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

From: David Laight <[email-masked]>
Date: Thu, 26 Mar 2026 22:18:09 +0000

On Thu, 26 Mar 2026 21:24:39 +0100
Pablo Neira Ayuso <[email-masked]> wrote:

> Hi David,
> 
> On Thu, Mar 26, 2026 at 08:18:19PM +0000, [email-masked] wrote:
> > From: David Laight <[email-masked]>
> > 
> > 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.  
> 
> Do you have a setup using this helper? Or you just found this via
> visual inspection?

Found with grep looking for places which might be affected by 'fixing'
the kernel printf code to be POSIX compliant.

	David

> 
> > Signed-off-by: David Laight <[email-masked]>
> > ---
> >  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;
> >  }
> > @@ -284,7 +284,7 @@ static int decode_nul(struct bitstr *bs, const struct field_t *f,
> >  static int decode_bool(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);
> >  
> >  	INC_BIT(bs);
> >  	if (nf_h323_error_boundary(bs, 0, 0))
> > @@ -297,7 +297,7 @@ static int decode_oid(struct bitstr *bs, const struct field_t *f,
> >  {
> >  	int len;
> >  
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	BYTE_ALIGN(bs);
> >  	if (nf_h323_error_boundary(bs, 1, 0))
> > @@ -316,7 +316,7 @@ static int decode_int(struct bitstr *bs, const struct field_t *f,
> >  {
> >  	unsigned int len;
> >  
> > -	PRINT("%*.s%s", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s", level * TAB_SIZE, " ", f->name);
> >  
> >  	switch (f->sz) {
> >  	case BYTE:		/* Range == 256 */
> > @@ -363,7 +363,7 @@ static int decode_int(struct bitstr *bs, const struct field_t *f,
> >  static int decode_enum(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);
> >  
> >  	if ((f->attr & EXT) && get_bit(bs)) {
> >  		INC_BITS(bs, 7);
> > @@ -381,7 +381,7 @@ static int decode_bitstr(struct bitstr *bs, const struct field_t *f,
> >  {
> >  	unsigned int len;
> >  
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	BYTE_ALIGN(bs);
> >  	switch (f->sz) {
> > @@ -417,7 +417,7 @@ static int decode_numstr(struct bitstr *bs, const struct field_t *f,
> >  {
> >  	unsigned int len;
> >  
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	/* 2 <= Range <= 255 */
> >  	if (nf_h323_error_boundary(bs, 0, f->sz))
> > @@ -437,7 +437,7 @@ static int decode_octstr(struct bitstr *bs, const struct field_t *f,
> >  {
> >  	unsigned int len;
> >  
> > -	PRINT("%*.s%s", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s", level * TAB_SIZE, " ", f->name);
> >  
> >  	switch (f->sz) {
> >  	case FIXD:		/* Range == 1 */
> > @@ -490,7 +490,7 @@ static int decode_bmpstr(struct bitstr *bs, const struct field_t *f,
> >  {
> >  	unsigned int len;
> >  
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	switch (f->sz) {
> >  	case BYTE:		/* Range == 256 */
> > @@ -522,7 +522,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
> >  	const struct field_t *son;
> >  	unsigned char *beg = NULL;
> >  
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	/* Decode? */
> >  	base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
> > @@ -544,7 +544,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
> >  	/* Decode the root components */
> >  	for (i = opt = 0, son = f->fields; i < f->lb; i++, son++) {
> >  		if (son->attr & STOP) {
> > -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> > +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
> >  			      son->name);
> >  			return H323_ERROR_STOP;
> >  		}
> > @@ -562,7 +562,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
> >  			if (nf_h323_error_boundary(bs, len, 0))
> >  				return H323_ERROR_BOUND;
> >  			if (!base || !(son->attr & DECODE)) {
> > -				PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
> > +				PRINT("%*s%s\n", (level + 1) * TAB_SIZE,
> >  				      " ", son->name);
> >  				bs->cur += len;
> >  				continue;
> > @@ -615,7 +615,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
> >  		}
> >  
> >  		if (son->attr & STOP) {
> > -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> > +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
> >  			      son->name);
> >  			return H323_ERROR_STOP;
> >  		}
> > @@ -629,7 +629,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
> >  		if (nf_h323_error_boundary(bs, len, 0))
> >  			return H323_ERROR_BOUND;
> >  		if (!base || !(son->attr & DECODE)) {
> > -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> > +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
> >  			      son->name);
> >  			bs->cur += len;
> >  			continue;
> > @@ -655,7 +655,7 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f,
> >  	const struct field_t *son;
> >  	unsigned char *beg = NULL;
> >  
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	/* Decode? */
> >  	base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
> > @@ -710,7 +710,7 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f,
> >  			if (nf_h323_error_boundary(bs, len, 0))
> >  				return H323_ERROR_BOUND;
> >  			if (!base || !(son->attr & DECODE)) {
> > -				PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
> > +				PRINT("%*s%s\n", (level + 1) * TAB_SIZE,
> >  				      " ", son->name);
> >  				bs->cur += len;
> >  				continue;
> > @@ -751,7 +751,7 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
> >  	const struct field_t *son;
> >  	unsigned char *beg = NULL;
> >  
> > -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> > +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
> >  
> >  	/* Decode? */
> >  	base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
> > @@ -792,7 +792,7 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
> >  	/* Transfer to son level */
> >  	son = &f->fields[type];
> >  	if (son->attr & STOP) {
> > -		PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ", son->name);
> > +		PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ", son->name);
> >  		return H323_ERROR_STOP;
> >  	}
> >  
> > @@ -804,7 +804,7 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
> >  		if (nf_h323_error_boundary(bs, len, 0))
> >  			return H323_ERROR_BOUND;
> >  		if (!base || !(son->attr & DECODE)) {
> > -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> > +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
> >  			      son->name);
> >  			bs->cur += len;
> >  			return H323_ERROR_NONE;
> > -- 
> > 2.39.5
> >