From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9799CC64E7C for ; Wed, 2 Dec 2020 17:51:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EAAE221FA for ; Wed, 2 Dec 2020 17:51:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728546AbgLBRvW (ORCPT ); Wed, 2 Dec 2020 12:51:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728475AbgLBRvW (ORCPT ); Wed, 2 Dec 2020 12:51:22 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6724BC0613D4 for ; Wed, 2 Dec 2020 09:50:42 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id i184so2756962ybg.7 for ; Wed, 02 Dec 2020 09:50:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:message-id:mime-version:subject:from:to:cc; bh=2BTQ0AJrFDxH/WMJtNujxQ6Jk2xi3yntXIn1/+/rMXI=; b=ralNzdZBrE/ynxoVTUNngfeXctDKAMr7C4Ru4EhNRaoOHC4UlDNujHEVMBf+iTYDze KpU7IQ+9rf/L+AZOM85SfqB8rx6fGglN4Sspa2yPLwLIiYN/g2PqbYFonUJ6r2t4oE+0 Ndup+/7nmjJmBe7DN7TwwZHvU1fKdza8PoeD8mVVVYcMYWS8Kt9h6AExHBltiIB9UXC+ uTzLpGLsONsQ63H+Lly56hmM8T1pHbZNgyD3mfYKv1rPIQdYwfOneapkDhQ5YP/l6ZkA RmzVVtQMVHh0T+9pN6m2+d9jLKWJpOb96MHXKBqr2lFKiV80wxcYRqDDCp2adOg4aJPT 8d8w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:message-id:mime-version:subject:from :to:cc; bh=2BTQ0AJrFDxH/WMJtNujxQ6Jk2xi3yntXIn1/+/rMXI=; b=A5sX3/tCuKpsZawaWIHI/WZ42om7aG12rjBvCwYcAz9X9Tw5rqwfZl/ANsP4d5mdxt DNy/y8hidNGRw69uKeSYvdX7J+wGY4nikR9vtteHxyL8o3VrbbHB/Cfo044nUQNX5wNP tokOPZPGLV7hAtl/4s2KOdKiasVijOiWEy44fUJwZVOPAD8Tr7EKAMPHxbIlb3NouqzF XCw+SWEvl9IVnwq2hegPXUWeARy0poGEasXk54P1m+AZDbckVl6UQG7LjNHcmTR65CGq ARF/LxDtdV0qoZCms3Ilw4Zbyg1YEjeQL+LrCipPK5vwEJ5GYgIk+nTpAGfdbCto6Hby y9gQ== X-Gm-Message-State: AOAM533iZy2MRNTTZOF/gqm5UObPmKh644FxrL5sxV5IdG8oM0vhf60C nVJ35EsZRn85dhXQzQV47Z2Zc1M= X-Google-Smtp-Source: ABdhPJxD3hXY7tZrRfT1pfemQ32+nTCPfIEX12LY3pVfDfiaooJkR1EIM9bELBtRgJ/IKXMzcdbwDck= Sender: "sdf via sendgmr" X-Received: from sdf2.svl.corp.google.com ([2620:15c:2c4:1:7220:84ff:fe09:7732]) (user=sdf job=sendgmr) by 2002:a25:41c5:: with SMTP id o188mr5742500yba.185.1606931441650; Wed, 02 Dec 2020 09:50:41 -0800 (PST) Date: Wed, 2 Dec 2020 09:50:39 -0800 Message-Id: <20201202175039.3625166-1-sdf@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.29.2.454.gaff20da3a2-goog Subject: [PATCH bpf-next] libbpf: add retries in sys_bpf_prog_load From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org I've seen a situation, where a process that's under pprof constantly generates SIGPROF which prevents program loading indefinitely. The right thing to do probably is to disable signals in the upper layers while loading, but it still would be nice to get some error from libbpf instead of an endless loop. Let's add some small retry limit to the program loading: try loading the program 10 (arbitrary) times and give up. Signed-off-by: Stanislav Fomichev --- tools/lib/bpf/bpf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index d27e34133973..31ebd6b3ec7c 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -67,11 +67,12 @@ static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size) { + int retries = 10; int fd; do { fd = sys_bpf(BPF_PROG_LOAD, attr, size); - } while (fd < 0 && errno == EAGAIN); + } while (fd < 0 && errno == EAGAIN && retries-- > 0); return fd; } -- 2.29.2.454.gaff20da3a2-goog