tools/nolibc: mips: add support for PIC

MIPS requires some extra instructions to set up the $gp register for the
with a pointer to the global data area.

This isn't needed for non-PIC builds, but this patch enables the code
unconditionally to prevent bitrot.

Also enable PIC in one of the test configurations for ongoing
validation.

Link: https://lore.kernel.org/r/20231108-nolibc-pic-v2-1-4fb0d6284757@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

selftests/nolibc: introduce QEMU_ARCH_USER

While ppc64le shares the same executable with regular ppc64 the user
variant needs has a dedicated executable.
Introduce a new QEMU_ARCH_USER Makefile variable to accommodate that.

Fixes: 17362f3d0bd3 ("selftests/nolibc: use qemu-system-ppc64 for ppc64le")
Link: https://lore.kernel.org/r/20770915-nolibc-run-user-v1-1-3caec61726dc@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

selftests/nolibc: add configuration for mipso32be

Allow testing MIPS O32 big endian.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: extraconfig support

Allow some postprocessing of defconfig files.

Suggested-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: explicitly specify ABI for MIPS

More ABIs exist, for better clarity specify it explicitly everywhere.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: use XARCH for MIPS

MIPS has many different configurations prepare the support of additional
ones by moving the build of MIPS to the generic XARCH infrastructure.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: support out-of-tree builds

Out of tree builds are much more convenient when building for multiple
architectures or configurations in parallel.

Only absolute O= parameters are supported as Makefile.include will
always resolve relative paths in relation to $(srctree) instead of the
current directory.

Add a call to "make outputmakefile" to verify that the sourcetree is
clean.

This is based on Zhangjins out-of-tree patch.
It extends that work for get_init_cpio support and also drops relative
O= specifications explicitly.

Link: https://lore.kernel.org/lkml/06d96bd81fe812a9718098a383678ad3beba98b1.1691215074.git.falcon@tinylab.org/
Co-developed-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20231031-nolibc-out-of-tree-v1-3-47c92f73590a@weissschuh.net

selftests/nolibc: anchor paths in $(srcdir) if possible

It is easier to recognize paths from their well-known location in the
source tree than having to resolve the relative path in ones head.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20231031-nolibc-out-of-tree-v1-2-47c92f73590a@weissschuh.net

selftests/nolibc: use EFI -bios for LoongArch qemu

qemu for LoongArch does not work properly with direct kernel boot.
The kernel will panic during initialization and hang without any output.

When booting in EFI mode everything work correctly.

While users most likely don't have the LoongArch EFI binary installed at
least an explicit error about 'file not found' is better than a hanging
test without output that can never succeed.

Link: https://lore.kernel.org/loongarch/1738d60a-df3a-4102-b1da-d16a29b6e06a@t-8ch.de/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20231031-nolibc-out-of-tree-v1-1-47c92f73590a@weissschuh.net

selftests/nolibc: don't hang on config input

When the kernel code has changed the build may ask for configuration
input and hang. Prevent this and instead use the default settings.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

selftests/nolibc: add tests for multi-object linkage

While uncommon, nolibc executables can be linked together from multiple
compilation units.
Add some tests to make sure everything works in that case.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20231012-nolibc-linkage-test-v1-1-315e682768b4@weissschuh.net/
Acked-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: use qemu-system-ppc64 for ppc64le

qemu-system-ppc64 can handle both big and little endian kernels.

While some setups, like Debian, provide a symlink to execute
qemu-system-ppc64 as qemu-system-ppc64le, others, like ArchLinux, do not.

So always use qemu-system-ppc64 directly.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20231008-nolibc-qemu-ppc64-v1-1-29e2326e0420@weissschuh.net/
Acked-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: allow building i386 with multiarch compiler

When building with a multiarch-capable compiler, like those provided by
common distributions the -m32 argument is required to build 32bit code.

Wrap it in cc-option in case the compiler is not multiarch-capable.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20230917-nolibc-syscall-nr-v2-1-03863d509b9a@weissschuh.net

selftests/nolibc: don't embed initramfs into kernel image

When the initramfs is embedded into the kernel each rebuild of it will
trigger a full kernel relink and all the expensive postprocessing steps.

