From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932499AbYETN7Z (ORCPT ); Tue, 20 May 2008 09:59:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754354AbYETN7R (ORCPT ); Tue, 20 May 2008 09:59:17 -0400 Received: from py-out-1112.google.com ([64.233.166.181]:37801 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754852AbYETN7Q (ORCPT ); Tue, 20 May 2008 09:59:16 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=tifIm2FV7wn3mPq/MPvARM6ng5NQR7SlG5MXepDwejOKX8UZi+38hrzu5r3WPLoqkYXI0CX4AsCUGi/vbXx5JI168l+ZNPYyb4Zlb990/Z0R7ktHvZuDXmCUeXjIjdAKVBdhbNcy9T/yxpYF23jS7UQ7oyv6+4/B5VmlOIEsyTE= Message-ID: <7b9198260805200659p6ed28403t9b0b0ea995f158d5@mail.gmail.com> Date: Tue, 20 May 2008 14:59:14 +0100 From: "Tom Spink" To: "Jeff Dike" Subject: Re: UML fails to locate address space Cc: LKML In-Reply-To: <20080520135238.GB6990@c2.user-mode-linux.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_808_25700784.1211291954948" References: <7b9198260805200408k1d6b70a8xc7e4c24106e5020f@mail.gmail.com> <20080520135238.GB6990@c2.user-mode-linux.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ------=_Part_808_25700784.1211291954948 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline 2008/5/20 Jeff Dike : > On Tue, May 20, 2008 at 12:08:24PM +0100, Tom Spink wrote: >> I've just recently pulled the latest GIT and compiled UML, however, >> when I run it a message appears saying "Locating the top of the >> address space... Address 0x0 no good?" and the program exits. > > Can you strace it and send me the output? Attached. I guess the line of interest is: mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = -1 EACCES (Permission denied) > >> After some digging, it appears that page_ok is returning false when >> checking 'bottom', in os_get_task_size >> (arch/um/os-Linux/sys-i386/task_size.c:96). After running through >> GDB, it seems that in line 31 of that file is where the segfault >> occurs: >> >> n = *address; >> >> i.e. when trying to read from the address space (at address zero). > > The segfaults are on purpose - it will trap SIGSEGV and longjmp out of > the handler and mark the affected address as not-usable. I gathered that much - I