From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf30.google.com (mail-qv1-xf30.google.com [IPv6:2607:f8b0:4864:20::f30]) by sourceware.org (Postfix) with ESMTPS id 2B95E38708BB for ; Tue, 19 Jan 2021 14:35:43 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 2B95E38708BB Received: by mail-qv1-xf30.google.com with SMTP id l7so9197077qvt.4 for ; Tue, 19 Jan 2021 06:35:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=87VwcabKGeUl9FTWS4xfw29MPQFREy2n9PlN/oSydzk=; b=NfVFEf8TdEX6EXazaQCC0WSgZYiVDmmiplr8+p2bAyAgMM1zoPegS0YFMKV69Y1bLw NaaHrcnrbPnNgW/gOJK/y8FTsIfywYn/ivZWvww08Edi7YuDYTdprNIWz1Bwf40etbwF +YzEeVD2pu7xMKG1E+Sb4SRKkzvbsmGrMtmJm5EF8GrE5QVh1B4s/Z3xZS8j43b993Ge /dcFJp/fD6Rgj6kAvGe2H0wQjhxuyLonDLSXn91c2P3E+tVt/f2IuH8CGf4+E/WEBgix 6R0Zr2sy1cdDn6j4akZbVaOXLTKs9HyInaTICS3muQ+GAmaH/dyJBhKWCbcOkZYKRTbc tVrg== X-Gm-Message-State: AOAM533zzfu6jfRFcZyQCC7OmvJyhO5zGFNv8gZkbLIyOM2D3fPvh1hi At6aR6iDa4L/ycc84RvoigKnBNJfyapHGw== X-Google-Smtp-Source: ABdhPJypNywpHnyK3fHBWflu7wLiEVaYrbuVWPlUjlIsqz5dBHz70JzoNsjN0aGx5xixC6LD2MAp6A== X-Received: by 2002:ad4:4e4d:: with SMTP id eb13mr4769334qvb.6.1611066942597; Tue, 19 Jan 2021 06:35:42 -0800 (PST) Received: from [192.168.1.4] ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id a3sm12402731qtp.63.2021.01.19.06.35.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 19 Jan 2021 06:35:41 -0800 (PST) Subject: Re: V2 [PATCH v4 06/10] elf: Avoid RELATIVE relocation for _dl_sysinfo To: "H.J. Lu" Cc: Szabolcs Nagy , GNU C Library References: <3ed8c627e3f1353e5539b458e596c4112121b3ba.1610986541.git.szabolcs.nagy@arm.com> <10ad0f8f-804f-c298-547a-325fdbf269f3@linaro.org> From: Adhemerval Zanella Autocrypt: addr=adhemerval.zanella@linaro.org; prefer-encrypt=mutual; keydata= mQINBFcVGkoBEADiQU2x/cBBmAVf5C2d1xgz6zCnlCefbqaflUBw4hB/bEME40QsrVzWZ5Nq 8kxkEczZzAOKkkvv4pRVLlLn/zDtFXhlcvQRJ3yFMGqzBjofucOrmdYkOGo0uCaoJKPT186L NWp53SACXguFJpnw4ODI64ziInzXQs/rUJqrFoVIlrPDmNv/LUv1OVPKz20ETjgfpg8MNwG6 iMizMefCl+RbtXbIEZ3TE/IaDT/jcOirjv96lBKrc/pAL0h/O71Kwbbp43fimW80GhjiaN2y WGByepnkAVP7FyNarhdDpJhoDmUk9yfwNuIuESaCQtfd3vgKKuo6grcKZ8bHy7IXX1XJj2X/ BgRVhVgMHAnDPFIkXtP+SiarkUaLjGzCz7XkUn4XAGDskBNfbizFqYUQCaL2FdbW3DeZqNIa nSzKAZK7Dm9+0VVSRZXP89w71Y7JUV56xL/PlOE+YKKFdEw+gQjQi0e+DZILAtFjJLoCrkEX w4LluMhYX/X8XP6/C3xW0yOZhvHYyn72sV4yJ1uyc/qz3OY32CRy+bwPzAMAkhdwcORA3JPb kPTlimhQqVgvca8m+MQ/JFZ6D+K7QPyvEv7bQ7M+IzFmTkOCwCJ3xqOD6GjX3aphk8Sr0dq3 4Awlf5xFDAG8dn8Uuutb7naGBd/fEv6t8dfkNyzj6yvc4jpVxwARAQABtElBZGhlbWVydmFs IFphbmVsbGEgTmV0dG8gKExpbmFybyBWUE4gS2V5KSA8YWRoZW1lcnZhbC56YW5lbGxhQGxp bmFyby5vcmc+iQI3BBMBCAAhBQJXFRpKAhsDBQsJCAcDBRUKCQgLBRYCAwEAAh4BAheAAAoJ EKqx7BSnlIjv0e8P/1YOYoNkvJ+AJcNUaM5a2SA9oAKjSJ/M/EN4Id5Ow41ZJS4lUA0apSXW