Re: [PATCH 3/6] hw-breakpoints: Change/Enforce some breakpoints policies

[Paul Mundt <lethal@linux-sh.org>]

On Fri, Apr 23, 2010 at 07:13:56AM +0200, Frederic Weisbecker wrote:
> diff --git a/arch/sh/kernel/hw_breakpoint.c b/arch/sh/kernel/hw_breakpoint.c
> index 675eea7..2d44a2d 100644
> --- a/arch/sh/kernel/hw_breakpoint.c
> +++ b/arch/sh/kernel/hw_breakpoint.c
> @@ -120,25 +120,16 @@ static int get_hbp_len(u16 hbp_len)
>  }
>  
>  /*
> - * Check for virtual address in user space.
> - */
> -int arch_check_va_in_userspace(unsigned long va, u16 hbp_len)
> -{
> -	unsigned int len;
> -
> -	len = get_hbp_len(hbp_len);
> -
> -	return (va <= TASK_SIZE - len);
> -}
> -
> -/*
>   * Check for virtual address in kernel space.
>   */

We were also using the va_in_userspace check for the case of signal
delivery, so I've just inverted the test for that. Perhaps there's a
cleaner way to handle it, though.

Other than that, everything seems to work ok. The ksym tracer and ptrace
tests still pass at least. Feel free to add my Tested/Acked-by on the
rest if you're respinning it at some point.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

---

diff --git a/arch/sh/include/asm/hw_breakpoint.h b/arch/sh/include/asm/hw_breakpoint.h
index 4d5e514..89890f6 100644
--- a/arch/sh/include/asm/hw_breakpoint.h
+++ b/arch/sh/include/asm/hw_breakpoint.h
@@ -54,8 +54,6 @@ static inline int hw_breakpoint_slots(int type)
 /* arch/sh/kernel/hw_breakpoint.c */
 extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
 extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
-extern int arch_validate_hwbkpt_settings(struct perf_event *bp,
-					 struct task_struct *tsk);
 extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
 					   unsigned long val, void *data);
 
diff --git a/arch/sh/kernel/hw_breakpoint.c b/arch/sh/kernel/hw_breakpoint.c
index 67564e3..efae6ab 100644
--- a/arch/sh/kernel/hw_breakpoint.c
+++ b/arch/sh/kernel/hw_breakpoint.c
@@ -344,8 +344,7 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args)
 		perf_bp_event(bp, args->regs);
 
 		/* Deliver the signal to userspace */
-		if (arch_check_va_in_userspace(bp->attr.bp_addr,
-					       bp->attr.bp_len)) {
+		if (!arch_check_bp_in_kernelspace(bp)) {
 			siginfo_t info;
 
 			info.si_signo = args->signr;