Re: [PATCH v2] lib_backtrace: fix kernel text address leak

From: Josh Poimboeuf <jpoimboe@redhat.com>
To: "Liu, Changcheng" <changcheng.liu@intel.com>
Cc: Petr Mladek <pmladek@suse.com>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] lib_backtrace: fix kernel text address leak
Date: Mon, 6 Nov 2017 11:14:01 -0600	[thread overview]
Message-ID: <20171106171401.4h546bbvdon45or2@treble> (raw)
In-Reply-To: <20171106165648.GA95243@sofia>

On Tue, Nov 07, 2017 at 12:56:48AM +0800, Liu, Changcheng wrote:
> Don't leak idle function address in NMI backtrace.
> 
> Signed-off-by: Liu Changcheng <changcheng.liu@intel.com>
> 
> diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
> index 46e4c749..61a6b5a 100644
> --- a/lib/nmi_backtrace.c
> +++ b/lib/nmi_backtrace.c
> @@ -93,8 +93,8 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
>  	if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
>  		arch_spin_lock(&lock);
>  		if (regs && cpu_in_idle(instruction_pointer(regs))) {
> -			pr_warn("NMI backtrace for cpu %d skipped: idling at pc %#lx\n",
> -				cpu, instruction_pointer(regs));
> +			pr_warn("NMI backtrace for cpu %d skipped: idling at %pS\n",
> +				cpu, (void *)instruction_pointer(regs));
>  		} else {
>  			pr_warn("NMI backtrace for cpu %d\n", cpu);
>  			if (regs)

Sorry, I had a typo in my suggestion.  The subject prefix should be:
"nmi_backtrace" instead of "lib_backtrace".

Also, when posting a followup patch, please remove the "Re: " from the
subject so that it's clear that it's a new patch, and not a comment for
the old one.

Otherwise it looks great to me.  Thanks!

-- 
Josh