X-Recipient:	archive-cygwin AT delorie DOT com
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org AB78F39450CD
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1599510926;
	bh=G0MhxPE/rotHlYR9uMg7C8AzAI7hxYoz8SZvzS5V7TI=;
	h=Subject:To:References:Date:In-Reply-To:List-Id:List-Unsubscribe:
	List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:
	From;
	b=BX4zjn9VFJQdI07BwnNYwBgU0oULLRkAZUq3B/OrPva7K2aPObI2EZ2SY2SOHxMI6
	Hw9op6YqEcs+qUEUp4s8Z69dT5bcZphgCFGwcbvrLmgj1duNblX5KUwx3xJv7PxOt2
	YLWZzwQ3nyBwwPk5m0t9cOrd5ZZ8ypaBw6uX9xEI=
X-Original-To:	cygwin AT cygwin DOT com
Delivered-To:	cygwin AT cygwin DOT com
DMARC-Filter:	OpenDMARC Filter v1.3.2 sourceware.org D6400388CC1C
ARC-Seal:	i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none;
	b=RT8sarKm3cX66f3ryF3K5h23A5iKmH34EtImy4fD/Mfq+33GxLjFH96X9918vHQ6hfSDwwiiJb6fgsmCzdMQHar4VwJuMUWxvE+Rk85HtEtC/8Y9zZU61AN4Dr60/LsF5FrumZPPTuRI4T3d2I+JwQm1HJLUvP3SEDrXG7Ig0pFmhGNJHPEHr6MNAP3XxvHgllZ16G4qWFXzF4noPdLr2vjzUNpQ2iT7URgjLhBlnpvGrp/uR/2WLxY5NCTG1nJy9R9JmdiQI1WAf8i4bBy057HYS5PqG3uVeshOBKwXSL1Xiss/O/6KCvjDthT9RGg0Kari0zGUxq3zeVOdxNXkCw==
ARC-Message-Signature:	i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com;
	s=arcselector9901;
	h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck;
	bh=WnIskhqZgRjQYrQC4nwnNSUARpkM0mf5W2JMuSU5Q7U=;
	b=N0mR9eRHYSlCvucx1RKER8ArQFhAi5jLyOk/ZqBgm2N/PaQ7wZlPAY9j4oYaGpQ+Npc+QMWweJm3XiXqYepzG34vg9zSDwbOeOlt7REMq+gCy/m9Fw8nRvPfhWtL2QsM/s+SF3120tQ5K5RUim9N0VoZ/ibg5gKmzTLz/L8cxh2FmmpbMwKid6djjLAasQPeCbjssuNOjy4rltur1+bn/0dJwjI10pcJ/DK0gF6cNMg+y5ck7aQNqTMNzag3OSxlYmgqfPXHHR6OsussLLCVqAT5PIBo2VfnqMn4j9nY2e0G23C60IV+LcbEdpanOPkJgYonwOibRLvqeGyiKuA/+g==
ARC-Authentication-Results:	i=1; mx.microsoft.com 1; spf=pass
	smtp.mailfrom=cornell.edu; dmarc=pass action=none header.from=cornell.edu;
	dkim=pass header.d=cornell.edu; arc=none
Subject:	Re: ag 2 <(echo 2) gets assertion "p >= path" failed: ..
	/cygwin-3.1.7 ... /cygwin/path.cc", line 3065, function: int
	symlink_info::check
To:	cygwin AT cygwin DOT com
References:	<CAJtSMgtgAvB3Fin-gtmU5qr3xYnq4_53S2UD3yqAVDVMkAfMSQ AT mail DOT gmail DOT com>
	<26aedc53-30f2-d1a2-f9e8-c8a5dfa548c1 AT cornell DOT edu>
	<6c7185c9-f0a5-2b73-974f-04b55f8e6508 AT cornell DOT edu>
Message-ID:	<e0744a67-33e7-57cc-3ebc-a0e812dbb83f@cornell.edu>
Date:	Mon, 7 Sep 2020 16:35:17 -0400
User-Agent:	Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101
	Thunderbird/68.12.0
In-Reply-To:	<6c7185c9-f0a5-2b73-974f-04b55f8e6508@cornell.edu>
X-ClientProxiedBy:	CH2PR12CA0026.namprd12.prod.outlook.com
	(2603:10b6:610:57::36) To MN2PR04MB6176.namprd04.prod.outlook.com
	(2603:10b6:208:e3::13)
MIME-Version:	1.0
X-MS-Exchange-MessageSentRepresentingType:	1
X-Originating-IP:	[68.175.129.7]
X-MS-PublicTrafficType:	Email
X-MS-Office365-Filtering-Correlation-Id:	10b921dd-f1d9-4db3-f6c3-08d8536d88e4
X-MS-TrafficTypeDiagnostic:	MN2PR04MB6158:
X-Microsoft-Antispam-PRVS:	<MN2PR04MB6158D7FAAECB3D039E8C323DD8280 AT MN2PR04MB6158 DOT namprd04 DOT prod DOT outlook DOT com>
X-MS-Oob-TLC-OOBClassifiers:	OLM:9508;
X-MS-Exchange-SenderADCheck:	1
X-Microsoft-Antispam:	BCL:0;
X-Microsoft-Antispam-Message-Info:	cCuAJY5gpFhgIDzgChlNq6gQ8pz0h3x0jP/I3kmvOz5F9x39yH9z3wGTaPj/BE+2AsVInkS08NcIbT4DpGA5wAauGkgpuoBq4er7lH5HmPkguC0DVzQ8q4F57MXvozPfH0P4BvG8r72Q1nMRcXkc9ZNbgHUPzm8BUrKanK/no+QCKBAgBx0lmpq36ANEVOjeD6VxYP7EjPKjPr8EqBdbF8/4LpCrbBTHcnj5W4K0MnzsRAaWxD82NIqtYTexJ7+DgR35iEgoYir8fHI+AET9L25BHzL3deLvAjkEST6q75UefL1qp4RhMBmo91VSy+sJnlDNCGHvkkZsvTza4vXAMi4Q26B4VLh1S22U4p+sueaEiZuISa7IAboXJ2gLqThE7s1bKEFXV6yykYaIKn0hw7KaSkIZN7iJkcqNGcBUmYmfYdIv4V0Hj2nzkWMNwBgR
X-Forefront-Antispam-Report:	CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:;
	IPV:NLI; SFV:NSPM; H:MN2PR04MB6176.namprd04.prod.outlook.com; PTR:; CAT:NONE;
	SFS:(4636009)(136003)(396003)(376002)(346002)(39860400002)(366004)(66556008)(66476007)(2616005)(83380400001)(26005)(956004)(6486002)(8676002)(75432002)(186003)(16526019)(66946007)(5660300002)(16576012)(86362001)(316002)(786003)(31696002)(478600001)(53546011)(52116002)(6916009)(2906002)(36756003)(8936002)(31686004)(43740500002)(460985005)(2480315003);
	DIR:OUT; SFP:1102;
X-MS-Exchange-AntiSpam-MessageData:	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
X-OriginatorOrg:	cornell.edu
X-MS-Exchange-CrossTenant-Network-Message-Id:	10b921dd-f1d9-4db3-f6c3-08d8536d88e4
X-MS-Exchange-CrossTenant-AuthSource:	MN2PR04MB6176.namprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs:	Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime:	07 Sep 2020 20:35:18.8271 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader:	Hosted
X-MS-Exchange-CrossTenant-Id:	5d7e4366-1b9b-45cf-8e79-b14b27df46e1
X-MS-Exchange-CrossTenant-MailboxType:	HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName:	5RlNX0ABTgtySzK6kIiHXlYA+gRxfEmq74XT/W0sHEgeWqOwT4TPDhN/CRjzYli6riCO0A/DuwKfNynp7cx4Qw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped:	MN2PR04MB6158
X-Spam-Status:	No, score=-1.2 required=5.0 tests=BAYES_00, BODY_8BITS,
	DKIM_INVALID, DKIM_SIGNED, KAM_DMARC_STATUS, MSGID_FROM_MTA_HEADER,
	NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_PASS,
	TXREP autolearn=no autolearn_force=no version=3.4.2
X-Spam-Checker-Version:	SpamAssassin 3.4.2 (2018-09-13) on
	server2.sourceware.org
X-BeenThere:	cygwin AT cygwin DOT com
X-Mailman-Version:	2.1.29
List-Id:	General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe:	<https://cygwin.com/mailman/options/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive:	<https://cygwin.com/pipermail/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe:	<https://cygwin.com/mailman/listinfo/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From:	Ken Brown via Cygwin <cygwin AT cygwin DOT com>
Reply-To:	Ken Brown <kbrown AT cornell DOT edu>
Errors-To:	cygwin-bounces AT cygwin DOT com
Sender:	"Cygwin" <cygwin-bounces AT cygwin DOT com>
X-MIME-Autoconverted:	from quoted-printable to 8bit by delorie.com id 087KZqRO004594

