kprobes: add (un)register_jprobes for batch registration

Introduce unregister_/register_jprobes() for jprobe batch registration.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 56 insertions, 9 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 5e3144ad9b64..1e0250cb9486 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -755,24 +755,69 @@ unsigned long __weak arch_deref_entry_point(void *entry)
         return (unsigned long)entry;
 }
 
-int __kprobes register_jprobe(struct jprobe *jp)
+static int __register_jprobes(struct jprobe **jps, int num,
+        unsigned long called_from)
 {
-        unsigned long addr = arch_deref_entry_point(jp->entry);
+        struct jprobe *jp;
+        int ret = 0, i;
 
-        if (!kernel_text_address(addr))
+        if (num <= 0)
                 return -EINVAL;
+        for (i = 0; i < num; i++) {
+                unsigned long addr;
+                jp = jps[i];
+                addr = arch_deref_entry_point(jp->entry);
+
+                if (!kernel_text_address(addr))
+                        ret = -EINVAL;
+                else {
+                        /* 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);
+                }
+                if (ret < 0 && i > 0) {
+                        unregister_jprobes(jps, i);
+                        break;
+                }
+        }
+        return ret;
+}
 
-        /* Todo: Verify probepoint is a function entry point */
-        jp->kp.pre_handler = setjmp_pre_handler;
-        jp->kp.break_handler = longjmp_break_handler;
-
-        return __register_kprobe(&jp->kp,
+int __kprobes register_jprobe(struct jprobe *jp)
+{
+        return __register_jprobes(&jp, 1,
                 (unsigned long)__builtin_return_address(0));
 }
 
 void __kprobes unregister_jprobe(struct jprobe *jp)
 {
-        unregister_kprobe(&jp->kp);
+        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;
+
+        if (num <= 0)
+                return;
+        mutex_lock(&kprobe_mutex);
+        for (i = 0; i < num; i++)
+                if (__unregister_kprobe_top(&jps[i]->kp) < 0)
+                        jps[i]->kp.addr = NULL;
+        mutex_unlock(&kprobe_mutex);
+
+        synchronize_sched();
+        for (i = 0; i < num; i++) {
+                if (jps[i]->kp.addr)
+                        __unregister_kprobe_bottom(&jps[i]->kp);
+        }
 }
 
 #ifdef CONFIG_KRETPROBES
@@ -1236,6 +1281,8 @@ EXPORT_SYMBOL_GPL(register_kprobes);
 EXPORT_SYMBOL_GPL(unregister_kprobes);
 EXPORT_SYMBOL_GPL(register_jprobe);
 EXPORT_SYMBOL_GPL(unregister_jprobe);
+EXPORT_SYMBOL_GPL(register_jprobes);
+EXPORT_SYMBOL_GPL(unregister_jprobes);
 #ifdef CONFIG_KPROBES
 EXPORT_SYMBOL_GPL(jprobe_return);
 #endif