NjQg3VeVc2RiHab2LIB4MxdJhaWTuzfLkYnBeoy4u6njYcaoSwf3g9dSsvsl3mhtuzm6aXFH /Qsauav77enJh99tI4T+58rp0EuLhDsQbnBic/ukYNv7sQV8dy9KxA54yLnYUFqH6pfH8Lly sTVAMyi5Fg5O5/hVV+Z0Kpr+ZocC1YFJkTsNLAW5EIYSP9ftniqaVsim7MNmodv/zqK0IyDB GLLH1kjhvb5+6ySGlWbMTomt/or/uvMgulz0bRS+LUyOmlfXDdT+t38VPKBBVwFMarNuREU2 69M3a3jdTfScboDd2ck1u7l+QbaGoHZQ8ZNUrzgObltjohiIsazqkgYDQzXIMrD9H19E+8fw kCNUlXxjEgH/Kg8DlpoYJXSJCX0fjMWfXywL6ZXc2xyG/hbl5hvsLNmqDpLpc1CfKcA0BkK+ k8R57fr91mTCppSwwKJYO9T+8J+o4ho/CJnK/jBy1pWKMYJPvvrpdBCWq3MfzVpXYdahRKHI ypk8m4QlRlbOXWJ3TDd/SKNfSSrWgwRSg7XCjSlR7PNzNFXTULLB34sZhjrN6Q8NQZsZnMNs TX8nlGOVrKolnQPjKCLwCyu8PhllU8OwbSMKskcD1PSkG6h3r0AquQINBFcVGkoBEACgAdbR Ck+fsfOVwT8zowMiL3l9a2DP3Eeak23ifdZG+8Avb/SImpv0UMSbRfnw/N81IWwlbjkjbGTu oT37iZHLRwYUFmA8fZX0wNDNKQUUTjN6XalJmvhdz9l71H3WnE0wneEM5ahu5V1L1utUWTyh VUwzX1lwJeV3vyrNgI1kYOaeuNVvq7npNR6t6XxEpqPsNc6O77I12XELic2+36YibyqlTJIQ V1SZEbIy26AbC2zH9WqaKyGyQnr/IPbTJ2Lv0dM3RaXoVf+CeK7gB2B+w1hZummD21c1Laua +VIMPCUQ+EM8W9EtX+0iJXxI+wsztLT6vltQcm+5Q7tY+HFUucizJkAOAz98YFucwKefbkTp eKvCfCwiM1bGatZEFFKIlvJ2QNMQNiUrqJBlW9nZp/k7pbG3oStOjvawD9ZbP9e0fnlWJIsj 6c7pX354Yi7kxIk/6gREidHLLqEb/otuwt1aoMPg97iUgDV5mlNef77lWE8vxmlY0FBWIXuZ yv0XYxf1WF6dRizwFFbxvUZzIJp3spAao7jLsQj1DbD2s5+S1BW09A0mI/1DjB6EhNN+4bDB SJCOv/ReK3tFJXuj/HbyDrOdoMt8aIFbe7YFLEExHpSk+HgN05Lg5TyTro8oW7TSMTk+8a5M kzaH4UGXTTBDP/g5cfL3RFPl79ubXwARAQABiQIfBBgBCAAJBQJXFRpKAhsMAAoJEKqx7BSn lIjvI/8P/jg0jl4Tbvg3B5kT6PxJOXHYu9OoyaHLcay6Cd+ZrOd1VQQCbOcgLFbf4Yr+rE9l mYsY67AUgq2QKmVVbn9pjvGsEaz8UmfDnz5epUhDxC6yRRvY4hreMXZhPZ1pbMa6A0a/WOSt AgFj5V6Z4dXGTM/lNManr0HjXxbUYv2WfbNt3/07Db9T+GZkpUotC6iknsTA4rJi6u2ls0W9 1UIvW4o01vb4nZRCj4rni0g6eWoQCGoVDk/xFfy7ZliR5B+3Z3EWRJcQskip/QAHjbLa3pml xAZ484fVxgeESOoaeC9TiBIp0NfH8akWOI0HpBCiBD5xaCTvR7ujUWMvhsX2n881r/hNlR9g fcE6q00qHSPAEgGr1bnFv74/1vbKtjeXLCcRKk3Ulw0bY1OoDxWQr86T2fZGJ/HIZuVVBf3+ gaYJF92GXFynHnea14nFFuFgOni0Mi1zDxYH/8yGGBXvo14KWd8JOW0NJPaCDFJkdS5hu0VY 7vJwKcyHJGxsCLU+Et0mryX8qZwqibJIzu7kUJQdQDljbRPDFd/xmGUFCQiQAncSilYOcxNU EMVCXPAQTteqkvA+gNqSaK1NM9tY0eQ4iJpo+aoX8HAcn4sZzt2pfUB9vQMTBJ2d4+m/qO6+ cFTAceXmIoFsN8+gFN3i8Is3u12u8xGudcBPvpoy4OoG Message-ID: <61f7edaf-9ad3-4cdc-3be1-5975a9beada4@linaro.org> Date: Tue, 19 Jan 2021 11:35:39 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-13.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Tue, 19 Jan 2021 14:35:44 -0000 On 19/01/2021 11:25, H.J. Lu wrote: > On Tue, Jan 19, 2021 at 5:51 AM Adhemerval Zanella via Libc-alpha > wrote: >> >> >> >> On 18/01/2021 13:24, Szabolcs Nagy via Libc-alpha wrote: >>> From: "H.J. Lu" >>> >>> In static PIE, set the default _dl_sysinfo in _dl_aux_init, instead of >>> using the RELATIVE relocation