BPF List
 help / color / mirror / Atom feed
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Eduard Zingerman <eddyz87@gmail.com>,
	Emil Tsalapatis <emil@etsalapatis.com>,
	kkd@meta.com, kernel-team@meta.com
Subject: [PATCH bpf-next v4 04/16] bpf: Prune verifier diagnostics when switching paths
Date: Thu, 13 Aug 2026 01:33:07 +0200	[thread overview]
Message-ID: <20260812233326.3575958-5-memxor@gmail.com> (raw)
In-Reply-To: <20260812233326.3575958-1-memxor@gmail.com>

Save the diagnostic event-log position with each verifier stack entry and
reset the environment-owned stream together with the normal verifier log
when a queued state is popped. Also reset the diagnostic stream after
successful subprogram verification even when level-2 logging preserves the
normal verifier log.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 kernel/bpf/verifier.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6ca366ff5037..2e915292265b 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -194,6 +194,7 @@ struct bpf_verifier_stack_elem {
 	struct bpf_verifier_stack_elem *next;
 	/* length of verifier log at the time this state was pushed on stack */
 	u32 log_pos;
+	u32 diag_log_pos;
 };
 
 #define BPF_COMPLEXITY_LIMIT_JMP_SEQ	8192
@@ -1700,6 +1701,7 @@ static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx,
 		err = bpf_copy_verifier_state(cur, &head->st);
 		if (err)
 			return err;
+		bpf_diag_event_log_reset(env, head->diag_log_pos);
 	}
 	if (pop_log)
 		bpf_vlog_reset(&env->log, head->log_pos);
@@ -1743,6 +1745,7 @@ static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env,
 	elem->prev_insn_idx = prev_insn_idx;
 	elem->next = env->head;
 	elem->log_pos = env->log.end_pos;
+	elem->diag_log_pos = bpf_diag_event_log_pos(env);
 	env->head = elem;
 	env->stack_size++;
 	err = bpf_copy_verifier_state(&elem->st, cur);
@@ -2264,6 +2267,7 @@ static struct bpf_verifier_state *push_async_cb(struct bpf_verifier_env *env,
 	elem->prev_insn_idx = prev_insn_idx;
 	elem->next = env->head;
 	elem->log_pos = env->log.end_pos;
+	elem->diag_log_pos = bpf_diag_event_log_pos(env);
 	env->head = elem;
 	env->stack_size++;
 	if (env->stack_size > BPF_COMPLEXITY_LIMIT_JMP_SEQ) {
@@ -18566,8 +18570,11 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog)
 
 	ret = do_check(env);
 out:
-	if (!ret && pop_log)
-		bpf_vlog_reset(&env->log, 0);
+	if (!ret) {
+		if (pop_log)
+			bpf_vlog_reset(&env->log, 0);
+		bpf_diag_event_log_reset(env, 0);
+	}
 	free_states(env);
 	return ret;
 }
-- 
2.53.0


  parent reply	other threads:[~2026-08-12 23:33 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-12 23:33 [PATCH bpf-next v4 00/16] Redesign Verification Errors Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 01/16] bpf: Add verifier diagnostics report helpers Kumar Kartikeya Dwivedi
2026-08-12 23:41   ` sashiko-bot
2026-08-12 23:33 ` [PATCH bpf-next v4 02/16] bpf: Add source and instruction diagnostic context Kumar Kartikeya Dwivedi
2026-08-13  0:15   ` sashiko-bot
2026-08-12 23:33 ` [PATCH bpf-next v4 03/16] bpf: Add verifier diagnostic event log Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` Kumar Kartikeya Dwivedi [this message]
2026-08-12 23:33 ` [PATCH bpf-next v4 05/16] bpf: Track verifier register diagnostic events Kumar Kartikeya Dwivedi
2026-08-12 23:53   ` sashiko-bot
2026-08-12 23:33 ` [PATCH bpf-next v4 06/16] bpf: Track verifier reference " Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 07/16] bpf: Track verifier context " Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 08/16] bpf: Report Register Type Safety errors Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 09/16] bpf: Report Memory Safety bounds errors Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 10/16] bpf: Report Resource Lifetime reference leaks Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 11/16] bpf: Report Call Type Safety argument errors Kumar Kartikeya Dwivedi
2026-08-12 23:58   ` sashiko-bot
2026-08-12 23:33 ` [PATCH bpf-next v4 12/16] bpf: Report Execution Context Safety errors Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 13/16] bpf: Report Program Structure CFG errors Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 14/16] bpf: Report Policy helper and kfunc errors Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 15/16] bpf: Report Verifier Limit errors Kumar Kartikeya Dwivedi
2026-08-12 23:33 ` [PATCH bpf-next v4 16/16] bpf: Gate verifier diagnostics on log level Kumar Kartikeya Dwivedi
2026-08-13  1:38 ` [PATCH bpf-next v4 00/16] Redesign Verification Errors Eduard Zingerman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260812233326.3575958-5-memxor@gmail.com \
    --to=memxor@gmail.com \
    --cc=andrii@kernel.org \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=eddyz87@gmail.com \
    --cc=emil@etsalapatis.com \
    --cc=kernel-team@meta.com \
    --cc=kkd@meta.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox