From patchwork Thu Aug 27 20:13:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 8490 Received: (qmail 3688 invoked by alias); 27 Aug 2015 20:13:20 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 3670 invoked by uid 89); 27 Aug 2015 20:13:19 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-yk0-f182.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:to:from:subject:message-id:date:user-agent :mime-version:content-type:content-transfer-encoding; bh=4I8xJFvtywDy4qrlIiYBeG3TzFBbQzxJsMYf58kZZN0=; b=JkjIFXhQXkb2SPdW618FOLr9EzWYegYT6cwmr1/hD7fDYfnY13EiHGNBkp3tj4+wZ7 uWkxZ32QHt7sTVMFcQvhtjJ9U6lwMZxwAyO9FIiJVaRr3Rg+ZuHrukmUt4KHK6Y9EP+C pOW11UWqJC+uybMtsvIKwY8jReLYLSE67qqU4C02Giw0RoeCXoTPlhh8kWyxDUV11RrK TqkB3RPmyOMGQ0YZLcT0qGQuJgQok47PcBhNz1Wqadpn+np41CeAmRx5LVzaftkNmX/Z DcnrFt9yPeXnIJ4jDqyKdwzKaN4x8U6tfEJ0uTV0hvidDPDaIOOwTH3JxIvvebSKu2OH c4dA== X-Gm-Message-State: ALoCoQlMjDnaUQNvWK/x3NxhYi/wcI6ZNGkF77I9kxMHBoapzaA2wBI9tkhShO2Dx0s6WOnz/qfo X-Received: by 10.129.157.67 with SMTP id u64mr1439779ywg.11.1440706396212; Thu, 27 Aug 2015 13:13:16 -0700 (PDT) To: GNU C Library From: Adhemerval Zanella Subject: [PATCH] Fix wordsize-32 mmap offset for negative value (BZ#18877) Message-ID: <55DF6F59.3000404@linaro.org> Date: Thu, 27 Aug 2015 17:13:13 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 This patch fixes the default wordsize-32 mmap implementation offset calculation for negative values. Current code uses signed shift operation to calculate the multiple size to use with syscall and it is implementation defined. Change it to use a division base on mmap page size (default being as before, 4096). Tested on armv7hf. [BZ #18877] * misc/Makefile (tests): Add tst-mmap * sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c (__mmap): Fix offset calculation for negative values. * misc/tst-mmap.c: New file. --- -- diff --git a/misc/Makefile b/misc/Makefile index aecb0da..2929d61 100644 --- a/misc/Makefile +++ b/misc/Makefile @@ -76,7 +76,8 @@ install-lib := libg.a gpl2lgpl := error.c error.h tests := tst-dirname tst-tsearch tst-fdset tst-efgcvt tst-mntent tst-hsearch \ - tst-error1 tst-pselect tst-insremque tst-mntent2 bug-hsearch1 + tst-error1 tst-pselect tst-insremque tst-mntent2 bug-hsearch1 \ + tst-mmap ifeq ($(run-built-tests),yes) tests-special += $(objpfx)tst-error1-mem.out endif diff --git a/misc/tst-mmap.c b/misc/tst-mmap.c new file mode 100644 index 0000000..8b006b5 --- /dev/null +++ b/misc/tst-mmap.c @@ -0,0 +1,67 @@ +/* mmap offset test. + + Copyright (C) 2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include + +static int +printmsg (int rc, const char *msg) +{ + printf ("%s failed: %m\n", msg); + return rc; +} + +/* Check if negative offset are handled correctly by mmap. */; +static int +do_test_bz18877 (void) +{ + const int prot = PROT_READ | PROT_WRITE; + const int flags = MAP_SHARED; + const unsigned long length = 0x10000; + const unsigned long offset = 0xace00000; + const unsigned long size = offset + length; + void *addr; + int fd; + char fname[] = "tst-mmap-offset-XXXXXX"; + + fd = mkstemp64 (fname); + if (fd < 0) + return printmsg (1, "mkstemp"); + + if (unlink (fname)) + return printmsg (1, "unlink"); + + if (ftruncate64 (fd, size)) + return printmsg (0, "ftruncate64"); + + addr = mmap (NULL, length, prot, flags, fd, offset); + if (MAP_FAILED == addr) + return printmsg (1, "mmap"); + + /* This memcpy is likely to SIGBUS if mmap has messed up with offset. */ + memcpy (addr, fname, sizeof (fname)); + + return 0; +} + +#define TEST_FUNCTION do_test_bz18877 () +#include "../test-skeleton.c" diff --git a/sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c b/sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c index 24835ce..f5a4c32 100644 --- a/sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c +++ b/sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c @@ -21,20 +21,20 @@ #include #include -#ifndef MMAP_PAGE_SHIFT -#define MMAP_PAGE_SHIFT 12 +#ifndef MMAP_PAGE_UNIT +#define MMAP_PAGE_UNIT 4096UL #endif __ptr_t __mmap (__ptr_t addr, size_t len, int prot, int flags, int fd, off_t offset) { - if (offset & ((1 << MMAP_PAGE_SHIFT) - 1)) + if (offset & (MMAP_PAGE_UNIT - 1)) { __set_errno (EINVAL); return MAP_FAILED; } return (__ptr_t) INLINE_SYSCALL (mmap2, 6, addr, len, prot, flags, fd, - offset >> MMAP_PAGE_SHIFT); + offset/MMAP_PAGE_UNIT); } weak_alias (__mmap, mmap)