Commit Graph

497 Commits

Author SHA1 Message Date
Florian Weimer
bd13cb19f5 scripts/glibcelf.py: Add hashing support
ELF and GNU hashes can now be computed using the elf_hash and
gnu_hash functions.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-08-23 19:33:38 +02:00
Joseph Myers
9125e43daf Use binutils 2.39 branch in build-many-glibcs.py
This patch makes build-many-glibcs.py use binutils 2.39 branch.

Tested with build-many-glibcs.py (compilers and glibcs builds).  Note:
binutils 2.39 shows the same failures for i686-linux-gnu-no-pie,
x86_64-linux-gnu-no-pie and x86_64-linux-gnu-x32-no-pie building the
glibc testsuite as binutils mainline does.
2022-08-18 13:16:56 +00:00
Adhemerval Zanella
841afa116e glibcextract.py: Add compile_c_snippet
It might be used on tests to check if a snippet build with the provided
compiler and flags.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-08-12 09:15:03 -03:00
Joseph Myers
a3393b3380 Use Linux 5.19 in build-many-glibcs.py
This patch makes build-many-glibcs.py use Linux 5.19.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2022-08-02 14:09:24 +00:00
caiyinyu
3be5fc00ad LoongArch: Update build-many-glibcs.py for the LoongArch Port. 2022-07-26 12:35:12 -03:00
caiyinyu
2d83247d90 LoongArch: Add relocations and ELF flags to elf.h and scripts/glibcelf.py 2022-07-26 12:35:12 -03:00
Adhemerval Zanella
8b84fb862c Update scripts/config.* files from upstream GNU config version
This patch updates various miscellaneous files from their upstream
sources (version 2022-05-25).

It is required for loongarch support.

Checked on aarch64-linux-gnu.
2022-07-19 09:32:19 -03:00
Joseph Myers
c33ada0602 Use GCC 12 branch in build-many-glibcs.py
This patch makes build-many-glibcs.py use GCC 12 branch by default.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2022-07-04 13:15:58 +00:00
Adhemerval Zanella
8521001731 scripts/glibcelf.py: Add PT_AARCH64_MEMTAG_MTE constant
It was added in commit 603e5c8ba7.
This caused the elf/tst-glibcelf consistency check to fail.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-06-06 15:56:48 -03:00
Sam James
7df596a58c grep: egrep -> grep -E, fgrep -> grep -F
Newer versions of GNU grep (after grep 3.7, not inclusive) will warn on
'egrep' and 'fgrep' invocations.

Convert usages within the tree to their expanded non-aliased counterparts
to avoid irritating warnings during ./configure and the test suite.

Signed-off-by: Sam James <sam@gentoo.org>
Reviewed-by: Fangrui Song <maskray@google.com>
2022-06-05 12:09:02 -07:00
Joseph Myers
31ec883990 Use Linux 5.18 in build-many-glibcs.py
This patch makes build-many-glibcs.py use Linux 5.18.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2022-05-24 13:51:24 +00:00
Florian Weimer
d055481ce3 scripts/glibcelf.py: Add *T_RISCV_* constants
SHT_RISCV_ATTRIBUTES, PT_RISCV_ATTRIBUTES, DT_RISCV_VARIANT_CC were
added in commit 0b6c675073
("Update RISC-V specific ELF definitions").  This caused the
elf/tst-glibcelf consistency check to fail.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-16 22:22:38 +02:00
Florian Weimer
f787e138aa csu: Implement and use _dl_early_allocate during static startup
This implements mmap fallback for a brk failure during TLS
allocation.

scripts/tls-elf-edit.py is updated to support the new patching method.
The script no longer requires that in the input object is of ET_DYN
type.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-16 18:42:03 +02:00
Adhemerval Zanella
3a0588ae48 elf: Fix DFS sorting algorithm for LD_TRACE_LOADED_OBJECTS with missing libraries (BZ #28868)
On _dl_map_object the underlying file is not opened in trace mode
(in other cases where the underlying file can't be opened,
_dl_map_object  quits with an error).  If there any missing libraries
being processed, they will not be considered on final nlist size
passed on _dl_sort_maps later in the function.  And it is then used by
_dl_sort_maps_dfs on the stack allocated working maps:

222   /* Array to hold RPO sorting results, before we copy back to  maps[].  */
223   struct link_map *rpo[nmaps];
224
225   /* The 'head' position during each DFS iteration. Note that we start at
226      one past the last element due to first-decrement-then-store (see the
227      bottom of above dfs_traversal() routine).  */
228   struct link_map **rpo_head = &rpo[nmaps];

However while transversing the 'l_initfini' on dfs_traversal it will
still consider the l_faked maps and thus update rpo more times than the
allocated working 'rpo', overflowing the stack object.

