uretprobes: Introduce uprobe_consumer->ret_handler()
Enclose return probes implementation, introduce ->ret_handler() and update
existing code to rely on ->handler() *and* ->ret_handler() for uprobe and
uretprobe respectively.
Signed-off-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 7312503..eb384e9 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -838,6 +838,14 @@
struct uprobe *uprobe;
int ret;
+ /* Uprobe must have at least one set consumer */
+ if (!uc->handler && !uc->ret_handler)
+ return -EINVAL;
+
+ /* TODO: Implement return probes */
+ if (uc->ret_handler)
+ return -ENOSYS;
+
/* Racy, just to catch the obvious mistakes */
if (offset > i_size_read(inode))
return -EINVAL;
@@ -1497,10 +1505,13 @@
down_read(&uprobe->register_rwsem);
for (uc = uprobe->consumers; uc; uc = uc->next) {
- int rc = uc->handler(uc, regs);
+ int rc = 0;
- WARN(rc & ~UPROBE_HANDLER_MASK,
- "bad rc=0x%x from %pf()\n", rc, uc->handler);
+ if (uc->handler) {
+ rc = uc->handler(uc, regs);
+ WARN(rc & ~UPROBE_HANDLER_MASK,
+ "bad rc=0x%x from %pf()\n", rc, uc->handler);
+ }
remove &= rc;
}