[PATCH] bpf: remove pointless code from bpf_do_trace_printk()

From: Rasmus Villemoes
Date: Wed Apr 21 2021 - 15:07:46 EST


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(-)

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