| delorie.com/archives/browse.cgi | search |
| X-Recipient: | archive-cygwin AT delorie DOT com |
| DomainKey-Signature: | a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id |
| :list-unsubscribe:list-subscribe:list-archive:list-post | |
| :list-help:sender:from:subject:reply-to:to:references:message-id | |
| :date:mime-version:in-reply-to:content-type; q=dns; s=default; b= | |
| BHmQXBvOHQrwGBJhv0cQ8nW2j2Dx+7PYXxSMTQC4MlYt4o41wZRNabf+PRw4sQO1 | |
| 9nkPU5kSADgVMBatGEnrIqtx1+A13Y6prvqW9nY3duYyYfqtFIy6U3vLBdbEYOHb | |
| KDyLeiqYw6RL3DzSYR1cKXw1VUoFY23MW1s080Lg/2Q= | |
| DKIM-Signature: | v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id |
| :list-unsubscribe:list-subscribe:list-archive:list-post | |
| :list-help:sender:from:subject:reply-to:to:references:message-id | |
| :date:mime-version:in-reply-to:content-type; s=default; bh=LQ5VL | |
| +otcZUhnjRIhsH5dtOQFGE=; b=QrbcigpibmSV5AmNeAAyaw4ahopBpP2E6x3Z0 | |
| GXOboi0xda0QnjE56+iMeF7tuwEd0UP6gsKEVuISNn++9Acn5AtWXvNE1acsBQRJ | |
| OBE9tUQK+PeYPp4hs8yV/7WlEkhM6y8WMb+DZ29/GfiDFMD36ukhGByC4iNLAafa | |
| foh6Lw= | |
| Mailing-List: | contact cygwin-help AT cygwin DOT com; run by ezmlm |
| List-Id: | <cygwin.cygwin.com> |
| List-Subscribe: | <mailto:cygwin-subscribe AT cygwin DOT com> |
| List-Archive: | <http://sourceware.org/ml/cygwin/> |
| List-Post: | <mailto:cygwin AT cygwin DOT com> |
| List-Help: | <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs> |
| Sender: | cygwin-owner AT cygwin DOT com |
| Mail-Followup-To: | cygwin AT cygwin DOT com |
| Delivered-To: | mailing list cygwin AT cygwin DOT com |
| Authentication-Results: | sourceware.org; auth=none |
| X-Spam-SWARE-Status: | No, score=-5.0 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_2,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy=proprietary, spread |
| X-HELO: | smtp-out-no.shaw.ca |
| From: | Brian Inglis <Brian DOT Inglis AT SystematicSw DOT ab DOT ca> |
| Subject: | Re: Question about the ldd output |
| Reply-To: | Brian DOT Inglis AT SystematicSw DOT ab DOT ca |
| To: | cygwin AT cygwin DOT com |
| References: | <BN6PR09MB2227BA2644949DB75A67A6B2A5F60 AT BN6PR09MB2227 DOT namprd09 DOT prod DOT outlook DOT com> <ee7608a2-2e13-d2eb-6410-c07362d75296 AT SystematicSw DOT ab DOT ca> <e0e8c9db-bd7a-638c-0bb5-88c43c5f9d98 AT dronecode DOT org DOT uk> |
| Openpgp: | preference=signencrypt |
| Message-ID: | <8841099f-6294-4aa7-9615-b42eda332573@SystematicSw.ab.ca> |
| Date: | Wed, 10 Jul 2019 16:55:04 -0600 |
| User-Agent: | Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 |
| MIME-Version: | 1.0 |
| In-Reply-To: | <e0e8c9db-bd7a-638c-0bb5-88c43c5f9d98@dronecode.org.uk> |
| X-IsSubscribed: | yes |