On 9/6/2020 4:28 PM, Ken Brown via Cygwin wrote:
> On 9/6/2020 3:47 PM, Ken Brown via Cygwin wrote:
>> On 9/6/2020 2:43 PM, David Dyck via Cygwin wrote:
>>> This command triggers an assertion failure
>>>    "ag" is from the_silver_searcher
>>>
>>> $ ag 2 <(echo 2)
>>> assertion "p >= path" failed: file
>>> "/home/corinna/src/cygwin/cygwin-3.1.7/cygwin-3.1.7-1.x86_64/src/newlib-cygwin/winsup/cygwin/path.cc", 
>>>
>>> line 3065, function: int symlink_info::check(char*, const
>>> suffix_info*, fs_info&, path_conv_handle&)
>>> Aborted (core dumped)
>>>
>>>   3473k 2020/08/22 C:\cygwin64\bin\cygwin1.dll
>>>      Cygwin DLL version info:
>>>          DLL version: 3.1.7
>>> bash                                    4.4.12-3                        OK
>>> the_silver_searcher                     2.2.0-1                         OK
>> [...]
>>> assertion "p >= path" failed: file
>>> "/home/corinna/src/cygwin/cygwin-3.1.7/cygwin-3.1.7-1.x86_64/src/newlib-cygwin/winsup/cygwin/path.cc", 
>>>
>>> line 3065, function: int symlink_info::check(char*, const
>>> suffix_info*, fs_info&, path_conv_handle&)
>>> Aborted (core dumped)
>> [...]
>>> I've reported this on github as an "ag" bug, but I think it is a bug in cygwin
>>
>> An assertion failure in Cygwin code is a Cygwin bug.  I'll take a look.
> 
> Running
> 
>    bash -c '/usr/bin/ag 2 <(echo 2)'
> 
> under strace yields the following:
> 
>    242  191767 [main] ag 33659 open: open(/dev/fd/63/.ignore, 0x0)
> [...]
>     30  192584 [main] ag 33659 mount_info::conv_to_win32_path: src_path 
> /proc/self/fd/63/.ignore, dst /proc/self/fd/63/.ignore, flags 0x0, rc 0
> [...]
>     31  193366 [main] ag 33659 mount_info::conv_to_win32_path: 
> conv_to_win32_path (pipe:[4295036184]/.ignore)
> [...]
>     31  193550 [main] ag 33659 mount_info::conv_to_win32_path: 
> conv_to_win32_path (pipe:[4295036184])
> [...]
>     34  193615 [main] ag 33659 symlink_info::check: 0xC0000034 = NtCreateFile 
> (\??\C:pipe:[4295036184])
> 
> The assertion fails because the path 'C:pipe:[4295036184]' doesn't contain a 
> backslash.  But probably we should never have allowed ourselves to get to the 
> point of considering that path.

