From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by sourceware.org (Postfix) with ESMTPS id 309103858D3C for ; Thu, 24 Mar 2022 21:26:56 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 309103858D3C Received: by mail-pg1-x531.google.com with SMTP id z128so4850914pgz.2 for ; Thu, 24 Mar 2022 14:26:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lA/PlKYgNM1K8ueoPoI3YGy8YXFVwCP1C0/L0VSareg=; b=CoGz4xbisynET/EQUbOWg5v/fYYbLwAEcgzflMfVi2NavK0ekpwL55JFRGtQoZX8rV IBArt08LsOq6bAHVWmu1xCWjofCyIWqHR/e39XzwwYtpywF5vVKWh65298lSUuY8JNfl cxlC2igpRGd5YnZj+C4cuPVj/RNb1hDwYbknhdJygERofCrVj910Xm9EH634tC/Ox2+g jEmw4Yi6FVnMt7okGnfXzGh7L6OtmlEkqPU9Y2s7h8vhsxu/Kf8jHMS6pNYe+hHbLqCA ZGoJnrRyP12/j9MWydRhapc8wxuAYSFEtM7zVa4kUlFjkmaryiCwjEuaTzehgsxQfCSQ l6MA== X-Gm-Message-State: AOAM5330DPi2mqL2+yEP0/yw5uK98RoJwt7vIG9JcStBeZR+AOu1kSV7 o54hj4PzxXT541izcpArYbVxRmMzRmEn8+wHFUMM694gobk= X-Google-Smtp-Source: ABdhPJyUonhqBpvnD7B2zj0t4NvEnIu6my4iWVEdduOup5L8reTRi/nDOGTtGMwXhmTOZIMs5d2h3vNKSXz4rgaX/cg= X-Received: by 2002:a63:3e47:0:b0:382:366:64ea with SMTP id l68-20020a633e47000000b00382036664eamr5454650pga.210.1648157215141; Thu, 24 Mar 2022 14:26:55 -0700 (PDT) MIME-Version: 1.0 References: <20220323215734.3927131-12-goldstein.w.n@gmail.com> <20220324205033.3274646-1-goldstein.w.n@gmail.com> In-Reply-To: <20220324205033.3274646-1-goldstein.w.n@gmail.com> From: "H.J. Lu" Date: Thu, 24 Mar 2022 14:26:19 -0700 Message-ID: Subject: Re: [PATCH v2 12/31] x86: Fix fallback for wcsncmp_avx2 in strcmp-avx2.S [BZ #28896] To: Noah Goldstein Cc: GNU C Library , "Carlos O'Donell" Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3026.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Mar 2022 21:26:58 -0000 On Thu, Mar 24, 2022 at 1:50 PM Noah Goldstein wrote: > > Overflow case for __wcsncmp_avx2_rtm should be __wcscmp_avx2_rtm not > __wcscmp_avx2. > > commit ddf0992cf57a93200e0c782e2a94d0733a5a0b87 > Author: Noah Goldstein > Date: Sun Jan 9 16:02:21 2022 -0600 > > x86: Fix __wcsncmp_avx2 in strcmp-avx2.S [BZ# 28755] > > Set the wrong fallback function for `__wcsncmp_avx2_rtm`. It was set > to fallback on to `__wcscmp_avx2` instead of `__wcscmp_avx2_rtm` which > can cause spurious aborts. > > This change will need to be backported. > > All string/memory tests pass. > --- > sysdeps/x86/tst-strncmp-rtm.c | 15 +++++++++++++++ > sysdeps/x86_64/multiarch/strcmp-avx2.S | 2 +- > 2 files changed, 16 insertions(+), 1 deletion(-) > > diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c > index 300bc8c281..a3b14e72ff 100644 > --- a/sysdeps/x86/tst-strncmp-rtm.c > +++ b/sysdeps/x86/tst-strncmp-rtm.c > @@ -70,6 +70,16 @@ function_overflow (void) > return 1; > } > > +__attribute__ ((noinline, noclone)) > +static int > +function_overflow2 (void) > +{ > + if (STRNCMP (string1, string2, SIZE_MAX >> 4) == 0) > + return 0; > + else > + return 1; > +} > + > static int > do_test (void) > { > @@ -77,5 +87,10 @@ do_test (void) > if (status != EXIT_SUCCESS) > return status; > status = do_test_1 (TEST_NAME, LOOP, prepare, function_overflow); > + if (status != EXIT_SUCCESS) > + return status; > + status = do_test_1 (TEST_NAME, LOOP, prepare, function_overflow2); > + if (status != EXIT_SUCCESS) > + return status; > return status; > } > diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S > index 52ff5ad724..86a86b68e3 100644 > --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S > +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S > @@ -122,7 +122,7 @@ ENTRY(STRCMP) > are cases where length is large enough that it can never be a > bound on valid memory so just use wcscmp. */ > shrq $56, %rcx > - jnz __wcscmp_avx2 > + jnz OVERFLOW_STRCMP > > leaq (, %rdx, 4), %rdx > # endif > -- > 2.25.1 > LGTM. Verified on AVX2 machine with RTM. Without the fix, the new testcase failed. Reviewed-by: H.J. Lu Thanks. -- H.J.