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Message-ID: <52F1B1CE.2040204@gmail.com>
Date: Wed, 05 Feb 2014 11:36:46 +0800
From: Chen Gang <gang.chen.5i5j@...il.com>
To: Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
CC: ananth@...ibm.com, anil.s.keshavamurthy@...el.com,
Håvard Skinnemoen
<hskinnemoen@...il.com>, David Miller <davem@...emloft.net>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Hans-Christian Egtvedt <egtvedt@...fundet.no>,
"yrl.pp-manager.tt@...achi.com" <yrl.pp-manager.tt@...achi.com>,
Ingo Molnar <mingo@...e.hu>
Subject: [PATCH] kernel/kprobes.c: move kretprobe implementation to CONFIG_KRETPROBES
area
When CONFIG_KRETPROBES disabled, kretprobe implementation are useless,
so need move them to CONFIG_KPROBES area.
- move all kretprobe* to CONFIG_KPROBES area and dummy outside.
- define kretprobe_flush_task() to let kprobe_flush_task() call.
- define init_kretprobes() to let init_kprobes() call.
Signed-off-by: Chen Gang <gang.chen.5i5j@...il.com>
---
kernel/kprobes.c | 323 +++++++++++++++++++++++++++++++------------------------
1 file changed, 181 insertions(+), 142 deletions(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ceeadfc..0619536 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -69,7 +69,6 @@
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 kprobes_all_disarmed;
@@ -77,14 +76,6 @@ static bool kprobes_all_disarmed;
/* This protects kprobe_table and optimizing_list */
static DEFINE_MUTEX(kprobe_mutex);
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
-static struct {
- raw_spinlock_t lock ____cacheline_aligned_in_smp;
-} kretprobe_table_locks[KPROBE_TABLE_SIZE];
-
-static raw_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
@@ -1079,125 +1070,6 @@ void __kprobes kprobes_inc_nmissed_count(struct kprobe *p)
return;
}
-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);
- INIT_HLIST_NODE(&ri->hlist);
- if (likely(rp)) {
- raw_spin_lock(&rp->lock);
- hlist_add_head(&ri->hlist, &rp->free_instances);
- raw_spin_unlock(&rp->lock);
- } else
- /* Unregistering */
- hlist_add_head(&ri->hlist, head);
-}
-
-void __kprobes kretprobe_hash_lock(struct task_struct *tsk,
- struct hlist_head **head, unsigned long *flags)
-__acquires(hlist_lock)
-{
- unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
- raw_spinlock_t *hlist_lock;
-
- *head = &kretprobe_inst_table[hash];
- hlist_lock = kretprobe_table_lock_ptr(hash);
- raw_spin_lock_irqsave(hlist_lock, *flags);
-}
-
-static void __kprobes kretprobe_table_lock(unsigned long hash,
- unsigned long *flags)
-__acquires(hlist_lock)
-{
- raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
- raw_spin_lock_irqsave(hlist_lock, *flags);
-}
-
-void __kprobes kretprobe_hash_unlock(struct task_struct *tsk,
- unsigned long *flags)
-__releases(hlist_lock)
-{
- unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
- raw_spinlock_t *hlist_lock;
-
- hlist_lock = kretprobe_table_lock_ptr(hash);
- raw_spin_unlock_irqrestore(hlist_lock, *flags);
-}
-
-static void __kprobes kretprobe_table_unlock(unsigned long hash,
- unsigned long *flags)
-__releases(hlist_lock)
-{
- raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
- raw_spin_unlock_irqrestore(hlist_lock, *flags);
-}
-
-/*
- * This function is called from finish_task_switch when task tk becomes dead,
- * so that we can recycle any function-return probe instances associated
- * with this task. These left over instances represent probed functions
- * that have been called but will never return.
