kprobes: Simplify register_jprobes()

Re-factor jprobe registration functions as the current version is
getting too unwieldy. Move the actual jprobe registration to
register_jprobe() and re-organize code accordingly.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/089cae4bfe73767f765291ee0e6fb0c3d240e5f1.1499443367.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 16 insertions, 14 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a519219169fd..db3cd3e60bdd 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1771,24 +1771,13 @@ unsigned long __weak arch_deref_entry_point(void *entry)
 
 int register_jprobes(struct jprobe **jps, int num)
 {
-        struct jprobe *jp;
         int ret = 0, i;
 
         if (num <= 0)
                 return -EINVAL;
+
         for (i = 0; i < num; i++) {
-                unsigned long addr, offset;
-                jp = jps[i];
-                addr = arch_deref_entry_point(jp->entry);
-
-                /* Verify probepoint is a function entry point */
-                if (kallsyms_lookup_size_offset(addr, NULL, &offset) &&
-                    offset == 0) {
-                        jp->kp.pre_handler = setjmp_pre_handler;
-                        jp->kp.break_handler = longjmp_break_handler;
-                        ret = register_kprobe(&jp->kp);
-                } else
-                        ret = -EINVAL;
+                ret = register_jprobe(jps[i]);
 
                 if (ret < 0) {
                         if (i > 0)
@@ -1796,13 +1785,26 @@ int register_jprobes(struct jprobe **jps, int num)
                         break;
                 }
         }
+
         return ret;
 }
 EXPORT_SYMBOL_GPL(register_jprobes);
 
 int register_jprobe(struct jprobe *jp)
 {
-        return register_jprobes(&jp, 1);
+        unsigned long addr, offset;
+        struct kprobe *kp = &jp->kp;
+
+        /* Verify probepoint is a function entry point */
+        addr = arch_deref_entry_point(jp->entry);
+
+        if (kallsyms_lookup_size_offset(addr, NULL, &offset) && offset == 0) {
+                kp->pre_handler = setjmp_pre_handler;
+                kp->break_handler = longjmp_break_handler;
+                return register_kprobe(kp);
+        }
+
+        return -EINVAL;
 }
 EXPORT_SYMBOL_GPL(register_jprobe);