[PATCH v2 2/3] kernel/kprobes: Simplify register_jprobes()

From: Naveen N. Rao
Date: Fri Jul 07 2017 - 13:08:21 EST


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@xxxxxxxxxx>
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
---
kernel/kprobes.c | 30 ++++++++++++++++--------------
1 file 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);

--
2.13.2