As suggested in bugzilla, one option would be to avoid sorting the maps
for trace mode.  However I think ignoring l_faked object does make
sense (there is one less constraint to call the sorting function), it
allows a slight less stack usage for trace, and it is slight simpler
solution.

The tests does trigger the stack overflow, however I tried to make
it more generic to check different scenarios or missing objects.

Checked on x86_64-linux-gnu.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-04-27 08:36:09 -03:00
H.J. Lu
57292f5741 Add GLIBC_ABI_DT_RELR for DT_RELR support
The EI_ABIVERSION field of the ELF header in executables and shared
libraries can be bumped to indicate the minimum ABI requirement on the
dynamic linker.  However, EI_ABIVERSION in executables isn't checked by
the Linux kernel ELF loader nor the existing dynamic linker.  Executables
will crash mysteriously if the dynamic linker doesn't support the ABI
features required by the EI_ABIVERSION field.  The dynamic linker should
be changed to check EI_ABIVERSION in executables.

Add a glibc version, GLIBC_ABI_DT_RELR, to indicate DT_RELR support so
that the existing dynamic linkers will issue an error on executables with
GLIBC_ABI_DT_RELR dependency.  When there is a DT_VERNEED entry with
libc.so on DT_NEEDED, issue an error if there is a DT_RELR entry without
GLIBC_ABI_DT_RELR dependency.

Support __placeholder_only_for_empty_version_map as the placeholder symbol
used only for empty version map to generate GLIBC_ABI_DT_RELR without any
symbols.
2022-04-26 10:16:11 -07:00
H.J. Lu
4610b24f5e elf: Define DT_RELR related macros and types 2022-04-26 10:16:11 -07:00
Florian Weimer
b571f3adff scripts/glibcelf.py: Mark as UNSUPPORTED on Python 3.5 and earlier
enum.IntFlag and enum.EnumMeta._missing_ support are not part of
earlier Python versions.
2022-04-25 09:14:49 +02:00
Florian Weimer
30035d6772 scripts: Add glibcelf.py module
Hopefully, this will lead to tests that are easier to maintain.  The
current approach of parsing readelf -W output using regular expressions
is not necessarily easier than parsing the ELF data directly.

This module is still somewhat incomplete (e.g., coverage of relocation
types and versioning information is missing), but it is sufficient to
perform basic symbol analysis or program header analysis.

The EM_* mapping for architecture-specific constant classes (e.g.,
SttX86_64) is not yet implemented.  The classes are defined for the
benefit of elf/tst-glibcelf.py.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-04-22 10:58:32 +02:00
Joseph Myers
f7fbb99652 Use Linux 5.17 in build-many-glibcs.py
This patch makes build-many-glibcs.py use Linux 5.17.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2022-03-22 18:01:16 +00:00
Florian Weimer
a2211c76c3 scripts/dso-ordering-test.py: Fix C&P error in * callrefs processing
The elf/dso-sort-tests-src subdirectory is not changed by this commit,
so it seems that the cut-and-paste error was not material.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-03-18 18:18:45 +01:00
Joseph Myers
fb55d9b945 Use binutils 2.38 branch in build-many-glibcs.py
This patch makes build-many-glibcs.py use binutils 2.38 branch.

Tested with build-many-glibcs.py (compilers and glibcs builds).
2022-02-10 15:52:21 +00:00
Adhemerval Zanella
e4ba8fee1a elf: Replace tst-p_alignmod1-editX with a python script
This avoid the cross-compiling breakage when the test should not run
($(run-built-tests) equal to no).