Currently nolibc-test and therefore the initramfs are always rebuild,
even without source changes, leading to lots of slow kernel relinks.

Instead of linking the initramfs into the kernel assemble it manually
and pass it explicitly to qemu.
This avoids all of the kernel relinks.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Link: https://lore.kernel.org/r/20230917-nolibc-initramfs-v2-1-f0f293a8b198@weissschuh.net

selftests/nolibc: use -nostdinc for nolibc-test

Avoid any accidental reliance on system includes.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: libc-test: use HOSTCC instead of CC

libc-test is mainly added to compare the behavior of nolibc to the
system libc, it is meaningless and error-prone with cross compiling.

Let's use HOSTCC instead of CC to avoid wrongly use cross compiler when
CROSS_COMPILE is passed or customized.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Fixes: cfb672f94f6e ("selftests/nolibc: add run-libc-test target")
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: allow report with existing test log

After the tests finish, it is valuable to report and summarize with
existing test log.

This avoid rerun or run the tests again when not necessary.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: add test support for ppc64

Kernel uses ARCH=powerpc for both 32-bit and 64-bit PowerPC, here adds a
ppc64 variant for big endian 64-bit PowerPC, users can pass XARCH=ppc64
to test it.

The powernv machine of qemu-system-ppc64 is used with
powernv_be_defconfig.

As the document [1] shows:

PowerNV (as Non-Virtualized) is the “bare metal” platform using the
OPAL firmware. It runs Linux on IBM and OpenPOWER systems and it can be
used as an hypervisor OS, running KVM guests, or simply as a host OS.

Notes,

- differs from little endian 64-bit PowerPC, vmlinux is used instead of
zImage, because big endian zImage [2] only boot on qemu with x-vof=on
(added from qemu v7.0) and a fixup patch [3] for qemu v7.0.51:

- since the VSX support may be disabled in kernel side, to avoid
"illegal instruction" errors due to missing VSX kernel support, let's
simply let compiler not generate vector/scalar (VSX) instructions via
the '-mno-vsx' option.

- as 'man gcc' shows, '-mmultiple' is used to generate code that uses
the load multiple word instructions and the store multiple word
instructions. Those instructions do not work when the processor is in
little-endian mode (except PPC740/PPC750), so, we only enable it
for big endian powerpc.

- for big endian ppc64, as the help message from arch/powerpc/Kconfig
shows, the V2 ABI is standard for 64-bit little-endian, but for
big-endian it is less well tested by kernel and toolchain, so, use
elfv1 as-is, no need to explicitly ask toolchain to use elfv2 here.

[1]: https://qemu.readthedocs.io/en/latest/system/ppc/powernv.html
[2]: https://github.com/linuxppc/issues/issues/402
[3]: https://lore.kernel.org/qemu-devel/20220504065536.3534488-1-aik@ozlabs.ru/

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230722121019.GD17311@1wt.eu/
Link: https://lore.kernel.org/lkml/20230719043353.GC5331@1wt.eu/
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: add test support for ppc64le

Kernel uses ARCH=powerpc for both 32-bit and 64-bit PowerPC, here adds a
ppc64le variant for little endian 64-bit PowerPC, users can pass
XARCH=ppc64le to test it.

The powernv machine of qemu-system-ppc64le is used for there is just a
working powernv_defconfig.

As the document [1] shows:

PowerNV (as Non-Virtualized) is the “bare metal” platform using the
OPAL firmware. It runs Linux on IBM and OpenPOWER systems and it can be
used as an hypervisor OS, running KVM guests, or simply as a host OS.

Notes,

- since the VSX support may be disabled in kernel side, to avoid
"illegal instruction" errors due to missing VSX kernel support, let's
simply let compiler not generate vector/scalar (VSX) instructions via
the '-mno-vsx' option.

- little endian ppc64 prefers elfv2 to elfv1 if the toolchain (e.g. gcc
13.1.0) supports it, let's align with kernel, otherwise, our elfv1
binary will not run on kernel with elfv2 ABI.

