From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-4.4 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, RCVD_IN_DNSWL_LOW,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 6DE641F5AE for ; Tue, 1 Jun 2021 16:16:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233904AbhFAQRg (ORCPT ); Tue, 1 Jun 2021 12:17:36 -0400 Received: from mout.web.de ([212.227.15.4]:55795 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230385AbhFAQRg (ORCPT ); Tue, 1 Jun 2021 12:17:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1622564141; bh=WhmR3MoUm2E7icAXdgWb8itQHwfQNe/eL2jrT7sfA2s=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=h9VP/62mMkD546RhismIBhNeZbGmed1+9213zL/Ku+nsq9XRRNpsq/lGeETbFrDTi yPxfUf+liQ2sktOUBFznHU11F5iRL/0gydIvFT5MFoARytv4j7WbNwNV0R07ltSmqX HEBv64VO80u2C/iJFwUhsadFzJu6gJFC271bTlh4= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from Mini-von-Rene.fritz.box ([79.203.31.60]) by smtp.web.de (mrweb001 [213.165.67.108]) with ESMTPSA (Nemesis) id 0MaajJ-1m86mC1Kvp-00K6bL; Tue, 01 Jun 2021 18:15:41 +0200 Subject: Re: [PATCH] t0001: fix broken not-quite getcwd(3) test in bed67874e2 To: =?UTF-8?B?w4Z2YXIgQXJuZmrDtnLDsCBCamFybWFzb24=?= , git@vger.kernel.org Cc: Junio C Hamano , David Coppa , "brian m . carlson" References: From: =?UTF-8?Q?Ren=c3=a9_Scharfe?= Message-ID: Date: Tue, 1 Jun 2021 18:15:39 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:hzf5DGWN8P4zhYNy5O5rS3N+P2WDQhUW48//fDc8FJHR2Ykx+sN 54dLb3Y5OVKSLwj0SG3PbIm0U1rc2ycdYa8tPMnTgL7U74lIRFYr1o3cVBGLQsRDvmxhTGK laBA23CMksyhv0MnvA9R2WYAbeqmpVcBybXlGYqoQ3czU+cIotfkEvGb4wq1XbgRkCwoTZa 0jgmawrn9enmrsZO0SaOA== X-UI-Out-Filterresults: notjunk:1;V03:K0:Bny1nZ3INKQ=:tkGRBlehBVB1e6r5MPWJtR 8yL07Sn1pufvrA5DlEnPRKBeOI2Updyc6fAzbrGZ61SgYQXgp0HlOxl9QICa4dZqmgz5Z4xCc s9yW0YBJ8e4GqKompaCuXrfMLJ0lmUXipr8WF2Ytsljdg7ODo4WJ0JCgWAzZ2xhtpFI2VJdd+ xrWZK+FxYxtbV/iaFG4b1BHVn11dOvKA7vsKVv6VzkWfKMkmhmDPtLPWqodnZ1AC8zbY8srUV elLpsGb1iSCWcUZH94xOzIs/OkE3+1nA5UNEft7SXeI/7AwST9UzrT4eQHeHnTRRu5YwVBfum HduXcSgr6bTddZ01sz18o4LY4qi4gepxbpNOPaHjJGROrcHjrG1PIO6p7uVykbn9Sa3lr46Q3 zt7Ago+gQWCDD/a4ULrRTHMckEsqnn5sRoTP+ffO5057GbtSKc4BAEpFGftCXQDWHXbToTcBW fommaX0v5nhKbKZ7k6/aTSWpL5m2IWdJxIfzgz8cZ/amWGqX6pOTdJ2C36rpFKmjhCjENnwwU sBIRKAI970VMkb00JfjraGVDTasQJ26GqNg79DGFUN+xbpoG7iukK0/xke8YlVmOX78InN7Yq gGY5jbq2N9X7MTmzHJPJaq45QQ93jgLJ8EYB6dMQH6pyPSatWRP7bD0K2zs8guDgAdfn7OpMK X/jc6VlOA6fdRlC8ThrQolpKRytJmI1TyKHQLWQUl3EfxpXimLyJDnnXMrnotTsF/AQbmLP60 AkILkTyCjvXX2ollGNKFHvx/8axrN3QCqYP0rMlb6kj+BZ+JkwPXjrX96Huj2uVhqTNnx2lah zhi7KsAAX7ERcm552sRxZqkqQ6JQZ19ZaAF3p5DtF+U7hxsWO5aSily8wLKNojvtcM24pEkW4 I9H8z9lP9S4t77nSyar4oLysTBCVDr5o4EFLx2tW6Janz+7/+Fi6Hvm4ow/js8qlKpzHaEgEZ AJ+m1Iq8x3mo9ghRRq6L7fqgjvgFo8FZM28dUOuNic+xb8hCP4V1xgEJ5Y3PVSo26PNIxuZnn L7xdUVUi8QgA4oLkfMZ6kZD7tFjjiHA2pxK5mYTQNS0blHwMxMgerREeCvGI3l4giVVP9AAH4 y7OS1Rtr4imX6taGZVdhmcAAydSNKHifGRH Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Am 01.06.21 um 02:38 schrieb =C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason: > With a54e938e5b (strbuf: support long paths w/o read rights in > strbuf_getcwd() on FreeBSD, 2017-03-26) we had t0001 break on systems > like OpenBSD and AIX whose getcwd(3) has standard (but not like glibc > et al) behavior. > > This was partially fixed in bed67874e2 (t0001: skip test with > restrictive permissions if getpwd(3) respects them, 2017-08-07). > > The problem with that fix is that while its analysis of the problem is > correct, it doesn't actually call getcwd(3), instead it invokes "pwd > -P". There is no guarantee that "pwd -P" is actually going to call > getcwd(3), as opposed to e.g. being a shell built-in. > > On AIX under both bash and ksh this test breaks because "pwd -P" will > happily display the current working directory, but getcwd(3) called by > the "git init" we're testing here will fail to get it. > > I checked whether clobbering the $PWD environment variable would > affect it, and it didn't. Presumably these shells keep track of their > working directory internally. > > Let's change the test to a new "test-tool getcwd". Makes sense. If /bin/pwd can figure out the path to the current working directory without read permissions to parent directories then it might be possible to teach strbuf_getcwd() the same trick, though. How does it do it? Perhaps it falls back to $PWD; POSIX says the behavior of pwd is unspecified if that variable would be changed, so a compliant implementation would be allowed