linux-kernel - Re: [PATCH] platform/x86/intel/tpmi/plr: Uninitialized variable in plr_print

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Message-ID: <428d4e27-6970-45d8-a7b9-7bf6af95c91a@suswa.mountain>
Date: Mon, 15 Jul 2024 10:44:51 -0500
From: Dan Carpenter <dan.carpenter@...aro.org>
To: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc: Tero Kristo <tero.kristo@...ux.intel.com>,
	Hans de Goede <hdegoede@...hat.com>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	platform-driver-x86@...r.kernel.org,
	LKML <linux-kernel@...r.kernel.org>,
	kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] platform/x86/intel/tpmi/plr: Uninitialized variable in
 plr_print_bits()

On Mon, Jul 15, 2024 at 12:25:21PM +0300, Ilpo Järvinen wrote:
> On Fri, 12 Jul 2024, Dan Carpenter wrote:
> 
> > Initialize the "str" pointer to NULL.  There is a test later for if "str"
> > is NULL but in the original code it was either valid or uninitialized.
> > 
> > Fixes: 9e9397a41b7b ("platform/x86/intel/tpmi/plr: Add support for the plr mailbox")
> > Signed-off-by: Dan Carpenter <dan.carpenter@...aro.org>
> > ---
> > Almost everyone automatically initializes stack variables to zero these days so
> > bugs like this don't show up in testing and we disabled GCC's uninitialized
> > variable warning so it's easy to miss.
> > 
> >  drivers/platform/x86/intel/intel_plr_tpmi.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/platform/x86/intel/intel_plr_tpmi.c b/drivers/platform/x86/intel/intel_plr_tpmi.c
> > index c1aa52c23d25..2725a1ddba92 100644
> > --- a/drivers/platform/x86/intel/intel_plr_tpmi.c
> > +++ b/drivers/platform/x86/intel/intel_plr_tpmi.c
> > @@ -162,7 +162,7 @@ static int plr_clear_cpu_status(struct tpmi_plr_die *plr_die, int cpu)
> >  static void plr_print_bits(struct seq_file *s, u64 val, int bits)
> >  {
> >  	const unsigned long mask[] = { BITMAP_FROM_U64(val) };
> > -	const char *str;
> > +	const char *str = NULL;
> >  	int bit, index;
> >  
> >  	for_each_set_bit(bit, mask, bits) {
> 
> This fix looks slightly incorrect.

s/slightly/totally/.

I'll resend.

regards,
dan carpenter