[1]: https://qemu.readthedocs.io/en/latest/system/ppc/powernv.html

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230722120747.GC17311@1wt.eu/
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: add test support for ppc

Kernel uses ARCH=powerpc for both 32-bit and 64-bit PowerPC, here adds a
ppc variant for 32-bit PowerPC and uses it as the default variant of
powerpc architecture.

Users can pass XARCH=ppc (or ARCH=powerpc) to test 32-bit PowerPC.

The default qemu-system-ppc g3beige machine [1] is used to run 32-bit
powerpc kernel with pmac32_defconfig. The missing PMACZILOG serial tty
and console are enabled in another patch [2].

Note,

- zImage doesn't boot due to "qemu-system-ppc: Some ROM regions are
overlapping" error, so, vmlinux is used instead.

- since the VSX support may be disabled in kernel side, to avoid
"illegal instruction" errors due to missing VSX kernel support, let's
simply let compiler not generate vector/scalar (VSX) instructions via
the '-mno-vsx' option.

- as 'man gcc' shows, '-mmultiple' is used to generate code that uses
the load multiple word instructions and the store multiple word
instructions. Those instructions do not work when the processor is in
little-endian mode (except PPC740/PPC750), so, we only enable it
for big endian powerpc.

[1]: https://qemu.readthedocs.io/en/latest/system/ppc/powermac.html
[2]: https://lore.kernel.org/lkml/bb7b5f9958b3e3a20f6573ff7ce7c5dc566e7e32.1690982937.git.tanyuan@tinylab.org/

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/ZL9leVOI25S2+0+g@1wt.eu/
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: add XARCH and ARCH mapping support

Most of the CPU architectures have different variants, but kernel
usually only accepts parts of them via the ARCH variable, the others
should be customized via kernel config files.

To simplify testing, a new XARCH variable is added to extend the
kernel's ARCH with a few variants of the same architecture, and it is
used to customize variant specific variables, at last XARCH is converted
to the kernel's ARCH:

e.g. make run XARCH=<one of the supported variants>
| \
| `-> variant specific variables:
| IMAGE, DEFCONFIG, QEMU_ARCH, QEMU_ARGS, CFLAGS ...
\
`---> kernel's ARCH

XARCH and ARCH are carefully mapped to allow users to pass architecture
variants via XARCH or pass architecture via ARCH from cmdline.

PowerPC is the first user and also a very good reference architecture of
this mapping, it has variants with different combinations of
32-bit/64-bit and bit endian/little endian.

To use this mapping, the other architectures can refer to PowerPC, If
the target architecture only has one variant, XARCH is simply an alias
of ARCH, no additional mapping required.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230702171715.GD16233@1wt.eu/
Link: https://lore.kernel.org/lkml/20230730061801.GA7690@1wt.eu/
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: enable compiler warnings

It will help the developers to avoid cruft and detect some bugs.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: don't strip nolibc-test

Binary size is not important for nolibc-test and some debugging
information is nice to have, so don't strip the binary during linking.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: allow test -include /path/to/nolibc.h

As the head comment of nolibc-test.c shows, it can be built in 3 ways:

$(CC) -nostdlib -include /path/to/nolibc.h => NOLIBC already defined
$(CC) -nostdlib -I/path/to/nolibc/sysroot => _NOLIBC_* guards are present
$(CC) with default libc => NOLIBC* never defined

Only last two of them are tested currently, let's allow test the first one too.

This may help to find issues about using nolibc.h to build programs. it
derives from this change:

commit 3a8039e289a3 ("tools/nolibc: Fix build of stdio.h due to header ordering")

Usage:

// test with sysroot by default
$ make run-user

// test without sysroot, using nolibc.h directly
$ make run-user NOLIBC_SYSROOT=0

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: allow run nolibc-test locally

It is able to run nolibc-test directly without qemu-user when the target
machine is the same as the host machine.

Sometimes, the result running locally may help a lot when the qemu-user
package is too old.

When the target machine differs from the host machine, it is also able
to run nolibc-test directly with qemu-user-static + binfmt_misc.

