Re: [PATCH] dump_stack: convert generic dump_stack into a weak symbol

From: Petr Mladek <pmladek@suse.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Tejun Heo <tj@kernel.org>, Steven Rostedt <rostedt@goodmis.org>,
	Dave Young <dyoung@redhat.com>, Andi Kleen <ak@linux.intel.com>,
	Greentime Hu <green.hu@gmail.com>,
	Vincent Chen <deanbo422@gmail.com>, Arnd Bergmann <arnd@arndb.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	adi-buildroot-devel@lists.sourceforge.net,
	linux-kernel@vger.kernel.org,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [PATCH] dump_stack: convert generic dump_stack into a weak symbol
Date: Tue, 6 Mar 2018 13:43:26 +0100	[thread overview]
Message-ID: <20180306124326.ucom526x6giwp2br@pathway.suse.cz> (raw)
In-Reply-To: <20180306042957.GE6713@jagdpanzerIV>

On Tue 2018-03-06 13:29:57, Sergey Senozhatsky wrote:
> On (03/05/18 15:48), Petr Mladek wrote:
> [..]
> > 
> > I hope that I did not miss anything. I could not try this at
> > runtime.
> 
> I think you can. The rules are universal, you can do on x86
> something like this
> 
> ---
> 
>  arch/x86/kernel/dumpstack.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> index a2d8a3908670..5d45f406717e 100644
> --- a/arch/x86/kernel/dumpstack.c
> +++ b/arch/x86/kernel/dumpstack.c
> @@ -375,3 +375,16 @@ static int __init code_bytes_setup(char *s)
>  	return 1;
>  }
>  __setup("code_bytes=", code_bytes_setup);
> +
> +void dump_stack(void)
> +{
> +	dump_stack_print_info(KERN_DEFAULT);
> +
> +	pr_crit("\t\tLinux\n\n");
> +
> +	pr_crit("An error has occurred. To continue:\n"
> +		"Press Enter to return to Linux, or\n"
> +		"Press CTRL+ALT+DEL to restart your computer.\n");
> +
> +	pr_crit("\n\n\tPress any key to continue _");
> +}
> 
> ---
> 
> Should be enough for testing.

Yup, this worked.

I have pushed the patch into printk.git for-4.17 branch,
see https://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk.git/commit/?h=for-4.17&id=33251b634b4aa1317e2f911e3b723179949a0605

Greentime Hu,

the for-4.17 branch in printk.git is based on Linus' tree. Therefore
I had to remove the hunk against arch/nds32/kernel/traps.c because
this file is only in linux-next.

I think that it might be easier if you remove the EXPORT_SYMBOL()
in your branch. Is it OK for you, please?

Best Regards,
Petr