Re: [PATCH next] netfilter: nf_conntrack_h323: Correct indentation when H323_TRACE defined

[David Laight]

On Fri, 27 Mar 2026 10:47:41 +0100
Petr Mladek <pmladek@xxxxxxxx> wrote:

> On Thu 2026-03-26 20:18:19, david.laight.linux@xxxxxxxxx wrote:
> > From: David Laight <david.laight.linux@xxxxxxxxx>
> > 
> > The trace lines are indented using PRINT("%*.s", xx, " ").
> > Userspace will treat this as "%*.0s" and will output no characters
> > when 'xx' is zero, the kernel treats it as "%*s" and will output
> > a single ' ' - which is probably what is intended.
> > 
> > Change all the formats to "%*s" removing the default precision.
> > This gives a single space indent when level is zero.
> > 
> > Signed-off-by: David Laight <david.laight.linux@xxxxxxxxx>
> > ---
> >  net/netfilter/nf_conntrack_h323_asn1.c | 38 +++++++++++++-------------
> >  1 file changed, 19 insertions(+), 19 deletions(-)
> > 
> > diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c
> > index 7b1497ed97d2..287402428975 100644
> > --- a/net/netfilter/nf_conntrack_h323_asn1.c
> > +++ b/net/netfilter/nf_conntrack_h323_asn1.c
> > @@ -276,7 +276,7 @@ static unsigned int get_uint(struct bitstr *bs, int b)
> >  static int decode_nul(struct bitstr *bs, const struct field_t *f,
> >                        char *base, int level)
> >  {
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	return H323_ERROR_NONE;
> >  }  
> 
> The change is important for making the kernel %*.s handling POSIX
> compliant. The dot '.' without any following number is handled
> a zero precision by POSIX. It would print no space "" when
> also the field width was zero, aka when level == 0.
> 
> It has no efect if the field width (@level) is always > 0 because
> vsprintf() would add the required emptry spaces ' ' anyway.

That looks like C&P AI output...

> 
> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
> 
> Best Regards,
> Petr
> 
>