Link: https://lore.kernel.org/lkml/ZKutZwIOfy5MqedG@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: report: add newline before test failures

a newline is inserted just before the test failures to avoid mixing the
test failures with the raw test log.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: report: extrude the test status line

two newlines are added around the test summary line to extrude the test
status.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: report: align passed, skipped and failed

align the test values for different runs and different architectures.

Since the total number of tests is not bigger than 1000 currently, let's
align them with "%3d".

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
[wt: s/%03d/%3d/ as discussed with Zhangjin]
Link: https://lore.kernel.org/lkml/20230709185112.97236-1-falcon@tinylab.org/
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: report: print total tests

Let's count and print the total number of tests, now, the data of
passed, skipped and failed have the same format.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: report: print a summarized test status

one of the test status: success, warning and failure is printed to
summarize the passed, skipped and failed values.

- "success" means no skipped and no failed.
- "warning" means has at least one skipped and no failed.
- "failure" means all tests are failed.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230702164358.GB16233@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: add run-libc-test target

allow run and report glibc or musl based libc-test.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: restore the failed tests print

The commit fa0df56a804b ("selftests/nolibc: also count skipped and
failed tests in output") added counting for the skipped and failed
tests, but also removed the 'FAIL' results print, let's restore it for
it really allow users to learn the failed details without opening the
log file.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: always print the path to test log file

Even when there is no failure, developers may be still interested in the
test log file, especially, string alignment, duplicated print, kernel
message and so forth, so, always print the path to test log file.

A new line is added for such a print to avoid annoying people who don't
care about it when the test pass completely.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/ZIB792FtG6ibOudp@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: add a standalone test report macro

The run-user, run and rerun targets use the same test report script,
let's add a standalone test report macro for them.

This shrinks code lines and simplify the future maintainability.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/ZIB792FtG6ibOudp@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

selftests/nolibc: make sure gcc always use little endian on MIPS

The test on MIPS stopped working after I upgraded some of my toolchains
to use the ones from kernel.org because the mips toolchain defaults to
big endian, even though it supports both endians. Let's just add an
explicit -EL to make sure it always succeeds like the kernel does.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: also count skipped and failed tests in output

Right now skipped and failed test counts are not reported, and a few
times already we missed skipped ones that ought not to. Let's now
count each category and continue to invite the user to check the
report file when skipped+fail > 0. E.g:

$ make run-user
(...)
CC nolibc-test
136 test(s) passed, 2 skipped, 0 failed. See all results in .../run.out

Note that it's important to be careful about the trailing \r on the qemu
output (thanks Zhangjin for noticing).

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: allow specify extra arguments for qemu

The opensbi package from Ubuntu 20.04 only provides rv64 firmwares:

$ dpkg -S opensbi | grep -E "fw_.*bin|fw_.*elf" | uniq
opensbi: /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_dynamic.bin
opensbi: /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_jump.bin
opensbi: /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_dynamic.elf
opensbi: /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_jump.elf

To run this nolibc test for rv32, users must build opensbi or download a
prebuilt one from qemu repository:

https://gitlab.com/qemu-project/qemu/-/blob/master/pc-bios/opensbi-riscv32-generic-fw_dynamic.bin

And then use -bios to tell qemu use it to avoid such failure:

$ qemu-system-riscv32 -display none -no-reboot -kernel /path/to/arch/riscv/boot/Image -serial stdio -M virt -append "console=ttyS0 panic=-1"
qemu-system-riscv32: Unable to load the RISC-V firmware "opensbi-riscv32-generic-fw_dynamic.bin"

To run from makefile, QEMU_ARGS_EXTRA is added to allow pass extra
arguments like -bios:

$ make run QEMU_ARGS_EXTRA="-bios /path/to/opensbi-riscv32-generic-fw_dynamic.bin" ...

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/linux-riscv/2ab94136-d341-4a26-964e-6d6c32e66c9b@t-8ch.de/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: simplify stackprotector compiler flags

Now that nolibc enable stackprotector support automatically when the
compiler enables it we only have to get the -fstack-protector flags
correct.

