From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by sourceware.org (Postfix) with ESMTPS id 3DD8E385841E for ; Fri, 28 Jan 2022 20:45:38 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3DD8E385841E Received: by mail-pj1-x102d.google.com with SMTP id oa14-20020a17090b1bce00b001b61aed4a03so6098139pjb.5 for ; Fri, 28 Jan 2022 12:45:38 -0800 (PST) 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=60xZL1Ok63UbbsEHc8avKThkgxH7LKEab8RNOEIyb/k=; b=zh/rOEGb8kJmG88ppU6tbITwkOkn34QgUrfjO5swIDHXgAyHxRsRVouthrNvlHF+eF oskvtqrdQfwQb3CwXHx9oxaiyVK/3xTtqbJDL/yzajLbF4R0XJbhkAy/aTVBhhfRA4En Mz+fa0uSkeNsOtaNRiapqsO8fw3BqosLcoXPSGBEJHjT0e4NIZU4bgI65fxmxrmpQbIh gT0uKy9PvbnB9kPgbmbf88R7TMbuXdi/qdRhRP9ryI9K99k8JBoEeRVBm7xLP7Yu2k4M pJofaSsvFC0LTfuysS7Hn2TRJZxB+KxSut1VcPiFXtg3ica+yUc2t1ZKq011resi1/kg sDuA== X-Gm-Message-State: AOAM532MzqVeQlwG+MahfUpEi6O5j1sM1OEdWE4qUIMPCEVWOaLkX2eX vAhVtTOnydkdgr6TFk5m3Lz4eemWx3/BgiasEEU= X-Google-Smtp-Source: ABdhPJw1SMerMtIsOsqIG/ZnMUw+WJM0lDorxkaRgTIrSPCipvlNL1ONQKWi/RnOmOJwVp9rkqZs/k1Z+Etryx/nvG0= X-Received: by 2002:a17:902:e851:: with SMTP id t17mr9834837plg.102.1643402737290; Fri, 28 Jan 2022 12:45:37 -0800 (PST) MIME-Version: 1.0 References: <046da3ae8fc57687b5a9480381904d3f53b1010f.camel@mengyan1223.wang> In-Reply-To: <046da3ae8fc57687b5a9480381904d3f53b1010f.camel@mengyan1223.wang> From: "H.J. Lu" Date: Fri, 28 Jan 2022 12:45:01 -0800 Message-ID: Subject: Re: [PATCH] mips: pldd: support DT_MIPS_RLD_MAP and DT_MIPS_RLD_MAP_REL To: Xi Ruoyao Cc: GNU C Library , syq@debian.org, Joseph Myers , Jiaxun Yang Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3027.6 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: Fri, 28 Jan 2022 20:45:39 -0000 On Fri, Jan 28, 2022 at 10:57 AM Xi Ruoyao via Libc-alpha wrote: > > MIPS uses DT_MIPS_RLD_MAP and DT_MIPS_RLD_MAP_REL for accessing r_debug, > instead of DT_DEBUG. > --- > elf/pldd-xx.c | 67 ++++++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 53 insertions(+), 14 deletions(-) > > diff --git a/elf/pldd-xx.c b/elf/pldd-xx.c > index 1cdfb49c53..ec397f00e5 100644 > --- a/elf/pldd-xx.c > +++ b/elf/pldd-xx.c > @@ -22,6 +22,12 @@ > #define EW_(e, w, t) EW__(e, w, _##t) > #define EW__(e, w, t) e##w##t > > +#if CLASS == 32 > +typedef Elf32_Word E(val_type); > +#else > +typedef Elf64_Xword E(val_type); > +#endif > + > struct E(link_map) > { > EW(Addr) l_addr; > @@ -70,6 +76,35 @@ _Static_assert (offsetof (struct r_debug, r_map) > == offsetof (struct E(r_debug), r_map), "r_map"); > #endif > > +static EW(Addr) > +E(r_debug_offset) (EW(Dyn) *d, int memfd, EW(Addr) d_addr) > +{ > +#ifdef __mips__ > + EW(Addr) ptr; > + > + switch (d->d_tag) > + { > + case DT_MIPS_RLD_MAP_REL: > + ptr = d_addr + d->d_un.d_val; > + break; > + case DT_MIPS_RLD_MAP: > + ptr = d->d_un.d_ptr; > + break; > + default: > + return 0; > + } > + > + if (pread (memfd, &ptr, sizeof (ptr), ptr) != sizeof (ptr)) > + return 0; > + > + return ptr; > +#else > + if (d->d_tag == DT_DEBUG) > + return (off_t) d->d_un.d_ptr; > + > + return 0; > +#endif > +} > > static int > > @@ -126,21 +161,25 @@ E(find_maps) (const char *exe, int memfd, pid_t pid, void *auxv, > != p[i].p_filesz) > error (EXIT_FAILURE, 0, gettext ("cannot read dynamic section")); > > - /* Search for the DT_DEBUG entry. */ > + /* Search for the r_debug struct. */ > for (unsigned int j = 0; j < p[i].p_filesz / sizeof (EW(Dyn)); ++j) > - if (dyn[j].d_tag == DT_DEBUG && dyn[j].d_un.d_ptr != 0) > - { > - struct E(r_debug) r; > - if (pread (memfd, &r, sizeof (r), dyn[j].d_un.d_ptr) > - != sizeof (r)) > - error (EXIT_FAILURE, 0, gettext ("cannot read r_debug")); > - > - if (r.r_map != 0) > - { > - list = r.r_map; > - break; > - } > - } > + { > + EW(Addr) d_addr = offset + p[i].p_vaddr + sizeof (EW(Dyn)) * j; > + EW(Addr) off = E(r_debug_offset)(&dyn[j], memfd, d_addr); > + if (off != 0) > + { > + struct E(r_debug) r; > + if (pread (memfd, &r, sizeof (r), off) > + != sizeof (r)) > + error (EXIT_FAILURE, 0, gettext ("cannot read r_debug")); > + > + if (r.r_map != 0) > + { > + list = r.r_map; > + break; > + } > + } > + } > > free (dyn); > break; > -- > 2.35.0 > > I think a header file to access r_debug works better. MIPS can provide one to override the generic header file. -- H.J.