Subject: Re: [PATCH bpf-next 3/3] bpftool: print the comm of the process that loaded the program

From: Stanislav Fomichev <[email-masked]>
Date: Fri, 11 Oct 2019 14:30:54 -0700

On 10/11, Arnaldo Carvalho de Melo wrote:
> On October 11, 2019 5:37:16 PM GMT-03:00, Stanislav Fomichev <[email-masked]> wrote:
> >On 10/11, Martin Lau wrote:
> >> On Fri, Oct 11, 2019 at 09:21:24AM -0700, Stanislav Fomichev wrote:
> >> > Example with loop1.o (loaded via 
> >
> >> What will be in "comm" for the python bcc script?
> >I guess it will be "python". But at least you get a signal that it's
> >not some other system daemon :-)
> 
> Perhaps bcc could use prctl to change its comm before calling sys_bpf and set the script name?
Good idea! prctl does indeed call set_task_comm to change the task comm.

> - Arnaldo
> 
> Sent from smartphone
> 
> >
> >> > 
> >> > Signed-off-by: Stanislav Fomichev <[email-masked]>
> >> > ---
> >> >  tools/bpf/bpftool/prog.c | 4 +++-
> >> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >> > 
> >> > diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
> >> > index 27da96a797ab..400771a942d7 100644
> >> > --- a/tools/bpf/bpftool/prog.c
> >> > +++ b/tools/bpf/bpftool/prog.c
> >> > @@ -296,7 +296,9 @@ static void print_prog_plain(struct
> >bpf_prog_info *info, int fd)
> >> >  		print_boot_time(info->load_time, buf, sizeof(buf));
> >> >  
> >> >  		/* Piggy back on load_time, since 0 uid is a valid one */
> >> > -		printf("\tloaded_at %s  uid %u\n", buf, info->created_by_uid);
> >> > +		printf("\tloaded_at %s  uid %u  comm %s\n", buf,
> >> > +		       info->created_by_uid,
> >> > +		       info->created_by_comm);
> >> >  	}
> >> >  
> >> >  	printf("\txlated %uB", info->xlated_prog_len);
> >> > -- 
> >> > 2.23.0.700.g56cf767bdb-goog
> >> > 
>