From patchwork Tue Jan 15 22:54:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 1025531 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="ljsf1LEF"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43fQdm694Jz9sD4 for ; Wed, 16 Jan 2019 09:54:52 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391275AbfAOWyv (ORCPT ); Tue, 15 Jan 2019 17:54:51 -0500 Received: from mail-pl1-f202.google.com ([209.85.214.202]:44860 "EHLO mail-pl1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391270AbfAOWyv (ORCPT ); Tue, 15 Jan 2019 17:54:51 -0500 Received: by mail-pl1-f202.google.com with SMTP id b24so2565009pls.11 for ; Tue, 15 Jan 2019 14:54:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=oX2Dz5nCGnb4hLjks6A5z8jw4XlFI4j5IYWgY4o7fhk=; b=ljsf1LEFw/cQHmSFQA6QiHLxCQ5H5RtyVKE4OsBh73Lm0RojO0ChsosSzs7sXHeyXQ Bq/mA7FvAKFElb3hRBR7ddY0vGlRjj5mZ1c5/2XheAuSI9T+Tg8ViVeZnnYs1yaJQgAA TaQkoj0eP+mCdm0iV+9BQ5GRCxwaOjZjRrPAI3JL029dtho+xdjIy+JWEwTd+hl1rOd7 w/0Dh9ujTyhu6MYxz9UYbZrKp5PVdr+2lVCOR9GvPlFJxzAi2SQa4/3G5YAJcRjYqJ9D 0UjbtLXsR8QyBVjedOb4nvJ3l5I2mAZmsi7srHhO9ubcF+cyLTiUEfZBtdU7D5/Nd9ld GVww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=oX2Dz5nCGnb4hLjks6A5z8jw4XlFI4j5IYWgY4o7fhk=; b=Nun98qntzbit+MPJUeaIrD2Tm/4CGW2qRvd9Mkp0ntvrGMMPlb/161q0GCfaWMRkr/ xO3W3qknJTnY96plN417mZbpujwkeXUd3tlYKlxRFesZv8JB61Y2TjnjzoK5Mt8MSJfx Z3Im/4iZgDKFLPMvsOq57z82cWWrYhM+AAJNEiIiIfuAaqza4+s0NUxijw0QhdHtJP44 BEjEjO8mktlPASBFt77mgseAafP2FkfDuuZgznCdprttxchQHvSm/ACZo46o/kRjMEDP QAA1znGdzpFrO1sTq7I2ZXOVx/s/xBk9wwEGxY8FZT11mE8zZ8K81RldWsKZhGKYQ8XU Wc7g== X-Gm-Message-State: AJcUukcJah3oqCpzsCbQr7vEkK3rOaYaLBn3AnlzPuigUm2+RjC0AFbN w3Hsv9oAjM/zIjraddnHj9j/lx+NTWs6MGlaMWnlw2u8GJSlw89IxsFz6eqy5VrYPH+thMN+Haw FvKy66jzD7X62VaOUCPJURMAjlOaNa5s1V0u6O9OTN+wm2EoQuZzvrg== X-Google-Smtp-Source: ALg8bN6+t5ZUv8QoZoF6x0reWPPRWAFgj+PxxDVO5Pt//V3qCZLmfqGW/HKOAvqZuwQ/As+IXf4pcLs= X-Received: by 2002:a17:902:248:: with SMTP id 66mr1939961plc.60.1547592890138; Tue, 15 Jan 2019 14:54:50 -0800 (PST) Date: Tue, 15 Jan 2019 14:54:45 -0800 Message-Id: <20190115225447.245788-1-sdf@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.20.1.97.g81188d93c3-goog Subject: [PATCH bpf 1/3] bpf: don't assume build-id length is always 20 bytes From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, songliubraving@fb.com, Stanislav Fomichev Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Build-id length is not fixed to 20, it can be (`man ld` /--build-id): * 128-bit (uuid) * 160-bit (sha1) * any length specified in ld --build-id=0xhexstring To fix the issue of missing BPF_STACK_BUILD_ID_VALID for shorter build-ids, assume that build-id is somewhere in the range of 1 .. 20. Set the remaining bytes to zero. Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Signed-off-by: Stanislav Fomichev Acked-by: Song Liu --- kernel/bpf/stackmap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index d9e2483669d0..8975d1768dcb 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -180,11 +180,15 @@ static inline int stack_map_parse_build_id(void *page_addr, if (nhdr->n_type == BPF_BUILD_ID && nhdr->n_namesz == sizeof("GNU") && - nhdr->n_descsz == BPF_BUILD_ID_SIZE) { + nhdr->n_descsz > 0 && + nhdr->n_descsz <= BPF_BUILD_ID_SIZE) { + __u32 len = min_t(__u32, + BPF_BUILD_ID_SIZE, nhdr->n_descsz); memcpy(build_id, note_start + note_offs + ALIGN(sizeof("GNU"), 4) + sizeof(Elf32_Nhdr), - BPF_BUILD_ID_SIZE); + len); + memset(build_id + len, 0, BPF_BUILD_ID_SIZE - len); return 0; } new_offs = note_offs + sizeof(Elf32_Nhdr) + From patchwork Tue Jan 15 22:54:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 1025532 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="g4KttRL9"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43fQdr5vSMz9sD4 for ; Wed, 16 Jan 2019 09:54:56 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391292AbfAOWyz (ORCPT ); Tue, 15 Jan 2019 17:54:55 -0500 Received: from mail-ot1-f73.google.com ([209.85.210.73]:33017 "EHLO mail-ot1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391269AbfAOWyy (ORCPT ); Tue, 15 Jan 2019 17:54:54 -0500 Received: by mail-ot1-f73.google.com with SMTP id r15so1740446ota.0 for ; Tue, 15 Jan 2019 14:54:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=yDJ/L6vBqpvGKdilXSKNogIcmuYewwcsCdqhrppxecw=; b=g4KttRL9eKp+0Q4uBHRILcbC8i/HpQmJ3NlLa7N8NQsPw9yDE3EeoCfMtAWYjpqIkp xph5dJV094ZOr+xhLdq8BWJUz2Itueba8BYJhDqhUVal3Twu3/o9gjPqZvw/FeBhJ9J6 bNxWku5FE4wxrIDzUhxUOfdppYijZjkjNCazmnxxHVUhDu/Y51vcNWeMO/5C73GWS7Eu GnMjmSi3oZ5bP5bMGxa9XL1VPpGggORXM3pQTUsSmMAW+ZfNjo5YejI1GDJ1tb/LrsD+ CzcfKHQrI2OZXaF4HcDnMcmJaCBBonVosrbF7MXU3x5ZhI//ObxP52aY6ygazleEWYX7 WA+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=yDJ/L6vBqpvGKdilXSKNogIcmuYewwcsCdqhrppxecw=; b=EO63hgcqjMbZs4WKAgv0atLgByuwTnXX6fjgYLGTR3fKX9wru3Rdw/Qw2mxdlhslLK j0D6EEPFP0+OXuleyzXC1s7b9uGJTo69JY4m9GFn8Pc20z37phrovNoRMFLQz2iiU/2x zRvK89YUMU1uuGPjGlMgfQVqtM8R3xJsiIOAu0b2t5raWW874AQPcFwQPNXFLUuX0amz QV+GAj4V2SS9MWtvxNnpYNb0Jo84znT48Pdi7LE7UA6/6JuB6AasDsHJCKHC3uAsK8Vs 7JaZWcqvsjfslvTcigaEp3mWZQsYq0bKRzt1HhGLDrkvPwtE+oh2xudmlQJpHMTbTgA3 gV+w== X-Gm-Message-State: AJcUukef0IZ928Le9/NamqpBLPIg97XzWCS3Kw/dS/ZhmxIzyW1smaBr 6uXdlJSJsoxjXPW9Q4XXogN7iq+dN3V8tptL/m8C5kUdogsKZu3POo3eoeGoXW4Lw0g+offPA/t ZUb5F71SHDKJxgKoN3wMEkw/dii9FXRNqUTOIIHStmFIwLEVOJdePVg== X-Google-Smtp-Source: ALg8bN6l+pCGxGnKFlRk4te5h/QiSLSugGCS9ccANiNNsPVhbzvt3U/DSzp5tw+uv4VwY2iEpbX92ec= X-Received: by 2002:a05:6830:200f:: with SMTP id e15mr3503064otp.61.1547592893525; Tue, 15 Jan 2019 14:54:53 -0800 (PST) Date: Tue, 15 Jan 2019 14:54:46 -0800 In-Reply-To: <20190115225447.245788-1-sdf@google.com> Message-Id: <20190115225447.245788-2-sdf@google.com> Mime-Version: 1.0 References: <20190115225447.245788-1-sdf@google.com> X-Mailer: git-send-email 2.20.1.97.g81188d93c3-goog Subject: [PATCH bpf 2/3] bpf: zero out build_id for BPF_STACK_BUILD_ID_IP From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, songliubraving@fb.com, Stanislav Fomichev Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When returning BPF_STACK_BUILD_ID_IP from stack_map_get_build_id_offset, make sure that build_id field is empty. Since we are using percpu free list, there is a possibility that we might reuse some previous bpf_stack_build_id with non-zero build_id. Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Signed-off-by: Stanislav Fomichev Acked-by: Song Liu --- kernel/bpf/stackmap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 8975d1768dcb..f4b57c68c45f 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -315,6 +315,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, for (i = 0; i < trace_nr; i++) { id_offs[i].status = BPF_STACK_BUILD_ID_IP; id_offs[i].ip = ips[i]; + memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE); } return; } @@ -325,6 +326,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, /* per entry fall back to ips */ id_offs[i].status = BPF_STACK_BUILD_ID_IP; id_offs[i].ip = ips[i]; + memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE); continue; } id_offs[i].offset = (vma->vm_pgoff << PAGE_SHIFT) + ips[i] From patchwork Tue Jan 15 22:54:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 1025533 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="MTDEN8JS"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43fQdv574Mz9sD4 for ; Wed, 16 Jan 2019 09:54:59 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403753AbfAOWy6 (ORCPT ); Tue, 15 Jan 2019 17:54:58 -0500 Received: from mail-pl1-f201.google.com ([209.85.214.201]:45564 "EHLO mail-pl1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391269AbfAOWy4 (ORCPT ); Tue, 15 Jan 2019 17:54:56 -0500 Received: by mail-pl1-f201.google.com with SMTP id h10so2562549plk.12 for ; Tue, 15 Jan 2019 14:54:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=O9lDcchyIR0ULzkPipbF9IITLIhRh87laB/Yzj0CKko=; b=MTDEN8JSo6m54iDzwj/VGM4Nl2Gi51trQYVREDqndh2wMKh7DQHckWZofp6dN8xNO7 rAbCjjcodAdaSt7iiyrCsLunyDgyfspGp1Y40NCqFdFhtesCyG9NFvxYGpGW0TrQ+jvD xFnARCJ7S0sLxehwGlLbeNrmnZH1k65QjHr9moJyN0fpj4NXxX+/cU1nHtW8tLbXX4UB XnNfEI1ourHW0n01wcO1pneJhDFq0r9nfoVFOufJOAbMl0zxU63gqrESPGBno16Y+TXO sEUbXrk1hWFMOwL78QMXrxY3RSLhFZoxonUktvusmvJo4Jxedl72u4rCy97GADffYvP/ RHkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=O9lDcchyIR0ULzkPipbF9IITLIhRh87laB/Yzj0CKko=; b=TGI+EHhsA4gaZrHeskkl/geZmDS2cg76gGGCfAtini2TDdY3IDUaNDgAT2V9N2XkY6 VxmAZgfUm6eq8iWgdhqbVOPuDv6eRdQnM5kQ1lorAqBpd/p4fk8e5O/jV/UvnpsbDMqe xx7chSJ2coMBZrfjUxMNzFp4WkFK531fBdB7BxDiONkijLlap2DSJVF5a84gByp9Qfj9 cLg0kH5DBk/iiqZRYZ3L585ikNJh3c0XgORYXc21MNu+No5XU23W/fF7Ty5UuDEhNkZZ jF2klfN41/VdFUX6/DfkAHggE7Epv19qf10QNo7rnJJL10XhmUgME8jdtpSkMsKvJi+V Cy3A== X-Gm-Message-State: AJcUukca0ChLpYzyAZuENAO/eYH4VeHOmNYREV8NAqeIWORS/1rWB7Q/ e/UdOuODofu8pE61XKa3ZSXz0OGla0adkT59DDv6ogPQqKFFZh1SgePLWIBWcY7B1QbOsxtUjTG kZp2MPC2foKwiYDYk0ik6TJnrHOjQW00muePV1dO10HoXP7MMdr9OFw== X-Google-Smtp-Source: ALg8bN6M5fxBo2NaKv6qlGtnFfDBNu4bk9dgj7A2mkuyMF9Q/VtPU1UdEp+ucSM8aFjV8Ww6TkRDp88= X-Received: by 2002:a17:902:e002:: with SMTP id ca2mr1854403plb.91.1547592896069; Tue, 15 Jan 2019 14:54:56 -0800 (PST) Date: Tue, 15 Jan 2019 14:54:47 -0800 