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[RFC] [PATCH 2.6.37-rc5-tip 12/20] 12: uprobes: get the breakpoint address.
- From: Srikar Dronamraju <srikar at linux dot vnet dot ibm dot com>
- To: Peter Zijlstra <peterz at infradead dot org>, Ingo Molnar <mingo at elte dot hu>
- Cc: Steven Rostedt <rostedt at goodmis dot org>, Srikar Dronamraju <srikar at linux dot vnet dot ibm dot com>, Arnaldo Carvalho de Melo <acme at infradead dot org>, Linus Torvalds <torvalds at linux-foundation dot org>, Andi Kleen <andi at firstfloor dot org>, Christoph Hellwig <hch at infradead dot org>, Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Masami Hiramatsu <masami dot hiramatsu dot pt at hitachi dot com>, Oleg Nesterov <oleg at redhat dot com>, LKML <linux-kernel at vger dot kernel dot org>, Linux-mm <linux-mm at vger dot kernel dot org>, Jim Keniston <jkenisto at linux dot vnet dot ibm dot com>, Frederic Weisbecker <fweisbec at gmail dot com>, SystemTap <systemtap at sources dot redhat dot com>, Andrew Morton <akpm at linux-foundation dot org>, "Paul E. McKenney" <paulmck at linux dot vnet dot ibm dot com>
- Date: Thu, 16 Dec 2010 15:29:36 +0530
- Subject: [RFC] [PATCH 2.6.37-rc5-tip 12/20] 12: uprobes: get the breakpoint address.
- References: <20101216095714.23751.52601.sendpatchset@localhost6.localdomain6>
On a breakpoint hit, perform a architecture specific calculation to
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 a631c42..ee12b2e 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -154,6 +154,7 @@ 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 */
@@ -173,5 +174,9 @@ 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 09e36f6..f486c4f 100644
--- a/kernel/uprobes.c
+++ b/kernel/uprobes.c
@@ -976,6 +976,17 @@ 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.