* [PATCH iproute2] lib/bpf: Fix btf_load error lead to enable debug log
@ 2021-08-01 6:07 Feng zhou
0 siblings, 0 replies; only message in thread
From: Feng zhou @ 2021-08-01 6:07 UTC (permalink / raw)
To: netdev, andrii.nakryiko
Cc: stephen, kuznet, duanxiongchun, wangdongdong.6,
chenzhuowen.simon, zhoufeng.zf, cong.wang
From: Feng Zhou <zhoufeng.zf@bytedance.com>
Use tc with no verbose, when bpf_btf_attach fail,
the conditions:
"if (fd < 0 && (errno == ENOSPC || !ctx->log_size))"
will make ctx->log_size != 0. And then, bpf_prog_attach,
ctx->log_size != 0. so enable debug log.
The verifier log sometimes is so chatty on larger programs.
bpf_prog_attach is failed.
"Log buffer too small to dump verifier log 16777215 bytes (9 tries)!"
BTF load failure does not affect prog load. prog still work.
So when BTF/PROG load fail, enlarge log_size and re-fail with
having verbose.
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
---
lib/bpf_legacy.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/bpf_legacy.c b/lib/bpf_legacy.c
index 8a03b9c2..d824388c 100644
--- a/lib/bpf_legacy.c
+++ b/lib/bpf_legacy.c
@@ -1531,7 +1531,7 @@ retry:
* into our buffer. Still, try to give a debuggable error
* log for the user, so enlarge it and re-fail.
*/
- if (fd < 0 && (errno == ENOSPC || !ctx->log_size)) {
+ if (fd < 0 && errno == ENOSPC) {
if (tries++ < 10 && !bpf_log_realloc(ctx))
goto retry;
@@ -2069,7 +2069,7 @@ retry:
fd = bpf_btf_load(ctx->btf_data->d_buf, ctx->btf_data->d_size,
ctx->log, ctx->log_size);
if (fd < 0 || ctx->verbose) {
- if (fd < 0 && (errno == ENOSPC || !ctx->log_size)) {
+ if (fd < 0 && errno == ENOSPC) {
if (tries++ < 10 && !bpf_log_realloc(ctx))
goto retry;
--
2.11.0
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2021-08-01 6:07 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-01 6:07 [PATCH iproute2] lib/bpf: Fix btf_load error lead to enable debug log Feng zhou
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).