In-Reply-To: <20190115225447.245788-1-sdf@google.com> Message-Id: <20190115225447.245788-3-sdf@google.com> Mime-Version: 1.0 References: <20190115225447.245788-1-sdf@google.com> X-Mailer: git-send-email 2.20.1.97.g81188d93c3-goog Subject: [PATCH bpf 3/3] selftests/bpf: retry tests that expect build-id From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, songliubraving@fb.com, Stanislav Fomichev Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While running test_progs in a loop I found out that I'm sometimes hitting "Didn't find expected build ID from the map" error. Looking at stack_map_get_build_id_offset() it seems that it is racy (by design) and can sometimes return BPF_STACK_BUILD_ID_IP (i.e. can't trylock current->mm->mmap_sem). Let's retry this test a single time. Fixes: 13790d1cc72c ("bpf: add selftest for stackmap with build_id in NMI context") Signed-off-by: Stanislav Fomichev Acked-by: Song Liu --- tools/testing/selftests/bpf/test_progs.c | 30 ++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index 126fc624290d..25f0083a9b2e 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -1188,7 +1188,9 @@ static void test_stacktrace_build_id(void) int i, j; struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; int build_id_matches = 0; + int retry = 1; +retry: err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) goto out; @@ -1301,6 +1303,19 @@ static void test_stacktrace_build_id(void) previous_key = key; } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); + /* stack_map_get_build_id_offset() is racy and sometimes can return + * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID; + * try it one more time. + */ + if (build_id_matches < 1 && retry--) { + ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); + close(pmu_fd); + bpf_object__close(obj); + printf("%s:WARN:Didn't find expected build ID from the map, retrying\n", + __func__); + goto retry; + } + if (CHECK(build_id_matches < 1, "build id match", "Didn't find expected build ID from the map\n")) goto disable_pmu; @@ -1341,7 +1356,9 @@ static void test_stacktrace_build_id_nmi(void) int i, j; struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; int build_id_matches = 0; + int retry = 1; +retry: err = bpf_prog_load(file, BPF_PROG_TYPE_PERF_EVENT, &obj, &prog_fd); if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) return; @@ -1436,6 +1453,19 @@ static void test_stacktrace_build_id_nmi(void) previous_key = key; } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); + /* stack_map_get_build_id_offset() is racy and sometimes can return + * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID; + * try it one more time. + */ + if (build_id_matches < 1 && retry--) { + ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); + close(pmu_fd); + bpf_object__close(obj); + printf("%s:WARN:Didn't find expected build ID from the map, retrying\n", + __func__); + goto retry; + } + if (CHECK(build_id_matches < 1, "build id match", "Didn't find expected build ID from the map\n")) goto disable_pmu;