--------------817BE2C1142F03618BE050CC Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit On 2019-07-09 12:02, Jon Turney wrote: > On 09/07/2019 17:40, Brian Inglis wrote: >> On 2019-07-08 12:00, Lavrentiev, Anton (NIH/NLM/NCBI) [C] via cygwin wrote: >>> Well, I don't think there's anything special that Cygwin does to load >>> executables, because these are essentially Windows processes, so they are >>> loaded by Windows, first and foremost. >>> >>> But it gets even weirder. Below are two _consecutive!_ runs of ldd on the >>> very same executable. Why the output differs so drastically (including the >>> unknown dlls all of a sudden)? > > This is probably a 'bug'. > >> Libraries may be loaded asynchronously as they are accessed, and ldd just dumps >> the dll import table once the subprocess is ready to run. >> Perhaps these are import entries that ldd should detect and skip or annotate in >> some more useful way. > > Please don't spread misinformation based upon guessing how Cygwin's ldd works. The ldd(1) man page documents how it works, and how to get dll info is documented: the guesses are about how and with what Windows populates the dll import table, and how ldd may misinterpret it: a slightly more informative version of "This is probably a 'bug'" ;^> > It's not necessary, as the source code is available [1] :) > [1] > https://cygwin.com/git/gitweb.cgi?p=newlib-cygwin.git;a=history;f=winsup/utils/ldd.cc Uncommented, undocumented source code with mainly Windows calls is no help to most of us with little background in Windows development. David Macek did some debugging and suggested a patch to ignore threads with entry points in ntdll.dll, but I could not see any followup, response, or similar patch in the commits or source: "Re: Why does ldd not show cyg*.dll in its output?" https://sourceware.org/ml/cygwin/2016-06/msg00478.html Based on what I see and PE format docs, ldd should iterate over all the entries in the dll import directory table, until the end or an all zeros/nulls entry is reached, and the name pointers should all be 32 bit image base relative addresses, but they are being handled as section relative addresses in dump_import_directory(), which might amount to the same thing here. The attached shows the opinions of ldd, cygcheck, and SysInternals listdlls64 run against "$ yes > /dev/null &" process, so a comparison of the first two might help, but the latter is proprietary closed source and the process is executing, so may show dlls dynamically loaded by other Windows dlls. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. --------------817BE2C1142F03618BE050CC Content-Type: text/plain; charset=UTF-8; name="y.txt" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="y.txt" JCBsZGQgL2Jpbi95ZXMKCW50ZGxsLmRsbCA9PiAvcHJvYy9jeWdkcml2ZS9j L1dJTkRPV1MvU1lTVEVNMzIvbnRkbGwuZGxsICgweDdmZjg4ZTdhMDAwMCkK CUtFUk5FTDMyLkRMTCA9PiAvcHJvYy9jeWdkcml2ZS9jL1dJTkRPV1MvU3lz dGVtMzIvS0VSTkVMMzIuRExMICgweDdmZjg4YmEzMDAwMCkKCUtFUk5FTEJB