From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf29.google.com (mail-qv1-xf29.google.com [IPv6:2607:f8b0:4864:20::f29]) by sourceware.org (Postfix) with ESMTPS id 64E793857020 for ; Mon, 15 Feb 2021 17:08:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 64E793857020 Received: by mail-qv1-xf29.google.com with SMTP id a1so3413372qvd.13 for ; Mon, 15 Feb 2021 09:08:17 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:references:from:autocrypt:subject:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=FVASrmisl2NrUbIovSf3A5KGzlP4vLJcFKxwqH9SCTg=; b=HL5F6NuCz1b6ff+CmHiuGnHR6W19eWd2fY5vAoW90dSUMMIpE6mUC40fhUNCckJoe5 VukOz9kY84NFmq19QN3TZDjVTorvJHgxN7k95wcfw/kWsjqF6C6nko2m59KRcZ+Vt0sc oerioRRIbceJsvt10NoABWnjIboN/k2IfrKzTEIe9hk7r635ZaSfRZYcTdXqrfGU3JpM /daLD2myWrmDVSxpukJZwrkBmvLANH2MYr7AyiGh2V0u0knI6bOyV6yaIF8HxxojBPDb hULwCKBxsE0J3e5lfnDLvLoDuAV/36akOSl9Gtr6eTGzuPeyafNkHW3bAiueBrLJkeqp wJQw== X-Gm-Message-State: AOAM530WJ8TX3YB0jaoxUAcRcNuo/tV/k4rFmHoAxaHlWBwOUtMC+D1K nrJKvQRnX4T8ZYmQ5P9t7wnISiJN2VbVPw== X-Google-Smtp-Source: ABdhPJwPGzXx7BGVHaftqmY+nCIAkH7vYRW2QBfx4Svz6CWA20bZnhKlwhNdUImQMpKGan/gFbKkgQ== X-Received: by 2002:ad4:576a:: with SMTP id r10mr15472930qvx.29.1613408896208; Mon, 15 Feb 2021 09:08:16 -0800 (PST) Received: from [192.168.1.4] ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id l128sm12466376qkf.68.2021.02.15.09.08.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 15 Feb 2021 09:08:15 -0800 (PST) To: libc-alpha@sourceware.org, Vivek Das Mohapatra References: <20210209171839.7911-1-vivek@collabora.com> <20210209171839.7911-6-vivek@collabora.com> 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 Subject: Re: [RFC][PATCH v8 05/20] elf/dl-fini.c: Handle proxy link_map entries in the shutdown path Message-ID: <71049f5d-09d2-2ab1-e0c4-4a716c0919fb@linaro.org> Date: Mon, 15 Feb 2021 14:08:13 -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: <20210209171839.7911-6-vivek@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-13.6 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: Mon, 15 Feb 2021 17:08:19 -0000 On 09/02/2021 14:18, Vivek Das Mohapatra via Libc-alpha wrote: > When cleaning up before exit we should not call destructors or > otherwise free [most of] the contents of proxied link_map entries > since they share [most of] their contents with the LM_ID_BASE > objects to which they point. > --- > elf/dl-close.c | 43 ++++++++++++++++++++++++++----------------- > elf/dl-fini.c | 6 ++++-- > 2 files changed, 30 insertions(+), 19 deletions(-) > > diff --git a/elf/dl-close.c b/elf/dl-close.c > index c51becd06b..a0432b884d 100644 > --- a/elf/dl-close.c > +++ b/elf/dl-close.c > @@ -283,8 +283,9 @@ _dl_close_worker (struct link_map *map, bool force) > > /* Call its termination function. Do not do it for > half-cooked objects. Temporarily disable exception > - handling, so that errors are fatal. */ > - if (imap->l_init_called) > + handling, so that errors are fatal. > + Proxies should never have this flag set, but we double check. */ > + if (imap->l_init_called && !imap->l_proxy) > { > /* When debugging print a message first. */ > if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, Ok. > @@ -360,7 +361,9 @@ _dl_close_worker (struct link_map *map, bool force) > one for the terminating NULL pointer. */ > size_t remain = (new_list != NULL) + 1; > bool removed_any = false; > - for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) > + for (size_t cnt = 0; > + imap->l_scope && imap->l_scope[cnt] != NULL; > + ++cnt) > /* This relies on l_scope[] entries being always set either > to its own l_symbolic_searchlist address, or some map's > l_searchlist address. */ Ok. > @@ -686,8 +689,10 @@ _dl_close_worker (struct link_map *map, bool force) > > /* We can unmap all the maps at once. We determined the > start address and length when we loaded the object and > - the `munmap' call does the rest. */ > - DL_UNMAP (imap); > + the `munmap' call does the rest. Proxies do not have > + any segments of their own to unmap. */ > + if (!imap->l_proxy) > + DL_UNMAP (imap); > > /* Finally, unlink the data structure and free it. */ Ok. > #if DL_NNS == 1 > @@ -727,19 +732,23 @@ _dl_close_worker (struct link_map *map, bool force) > _dl_debug_printf ("\nfile=%s [%lu]; destroying link map\n", > imap->l_name, imap->l_ns); > > - /* This name always is allocated. */ > - free (imap->l_name); > - /* Remove the list with all the names of the shared object. */ > + /* Skip structures borrowed by proxies from the real map. */ > + if (!imap->l_proxy) > + { > + /* This name always is allocated. */ > + free (imap->l_name); > + /* Remove the list with all the names of the shared object. */ > > - struct libname_list *lnp = imap->l_libname; > - do > - { > - struct libname_list *this = lnp; > - lnp = lnp->next; > - if (!this->dont_free) > - free (this); > - } > - while (lnp != NULL); > + struct libname_list *lnp = imap->l_libname; > + do > + { > + struct libname_list *this = lnp; > + lnp = lnp->next; > + if (!this->dont_free) > + free (this); > + } > + while (lnp != NULL); > + } > > /* Remove the searchlists. */ > free (imap->l_initfini); Ok. > diff --git a/elf/dl-fini.c b/elf/dl-fini.c > index 6dbdfe4b3e..10194488bb 100644 > --- a/elf/dl-fini.c > +++ b/elf/dl-fini.c > @@ -73,7 +73,7 @@ _dl_fini (void) > assert (nloaded != 0 || GL(dl_ns)[ns]._ns_loaded == NULL); > for (l = GL(dl_ns)[ns]._ns_loaded, i = 0; l != NULL; l = l->l_next) > /* Do not handle ld.so in secondary namespaces. */ > - if (l == l->l_real) > + if (l == l->l_real || l->l_proxy) > { > assert (i < nloaded); > > @@ -111,7 +111,9 @@ _dl_fini (void) > { > struct link_map *l = maps[i]; > > - if (l->l_init_called) > + /* Do not call fini functions via proxies, or for > + objects which are not marked as initialised. */ > + if (l->l_init_called && !l->l_proxy) > { > /* Make sure nothing happens if we are called twice. */ > l->l_init_called = 0; > Ok.