- */
-void __kprobes kprobe_flush_task(struct task_struct *tk)
-{
- struct kretprobe_instance *ri;
- struct hlist_head *head, empty_rp;
- struct hlist_node *tmp;
- unsigned long hash, flags = 0;
-
- if (unlikely(!kprobes_initialized))
- /* Early boot. kretprobe_table_locks not yet initialized. */
- return;
-
- INIT_HLIST_HEAD(&empty_rp);
- hash = hash_ptr(tk, KPROBE_HASH_BITS);
- head = &kretprobe_inst_table[hash];
- kretprobe_table_lock(hash, &flags);
- hlist_for_each_entry_safe(ri, tmp, head, hlist) {
- if (ri->task == tk)
- recycle_rp_inst(ri, &empty_rp);
- }
- kretprobe_table_unlock(hash, &flags);
- hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
- hlist_del(&ri->hlist);
- kfree(ri);
- }
-}
-
-static inline void free_rp_inst(struct kretprobe *rp)
-{
- struct kretprobe_instance *ri;
- struct hlist_node *next;
-
- hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) {
- hlist_del(&ri->hlist);
- kfree(ri);
- }
-}
-
-static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
-{
- unsigned long flags, hash;
- struct kretprobe_instance *ri;
- struct hlist_node *next;
- struct hlist_head *head;
-
- /* No race here */
- for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
- kretprobe_table_lock(hash, &flags);
- head = &kretprobe_inst_table[hash];
- hlist_for_each_entry_safe(ri, next, head, hlist) {
- if (ri->rp == rp)
- ri->rp = NULL;
- }
- kretprobe_table_unlock(hash, &flags);
- }
- free_rp_inst(rp);
-}
-
/*
* Add the new probe to ap->list. Fail if this is the
* second jprobe at the address - two jprobes can't coexist
@@ -1764,6 +1636,55 @@ void __kprobes unregister_jprobes(struct jprobe **jps, int num)
EXPORT_SYMBOL_GPL(unregister_jprobes);
#ifdef CONFIG_KRETPROBES
+static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
+static struct {
+ raw_spinlock_t lock ____cacheline_aligned_in_smp;
+} kretprobe_table_locks[KPROBE_TABLE_SIZE];
+
+static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
+{
+ return &(kretprobe_table_locks[hash].lock);
+}
+
+void __kprobes kretprobe_hash_lock(struct task_struct *tsk,
+ struct hlist_head **head, unsigned long *flags)
+__acquires(hlist_lock)
+{
+ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
+ raw_spinlock_t *hlist_lock;
+
+ *head = &kretprobe_inst_table[hash];
+ hlist_lock = kretprobe_table_lock_ptr(hash);
+ raw_spin_lock_irqsave(hlist_lock, *flags);
+}
+
+void __kprobes kretprobe_hash_unlock(struct task_struct *tsk,
+ unsigned long *flags)
+__releases(hlist_lock)
+{
+ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
+ raw_spinlock_t *hlist_lock;
+
+ hlist_lock = kretprobe_table_lock_ptr(hash);
+ raw_spin_unlock_irqrestore(hlist_lock, *flags);
+}
+
+static void __kprobes kretprobe_table_lock(unsigned long hash,
+ unsigned long *flags)
+__acquires(hlist_lock)
+{
+ raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ raw_spin_lock_irqsave(hlist_lock, *flags);
+}
+
+static void __kprobes kretprobe_table_unlock(unsigned long hash,
+ unsigned long *flags)
+__releases(hlist_lock)
+{
+ raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ raw_spin_unlock_irqrestore(hlist_lock, *flags);
+}
+
/*
* This kprobe pre_handler is registered with every kretprobe. When probe
* hits it will set up the return probe.
