Re: [RFC] building postgres with meson

Thomas Munro <thomas.munro@gmail.com>

From: Thomas Munro <thomas.munro@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, John Naylor <john.naylor@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-10-15T00:36:28Z
Lists: pgsql-hackers
On Fri, Oct 15, 2021 at 12:04 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> [tgl@pro ~]$ cat checkenv.c
> #include <stdio.h>
> #include <stdlib.h>
>
> int
> main(int argc, char **argv)
> {
>   char *pth = getenv("DYLD_LIBRARY_PATH");
>
>   if (pth)
>     printf("DYLD_LIBRARY_PATH = %s\n", pth);
>   else
>     printf("DYLD_LIBRARY_PATH is unset\n");
>
>   return 0;
> }
> [tgl@pro ~]$ gcc checkenv.c
> [tgl@pro ~]$ ./a.out
> DYLD_LIBRARY_PATH is unset
> [tgl@pro ~]$ export DYLD_LIBRARY_PATH=/Users/tgl/pginstall/lib
> [tgl@pro ~]$ ./a.out
> DYLD_LIBRARY_PATH = /Users/tgl/pginstall/lib
> [tgl@pro ~]$ sh -c ./a.out
> DYLD_LIBRARY_PATH is unset
> [tgl@pro ~]$ ./a.out
> DYLD_LIBRARY_PATH = /Users/tgl/pginstall/lib
> [tgl@pro ~]$ bash -c ./a.out
> DYLD_LIBRARY_PATH is unset
>
> You have to check the environment using an "unprivileged" program.
> If you try to examine the environment using, say, "env", you will get
> very misleading results.  AFAICT, /usr/bin/env is *also* considered
> security-critical, because I cannot get it to ever report that
> DYLD_LIBRARY_PATH is set.
>
> Hmm ... /usr/bin/perl seems to act the same way.  It can see
> ENV{'PATH'} but not ENV{'DYLD_LIBRARY_PATH'}.
>
> This may indicate that they've applied this policy on a blanket
> basis to everything in /bin and /usr/bin (and other system
> directories, maybe), rather than singling out the shell.

Looks like it.  If I've found the right code here, it looks like where
any common-or-garden Unix runtime linker would ignore LD_LIBRARY_PATH
for a setuid binary, they've trained theirs to whack DYLD_*, and also
for code-signed and __RESTRICT-marked executables.

https://github.com/opensource-apple/dyld/blob/master/src/dyld.cpp#L1681

I suppose you could point SHELL at an unsigned copy of sh (codesign
--remove-signature, or something from brew/ports/x) so that GNU make
should respect, but I don't know how many other exec("/bin/sh") calls
might be hiding around the place (I guess perl calls system()?) and
might require some kind of LD_PRELOAD hackery... not much fun.



Commits

  1. meson: Add 'running' test setup, as a replacement for installcheck

  2. meson: Add support for building with precompiled headers

  3. windows: Adjust FD_SETSIZE via commandline define

  4. meson: docs: Add xml{lint,proc} wrapper to collect dependencies

  5. meson: ecpg: Split definition of static and shared libraries

  6. windows: Set UMDF_USING_NTSTATUS globally, include ntstatus.h

  7. ci: Add hint about downloadable logs to README

  8. meson: Set up absolute rpaths to libdir

  9. meson: Include CFLAGS/c_args in summary and pg_config output

  10. windows: remove date from version number in win32ver.rc

  11. meson: Add initial version of meson based build system

  12. ci: windows: set error mode to not include SEM_NOGPFAULTERRORBOX

  13. Refactor PG_TEST_EXTRA logic in autoconf build

  14. Split TESTDIR into TESTLOGDIR and TESTDATADIR

  15. Don't hardcode tmp_check/ as test directory for tap tests

  16. Extend gendef.pl in preparation for meson

  17. Include c.h instead of postgres.h in src/port/*p{read,write}*.c

  18. Remove DLLTOOL, DLLWRAP from configure / Makefile.global.in

  19. Run xmllint validation only once

  20. Bump minimum Perl version to 5.14

  21. Move gramparse.h to src/backend/parser

  22. Run perltidy over Catalog.pm

  23. Parse catalog .dat files as a whole when compiling the backend

  24. Build all Flex files standalone

  25. Move private declarations shared between guc.c and guc-file.l to new header

  26. Preparatory refactoring for compiling guc-file.c standalone

  27. Move darwin sysroot determination into separate file

  28. Fix MSVC warning in compat_informix/rnull.pgc

  29. solaris: Use versioning scripts instead of -Bsymbolic

  30. Change shared library installation naming on macOS

  31. regress: allow to specify directory containing expected files, for ecpg

  32. Don't add HAVE_LDAP_H HAVE_WINLDAP_H to pg_config.h

  33. Refactor dtrace postprocessing make rules

  34. Add output directory option to gen_node_support.pl

  35. Add output directory argument to generate-unicode_norm_table.pl

  36. Add output file argument to generate-errcodes.pl

  37. Add output path arg in generate-lwlocknames.pl

  38. Move snowball_create.sql creation into perl file

  39. ecpg: Output dir, source dir, stamp file argument for preproc/*.pl

  40. psql: Output dir and dependency generation for sql_help

  41. Deal with paths containing \ and spaces in basebackup_to_shell tests

  42. Remove LLVM_CONFIG from Makefile.global.in

  43. Make update-unicode target work in vpath builds

  44. Refactor DLSUFFIX handling

  45. ldap tests: Add paths for openbsd.

  46. ldap tests: Don't run on unsupported operating systems.

  47. Remove check for accept() argument types

  48. Move our p{read,write}v replacements into their own files.

  49. Adjust yywrap macro for non-reentrant scanners for MSVC.

  50. Remove any -arch switches given in ExtUtils::Embed's ldopts from our

  51. Change PL/Perl and Pg interface build to use configured compiler and

  52. Apparently, on some systems, ExtUtils::Embed and MakeMaker are slightly