[PATCH v4 3.0-rc2-tip 11/22] 11: uprobes: get the breakpoint address.

Srikar Dronamraju
2011-06-07T13:07:21Z

On a breakpoint hit, return the address where the breakpoint was hit.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
---
include/linux/uprobes.h | 5 +++++
kernel/uprobes.c | 11 +++++++++++
2 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 4590e9a..838fbaa 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -161,6 +161,7 @@ struct vm_area_struct;
extern int mmap_uprobe(struct vm_area_struct *vma);
extern void dup_mmap_uprobe(struct mm_struct *old_mm, struct mm_struct *mm);
extern void free_uprobes_xol_area(struct mm_struct *mm);
+extern unsigned long __weak get_uprobe_bkpt_addr(struct pt_regs *regs);
#else /* CONFIG_UPROBES is not defined */
static inline int register_uprobe(struct inode *inode, loff_t offset,
struct uprobe_consumer *consumer)
@@ -181,5 +182,9 @@ static inline int mmap_uprobe(struct vm_area_struct *vma)
}
static inline void free_uprobe_utask(struct task_struct *tsk) {}
static inline void free_uprobes_xol_area(struct mm_struct *mm) {}
+static inline unsigned long get_uprobe_bkpt_addr(struct pt_regs *regs)
+{
+ return 0;
+}
#endif /* CONFIG_UPROBES */
#endif /* _LINUX_UPROBES_H */
diff --git a/kernel/uprobes.c b/kernel/uprobes.c
index d19c3b0..fa9e9ba 100644
--- a/kernel/uprobes.c
+++ b/kernel/uprobes.c
@@ -1263,6 +1263,17 @@ static void xol_free_insn_slot(struct task_struct *tsk)
__func__, slot_addr);
}

+/**
+ * get_uprobe_bkpt_addr - compute address of bkpt given post-bkpt regs
+ * @regs: Reflects the saved state of the task after it has hit a breakpoint
+ * instruction.
+ * Return the address of the breakpoint instruction.
+ */
+unsigned long __weak get_uprobe_bkpt_addr(struct pt_regs *regs)
+{
+ return instruction_pointer(regs) - UPROBES_BKPT_INSN_SIZE;
+}
+
/*
* Called with no locks held.
* Called in context of a exiting or a exec-ing thread.