Commit 49ad2fd7 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Linus Torvalds
Browse files

kprobes: remove called_from argument 



Remove called_from argument from kprobes which had been used for
preventing self-refering of kernel module.  However, since we don't keep
module's refcount after registering kprobe any more, there is no reason to
check that.

This patch also simplifies registering/unregistering functions because we
don't need to use __builtin_return_address(0) which was passed to
called_from.

[ananth@in.ibm.com: build fix]
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e8386a0c

kernel/kprobes.c

+14 −58
Original line number Diff line number Diff line
@@ -644,8 +644,7 @@ static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) 
	return (kprobe_opcode_t *)(((char *)addr) + p->offset);

}



static int __kprobes __register_kprobe(struct kprobe *p,

	unsigned long called_from)

int __kprobes register_kprobe(struct kprobe *p)

{

	int ret = 0;

	struct kprobe *old_p;
@@ -670,19 +669,14 @@ static int __kprobes __register_kprobe(struct kprobe *p, 
	 */

	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 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;

		}

		} else

			probed_mod = NULL;

	}

	preempt_enable();
@@ -776,15 +770,14 @@ static void __kprobes __unregister_kprobe_bottom(struct kprobe *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);
@@ -794,26 +787,11 @@ static int __kprobes __register_kprobes(struct kprobe **kps, int num, 
	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;
@@ -842,8 +820,7 @@ unsigned long __weak arch_deref_entry_point(void *entry) 
	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;
@@ -861,7 +838,7 @@ static int __kprobes __register_jprobes(struct jprobe **jps, int num, 
			/* 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)
@@ -874,8 +851,7 @@ static int __kprobes __register_jprobes(struct jprobe **jps, int num, 


int __kprobes register_jprobe(struct jprobe *jp)

{

	return __register_jprobes(&jp, 1,

		(unsigned long)__builtin_return_address(0));

	return register_jprobes(&jp, 1);

}



void __kprobes unregister_jprobe(struct jprobe *jp)
@@ -883,12 +859,6 @@ 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));

}



void __kprobes unregister_jprobes(struct jprobe **jps, int num)

{

	int i;
@@ -951,8 +921,7 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, 
	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;
@@ -998,21 +967,20 @@ static int __kprobes __register_kretprobe(struct kretprobe *rp, 


	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;

}



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);
@@ -1022,23 +990,11 @@ static int __kprobes __register_kretprobes(struct kretprobe **rps, int num, 
	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;

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