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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 74BB4C433E0 for ; Wed, 20 Jan 2021 01:24:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35E8D23110 for ; Wed, 20 Jan 2021 01:24:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726841AbhATBXw (ORCPT ); Tue, 19 Jan 2021 20:23:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725968AbhATBXv (ORCPT ); Tue, 19 Jan 2021 20:23:51 -0500 Received: from mail-yb1-xb2e.google.com (mail-yb1-xb2e.google.com [IPv6:2607:f8b0:4864:20::b2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66CD2C061573; Tue, 19 Jan 2021 17:23:11 -0800 (PST) Received: by mail-yb1-xb2e.google.com with SMTP id p185so6732798ybg.8; Tue, 19 Jan 2021 17:23:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=aB5Or3lI/qRSS51C0pnoSQ5oKzBYbujWPgstkZELdzc=; b=nUo0RPzs4UZN3xplRgxSRNcEG4O2fOa+m3P0tm6toHW/drXs6XA9kQ2F9OhEhEQfQS 71bIJkWG2A9Nyv1ZqdsI9fiKGEiL5QZH6d+cU96DMUlCKra6+Wd0lqlRc8M0SLf3Zx9J XrxL0K8lTYsvZRVwlGXeMf7dWzjst0rC1TM7H9pQwe2IxThCjtGIqUPcQqxgQxQgYlzf h3M1NmSC5Q55o1gC4vo3pfixMngLsbWIBNX2AiHvnwnAUYREYj0bZqjMbSV7rVytC9gC pCZS+PYPihvTa8Ce4r+Ui/20GFmt+KIucSCpp1Lzt0i+fqnJgfkkQ8+NVO3BD9iCc3XI /Tqg== 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=aB5Or3lI/qRSS51C0pnoSQ5oKzBYbujWPgstkZELdzc=; b=AR9scsC41kTTNdIT2Iu9KzRQ+EBR2QjFY5zHYnIjAYUNQm5j+awda5fkgslwMJXo9s RHbjv6vM3tJXmXs1rfhb4uGgqaqhIOdgWrRtudtWu3THDKjY4mK0JUUH0yldOnuYlzp1 lOZ6j3p6f8ZLNcufm4ciWnmLyKQKfw5/UABaA8vPgqo7Cwnck2HcQwdXAjV4XirYreON JSKn/2wNkv3HyDwbHFEte1w3l/AHZ5iTgL/OTHP7qj0IpfWCnzQ7dt/sX98b8SLgeUud c5MBDrAmka+e4ZgimTCNPPUSCEYnlhkVM+bABqv3+sT3Iu3mPnKl1/BFbi/Ybx2Srr9l 2B7A== X-Gm-Message-State: AOAM532yyqd8B7OcoQPlZR6HFBxuEmBKbusaryqzHY6Q6n9sxIjVhbQ4 dLTSAjASWr1OB45I5eQ5NxJert59Tl8jubeGGEc= X-Google-Smtp-Source: ABdhPJyip/5H2uffx15cFVwjuNyjEmFH1RNGvII/8jaSthBZ1cgbXvygTsqcrsluYwIoAaH179cExlx8SzTBIvAKK9s= X-Received: by 2002:a25:9882:: with SMTP id l2mr9371267ybo.425.1611105790757; Tue, 19 Jan 2021 17:23:10 -0800 (PST) MIME-Version: 1.0 References: <20210119221220.1745061-1-jolsa@kernel.org> <20210119221220.1745061-2-jolsa@kernel.org> In-Reply-To: <20210119221220.1745061-2-jolsa@kernel.org> From: Andrii Nakryiko Date: Tue, 19 Jan 2021 17:23:00 -0800 Message-ID: Subject: Re: [PATCH 1/3] elf_symtab: Add support for SHN_XINDEX index to elf_section_by_name To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , dwarves@vger.kernel.org, Networking , bpf , Yonghong Song , Hao Luo , Martin KaFai Lau , Song Liu , John Fastabend , KP Singh , Joe Lawrence , Mark Wielaard Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Tue, Jan 19, 2021 at 2:16 PM Jiri Olsa wrote: > > In case the elf's header e_shstrndx contains SHN_XINDEX, > we need to call elf_getshdrstrndx to get the proper > string table index. > > Signed-off-by: Jiri Olsa > --- > dutil.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/dutil.c b/dutil.c > index 7b667647420f..321f4be6669e 100644 > --- a/dutil.c > +++ b/dutil.c > @@ -179,13 +179,17 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, > { > Elf_Scn *sec = NULL; > size_t cnt = 1; > + size_t shstrndx = ep->e_shstrndx; > + > + if (shstrndx == SHN_XINDEX && elf_getshdrstrndx(elf, &shstrndx)) > + return NULL; > see comment for patch #3, no need for SHN_XINDEX checks, elf_getshdrstrndx() handles this transparently > while ((sec = elf_nextscn(elf, sec)) != NULL) { > char *str; > > gelf_getshdr(sec, shp); > - str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); > - if (!strcmp(name, str)) { > + str = elf_strptr(elf, shstrndx, shp->sh_name); > + if (str && !strcmp(name, str)) { > if (index) > *index = cnt; > break; > -- > 2.27.0 >