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=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 4104AC433E0 for ; Tue, 26 May 2020 15:15:18 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0452620776 for ; Tue, 26 May 2020 15:15:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="i93tMEtj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0452620776 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53630 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jdbIT-0002Ew-6K for qemu-devel@archiver.kernel.org; Tue, 26 May 2020 11:15:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45886) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jdbHa-0001kq-Lv for qemu-devel@nongnu.org; Tue, 26 May 2020 11:14:22 -0400 Received: from mail-lj1-x242.google.com ([2a00:1450:4864:20::242]:43498) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jdbHZ-0002jA-A8 for qemu-devel@nongnu.org; Tue, 26 May 2020 11:14:22 -0400 Received: by mail-lj1-x242.google.com with SMTP id q2so24923740ljm.10 for ; Tue, 26 May 2020 08:14:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=E+XMLlWa2GKIgemfr2YQ4Di+1zf8OSoofAjdVOCTmpg=; b=i93tMEtjjrd0IzWq1ZiAYguj42u+EWAFzLOV4g0gGHMZgIujhIzCmIcX80Z3JI6tlP /vjxSSbNGYxcRKXvI4zRAYUbjRjPOLFZfQamAMPUawm5b9L8b+oWBjCLig5iC5rd+X/b w9XhVlwAAlmC8npyHV1uUXObEtQY6s5OJEqN454ZGKrN57MNvhOMhHa8QZjj0+tJb6rh ObgV2LXCOmPFVb03lkHArox1zuxBVhzMsKCzdMRqllqxlaR/f7e74/tWLGzwXpr/2PaH 9K86iA1rCpXxopLFEOMdpN0egvtqwa9p2gS21vCLSnGiyIo6N7girWIHznZGvDeNTDcb PHdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=E+XMLlWa2GKIgemfr2YQ4Di+1zf8OSoofAjdVOCTmpg=; b=ClP5TUyQQL4O3p5aIBcYSsT08XafjpLnifH9fxJEVTTPfKjj70JIjz5oWCqVXUqQoV B7RC9Hr4Mp1VJJx2yYNfIqONhztDRYsyRwS9U0TEhsQuqFz+Hmau151VU+QTwJXBr9QJ Wxh+cUsH8vgwjRLWE0OwiS0TJAqzy1qHCryaGF+MxgawYcPcqTME2Z1Qu0iLNZiEsHa3 vkRT3Q7S8xE0pCMmrIyGfakyezPWor8JaKOy6lEr6FzYBGEWiX+p3LQeO8UbJjVD7w6f PJRcoheotjv5RUi9JskOgWyuKwXzFGcqw40p0i4sLoc8VJ+u+XNu+/Y6t2XHZLZ3Jd7o qZZg== X-Gm-Message-State: AOAM533sCKlbemTrTDn5/ziycOEfr2Zly/mPsEh8k8MLBzgc5hCM4yK9 aPSI5gOpOhRaMqdqdbZKVkltKij4DMgnDEoNHfLp7A== X-Google-Smtp-Source: ABdhPJwmBzxH3CwB+KlzDQRwjv6PvjoHfxc/R0ivY7mzoFnpRVNFcd7uKmSYm689dFji/I8IgPXptw8EyKDuHW2pheM= X-Received: by 2002:a2e:8811:: with SMTP id x17mr832598ljh.140.1590506059444; Tue, 26 May 2020 08:14:19 -0700 (PDT) MIME-Version: 1.0 References: <20200522160755.886-1-robert.foley@linaro.org> <20200522160755.886-14-robert.foley@linaro.org> <20200523200631.GE382220@sff> In-Reply-To: <20200523200631.GE382220@sff> From: Robert Foley Date: Tue, 26 May 2020 11:14:14 -0400 Message-ID: Subject: Re: [PATCH 13/19] accel/tcg: Fixed tsan warnings. To: "Emilio G. Cota" Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2a00:1450:4864:20::242; envelope-from=robert.foley@linaro.org; helo=mail-lj1-x242.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Puhov , Richard Henderson , =?UTF-8?B?QWxleCBCZW5uw6ll?= , QEMU Developers , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Sat, 23 May 2020 at 16:06, Emilio G. Cota wrote: > > On Fri, May 22, 2020 at 12:07:49 -0400, Robert Foley wrote: > > For example: > > WARNING: ThreadSanitizer: data race (pid=35425) > > Write of size 4 at 0x7bbc000000ac by main thread (mutexes: write M875): > > #0 cpu_reset_interrupt hw/core/cpu.c:107:28 (qemu-system-aarch64+0x843790) > > #1 arm_cpu_set_irq target/arm/cpu.c (qemu-system-aarch64+0x616265) > > #2 qemu_set_irq hw/core/irq.c:44:5 (qemu-system-aarch64+0x8462ca) > > Previous atomic read of size 4 at 0x7bbc000000ac by thread T6: > > #0 __tsan_atomic32_load (qemu-system-aarch64+0x394c1c) > > #1 cpu_handle_interrupt accel/tcg/cpu-exec.c:534:9 (qemu-system-aarch64+0x4b7e79) > > #2 cpu_exec accel/tcg/cpu-exec.c:720:17 (qemu-system-aarch64+0x4b7e79) > > or > > WARNING: ThreadSanitizer: data race (pid=25425) > > Read of size 8 at 0x7f8ad8e138d0 by thread T10: > > #0 tb_lookup_cmp accel/tcg/cpu-exec.c:307:13 (qemu-system-aarch64+0x4ac4d2) > > #1 qht_do_lookup util/qht.c:502:34 (qemu-system-aarch64+0xd05264) > > Previous write of size 8 at 0x7f8ad8e138d0 by thread T15 (mutexes: write M728311726235541804): > > #0 tb_link_page accel/tcg/translate-all.c:1625:26 (qemu-system-aarch64+0x4b0bf2) > > #1 tb_gen_code accel/tcg/translate-all.c:1865:19 (qemu-system-aarch64+0x4b0bf2) > > #2 tb_find accel/tcg/cpu-exec.c:407:14 (qemu-system-aarch64+0x4ad77c) > > I see you're working through the warnings in this file, but I think it would > be better to forget about files and focus on the data itself. > Therefore this patch should be split in two: (1) cpu- and (2) gen_code_buf. (1) requires a lot of changes with a proper audit; > the per-cpu-lock series has a possible solution for that, so I will > ignore those hunks and just comment on (2) below. We will be dropping the changes in this file which overlap with the per-cpu-locks patch. > > > Cc: Richard Henderson > > Cc: Paolo Bonzini > > Signed-off-by: Robert Foley > > --- > > accel/tcg/tcg-all.c | 4 ++-- > > accel/tcg/tcg-runtime.c | 7 ++++++- > > accel/tcg/translate-all.c | 6 +++++- > > hw/core/cpu.c | 2 +- > > 4 files changed, 14 insertions(+), 5 deletions(-) > > > (snip) > > diff --git a/accel/tcg/tcg-runtime.c b/accel/tcg/tcg-runtime.c > > index 446465a09a..bd0cd77450 100644 > > --- a/accel/tcg/tcg-runtime.c > > +++ b/accel/tcg/tcg-runtime.c > > @@ -31,6 +31,7 @@ > > #include "disas/disas.h" > > #include "exec/log.h" > > #include "tcg/tcg.h" > > +#include "qemu/tsan.h" > > > > /* 32-bit helpers */ > > > > @@ -151,6 +152,7 @@ void *HELPER(lookup_tb_ptr)(CPUArchState *env) > > TranslationBlock *tb; > > target_ulong cs_base, pc; > > uint32_t flags; > > + void *tc_ptr; > > > > tb = tb_lookup__cpu_state(cpu, &pc, &cs_base, &flags, curr_cflags()); > > if (tb == NULL) { > > @@ -161,7 +163,10 @@ void *HELPER(lookup_tb_ptr)(CPUArchState *env) > > TARGET_FMT_lx "/" TARGET_FMT_lx "/%#x] %s\n", > > cpu->cpu_index, tb->tc.ptr, cs_base, pc, flags, > > lookup_symbol(pc)); > > - return tb->tc.ptr; > > + TSAN_ANNOTATE_IGNORE_READS_BEGIN(); > > + tc_ptr = tb->tc.ptr; > > + TSAN_ANNOTATE_IGNORE_READS_END(); > > + return tc_ptr; > > I'm not sure these are needed. At least after applying all other patches > in this series, I don't get a warning here. I think we will also be dropping the ANNOTATE calls here as we re-focus the patch series. Thanks & Regards, -Rob > > > } > > > > void HELPER(exit_atomic)(CPUArchState *env) > > diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c > > index 3fb71a1503..6c0e61994c 100644 > > --- a/accel/tcg/translate-all.c > > +++ b/accel/tcg/translate-all.c > > @@ -58,6 +58,7 @@ > > #include "exec/log.h" > > #include "sysemu/cpus.h" > > #include "sysemu/tcg.h" > > +#include "qemu/tsan.h" > > > > /* #define DEBUG_TB_INVALIDATE */ > > /* #define DEBUG_TB_FLUSH */ > > @@ -1704,6 +1705,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu, > > max_insns = 1; > > } > > > > + TSAN_ANNOTATE_IGNORE_WRITES_BEGIN(); > > Same here, I don't get a warning in this hunk if I remove these, > except for: > --- > WARNING: ThreadSanitizer: data race (pid=445867) > Atomic read of size 1 at 0x7f906e050158 by thread T7: > #0 __tsan_mutex_post_lock (qemu-system-aarch64+0x481721) > #1 qemu_spin_lock /home/cota/src/qemu/include/qemu/thread.h:244:5 (qemu-system-aarch64+0x5578e9) > #2 tb_add_jump /home/cota/src/qemu/accel/tcg/cpu-exec.c:363:5 (qemu-system-aarch64+0x5578e9) > #3 tb_find /home/cota/src/qemu/accel/tcg/cpu-exec.c:423:9 (qemu-system-aarch64+0x5578e9) > > Previous write of size 1 at 0x7f906e050158 by thread T8: > #0 __tsan_mutex_create (qemu-system-aarch64+0x481589) > #1 qemu_spin_init /home/cota/src/qemu/include/qemu/thread.h:221:5 (qemu-system-aarch64+0x559a71) > #2 tb_gen_code /home/cota/src/qemu/accel/tcg/translate-all.c:1875:5 (qemu-system-aarch64+0x559a71) > > Thread T7 'CPU 0/TCG' (tid=445875, running) created by main thread at: > #0 pthread_create (qemu-system-aarch64+0x43915b) > #1 qemu_thread_create /home/cota/src/qemu/util/qemu-thread-posix.c:558:11 (qemu-system-aarch64+0xaf91ff) > > Thread T8 'CPU 1/TCG' (tid=445876, running) created by main thread at: > #0 pthread_create (qemu-system-aarch64+0x43915b) > #1 qemu_thread_create /home/cota/src/qemu/util/qemu-thread-posix.c:558:11 (qemu-system-aarch64+0xaf91ff) > > SUMMARY: ThreadSanitizer: data race (/home/cota/src/qemu/build/aarch64-softmmu/qemu-system-aarch64+0x481721) in __tsan_mutex_post_lock > --- > > Seems like tsan is confusing itself here. > > Thanks, > E.