Re: [PATCH v4 5/6] powerpc: Add show_user_instructions()

From: Joe Perches <joe@perches.com>
To: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>,
	Christophe LEROY <christophe.leroy@c-s.fr>
Cc: linux-kernel@vger.kernel.org,
	Alastair D'Silva <alastair@d-silva.org>,
	Andrew Donnellan <andrew.donnellan@au1.ibm.com>,
	Balbir Singh <bsingharora@gmail.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Cyril Bur <cyrilbur@gmail.com>,
	"Eric W . Biederman" <ebiederm@xmission.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Michael Neuling <mikey@neuling.org>,
	Nicholas Piggin <npiggin@gmail.com>,
	Paul Mackerras <paulus@samba.org>,
	Simon Guo <wei.guo.simon@gmail.com>,
	Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>,
	"Tobin C . Harding" <me@tobin.cc>,
	linuxppc-dev@lists.ozlabs.org,
	Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH v4 5/6] powerpc: Add show_user_instructions()
Date: Thu, 02 Aug 2018 18:22:29 -0700	[thread overview]
Message-ID: <f6d9bc125a4b8e6cd4358c5dd9656730a7716b23.camel@perches.com> (raw)
In-Reply-To: <20180803004201.GA5891@kermit-br-ibm-com>

On Thu, 2018-08-02 at 21:42 -0300, Murilo Opsfelder Araujo wrote:
> > > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
[]
> > > @@ -1299,6 +1299,46 @@ static void show_instructions(struct pt_regs *regs)
> > >   	pr_cont("\n");
> > >   }
> > > +void show_user_instructions(struct pt_regs *regs)
> > > +{
> > > +	int i;
> > > +	const char *prefix = KERN_INFO "%s[%d]: code: ";
> > > +	unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
> > > +					sizeof(int));
> > > +
> > > +	printk(prefix, current->comm, current->pid);
> > 
> > Why not use pr_info() and remove KERN_INFO from *prefix ?
> 
> Because it doesn't compile:
> 
>   arch/powerpc/kernel/process.c:1317:10: error: expected ‘)’ before ‘prefix’
>     pr_info(prefix, current->comm, current->pid);
>             ^
>   ./include/linux/printk.h:288:21: note: in definition of macro ‘pr_fmt’
>    #define pr_fmt(fmt) fmt
>                      ^

What being suggested is using:

	pr_info("%s[%d]: code: ", current->comm, current->pid);