On Wed, Apr 21, 2021 at 6:19 PM Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> wrote: > > The comment is wrong. snprintf(buf, 16, "") and snprintf(buf, 16, > "%s", "") etc. will certainly put '\0' in buf[0]. The only case where > snprintf() does not guarantee a nul-terminated string is when it is > given a buffer size of 0 (which of course prevents it from writing > anything at all to the buffer). > > Remove it before it gets cargo-culted elsewhere. > > Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> > --- > kernel/trace/bpf_trace.c | 3 --- > 1 file changed, 3 deletions(-) > The change looks good to me, but please rebase it on top of the bpf-next tree. This is not a bug, so it doesn't have to go into the bpf tree. As it is right now, it doesn't apply cleanly onto bpf-next. > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index b0c45d923f0f..4ee55df84cd3 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -412,9 +412,6 @@ static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...) > va_start(ap, fmt); > ret = vsnprintf(buf, sizeof(buf), fmt, ap); > va_end(ap); > - /* vsnprintf() will not append null for zero-length strings */ > - if (ret == 0) > - buf[0] = '\0'; > trace_bpf_trace_printk(buf); > raw_spin_unlock_irqrestore(&trace_printk_lock, flags); > > -- > 2.29.2 >