to intialize it. >>> >>> This is needed for fixing bug 27072 on x86. >>> --- >>> elf/dl-support.c | 12 +++++++++++- >>> 1 file changed, 11 insertions(+), 1 deletion(-) >>> >>> diff --git a/elf/dl-support.c b/elf/dl-support.c >>> index 384080dd80..5acd59290f 100644 >>> --- a/elf/dl-support.c >>> +++ b/elf/dl-support.c >>> @@ -200,7 +200,12 @@ struct dl_scope_free_list *_dl_scope_free_list; >>> >>> #ifdef NEED_DL_SYSINFO >>> /* Needed for improved syscall handling on at least x86/Linux. */ >>> -uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT; >>> +uintptr_t _dl_sysinfo >>> +/* NB: Avoid RELATIVE relocation in static PIE. */ >>> +# ifndef BUILD_PIE_DEFAULT >>> + = DL_SYSINFO_DEFAULT >>> +# endif >>> +; >>> #endif >>> #ifdef NEED_DL_SYSINFO_DSO >>> /* Address of the ELF headers in the vsyscall page. */ >>> @@ -238,6 +243,11 @@ _dl_aux_init (ElfW(auxv_t) *av) >>> uid_t uid = 0; >>> gid_t gid = 0; >>> >>> +#if defined NEED_DL_SYSINFO && BUILD_PIE_DEFAULT >>> + /* NB: Avoid RELATIVE relocation in static PIE. */ >>> + GL(dl_sysinfo) = DL_SYSINFO_DEFAULT; >>> +#endif >>> + >> >> Couldn't we make it the default instead? >> >>> _dl_auxv = av; >>> for (; av->a_type != AT_NULL; ++av) >>> switch (av->a_type) >>> > > Like this? > > From af3c44826b8ff07082eb5020213652e6b1fadfa4 Mon Sep 17 00:00:00 2001 > From: "H.J. Lu" > Date: Mon, 18 Jan 2021 11:45:46 +0000 > Subject: [PATCH] elf: Avoid RELATIVE relocation for _dl_sysinfo > > Set the default _dl_sysinfo in _dl_aux_init to avoid RELATIVE relocation > in static PIE. > > This is needed for fixing bug 27072 on x86. LGTM, thanks. Reviewed-by: Adhemerval Zanella > --- > elf/dl-support.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/elf/dl-support.c b/elf/dl-support.c > index 384080dd80..7abb65d8e3 100644 > --- a/elf/dl-support.c > +++ b/elf/dl-support.c > @@ -199,8 +199,9 @@ int _dl_thread_gscope_count; > struct dl_scope_free_list *_dl_scope_free_list; > > #ifdef NEED_DL_SYSINFO > -/* Needed for improved syscall handling on at least x86/Linux. */ > -uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT; > +/* Needed for improved syscall handling on at least x86/Linux. NB: Don't > + initialize it here to avoid RELATIVE relocation in static PIE. */ > +uintptr_t _dl_sysinfo; > #endif > #ifdef NEED_DL_SYSINFO_DSO > /* Address of the ELF headers in the vsyscall page. */ > @@ -238,6 +239,11 @@ _dl_aux_init (ElfW(auxv_t) *av) > uid_t uid = 0; > gid_t gid = 0; > > +#ifdef NEED_DL_SYSINFO > + /* NB: Avoid RELATIVE relocation in static PIE. */ > + GL(dl_sysinfo) = DL_SYSINFO_DEFAULT; > +#endif > + > _dl_auxv = av; > for (; av->a_type != AT_NULL; ++av) > switch (av->a_type) > -- > 2.29.2