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authorAnton Arapov <anton@redhat.com>2013-04-03 18:00:31 +0200
committerOleg Nesterov <oleg@redhat.com>2013-04-13 15:31:53 +0200
commitea024870cf10687b3fded66a9deb6253888f30b7 (patch)
tree6071017ca5e987d991b42ceae519d92476ed3b36
parent3f47107c5c2972ca47f216889080f6ef818b25e3 (diff)
downloadlinux-ea024870cf10687b3fded66a9deb6253888f30b7.tar.bz2
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>
-rw-r--r--include/linux/uprobes.h3
-rw-r--r--kernel/events/uprobes.c17
2 files changed, 17 insertions, 3 deletions
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 19612881399a..5c8d3290df41 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -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);
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 7312503caf2e..eb384e90ac92 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -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;
}