was just letting you know which test it was that was failing. > > Jeff > Thanks! -- Tom Spink ------=_Part_808_25700784.1211291954948 Content-Type: application/octet-stream; name=uml-strace Content-Transfer-Encoding: base64 X-Attachment-Id: f_fggjwu0x0 Content-Disposition: attachment; filename=uml-strace ZXhlY3ZlKCJsaW51eC0yLjYvdm1saW51eCIsIFsibGludXgtMi42L3ZtbGludXgiLCAidWJkMD0u L3Jvb3RmcyJdLCBbLyogMzMgdmFycyAqL10pID0gMApicmsoMCkgICAgICAgICAgICAgICAgICAg ICAgICAgICAgICAgICAgPSAweDgzNGQwMDAKYWNjZXNzKCIvZXRjL2xkLnNvLm5vaHdjYXAiLCBG X09LKSAgICAgID0gLTEgRU5PRU5UIChObyBzdWNoIGZpbGUgb3IgZGlyZWN0b3J5KQptbWFwMihO VUxMLCA4MTkyLCBQUk9UX1JFQUR8UFJPVF9XUklURSwgTUFQX1BSSVZBVEV8TUFQX0FOT05ZTU9V UywgLTEsIDApID0gMHhiN2Y5MzAwMAphY2Nlc3MoIi9ldGMvbGQuc28ucHJlbG9hZCIsIFJfT0sp ICAgICAgPSAtMSBFTk9FTlQgKE5vIHN1Y2ggZmlsZSBvciBkaXJlY3RvcnkpCm9wZW4oIi9saWIv dGxzL2k2ODYvc3NlMi9jbW92L2xpYnV0aWwuc28uMSIsIE9fUkRPTkxZKSA9IC0xIEVOT0VOVCAo Tm8gc3VjaCBmaWxlIG9yIGRpcmVjdG9yeSkKc3RhdDY0KCIvbGliL3Rscy9pNjg2L3NzZTIvY21v diIsIDB4YmZlNTc3YTApID0gLTEgRU5PRU5UIChObyBzdWNoIGZpbGUgb3IgZGlyZWN0b3J5KQpv cGVuKCIvbGliL3Rscy9pNjg2L3NzZTIvbGlidXRpbC5zby4xIiwgT19SRE9OTFkpID0gLTEgRU5P RU5UIChObyBzdWNoIGZpbGUgb3IgZGlyZWN0b3J5KQpzdGF0NjQoIi9saWIvdGxzL2k2ODYvc3Nl MiIsIDB4YmZlNTc3YTApID0gLTEgRU5PRU5UIChObyBzdWNoIGZpbGUgb3IgZGlyZWN0b3J5KQpv cGVuKCIvbGliL3Rscy9pNjg2L2Ntb3YvbGlidXRpbC5zby4xIiwgT19SRE9OTFkpID0gMwpyZWFk KDMsICJcMTc3RUxGXDFcMVwxXDBcMFwwXDBcMFwwXDBcMFwwXDNcMFwzXDBcMVwwXDBcMEBcblww XDAwMCIuLi4sIDUxMikgPSA1MTIKZnN0YXQ2NCgzLCB7c3RfbW9kZT1TX0lGUkVHfDA2NDQsIHN0 X3NpemU9OTY5NiwgLi4ufSkgPSAwCm1tYXAyKE5VTEwsIDEyNDMyLCBQUk9UX1JFQUR8UFJPVF9F WEVDLCBNQVBfUFJJVkFURXxNQVBfREVOWVdSSVRFLCAzLCAwKSA9IDB4YjdmOGYwMDAKbW1hcDIo MHhiN2Y5MTAwMCwgODE5MiwgUFJPVF9SRUFEfFBST1RfV1JJVEUsIE1BUF9QUklWQVRFfE1BUF9G SVhFRHxNQVBfREVOWVdSSVRFLCAzLCAweDEpID0gMHhiN2Y5MTAwMApjbG9zZSgzKSAgICAgICAg ICAgICAgICAgICAgICAgICAgICAgICAgPSAwCm9wZW4oIi9saWIvdGxzL2k2ODYvY21vdi9saWJj LnNvLjYiLCBPX1JET05MWSkgPSAzCnJlYWQoMywgIlwxNzdFTEZcMVwxXDFcMFwwXDBcMFwwXDBc MFwwXDBcM1wwXDNcMFwxXDBcMFwwXDI2MGVcMSIuLi4sIDUxMikgPSA1MTIKZnN0YXQ2NCgzLCB7 c3RfbW9kZT1TX0lGUkVHfDA3NTUsIHN0X3NpemU9MTM2NDM4OCwgLi4ufSkgPSAwCm1tYXAyKE5V TEwsIDEzNjk3MTIsIFBST1RfUkVBRHxQUk9UX0VYRUMsIE1BUF9QUklWQVRFfE1BUF9ERU5ZV1JJ VEUsIDMsIDApID0gMHhiN2U0MDAwMAptbWFwMigweGI3Zjg5MDAwLCAxMjI4OCwgUFJPVF9SRUFE fFBST1RfV1JJVEUsIE1BUF9QUklWQVRFfE1BUF9GSVhFRHxNQVBfREVOWVdSSVRFLCAzLCAweDE0 OSkgPSAweGI3Zjg5MDAwCm1tYXAyKDB4YjdmOGMwMDAsIDk4NDAsIFBST1RfUkVBRHxQUk9UX1dS SVRFLCBNQVBfUFJJVkFURXxNQVBfRklYRUR8TUFQX0FOT05ZTU9VUywgLTEsIDApID0gMHhiN2Y4 YzAwMApjbG9zZSgzKSAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgPSAwCm1tYXAyKE5V TEwsIDQwOTYsIFBST1RfUkVBRHxQUk9UX1dSSVRFLCBNQVBfUFJJVkFURXxNQVBfQU5PTllNT1VT LCAtMSwgMCkgPSAweGI3ZTNmMDAwCnNldF90aHJlYWRfYXJlYSh7ZW50cnlfbnVtYmVyOi0xIC0+ IDYsIGJhc2VfYWRkcjoweGI3ZTNmYWQwLCBsaW1pdDoxMDQ4NTc1LCBzZWdfMzJiaXQ6MSwgY29u dGVudHM6MCwgcmVhZF9leGVjX29ubHk6MCwgbGltaXRfaW5fcGFnZXM6MSwgc2VnX25vdF9wcmVz ZW50OjAsIHVzZWFibGU6MX0pID0gMAptcHJvdGVjdCgweGI3Zjg5MDAwLCA0MDk2LCBQUk9UX1JF QUQpICAgPSAwCmdldHJsaW1pdChSTElNSVRfU1RBQ0ssIHtybGltX2N1cj04MTkyKjEwMjQsIHJs aW1fbWF4PVJMSU1fSU5GSU5JVFl9KSA9IDAKYnJrKDApICAgICAgICAgICAgICAgICAgICAgICAg ICAgICAgICAgID0gMHg4MzRkMDAwCmJyaygweDgzNmUwMDApICAgICAgICAgICAgICAgICAgICAg ICAgICA9IDB4ODM2ZTAwMApydF9zaWdhY3Rpb24oU0lHSU5ULCB7MHg4MDZhNzcwLCBbXSwgU0Ff Tk9NQVNLfFNBX09ORVNIT1R9LCBOVUxMLCA4KSA9IDAKcnRfc2lnYWN0aW9uKFNJR1RFUk0sIHsw eDgwNmE3NzAsIFtdLCBTQV9OT01BU0t8U0FfT05FU0hPVH0sIE5VTEwsIDgpID0gMApydF9zaWdh Y3Rpb24oU0lHSFVQLCB7MHg4MDZhNzcwLCBbXSwgU0FfTk9NQVNLfFNBX09ORVNIT1R9LCBOVUxM LCA4KSA9IDAKZnN0YXQ2NCgxLCB7c3RfbW9kZT1TX0lGQ0hSfDA2MjAsIHN0X3JkZXY9bWFrZWRl digxMzYsIDApLCAuLi59KSA9IDAKbW1hcDIoTlVMTCwgNDA5NiwgUFJPVF9SRUFEfFBST1RfV1JJ VEUsIE1BUF9QUklWQVRFfE1BUF9BTk9OWU1PVVMsIC0xLCAwKSA9IDB4YjdlM2UwMDAKd3JpdGUo MSwgIkxvY2F0aW5nIHRoZSB0b3Agb2YgdGhlIGFkZHJlc3MgIi4uLiwgNDIpID0gNDIKcnRfc2ln YWN0aW9uKFNJR1NFR1YsIHsweDgwNmQ5NTAsIFtdLCBTQV9OT01BU0t9LCB7U0lHX0RGTH0sIDgp ID0gMAotLS0gU0lHU0VHViAoU2VnbWVudGF0aW9uIGZhdWx0KSBAIDAgKDApIC0tLQptbWFwMihO VUxMLCA0MDk2LCBQUk9UX1JFQUR8UFJPVF9XUklURSwgTUFQX1BSSVZBVEV8TUFQX0ZJWEVEfE1B UF9BTk9OWU1PVVMsIC0xLCAwKSA9IC0xIEVBQ0NFUyAoUGVybWlzc2lvbiBkZW5pZWQpCndyaXRl KDIsICJBZGRyZXNzIDB4MCBubyBnb29kP1xuIiwgMjFBZGRyZXNzIDB4MCBubyBnb29kPwopICA9 IDIxCmV4aXRfZ3JvdXAoMSkgICAgICAgICAgICAgICAgICAgICAgICAgICA9ID8KUHJvY2VzcyAx MDM3MSBkZXRhY2hlZAo= ------=_Part_808_25700784.1211291954948--