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>
This commit is contained in:
Anton Arapov 2013-04-03 18:00:31 +02:00 committed by Oleg Nesterov
parent 3f47107c5c
commit ea024870cf
2 changed files with 17 additions and 3 deletions

View File

@ -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);

View File

@ -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;
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;
}