The cc-options are structured so that -fstack-protector-all is only
enabled if -mstack-protector=guard works, as that is the only mode
supported by nolibc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: riscv: add stackprotector support

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: mips: add stackprotector support

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: loongarch: add stackprotector support

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: arm: add stackprotector support

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: aarch64: add stackprotector support

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: validate C89 compatibility

To make sure no non-compatible changes are introduced accidentally
validate the language standard when building the tests.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: add libc-test binary

This can be used to easily compare the behavior of nolibc to the system
libc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: x86_64: add stackprotector support

Enable the new stackprotector support for x86_64.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: i386: add stackprotector support

Enable the new stackprotector support for i386.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: tests: add test for -fstack-protector

Test the previously introduce stack protector functionality in nolibc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: tests: fold in no-stack-protector cflags

For the cflags to enable stack protectors to work properly they need to
be specified after -fno-stack-protector.

To do this fold all cflags into a single variable and move
-fno-stack-protector before the arch-specific cflags and another
one specific to stack protectors since we don't want to enable them
on all archs.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: Adjust indentation for Makefile

Reindent only, no functional changes.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: Add support for LoongArch

Add support for LoongArch (64 bit) to nolibc selftest.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc: always disable stack protector for tests

Stack protectors need support from libc.
This support is not provided by nolibc which leads to compiler errors
when stack protectors are enabled by default in a compiler:

CC nolibc-test
/usr/bin/ld: /tmp/ccqbHEPk.o: in function `stat':
nolibc-test.c:(.text+0x1d1): undefined reference to `__stack_chk_fail'
/usr/bin/ld: /tmp/ccqbHEPk.o: in function `poll.constprop.0':
nolibc-test.c:(.text+0x37b): undefined reference to `__stack_chk_fail'
/usr/bin/ld: /tmp/ccqbHEPk.o: in function `vfprintf.constprop.0':
nolibc-test.c:(.text+0x712): undefined reference to `__stack_chk_fail'
/usr/bin/ld: /tmp/ccqbHEPk.o: in function `pad_spc.constprop.0':
nolibc-test.c:(.text+0x80d): undefined reference to `__stack_chk_fail'
/usr/bin/ld: /tmp/ccqbHEPk.o: in function `printf':
nolibc-test.c:(.text+0x8c4): undefined reference to `__stack_chk_fail'
/usr/bin/ld: /tmp/ccqbHEPk.o:nolibc-test.c:(.text+0x12d4): more undefined references to `__stack_chk_fail' follow
collect2: error: ld returned 1 exit status

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: Add a "run-user" target to test the program in user land

When developing tests, it is much faster to use the QEMU Linux
emulator instead of the system emulator, which among other things avoids
kernel-build latencies. Although use of the QEMU Linux emulator does have
its limitations (please see below), it is sufficient to test startup code,
stdlib code, and syscall calling conventions.

However, the current mainline Linux-kernel nolibc setup does not
support this. Therefore, add a "run-user" target that immediately
executes the prebuilt executable.

Again, this approach does have its limitations. For example, the
executable runs with the user's privilege level, which can cause some
false-positive failures due to insufficient permissions. In addition,
if the underlying kernel is old enough to lack some features that
nolibc relies on, the result will be false-positive failures in the
corresponding tests. However, for nolibc changes not affected by these
limittions, the result is a much faster code-compile-test-debug cycle.

With this patch, running a userland test is as simple as issuing:

make ARCH=xxx CROSS_COMPILE=xxx run-user

Signed-off-by: Willy Tarreau <w@1wt.eu>
Tested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: Support "x86_64" for arch name

Building the kernel with ARCH=x86_64 works fine, but nolibc-test
only supports "x86", which causes errors when reusing existing build
environment. Let's permit this environment to be used as well by making
nolibc also accept ARCH=x86_64.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Tested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: add s390 support

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: Always rebuild the sysroot when running a test

Paul and I got trapped a few times by not seeing the effects of applying
a patch to the nolibc source code until a "make clean" was issued in
the nolibc directory. It's particularly annoying when trying to confirm
that a proposed patch really solves a problem (or that reverting it
reintroduces the problem).