Checked on x86_64-linux-gnu and i686-linux-gnu as well with a cross
compile to aarch64-linux-gnu and powerpc64-linux-gnu.
2022-01-26 08:57:47 -03:00
H.J. Lu
7de501f941 Disable debuginfod in printer tests [BZ #28757]
With gdb-11.1-6.fc35.x86_64, I got

FAIL: nptl/test-cond-printers
FAIL: nptl/test-condattr-printers
FAIL: nptl/test-mutex-printers
FAIL: nptl/test-mutexattr-printers
FAIL: nptl/test-rwlock-printers
FAIL: nptl/test-rwlockattr-printers

$ cat nptl/test-condattr-printers.out
Error: Response does not match the expected pattern.
Command: start
Expected pattern: main
Response:  Temporary breakpoint 1 at 0x11d5: file test-condattr-printers.c, line 43.
Starting program: /export/build/gnu/tools-build/glibc-cet-gitlab/build-x86_64-linux/nptl/test-condattr-printers

This GDB supports auto-downloading debuginfo from the following URLs:
https://debuginfod.fedoraproject.org/
Enable debuginfod for this session? (y or [n])

Disable debuginfod to avoid GDB messages.  This fixes BZ #28757.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-01-14 05:07:29 -08:00
Joseph Myers
a59cd1328a Use Linux 5.16 in build-many-glibcs.py
This patch makes build-many-glibcs.py use Linux 5.16.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2022-01-11 15:38:06 +00:00
Stafford Horne
e981650654 build-many-glibcs.py: add OpenRISC support
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-01-05 06:40:06 +09:00
Paul Eggert
0933a4a1b7 Sync move-if-change from Gnulib, updating copyright 2022-01-01 11:42:26 -08:00
Paul Eggert
634b5ebac6 Update copyright dates not handled by scripts/update-copyrights.
I've updated copyright dates in glibc for 2022.  This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files.  As well as the usual annual
updates, mainly dates in --version output (minus csu/version.c which
previously had to be handled manually but is now successfully updated
by update-copyrights), there is a small change to the copyright notice
in NEWS which should let NEWS get updated automatically next year.

Please remember to include 2022 in the dates for any new files added
in future (which means updating any existing uncommitted patches you
have that add new files to use the new copyright dates in them).
2022-01-01 11:42:26 -08:00
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Siddhesh Poyarekar
72e4a717bd Fix The GNU ToolChain Authors copyright notice
I (and maybe one or two others) added a (C) to the copyright notice
regardless of the contribution checklist[1] not mentioning it.  Fix all
these instances so that the notice reads as "Copyright The GNU Toolchain
Authors" across the source code.

[1] https://sourceware.org/glibc/wiki/Contribution%20checklist

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-12-17 07:59:45 +05:30
Siddhesh Poyarekar
23645707f1 Replace --enable-static-pie with --disable-default-pie
Build glibc programs and tests as PIE by default and enable static-pie
automatically if the architecture and toolchain supports it.

Also add a new configuration option --disable-default-pie to prevent
building programs as PIE.

Only the following architectures now have PIE disabled by default
because they do not work at the moment.  hppa, ia64, alpha and csky
don't work because the linker is unable to handle a pcrel relocation
generated from PIE objects.  The microblaze compiler is currently
failing with an ICE.  GNU hurd tries to enable static-pie, which does
not work and hence fails.  All these targets have default PIE disabled
at the moment and I have left it to the target maintainers to enable PIE
on their targets.

build-many-glibcs runs clean for all targets.  I also tested x86_64 on
Fedora and Ubuntu, to verify that the default build as well as
--disable-default-pie work as expected with both system toolchains.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-12-13 08:08:59 +05:30
H.J. Lu
b4bbedb1e7 dso-ordering-test.py: Put all sources in one directory [BZ #28550]
Put all sources for DSO sorting tests in the dso-sort-tests-src directory
and compile test relocatable objects with

$(objpfx)tst-dso-ordering1-dir/tst-dso-ordering1-a.os: $(objpfx)dso-sort-tests-src/tst-dso-ordering1-a.c
	$(compile.c) $(OUTPUT_OPTION)

to avoid random $< values from $(before-compile) when compiling test
relocatable objects with

$(objpfx)%$o: $(objpfx)%.c $(before-compile); $$(compile-command.c)
compile-command.c = $(compile.c) $(OUTPUT_OPTION) $(compile-mkdep-flags)
compile.c = $(CC) $< -c $(CFLAGS) $(CPPFLAGS)

for 3 "make -j 28" parallel builds on a machine with 112 cores at the
same time.

