On Wed, Jun 11, 2025 at 4:30 PM Breno Leitao <lei...@debian.org> wrote:
>
> On Wed, Jun 11, 2025 at 07:36:05AM -0700, Gustavo Luiz Duarte wrote:
> > Add msgcounter to the netconsole_target struct to generate message IDs.
> > If the msgid_enabled attribute is true, increment msgcounter and append
> > msgid=<msgcounter> to sysdata buffer before sending the message.
> >
> > Signed-off-by: Gustavo Luiz Duarte <gustav...@gmail.com>
> > ---
> > drivers/net/netconsole.c | 14 +++++++++++++-
> > 1 file changed, 13 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> > index 813f50abaf9f..34b61e299eeb 100644
> > --- a/drivers/net/netconsole.c
> > +++ b/drivers/net/netconsole.c
> > @@ -155,6 +155,8 @@ struct netconsole_target {
> > size_t userdata_length;
> > /* bit-wise with sysdata_feature bits */
> > u32 sysdata_fields;
> > + /* protected by target_list_lock */
> > + u32 msgcounter;
> > #endif
> > struct netconsole_target_stats stats;
> > bool enabled;
> > @@ -1345,13 +1347,21 @@ static int sysdata_append_release(struct
> > netconsole_target *nt, int offset)
> > init_utsname()->release);
> > }
> >
> > +static int sysdata_append_msgid(struct netconsole_target *nt, int offset)
> > +{
> > + nt->msgcounter++;
>
> This will eventually wrap. I am wondering if you should use the
> overflow.h helpers to avoid warnings in UBSAN and friends.
Good point. I will send v2 using one of the overflow safe macros.
Thanks for reviewing!
>
> Quick glanced over that filed, I found:
>
> /**
> * wrapping_add() - Intentionally perform a wrapping addition
> * @type: type for result of calculation
> * @a: first addend
> * @b: second addend
> *
> * Return the potentially wrapped-around addition without
> * tripping any wrap-around sanitizers that may be enabled.
> */
>
> > + return scnprintf(&nt->extradata_complete[offset],
> > + MAX_EXTRADATA_ENTRY_LEN, " msgid=%u\n",
> > + nt->msgcounter);
> > +}
> > +
> > /*
> > * prepare_extradata - append sysdata at extradata_complete in runtime
> > * @nt: target to send message to
> > */
> > static int prepare_extradata(struct netconsole_target *nt)
> > {
> > - u32 fields = SYSDATA_CPU_NR | SYSDATA_TASKNAME;
> > + u32 fields = SYSDATA_CPU_NR | SYSDATA_TASKNAME | SYSDATA_MSGID;
>
> This might be gone now, according to your last patch.,
>
> LGTM.