The reason for the sysroot not being rebuilt was that it can be quite
slow. But in fact it's only slow after a "make clean" issued at the
kernel's topdir, because it's the main "make headers" that can take a
tens of seconds; as long as "usr/include" still contains headers, the
"headers_install" phase is only a quick "rsync", and rebuilding the
whole nolibc sysroot takes a bit less than one second, which is perfectly
acceptable for a test, even more once the time lost caused by misleading
results is factored in.

This patch marks the sysroot target as phony and starts by clearing
the previous sysroot for the current architecture before reinstalling
it. Thanks to this, applying a patch to nolibc makes the effect
immediately visible to "make nolibc-test":

$ time make -j -C tools/testing/selftests/nolibc nolibc-test
make: Entering directory '/k/tools/testing/selftests/nolibc'
MKDIR sysroot/x86/include
make[1]: Entering directory '/k/tools/include/nolibc'
make[2]: Entering directory '/k'
make[2]: Leaving directory '/k'
make[2]: Entering directory '/k'
INSTALL /k/tools/testing/selftests/nolibc/sysroot/sysroot/include
make[2]: Leaving directory '/k'
make[1]: Leaving directory '/k/tools/include/nolibc'
CC nolibc-test
make: Leaving directory '/k/tools/testing/selftests/nolibc'

real 0m0.869s
user 0m0.716s
sys 0m0.149s

Cc: "Paul E. McKenney" <paulmck@kernel.org>
Link: https://lore.kernel.org/all/20221021155645.GK5600@paulmck-ThinkPad-P17-Gen-1/
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: add a "help" target

It presents the supported targets, and becomes the default target to
save the user from having to read the makefile. The "all" target was
placed after it and now points to "run" to do everything since it's
no longer the default one.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: "sysroot" target installs a local copy of the sysroot

It's not convenient to rely on a sysroot built in another directory,
especially when running cross-compilation tests, where one has to
switch back and forth between directories.

Let's make it possible to install the sysroot directly in the test
directory. It's not big and even benefits from being copied by arch
so that it's easier to switch between archs if needed. The new
"sysroot" target does this, it just calls "headers_standalone" from
nolibc to install the sysroot right here.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: add a "run" target to start the kernel in QEMU

The "run" target will build the kernel and start it in QEMU. The
"rerun" target will not have the kernel dependency and will just try
to start QEMU. The QEMU architecture used to start the kernel is
derived from the configured ARCH. This might need to be improved
for archs which include different variants under the same name
(mips vs mipsel, +/-64, riscv32 vs riscv64). This could be tested
for i386, x86, arm, arm64, mips and riscv (the later two reporting
issues on some tests).

It is possible to pass a test specification for nolibc-test in the TEST
variable, which will be passed as-is as NOLIBC_TEST.

On success, the number of successful tests is printed. On failure, failed
lines are individually printed.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: add a "defconfig" target

While most archs will work fine with "make defconfig", not all will
do, and it's not always easy to remember the most suitable choice to
use for a specific architecture.

This adds a "defconfig" target to the Makefile so that one may easily
run "make -C ... defconfig" and make sure to clean and rebuild a fresh
config. This is *not* used by default because we want to preserve the
user's config by default.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: add a "kernel" target to build the kernel with the initramfs

The "kernel" target rebuilds the kernel with the current config for the
selected arch, with an initramfs containing the nolibc-test utility.

Since image names depend on the architecture, the currently supported
ones are referenced and resolved based on the architecture.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

selftests/nolibc: add basic infrastructure to ease creation of nolibc tests

This creates a "nolibc" selftest that intends to test various parts of
the nolibc component, both in terms of build and execution for a given
architecture.

The aim is for it to be as simple to run as a kernel build, by just
passing the compiler (for the build) and the ARCH (for kernel and
execution).

It brings a basic squeleton made of a single C file that will ease testing
and error reporting. The code will be arranged so that it remains easy to
add basic tests for syscalls or library calls that may rely on a condition
to be executed, and whose result is compared to a value or to an error
with a specific errno value.

Tests will just use a relative line number in switch/case statements as
an index, saving the user from having to maintain arrays and complicated
functions which can often just be one-liners.

MAINTAINERS was updated.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>