[PATCH v2 2.6.38-rc8-tip 12/20] 12: uprobes: get the breakpoint address.

Srikar Dronamraju
2011-03-14T13:42:09Z

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 c42975b..aef55de 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -146,6 +146,7 @@ extern void uprobe_free_utask(struct task_struct *tsk);

struct vm_area_struct;
extern void uprobe_mmap(struct vm_area_struct *vma);
+extern unsigned long uprobes_get_bkpt_addr(struct pt_regs *regs);
extern void uprobe_dup_mmap(struct mm_struct *old_mm, struct mm_struct *mm);
extern void uprobes_free_xol_area(struct mm_struct *mm);
#else /* CONFIG_UPROBES is not defined */
@@ -165,5 +166,9 @@ static inline void uprobe_dup_mmap(struct mm_struct *old_mm,
static inline void uprobe_free_utask(struct task_struct *tsk) {}
static inline void uprobe_mmap(struct vm_area_struct *vma) { }
static inline void uprobes_free_xol_area(struct mm_struct *mm) {}
+static inline unsigned long uprobes_get_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 9d3d402..307f0cd 100644
--- a/kernel/uprobes.c
+++ b/kernel/uprobes.c
@@ -1044,6 +1044,17 @@ static void xol_free_insn_slot(struct task_struct *tsk, unsigned long slot_addr)
__func__, slot_addr);
}

+/**
+ * uprobes_get_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 uprobes_get_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.