U0UuZGxsID0+IC9wcm9jL2N5Z2RyaXZlL2MvV0lORE9XUy9TeXN0ZW0zMi9L RVJORUxCQVNFLmRsbCAoMHg3ZmY4OGIyZTAwMDApCgljeWd3aW4xLmRsbCA9 PiAvdXNyL2Jpbi9jeWd3aW4xLmRsbCAoMHgxODAwNDAwMDApCgljeWdpbnRs LTguZGxsID0+IC91c3IvYmluL2N5Z2ludGwtOC5kbGwgKDB4M2QxN2QwMDAw KQoJY3lnaWNvbnYtMi5kbGwgPT4gL3Vzci9iaW4vY3lnaWNvbnYtMi5kbGwg KDB4M2UyMWYwMDAwKQokIGN5Z2NoZWNrIC9iaW4veWVzCkM6XGN5Z3dpbjY0 XGJpblx5ZXMuZXhlCiAgQzpcY3lnd2luNjRcYmluXGN5Z3dpbjEuZGxsCiAg ICBDOlxXSU5ET1dTXHN5c3RlbTMyXEtFUk5FTDMyLmRsbAogICAgICBDOlxX SU5ET1dTXHN5c3RlbTMyXG50ZGxsLmRsbAogICAgICBDOlxXSU5ET1dTXHN5 c3RlbTMyXEtFUk5FTEJBU0UuZGxsCiAgICAgIEM6XFdJTkRPV1Ncc3lzdGVt MzJcYXBpLW1zLXdpbi1jb3JlLXByb2Nlc3N0aHJlYWRzLWwxLTEtMS5kbGwK ICAgICAgQzpcV0lORE9XU1xzeXN0ZW0zMlxhcGktbXMtd2luLWNvcmUtc3lu Y2gtbDEtMi0wLmRsbAogICAgICBDOlxXSU5ET1dTXHN5c3RlbTMyXGFwaS1t cy13aW4tY29yZS1maWxlLWwxLTItMC5kbGwKICAgICAgQzpcV0lORE9XU1xz eXN0ZW0zMlxhcGktbXMtd2luLWNvcmUtdGltZXpvbmUtbDEtMS0wLmRsbAog ICAgICBDOlxXSU5ET1dTXHN5c3RlbTMyXGFwaS1tcy13aW4tY29yZS1sb2Nh bGl6YXRpb24tbDEtMi0wLmRsbAogICAgICBDOlxXSU5ET1dTXHN5c3RlbTMy XGFwaS1tcy13aW4tY29yZS1maWxlLWwyLTEtMC5kbGwKICAgICAgQzpcV0lO RE9XU1xzeXN0ZW0zMlxhcGktbXMtd2luLWNvcmUteHN0YXRlLWwyLTEtMC5k bGwKICBDOlxjeWd3aW42NFxiaW5cY3lnaW50bC04LmRsbAogICAgQzpcY3ln d2luNjRcYmluXGN5Z2ljb252LTIuZGxsCiQgbGlzdGRsbHM2NCB5ZXMJCQkj IFN5c0ludGVybmFscyBTdWl0ZQotLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0KeWVzLmV4ZSBwaWQ6IDc5NDgKQ29tbWFuZCBsaW5lOiAiQzpc Y3lnd2luNjRcYmluXHllcy5leGUiCgpCYXNlICAgICAgICAgICAgICAgIFNp emUgICAgICBQYXRoCjB4MDAwMDAwMDAwMDQwMDAwMCAgMHhmMDAwICAgIEM6 XGN5Z3dpbjY0XGJpblx5ZXMuZXhlCjB4MDAwMDAwMDA4ZTdhMDAwMCAgMHgx ZWQwMDAgIEM6XFdJTkRPV1NcU1lTVEVNMzJcbnRkbGwuZGxsCjB4MDAwMDAw MDA4YmEzMDAwMCAgMHhiMzAwMCAgIEM6XFdJTkRPV1NcU3lzdGVtMzJcS0VS TkVMMzIuRExMCjB4MDAwMDAwMDA4YjJlMDAwMCAgMHgyOTMwMDAgIEM6XFdJ TkRPV1NcU3lzdGVtMzJcS0VSTkVMQkFTRS5kbGwKMHgwMDAwMDAwMGQxN2Qw MDAwICAweDE0MDAwICAgQzpcY3lnd2luNjRcYmluXGN5Z2ludGwtOC5kbGwK MHgwMDAwMDAwMDgwMDQwMDAwICAweDVmMDAwMCAgQzpcY3lnd2luNjRcYmlu XGN5Z3dpbjEuZGxsCjB4MDAwMDAwMDBlMjFmMDAwMCAgMHgxMDUwMDAgIEM6 XGN5Z3dpbjY0XGJpblxjeWdpY29udi0yLmRsbAoweDAwMDAwMDAwOGMwOTAw MDAgIDB4YTMwMDAgICBDOlxXSU5ET1dTXFN5c3RlbTMyXGFkdmFwaTMyLmRs bAoweDAwMDAwMDAwOGUzNTAwMDAgIDB4OWUwMDAgICBDOlxXSU5ET1dTXFN5 c3RlbTMyXG1zdmNydC5kbGwKMHgwMDAwMDAwMDhjMjUwMDAwICAweDllMDAw ICAgQzpcV0lORE9XU1xTeXN0ZW0zMlxzZWNob3N0LmRsbAoweDAwMDAwMDAw OGQ5YTAwMDAgIDB4MTIyMDAwICBDOlxXSU5ET1dTXFN5c3RlbTMyXFJQQ1JU NC5kbGwKMHgwMDAwMDAwMDhhMTkwMDAwICAweGMwMDAgICAgQzpcV0lORE9X U1xTWVNURU0zMlxDUllQVEJBU0UuRExMCjB4MDAwMDAwMDA4YjY4MDAwMCAg MHg3ZTAwMCAgIEM6XFdJTkRPV1NcU3lzdGVtMzJcYmNyeXB0UHJpbWl0aXZl cy5kbGwKCg== --------------817BE2C1142F03618BE050CC Content-Type: text/plain; charset=us-ascii -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple --------------817BE2C1142F03618BE050CC--
| webmaster | delorie software privacy |
| Copyright © 2019 by DJ Delorie | Updated Jul 2019 |