This partially fixes BZ #28550.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-11-15 11:53:40 -08:00
H.J. Lu
cbcd65c8b5 Add a comment for --enable-initfini-array [BZ #27945]
Document that --enable-initfini-array is enabled by default in GCC 12,
which can be removed when GCC 12 becomes the minimum requirement.
2021-11-13 09:50:07 -08:00
H.J. Lu
a586fe9c80 Configure GCC with --enable-initfini-array [BZ #27945]
Starting from GCC 12, the .init_array and .fini_array sections are enabled
unconditionally by

commit 13a39886940331149173b25d6ebde0850668d8b9
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Tue Jun 8 16:09:24 2021 -0700

    Always enable DT_INIT_ARRAY/DT_FINI_ARRAY on Linux

configure GCC with --enable-initfini-array to enable them when using GCC
release branches.

Fixes BZ #27945.
2021-11-05 15:30:02 -07:00
Joseph Myers
db432f033d Use Linux 5.15 in build-many-glibcs.py
This patch makes build-many-glibcs.py use Linux 5.15.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2021-11-02 16:54:59 +00:00
Chung-Lin Tang
e6fd79f379 elf: Testing infrastructure for ld.so DSO sorting (BZ #17645)
This is the first of a 2-part patch set that fixes slow DSO sorting behavior in
the dynamic loader, as reported in BZ #17645. In order to facilitate such a
large modification to the dynamic loader, this first patch implements a testing
framework for validating shared object sorting behavior, to enable comparison
between old/new sorting algorithms, and any later enhancements.

This testing infrastructure consists of a Python script
scripts/dso-ordering-test.py' which takes in a description language, consisting
of strings that describe a set of link dependency relations between DSOs, and
generates testcase programs and Makefile fragments to automatically test the
described situation, for example:

  a->b->c->d          # four objects linked one after another

  a->[bc]->d;b->c     # a depends on b and c, which both depend on d,
                      # b depends on c (b,c linked to object a in fixed order)

  a->b->c;{+a;%a;-a}  # a, b, c serially dependent, main program uses
                      # dlopen/dlsym/dlclose on object a

  a->b->c;{}!->[abc]  # a, b, c serially dependent; multiple tests generated
                      # to test all permutations of a, b, c ordering linked
                      # to main program

 (Above is just a short description of what the script can do, more
  documentation is in the script comments.)

Two files containing several new tests, elf/dso-sort-tests-[12].def are added,
including test scenarios for BZ #15311 and Redhat issue #1162810 [1].

Due to the nature of dynamic loader tests, where the sorting behavior and test
output occurs before/after main(), generating testcases to use
support/test-driver.c does not suffice to control meaningful timeout for ld.so.
Therefore a new utility program 'support/test-run-command', based on
test-driver.c/support_test_main.c has been added. This does the same testcase
control, but for a program specified through a command-line rather than at the
source code level. This utility is used to run the dynamic loader testcases
generated by dso-ordering-test.py.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1162810

Signed-off-by: Chung-Lin Tang  <cltang@codesourcery.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-21 11:23:53 -03:00
Fangrui Song
46baeb61e1 glibcextract.py: Place un-assemblable @@@ in a comment
Unlike GCC, Clang parses asm statements and verifies they are valid
instructions/directives. Place the magic @@@ into a comment to avoid
a parse error.
2021-10-19 09:58:16 -07:00
Paul E. Murphy
4ae2b8a423 build-many-glibcs.py: add powerpc64le glibc variant without multiarch
This configuration tests the float128 to ldouble128 redirect support
on powerpc64le without the extra wrappers needed to support ifunc
on this target.
2021-09-24 14:32:35 -05:00
Joseph Myers
876e51548c Fix build-many-glibcs.py --strip for installed library renaming
The renaming of installed shared libraries to use the SONAME directly
rather than linking to a versioned name stopped build-many-glibcs.py
--strip (used to facilitate comparing binaries before and after
changes that aren't meant to change any generated code in installed
glibc shared libraries) from stripping most of the installed shared
libraries, because it stripped only the *.so names.  Fix it to strip
*.so* names instead and to detect the case of linker scripts using
grep instead of hardcoding particular files that are linker scripts.

