From patchwork Fri May 10 10:45:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 1097966 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=vivier.eu Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 450n6b1Dbhz9sML for ; Fri, 10 May 2019 20:50:15 +1000 (AEST) Received: from localhost ([127.0.0.1]:40970 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP36T-0001hj-4k for incoming@patchwork.ozlabs.org; Fri, 10 May 2019 06:50:13 -0400 Received: from eggs.gnu.org ([209.51.188.92]:59583) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP32J-0007Ge-1e for qemu-devel@nongnu.org; Fri, 10 May 2019 06:45:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hP32I-0003a4-4u for qemu-devel@nongnu.org; Fri, 10 May 2019 06:45:55 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:41519) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hP32H-0003ZS-Sc for qemu-devel@nongnu.org; Fri, 10 May 2019 06:45:54 -0400 Received: from localhost.localdomain ([78.238.229.36]) by mrelayeu.kundenserver.de (mreue012 [212.227.15.167]) with ESMTPSA (Nemesis) id 1MGxYh-1hTjrv2HSt-00E5T6; Fri, 10 May 2019 12:45:44 +0200 From: Laurent Vivier To: qemu-devel@nongnu.org Date: Fri, 10 May 2019 12:45:34 +0200 Message-Id: <20190510104536.17483-6-laurent@vivier.eu> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190510104536.17483-1-laurent@vivier.eu> References: <20190510104536.17483-1-laurent@vivier.eu> MIME-Version: 1.0 X-Provags-ID: V03:K1:XTBnFtqzqOl1augywSMETV/XokhJfZPtKFteLyMcMV1wCHIzu1r mtszKZUX+/G84uveq+tSFMPOKMNBCDu8ypqIPzOZqyJ71rvn1Q59lERCS9kmD6w2Zck7fTf TsSupJqbhdLY6tcTJbyBsw+UwEuNjkYThwY/z7oJaXNwx7sVl94XEz2cO7JrFmb6r2DVWVy UurXWy785I478K6kgnQUQ== X-UI-Out-Filterresults: notjunk:1; V03:K0:glrErueLIBo=:iAXBGMbIdHKDVAVN4EYJK6 y1hvovHyjlhqRacqF14MMmWlxOBP9z68dPlhIB52fzBdafH6uGIn0q0OXjKI/IJVkbVKE2ifm Z8GIEfWHlyNf/kB51g/jdQgB4vkuRqWSRUtB1tbfcHJk/A4jWnlZAFpKm9CkkQp6sY3+StMGD gjMIZYbP0nZWeHVkLEQzZtdiP0mzHDfzboj86IaYkEwUXXixiGeM2Xy6gZ/mg6lqzfyXBIGKG 11hqwCreWGd0Ul342GjpG5cKMUkuHzCc55Z9IA02wnsb5uR5ZnxLK/sO6mDingSSJMqZ2N13c kIL3w8X5TmMAJg6kLpo4MA7XJsmuSIwAcX0faw8gbd7QuAwk9NBa4Om/F43jDCyn1Sw6NjPR/ NRWu8pjl/sYjtxmht1+mgvz0XS0K72u6R3HcYzmqvBRc6vkrdbLmv/fC65HmiBqjkLtbTPa98 px40B2LxHUEyr/i4ELNJkr2IUT8RmLaGL44p8sMdGmKWMCylK2ah2W5to9viSVchdTql2+vap UiwliR+jFIov0GYgfUi35dk11JiBbWoPefembDaIQUBZImJakzMXUM1ahqwsOas7EW3YzRX4a fEfBnUJf0yfRqWnBXdSto8IFWMpq+1LtdfNi7lICqxN6zm9JAf6G4eW8JUwV9WFNc46Ei1LB5 Qe5ufzrCddhGfnMoSpEjnY2/bvv2CXmHfrPH26FUSGHafH9EalCHlgnv26NgCi9Fai4XqUy2u gMR+IFi2jUGaPXX70xP/pCmHw300tGdAOl6wIA== X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 212.227.126.187 Subject: [Qemu-devel] [PULL v2 5/7] linux-user: elf: Map empty PT_LOAD segments X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Giuseppe Musacchio , Peter Maydell , Riku Voipio , Laurent Vivier Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Giuseppe Musacchio Some PT_LOAD segments may be completely zeroed out and their p_filesize is zero, in that case the loader should just allocate a page that's at least p_memsz bytes large (plus eventual alignment padding). Calling zero_bss does this job for us, all we have to do is make sure we don't try to mmap a zero-length page. Signed-off-by: Giuseppe Musacchio Reviewed-by: Peter Maydell Message-Id: <20190503122007.lkjsvztgt4ycovac@debian> Signed-off-by: Laurent Vivier --- linux-user/elfload.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index d08fe2346683..ef42e02d8233 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -2366,11 +2366,19 @@ static void load_elf_image(const char *image_name, int image_fd, vaddr_ps = TARGET_ELF_PAGESTART(vaddr); vaddr_len = TARGET_ELF_PAGELENGTH(eppnt->p_filesz + vaddr_po); - error = target_mmap(vaddr_ps, vaddr_len, - elf_prot, MAP_PRIVATE | MAP_FIXED, - image_fd, eppnt->p_offset - vaddr_po); - if (error == -1) { - goto exit_perror; + /* + * Some segments may be completely empty without any backing file + * segment, in that case just let zero_bss allocate an empty buffer + * for it. + */ + if (eppnt->p_filesz != 0) { + error = target_mmap(vaddr_ps, vaddr_len, elf_prot, + MAP_PRIVATE | MAP_FIXED, + image_fd, eppnt->p_offset - vaddr_po); + + if (error == -1) { + goto exit_perror; + } } vaddr_ef = vaddr + eppnt->p_filesz;