15 Commits

Author SHA1 Message Date
Fernanda Ma'rouf
43cf168fa9 selftests/nolibc: Avoid generated files being committed
After running the nolibc tests, the "git status" is not clean because
the generated files are not ignored. Create a `.gitignore` inside the
selftests/nolibc directory to ignore them.

Cc: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Cc: Fernanda Ma'rouf <fernandafmr2@gmail.com>
Signed-off-by: Fernanda Ma'rouf <fernandafmr12@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:45 -07:00
Willy Tarreau
ffc297fe22 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>
2022-08-31 05:17:45 -07:00
Willy Tarreau
b25c5284db 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>
2022-08-31 05:17:45 -07:00
Willy Tarreau
662ea60e37 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>
2022-08-31 05:17:45 -07:00
Willy Tarreau
5c43fd7954 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>
2022-08-31 05:17:45 -07:00
Willy Tarreau
d248cabff5 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>
2022-08-31 05:17:45 -07:00
Willy Tarreau
1da02f5108 selftests/nolibc: support glibc as well
Adding support for glibc can be useful to distinguish between bugs in
nolibc and bugs in the kernel when a syscall reports an unusual value.

It's not that much work and should not affect the long term
maintainability of the tests. The necessary changes can essentially be
summed up like this:
  - set _GNU_SOURCE a the top to access some definitions
  - many includes added when we know we don't come from nolibc (missing
    the stdio include guard)
  - disable gettid() which is not exposed by glibc
  - disable gettimeofday's support of bad pointers since these  crash
    in glibc
  - add a simple itoa() for errorname(); strerror() is too verbose (no
    way to get short messages). strerrorname_np() was added in modern
    glibc (2.32) to do exactly this but that 's too recent to be usable
    as the default fallback.
  - use the standard ioperm() definition. May be we need to implement
    ioperm() in nolibc if that's useful.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
7172f1c685 selftests/nolibc: condition some tests on /proc existence
If /proc is not available (program run inside a chroot or without
sufficient permissions), it's better to disable the associated tests.
Some will be preserved like the ones which check for a failure to
create some entries there since they're still supposed to fail.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
1a5454f625 selftests/nolibc: recreate and populate /dev and /proc if missing
Most of the time the program will be run alone in an initramfs. There
is no value in requiring the user to populate /dev and /proc for such
tests, we can do it ourselves, and it participates to the tests at the
same time.

What's done here is that when called as init (getpid()==1) we check
if /dev exists or create it, if /dev/console and /dev/null exists,
otherwise we try to mount a devtmpfs there, and if it fails we fall
back to mknod. The console is reopened if stdout was closed. Finally
/proc is created and mounted if /proc/self cannot be found. This is
sufficient for most tests.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
aa73a86cda selftests/nolibc: on x86, support exiting with isa-debug-exit
QEMU, when started with "-device isa-debug-exit -no-reboot" will exit
with status code 2N+1 when N is written to 0x501. This is particularly
convenient for automated tests but this is not portable. As such we
only enable this on x86_64 when pid==1. In addition, this requires an
ioperm() call but in order not to have to define arch-specific syscalls
we just perform the syscall by hand there.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
f49896d7d9 selftests/nolibc: exit with poweroff on success when getpid() == 1
The idea is to ease automated testing under qemu. If the test succeeds
while running as PID 1, indicating the system was booted with init=/test,
let's just power off so that qemu can exit with a successful code. In
other situations it will exit and provoke a panic, which may be caught
for example with CONFIG_PVPANIC.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
95bc989488 selftests/nolibc: add a few tests for some libc functions
The test series called "stdlib" covers some libc functions (string,
stdlib etc). By default they are automatically run after "syscall"
but may be requested in argument or in variable NOLIBC_TEST.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
b4844fa0bd selftests/nolibc: implement a few tests for various syscalls
This adds 63 tests covering about 34 syscalls. Both successes and
failures are tested. Two tests fail when run as unprivileged user
(link_dir which returns EACCESS instead of EPERM, and chroot which
returns EPERM). One test (execve("/")) expects to fail on EACCESS,
but needs to have valid arguments otherwise the kernel will log a
message. And a few tests require /proc to be mounted.

The code is not pretty since all tests are one-liners, sometimes
resulting in long lines, especially when using compount statements to
preset a line, but it's convenient and doesn't obfuscate the code,
which is important to understand what failed.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
23da7bc923 selftests/nolibc: support a test definition format
It now becomes possible to pass a string either in argv[1] or in the
NOLIBC_TEST environment variable (the former having precedence), to
specify which tests to run. The format is:

   testname[:range]*[,testname...]

Where a range is either a single value or the min and max numbers of the
test IDs in a sequence, delimited by a dash. Multiple ranges are possible.
This should provide enough flexibility to focus on certain failing parts
just by playing with the boot command line in a boot loader or in qemu
depending on what is accessible.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:44 -07:00
Willy Tarreau
362aecb2d8 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>
2022-08-31 05:17:44 -07:00