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authorKeshavamurthy Anil S <anil.s.keshavamurthy@intel.com>2006-01-09 20:52:44 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-10 08:01:40 -0800
commitf709b122343fb9a010b6cf2d5559641f1820f7c9 (patch)
tree5019515d4debd995570ffd35b6311fdd26456306
parent49a2a1b83ba6fa40c41968d6a28ba16e7ed0c3f7 (diff)
downloadop-kernel-dev-f709b122343fb9a010b6cf2d5559641f1820f7c9.zip
op-kernel-dev-f709b122343fb9a010b6cf2d5559641f1820f7c9.tar.gz
[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: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/powerpc/kernel/kprobes.c3
-rw-r--r--arch/x86_64/kernel/kprobes.c4
-rw-r--r--kernel/kprobes.c32
3 files changed, 20 insertions, 19 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 331e169..2cd32dd 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -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;
}
diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c
index 8b8943b..128e181 100644
--- a/arch/x86_64/kernel/kprobes.c
+++ b/arch/x86_64/kernel/kprobes.c
@@ -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);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index f14ccd3..f1c0e61 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -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);
}
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