to do that. I think that way is not interesting for strbuf_getcwd(), though, because if we trust that variable then we can read it directly instead. It gets stale if any parent directory is renamed. E.g. the following commands would print a string ending in "stale": mkdir stale cd stale mv ../stale ../fresh chmod 111 ../fresh /bin/pwd -P Perhaps it asks the kernel, like getcwd() does on FreeBSD. It would be a bit weird to expose this functionality in a command line tool, but not in the library function, so this is unlikely. You seem to say that /bin/pwd is a shell builtin on your system, which is also weird, though. The commands above would print a string ending in "fresh" with the syscall method. An evil way would be to temporarily add read permission to all parent directories. It would also print a string ending in "fresh". You'd probably see chmod calls when running /bin/pwd using truss in that case, and it would fail if chmod is not allowed. That's all I can think of. If strbuf_getcwd() were to learn any of these tricks, then so would "test-tool getcwd", via its xgetcwd() call. At that point we'd better rename GETCWD_IGNORES_PERMS to XGETCWD_IGNORES_PERMS. But I guess we need none of that because we never got a request from an AIX user to support a /home directory without read permissions, right? > > Signed-off-by: =C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason > --- > > Not an issue new in v2.32.0, but an easy enough fix, so I thought I'd > send it now anyway in case we'd like these various AIX fixes in one > batch... > > Makefile | 1 + > t/helper/test-getcwd.c | 26 ++++++++++++++++++++++++++ > t/helper/test-tool.c | 1 + > t/helper/test-tool.h | 1 + > t/t0001-init.sh | 5 ++++- > 5 files changed, 33 insertions(+), 1 deletion(-) > create mode 100644 t/helper/test-getcwd.c > > diff --git a/Makefile b/Makefile > index c3565fc0f8..8c000ba48b 100644 > --- a/Makefile > +++ b/Makefile > @@ -711,6 +711,7 @@ TEST_BUILTINS_OBJS +=3D test-example-decorate.o > TEST_BUILTINS_OBJS +=3D test-fast-rebase.o > TEST_BUILTINS_OBJS +=3D test-genrandom.o > TEST_BUILTINS_OBJS +=3D test-genzeros.o > +TEST_BUILTINS_OBJS +=3D test-getcwd.o > TEST_BUILTINS_OBJS +=3D test-hash-speed.o > TEST_BUILTINS_OBJS +=3D test-hash.o > TEST_BUILTINS_OBJS +=3D test-hashmap.o > diff --git a/t/helper/test-getcwd.c b/t/helper/test-getcwd.c > new file mode 100644 > index 0000000000..d680038a78 > --- /dev/null > +++ b/t/helper/test-getcwd.c > @@ -0,0 +1,26 @@ > +#include "test-tool.h" > +#include "git-compat-util.h" > +#include "parse-options.h" > + > +static const char *getcwd_usage[] =3D { > + "test-tool getcwd", > + NULL > +}; > + > +int cmd__getcwd(int argc, const char **argv) > +{ > + struct option options[] =3D { > + OPT_END() > + }; > + char *cwd; > + > + argc =3D parse_options(argc, argv, "test-tools", options, getcwd_usage= , 0); > + if (argc > 0) > + usage_with_options(getcwd_usage, options); > + > + cwd =3D xgetcwd(); > + puts(cwd); > + free(cwd); > + > + return 0; > +} > diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c > index c5bd0c6d4c..3c13cb19b5 100644 > --- a/t/helper/test-tool.c > +++ b/t/helper/test-tool.c > @@ -33,6 +33,7 @@ static struct test_cmd cmds[] =3D { > { "fast-rebase", cmd__fast_rebase }, > { "genrandom", cmd__genrandom }, > { "genzeros", cmd__genzeros }, > + { "getcwd", cmd__getcwd }, > { "hashmap", cmd__hashmap }, > { "hash-speed", cmd__hash_speed }, > { "index-version", cmd__index_version }, > diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h > index e8069a3b22..e691a4d9e9 100644 > --- a/t/helper/test-tool.h > +++ b/t/helper/test-tool.h > @@ -23,6 +23,7 @@ int cmd__example_decorate(int argc, const char **argv)= ; > int cmd__fast_rebase(int argc, const char **argv); > int cmd__genrandom(int argc, const char **argv); > int cmd__genzeros(int argc, const char **argv); > +int cmd__getcwd(int argc, const char **argv); > int cmd__hashmap(int argc, const char **argv); > int cmd__hash_speed(int argc, const char **argv); > int cmd__index_version(int argc, const char **argv); > diff --git a/t/t0001-init.sh b/t/t0001-init.sh > index acd662e403..df544bb321 100755 > --- a/t/t0001-init.sh > +++ b/t/t0001-init.sh > @@ -356,7 +356,10 @@ test_lazy_prereq GETCWD_IGNORES_PERMS ' > chmod 100 $base || > BUG "cannot prepare $base" > > - (cd $base/dir && /bin/pwd -P) > + ( > + cd $base/dir && > + test-tool getcwd > + ) > status=3D$? > > chmod 700 $base && >