From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B68E718D630; Thu, 15 Aug 2024 13:54:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723730084; cv=none; b=td2FibY8PzpuDTFDpoNfLJ3UqEXl930vESfCuc8q6z1q/gr1CdrVrCjwUsQr7P1qqSmfIPBBGqG+hXYE29DbV9P/KEYGgcVjN+kAZ06Sq07cPxlQuyZVuSYUttnO/286j4FLSROO75lCBVlLrMp6sab9M7aucNikqBVbGz6b6M4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723730084; c=relaxed/simple; bh=GT2SSdGaTUmbNR6ukWX73Q98KDBPoTkHd32XV8bgqKU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aEcm19ux7h3Twpguus9S66H8rU6RXzl0NCGKo7b36Hrw2jUbAAMWr7DJMG1O/7+AdFK7JVrbebZGDQA+otrXQSapDSFxwKZMDZ/n2hLuSO0Ak9NoFjD9zt5rU9OyEIEAqfny1UiHVjQCuYmIE0rAsw3LRQnX73+R0pV62ECXB4s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wXYZV44y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wXYZV44y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D57FC32786; Thu, 15 Aug 2024 13:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723730084; bh=GT2SSdGaTUmbNR6ukWX73Q98KDBPoTkHd32XV8bgqKU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wXYZV44ynB5z0RNWm6QnJu54MQ1ecaw+KFn9tr/9FKWj22eMgL8j5wsW7ugXNy/xJ cJlFTXzOtDAut1L+IrXBezRFH7FKhmY1m1+5swJOORhICJG7mfAxFBdzke0sXdYqK+ 0/zhQd2uwXh32iq0IO+5kYxKvHp8QyplUFRhHb9U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hou Tao , Daniel Borkmann , Yonghong Song , Krister Johansen , Jiri Olsa , Sasha Levin Subject: [PATCH 5.15 269/484] bpf, events: Use prog to emit ksymbol event for main program Date: Thu, 15 Aug 2024 15:22:07 +0200 Message-ID: <20240815131951.793192871@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240815131941.255804951@linuxfoundation.org> References: <20240815131941.255804951@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hou Tao [ Upstream commit 0be9ae5486cd9e767138c13638820d240713f5f1 ] Since commit 0108a4e9f358 ("bpf: ensure main program has an extable"), prog->aux->func[0]->kallsyms is left as uninitialized. For BPF programs with subprogs, the symbol for the main program is missing just as shown in the output of perf script below: ffffffff81284b69 qp_trie_lookup_elem+0xb9 ([kernel.kallsyms]) ffffffffc0011125 bpf_prog_a4a0eb0651e6af8b_lookup_qp_trie+0x5d (bpf...) ffffffff8127bc2b bpf_for_each_array_elem+0x7b ([kernel.kallsyms]) ffffffffc00110a1 +0x25 () ffffffff8121a89a trace_call_bpf+0xca ([kernel.kallsyms]) Fix it by always using prog instead prog->aux->func[0] to emit ksymbol event for the main program. After the fix, the output of perf script will be correct: ffffffff81284b96 qp_trie_lookup_elem+0xe6 ([kernel.kallsyms]) ffffffffc001382d bpf_prog_a4a0eb0651e6af8b_lookup_qp_trie+0x5d (bpf...) ffffffff8127bc2b bpf_for_each_array_elem+0x7b ([kernel.kallsyms]) ffffffffc0013779 bpf_prog_245c55ab25cfcf40_qp_trie_lookup+0x25 (bpf...) ffffffff8121a89a trace_call_bpf+0xca ([kernel.kallsyms]) Fixes: 0108a4e9f358 ("bpf: ensure main program has an extable") Signed-off-by: Hou Tao Signed-off-by: Daniel Borkmann Tested-by: Yonghong Song Reviewed-by: Krister Johansen Reviewed-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20240714065533.1112616-1-houtao@huaweicloud.com Signed-off-by: Sasha Levin --- kernel/events/core.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9194,21 +9194,19 @@ static void perf_event_bpf_emit_ksymbols bool unregister = type == PERF_BPF_EVENT_PROG_UNLOAD; int i; - if (prog->aux->func_cnt == 0) { - perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, - (u64)(unsigned long)prog->bpf_func, - prog->jited_len, unregister, - prog->aux->ksym.name); - } else { - for (i = 0; i < prog->aux->func_cnt; i++) { - struct bpf_prog *subprog = prog->aux->func[i]; + perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, + (u64)(unsigned long)prog->bpf_func, + prog->jited_len, unregister, + prog->aux->ksym.name); - perf_event_ksymbol( - PERF_RECORD_KSYMBOL_TYPE_BPF, - (u64)(unsigned long)subprog->bpf_func, - subprog->jited_len, unregister, - subprog->aux->ksym.name); - } + for (i = 1; i < prog->aux->func_cnt; i++) { + struct bpf_prog *subprog = prog->aux->func[i]; + + perf_event_ksymbol( + PERF_RECORD_KSYMBOL_TYPE_BPF, + (u64)(unsigned long)subprog->bpf_func, + subprog->jited_len, unregister, + subprog->aux->ksym.name); } }