This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
Re: [RFC] [PATCH 2.6.37-rc5-tip 12/20] 12: uprobes: get the breakpoint address.
- From: Peter Zijlstra <peterz at infradead dot org>
- To: Srikar Dronamraju <srikar at linux dot vnet dot ibm dot com>
- Cc: Ingo Molnar <mingo at elte dot hu>, Steven Rostedt <rostedt at goodmis dot org>, 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: Tue, 25 Jan 2011 14:56:21 +0100
- Subject: Re: [RFC] [PATCH 2.6.37-rc5-tip 12/20] 12: uprobes: get the breakpoint address.
- References: <20101216095714.23751.52601.sendpatchset@localhost6.localdomain6> <20101216095936.23751.62727.sendpatchset@localhost6.localdomain6>
On Thu, 2010-12-16 at 15:29 +0530, Srikar Dronamraju wrote:
> On a breakpoint hit, perform a architecture specific calculation to
> return the address where the breakpoint was hit.
And yet all the code added is generic ;-)
> 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.