From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4845 invoked by alias); 11 Feb 2010 15:07:07 -0000 Received: (qmail 4827 invoked by uid 22791); 11 Feb 2010 15:07:06 -0000 X-SWARE-Spam-Status: No, hits=-6.5 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 11 Feb 2010 15:07:02 +0000 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o1BF70kP004402 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 11 Feb 2010 10:07:00 -0500 Received: from host0.dyn.jankratochvil.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o1BF6whc005638 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 11 Feb 2010 10:07:00 -0500 Received: from host0.dyn.jankratochvil.net (localhost [127.0.0.1]) by host0.dyn.jankratochvil.net (8.14.3/8.14.3) with ESMTP id o1BF6wej014297; Thu, 11 Feb 2010 16:06:58 +0100 Received: (from jkratoch@localhost) by host0.dyn.jankratochvil.net (8.14.3/8.14.3/Submit) id o1BF6vGV014296; Thu, 11 Feb 2010 16:06:57 +0100 Date: Thu, 11 Feb 2010 15:07:00 -0000 From: Jan Kratochvil To: gdb-patches@sourceware.org Cc: Mark Kettenis Subject: [patch] Fix PIE for 64bit gdb -> 32bit inferior Message-ID: <20100211150657.GA14066@host0.dyn.jankratochvil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-08-17) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2010-02/txt/msg00289.txt.bz2 Hi, according to the suggestion by Mark Kettenis the fix for biarch PIE is in fact simple. The displacement for cross-arch inferiors can use 64bit math operations if its bits 32..63 are properly set to either 0x00000000 << 32 or 0xffffffff << 32 as appropriate. No regressions on {x86_64,x86_64-m32,i686}-fedora12-linux-gnu. It fixes some FAILs of gdb.base/break-interp.exp on {x86_64-m32}-fedora12-linux-gnu (therefore host=x86_64-fedora12-linux-gnu target=i686-fedora12-linux-gnu). Thanks, Jan 2010-02-11 Jan Kratochvil * solib-svr4.c (enable_break ): New variable addr_bit. Adjust LOAD_ADDR sign for cross-arch inferiors. --- a/gdb/solib-svr4.c +++ b/gdb/solib-svr4.c @@ -1428,7 +1428,32 @@ enable_break (struct svr4_info *info, int from_tty) from our so_list, then try using the AT_BASE auxilliary entry. */ if (!load_addr_found) if (target_auxv_search (¤t_target, AT_BASE, &load_addr) > 0) - load_addr_found = 1; + { + int addr_bit = gdbarch_addr_bit (target_gdbarch); + + /* Ensure LOAD_ADDR has proper sign in its possible upper bits so + that `+ load_addr' will overflow CORE_ADDR width not creating + invalid addresses like 0x101234567 for 32bit inferiors on 64bit + GDB. */ + + if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) + { + CORE_ADDR space_size = (ULONGEST) 1 << addr_bit; + CORE_ADDR tmp_entry_point = exec_entry_point (tmp_bfd, + tmp_bfd_target); + + gdb_assert (load_addr < space_size); + + /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked + 64bit ld.so with 32bit executable, it should not happen. */ + + if (tmp_entry_point < space_size + && tmp_entry_point + load_addr >= space_size) + load_addr -= space_size; + } + + load_addr_found = 1; + } /* Otherwise we find the dynamic linker's base address by examining the current pc (which should point at the entry point for the