[RFC PATCH v4 1/6] uretprobes: preparation patch

Anton Arapov
2013-03-04T14:40:19Z

1/6 and 6/6 patches are here to enclose return probes implementation as well
as prohibit uprobe_register() routine with no consumer set.

v3 changes: (the patch is introduced in v3)
- check whether at least one of the consumer's handlers were set
- a 'TODO' cap that will be removed once return probes be implemented

Signed-off-by: Anton Arapov <anton@redhat.com>
---
include/linux/uprobes.h | 1 +
kernel/events/uprobes.c | 8 ++++++++
2 files changed, 9 insertions(+)

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 02b83db..a28bdee 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -46,6 +46,7 @@ enum uprobe_filter_ctx {

struct uprobe_consumer {
int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
+ int (*rp_handler)(struct uprobe_consumer *self, 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 a567c8c..d904164 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -828,6 +828,14 @@ 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->rp_handler)
+ return -EINVAL;
+
+ /* TODO: Implement return probes */
+ if (uc->rp_handler)
+ return -ENOSYS;
+
/* Racy, just to catch the obvious mistakes */
if (offset > i_size_read(inode))
return -EINVAL;
--
1.8.1.2