From 34d0b5af50a063cded842716633501b38ff815fb Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Mon, 28 Dec 2009 17:53:47 +0900 Subject: sh: Convert ptrace to hw_breakpoint API. This is the initial step for converting singlestep handling via ptrace over to hw_breakpoints. Signed-off-by: Paul Mundt --- arch/sh/kernel/ptrace_32.c | 53 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 52 insertions(+), 1 deletion(-) (limited to 'arch/sh/kernel/ptrace_32.c') diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c index bdb10446cba..8e094c4c7bb 100644 --- a/arch/sh/kernel/ptrace_32.c +++ b/arch/sh/kernel/ptrace_32.c @@ -2,7 +2,7 @@ * SuperH process tracing * * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka - * Copyright (C) 2002 - 2008 Paul Mundt + * Copyright (C) 2002 - 2009 Paul Mundt * * Audit support by Yuichi Nakamura * @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -63,9 +64,59 @@ static inline int put_stack_long(struct task_struct *task, int offset, return 0; } +void ptrace_triggered(struct perf_event *bp, int nmi, + struct perf_sample_data *data, struct pt_regs *regs) +{ + struct perf_event_attr attr; + + /* + * Disable the breakpoint request here since ptrace has defined a + * one-shot behaviour for breakpoint exceptions. + */ + attr = bp->attr; + attr.disabled = true; + modify_user_hw_breakpoint(bp, &attr); +} + +static int set_single_step(struct task_struct *tsk, unsigned long addr) +{ + struct thread_struct *thread = &tsk->thread; + struct perf_event *bp; + struct perf_event_attr attr; + + bp = thread->ptrace_bps[0]; + if (!bp) { + hw_breakpoint_init(&attr); + + attr.bp_addr = addr; + attr.bp_len = HW_BREAKPOINT_LEN_2; + attr.bp_type = HW_BREAKPOINT_R; + + bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk); + if (IS_ERR(bp)) + return PTR_ERR(bp); + + thread->ptrace_bps[0] = bp; + } else { + int err; + + attr = bp->attr; + attr.bp_addr = addr; + err = modify_user_hw_breakpoint(bp, &attr); + if (unlikely(err)) + return err; + } + + return 0; +} + void user_enable_single_step(struct task_struct *child) { + unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc)); + set_tsk_thread_flag(child, TIF_SINGLESTEP); + + set_single_step(child, pc); } void user_disable_single_step(struct task_struct *child) -- cgit v1.2.3