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authorMasami Hiramatsu <mhiramat@redhat.com>2009-01-06 14:41:53 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 15:59:21 -0800
commit49ad2fd76c97133fb396edc24ded7fe26093a578 (patch)
tree59cf1df91ff982f16a17d56a4a76f159920c3904 /kernel/kprobes.c
parente8386a0cb22f4a2d439384212c494ad0bda848fe (diff)
downloadlinux-2.6.34-ux500-49ad2fd76c97133fb396edc24ded7fe26093a578.tar.gz
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: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c72
1 files changed, 14 insertions, 58 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index cb732a9aa55..ddefb9fae0c 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -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;
+ if (unlikely(!try_module_get(probed_mod))) {
+ preempt_enable();
+ return -EINVAL;
+ }
}
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;