Commit ea024870 authored by Anton Arapov's avatar Anton Arapov Committed by Oleg Nesterov
Browse files

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: default avatarAnton Arapov <anton@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
parent 3f47107c

include/linux/uprobes.h

+3 −0
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ enum uprobe_filter_ctx { 


struct uprobe_consumer {

	int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);

	int (*ret_handler)(struct uprobe_consumer *self,

				unsigned long func,

				struct pt_regs *regs);

	bool (*filter)(struct uprobe_consumer *self,

				enum uprobe_filter_ctx ctx,

				struct mm_struct *mm);

kernel/events/uprobes.c

+14 −3
Original line number Diff line number Diff line
@@ -838,6 +838,14 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer * 
	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 @@ static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs) 


	down_read(&uprobe->register_rwsem);

	for (uc = uprobe->consumers; uc; uc = uc->next) {

		int rc = uc->handler(uc, regs);

		int rc = 0;



		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;

	}