Tested with build-many-glibcs.py --strip.
2021-09-16 14:08:05 +00:00
Joseph Myers
4e04a47208 Use Linux 5.14 in build-many-glibcs.py
This patch makes build-many-glibcs.py use Linux 5.14.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2021-09-07 13:08:38 +00:00
Siddhesh Poyarekar
30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30
Siddhesh Poyarekar
04f2125c6e Port shared code information from the wiki
Since the shared code now has special status with respect to
copyrights, port them into a more structured format in the source tree
and add a python function that parses and returns a dictionary with
the information.

I need this to exclude these files from the Contributed-by changes and
I reckon it would be useful to know these files for future tooling.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:00:37 +05:30
Joseph Myers
1d7b32ee61 Use binutils 2.37 branch in build-many-glibcs.py
This patch makes build-many-glibcs.py use binutils 2.37 branch.

Tested with build-many-glibcs.py (compilers and glibcs builds).
2021-08-09 17:00:36 +00:00
Florian Weimer
5f18453d1c build-many-glibcs.py: Add x86_64-linux-gnu-minimal configuration
This configuration exercises various --disable-* configure options.
It is expected to catch -Werror failures that only affect these
configurations.
2021-07-28 14:47:33 +02:00
Florian Weimer
1e5235c561 build-many-glibcs.py: Add glibcs-arm-linux-gnueabihf-thumb
Previously, there was no thumb variant, despite that building
glibc in Thumb-2 mode is supported.
2021-07-09 10:59:22 +02:00
Joseph Myers
38f58041ba Use Linux 5.13 in build-many-glibcs.py
This patch makes build-many-glibcs.py use Linux 5.13.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2021-06-30 13:29:08 +00:00
Florian Weimer
3640654575 nptl_db: Re-use the ELF-to-abilist converter for ABI checking
The previous approach uses readelf -DWs, which does not produce
a stable output format (older binutils versions do not include
symbol version information).  This commit re-uses scripts/abilist.awk
with a tweak to include GLIBC_PRIVATE symbols.  This awk script
is based on objdump -T output, which appears to be stable over time.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-06-29 22:17:08 +02:00
Florian Weimer
c44838ebf8 Add libc ABI extension kludge for baseline-violating libdl symbols
Some targets have a GLIBC_2.0 baseline for libdl, while using
GLIBC_2.2 for libc.  This means that the generated libc.map file
does not have any version nodes for GLIBC_2.0 or GLIBC_2.1.  However,
moving symbols from libdl into libc needs such version nodes.
(Future symbol moves from librt will need this as well.)

This kludge is only necessary for symbols predating GLIBC_2.2 because
the affected targets use GLIBC_2.2 as the baseline for libc.  Given
the small number and fixed set of affected architectures, no generic
mechanism is implemented, and instead the map file fragment is
hard-coded in scripts/versions.mk.

The compat_symbol macro already emits the appropriate version strings,
so no adjustments are needed there.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-02 07:34:24 +02:00
Florian Weimer
d32ee64df7 scripts/versions.awk: Add local: * to all version nodes
This requires that all exported symbol versions are listed in
Versions files.  It results in more consistent behavior across
architectures because previously, symbols could be exported
via explicit versioned_symbol and compat_symbol macros if the
version node existed in some Versions file (without listing the
symbol), and it was not the base version for the library (which
already had the local: * directive).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-02 07:32:44 +02:00
Florian Weimer
a64af8c9b6 scripts/versions.awk: Add strings and hashes to <first-versions.h>
This generates new macros of this from:

They are useful for symbol lookups using _dl_lookup_direct.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-05-10 10:31:41 +02:00
Joseph Myers
876cdfd154 Use Linux 5.12 and GCC 11 branch in build-many-glibcs.py.
This patch makes build-many-glibcs.py use Linux 5.12 and GCC 11
branch.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).
2021-04-27 15:19:08 +00:00