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Commit f709b122 authored by Keshavamurthy Anil S's avatar Keshavamurthy Anil S Committed by Linus Torvalds
Browse files

[PATCH] kprobes-changed-from-using-spinlock-to-mutex fix 



Based on some feedback from Oleg Nesterov, I have made few changes to
previously posted patch.

Signed-off-by: default avatarAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 49a2a1b8

arch/powerpc/kernel/kprobes.c

+0 −3
Original line number Diff line number Diff line
@@ -35,7 +35,6 @@ 
#include <asm/kdebug.h>

#include <asm/sstep.h>



static DECLARE_MUTEX(kprobe_mutex);

DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;

DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -54,9 +53,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) 


	/* insn must be on a special executable page on ppc64 */

	if (!ret) {

		down(&kprobe_mutex);

		p->ainsn.insn = get_insn_slot();

		up(&kprobe_mutex);

		if (!p->ainsn.insn)

			ret = -ENOMEM;

	}

arch/x86_64/kernel/kprobes.c

+2 −2
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ 
#include <asm/kdebug.h>



void jprobe_return_end(void);

void __kprobes arch_copy_kprobe(struct kprobe *p);

static void __kprobes arch_copy_kprobe(struct kprobe *p);



DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;

DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -180,7 +180,7 @@ static inline s32 *is_riprel(u8 *insn) 
	return NULL;

}



void __kprobes arch_copy_kprobe(struct kprobe *p)

static void __kprobes arch_copy_kprobe(struct kprobe *p)

{

	s32 *ripdisp;

	memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);

kernel/kprobes.c

+18 −14
Original line number Diff line number Diff line
@@ -431,7 +431,7 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p, 
		copy_kprobe(old_p, p);

		ret = add_new_kprobe(old_p, p);

	} else {

		ap = kcalloc(1, sizeof(struct kprobe), GFP_ATOMIC);

		ap = kcalloc(1, sizeof(struct kprobe), GFP_KERNEL);

		if (!ap)

			return -ENOMEM;

		add_aggr_kprobe(ap, old_p);
@@ -491,7 +491,8 @@ out: 
void __kprobes unregister_kprobe(struct kprobe *p)

{

	struct module *mod;

	struct kprobe *old_p, *cleanup_p;

	struct kprobe *old_p, *list_p;

	int cleanup_p;



	down(&kprobe_mutex);

	old_p = get_kprobe(p->addr);
@@ -499,22 +500,25 @@ void __kprobes unregister_kprobe(struct kprobe *p) 
		up(&kprobe_mutex);

		return;

	}



	if ((old_p->pre_handler == aggr_pre_handler) &&

	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;

		up(&kprobe_mutex);

		return;

	}

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)) {

		/* Only one element in the aggregate list */

		(p->list.prev == &old_p->list))) {

		/* Only probe on the hash list */

		arch_disarm_kprobe(p);

		hlist_del_rcu(&old_p->hlist);

		cleanup_p = old_p;

	} else if (old_p == p) {

		/* Only one kprobe element in the hash list */

		arch_disarm_kprobe(p);

		hlist_del_rcu(&p->hlist);

		cleanup_p = p;

		cleanup_p = 1;

	} else {

		list_del_rcu(&p->list);

		cleanup_p = NULL;

		cleanup_p = 0;

	}



	up(&kprobe_mutex);
@@ -524,7 +528,7 @@ void __kprobes unregister_kprobe(struct kprobe *p) 
		module_put(mod);



	if (cleanup_p) {

		if (cleanup_p->pre_handler == aggr_pre_handler) {

		if (p != old_p) {

			list_del_rcu(&p->list);

			kfree(old_p);

		}