I've made some progress but haven't figured out the fix yet.  First, for easier 
debugging, here's a simpler way to reproduce the problem:

$ cat proc_bug.c
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>

int
main ()
{
   int fd[2];
   char fname[100];

   if (pipe (fd) < 0)
     {
       perror ("pipe");
       exit (1);
     }
   sprintf (fname, "/dev/fd/%d/foo", fd[0]);
   if (open (fname, O_RDONLY) < 0)
     {
       perror ("open");
       exit (1);
     }
}

$ gcc -o proc_bug proc_bug.c

$ ./proc_bug.exe
assertion "p >= path" failed: file 
"../../../../newlib-cygwin/winsup/cygwin/path.cc", line 3065, function: int 
symlink_info::check(char*, const suffix_info*, fs_info&, path_conv_handle&)
Aborted (core dumped)

Here's what happens.  The program is trying to open /dev/fd/3/foo, where file 
descriptor 3 is the read end of a pipe.  path_conv check resolves this to 
/proc/<pid>/fd/3/foo, creates an fhandler_process for this path, and calls (at 
path.cc:782) fhandler_process::exists.  The latter fills the filebuf with 
"pipe:[xxxxxxxxxx]/foo" and returns virt_fsdir.  We're now at path.cc:808, and 
everything is set up for the assertion failure.

I think fhandler_process::exists is not doing the right thing here, but I'm not 
familiar with this part of the code, so I'll have to stare at it for a while to 
see what's going wrong.

Corinna, if you are able to see it more quickly and want to go ahead and fix it, 
you won't hurt my feelings.

Ken
--
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple

- Raw text -