@@ -1808,6 +1729,17 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p,
return 0;
}
+static inline void free_rp_inst(struct kretprobe *rp)
+{
+ struct kretprobe_instance *ri;
+ struct hlist_node *next;
+
+ hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
+}
+
int __kprobes register_kretprobe(struct kretprobe *rp)
{
int ret = 0;
@@ -1885,6 +1817,26 @@ void __kprobes unregister_kretprobe(struct kretprobe *rp)
}
EXPORT_SYMBOL_GPL(unregister_kretprobe);
+static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
+{
+ unsigned long flags, hash;
+ struct kretprobe_instance *ri;
+ struct hlist_node *next;
+ struct hlist_head *head;
+
+ /* No race here */
+ for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
+ kretprobe_table_lock(hash, &flags);
+ head = &kretprobe_inst_table[hash];
+ hlist_for_each_entry_safe(ri, next, head, hlist) {
+ if (ri->rp == rp)
+ ri->rp = NULL;
+ }
+ kretprobe_table_unlock(hash, &flags);
+ }
+ free_rp_inst(rp);
+}
+
void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
{
int i;
@@ -1907,7 +1859,78 @@ void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
}
EXPORT_SYMBOL_GPL(unregister_kretprobes);
+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);
+ INIT_HLIST_NODE(&ri->hlist);
+ if (likely(rp)) {
+ raw_spin_lock(&rp->lock);
+ hlist_add_head(&ri->hlist, &rp->free_instances);
+ raw_spin_unlock(&rp->lock);
+ } else
+ /* Unregistering */
+ hlist_add_head(&ri->hlist, head);
+}
+
+static void __kprobes kretprobe_flush_task(struct task_struct *tk)
+{
+ struct kretprobe_instance *ri;
+ struct hlist_head *head, empty_rp;
+ struct hlist_node *tmp;
+ unsigned long hash, flags = 0;
+
+ if (unlikely(!kprobes_initialized))
+ /* Early boot. kretprobe_table_locks not yet initialized. */
+ return;
+
+ INIT_HLIST_HEAD(&empty_rp);
+ hash = hash_ptr(tk, KPROBE_HASH_BITS);
+ head = &kretprobe_inst_table[hash];
+ kretprobe_table_lock(hash, &flags);
+ hlist_for_each_entry_safe(ri, tmp, head, hlist) {
+ if (ri->task == tk)
+ recycle_rp_inst(ri, &empty_rp);
+ }
+ kretprobe_table_unlock(hash, &flags);
+ hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
+}
+
+static void __init init_kretprobes(void)
+{
+ int i;
+
+ /* FIXME allocate the probe table, currently defined statically */
+ /* initialize all list heads */
+ for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
+ INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
+ raw_spin_lock_init(&(kretprobe_table_locks[i].lock));
+ }
+
+ if (kretprobe_blacklist_size) {
+ /* lookup the function address from its name */
+ for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
+ kprobe_lookup_name(kretprobe_blacklist[i].name,
+ kretprobe_blacklist[i].addr);
+ if (!kretprobe_blacklist[i].addr)
+ printk(KERN_WARNING
+ "kretprobe: lookup failed: %s\n",
+ kretprobe_blacklist[i].name);
+ }
+ }
+}
+
#else /* CONFIG_KRETPROBES */
+
+#define kretprobe_flush_task(p) do {} while (0)
+#define init_kretprobes() do {} while (0)
+
int __kprobes register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
@@ -1936,8 +1959,35 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p,
return 0;
}
+void __kprobes recycle_rp_inst(struct kretprobe_instance *ri,
+ struct hlist_head *head)
+{
+}
+
+void __kprobes kretprobe_hash_lock(struct task_struct *tsk,
+ struct hlist_head **head, unsigned long *flags)
+__acquires(hlist_lock)
+{
+}
+
+void __kprobes kretprobe_hash_unlock(struct task_struct *tsk,
+ unsigned long *flags)
+__releases(hlist_lock)
+{
+}
#endif /* CONFIG_KRETPROBES */
+/*
+ * This function is called from finish_task_switch when task tk becomes dead,
+ * so that we can recycle any function-return probe instances associated
+ * with this task. These left over instances represent probed functions
+ * that have been called but will never return.
+ */
+void __kprobes kprobe_flush_task(struct task_struct *tk)
+{
+ kretprobe_flush_task(tk);
+}
+
/* Set the kprobe gone and remove its instruction buffer. */
static void __kprobes kill_kprobe(struct kprobe *p)
{
@@ -2073,11 +2123,8 @@ static int __init init_kprobes(void)
/* FIXME allocate the probe table, currently defined statically */
/* initialize all list heads */
- for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
+ for (i = 0; i < KPROBE_TABLE_SIZE; i++)
INIT_HLIST_HEAD(&kprobe_table[i]);
- INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
- raw_spin_lock_init(&(kretprobe_table_locks[i].lock));
- }
/*
* Lookup and populate the kprobe_blacklist.
@@ -2101,16 +2148,8 @@ static int __init init_kprobes(void)
kb->range = size;
}
- if (kretprobe_blacklist_size) {
- /* lookup the function address from its name */
- for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
- kprobe_lookup_name(kretprobe_blacklist[i].name,
- kretprobe_blacklist[i].addr);
- if (!kretprobe_blacklist[i].addr)
- printk("kretprobe: lookup failed: %s\n",
- kretprobe_blacklist[i].name);
- }
- }
+ /* Initialize kretprobes */
+ init_kretprobes();
#if defined(CONFIG_OPTPROBES)
#if defined(__ARCH_WANT_KPROBES_INSN_SLOT)
--
1.7.11.7
--
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