
-EXPORT_SYMBOL_GPL(unregister_kretprobes);
Code Review / linux-2.6.git / blobdiff