The UAPI header do already provide an elf.h implementation.
Reexport it under its libc name.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250416-nolibc-split-sys-v1-2-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
To support headers in subdirectories (like sys/), their subdirectory needs
to be preserved during installation into the sysroot.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250416-nolibc-split-sys-v1-1-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
In twos complement the most negative number can not be negated.
Fixes: b1c21e7d99 ("tools/nolibc/stdlib: add i64toa() and u64toa()")
Fixes: 66c397c4d2 ("tools/nolibc/stdlib: replace the ltoa() function with more efficient ones")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-5-060b8a016917@weissschuh.net
Both constructors and main() may be executed with different function
signatures than they are actually using.
This is intentional but trips up UBSAN.
Disable the function sanitizer of UBSAN in _start_c().
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-3-060b8a016917@weissschuh.net
Certain compiler features are signaled via the __has_feature()
preprocessor builtin.
Add a nolibc wrapper for it, similar to __nolibc_has_attribute().
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-1-060b8a016917@weissschuh.net
The stack pointer is already aligned by the kernel to a multiple of 16.
See STACK_ROUND() in fs/binfmt_elf.c.
The manual realignment is unnecessary, drop it.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250316-nolibc-sp-align-v1-1-1e1fb073ca1e@weissschuh.net
Fix an imbalance where opening parentheses exceed closing ones.
Fixes: eba6d00d38 ("tools/nolibc/types: move makedev to types.h and make it a macro")
Signed-off-by: Jemmy Wong <jemmywong512@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250411073624.22153-1-jemmywong512@gmail.com
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
- Consolidate the VDSO storage
The VDSO data storage and data layout has been largely architecture
specific for historical reasons. That increases the maintenance effort
and causes inconsistencies over and over.
There is no real technical reason for architecture specific layouts and
implementations. The architecture specific details can easily be
integrated into a generic layout, which also reduces the amount of
duplicated code for managing the mappings.
Convert all architectures over to a unified layout and common mapping
infrastructure. This splits the VDSO data layout into subsystem
specific blocks, timekeeping, random and architecture parts, which
provides a better structure and allows to improve and update the
functionalities without conflict and interaction.
- Rework the timekeeping data storage
The current implementation is designed for exposing system timekeeping
accessors, which was good enough at the time when it was designed.
PTP and Time Sensitive Networking (TSN) change that as there are
requirements to expose independent PTP clocks, which are not related to
system timekeeping.
Replace the monolithic data storage by a structured layout, which
allows to add support for independent PTP clocks on top while reusing
both the data structures and the time accessor implementations.
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Merge tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull VDSO infrastructure updates from Thomas Gleixner:
- Consolidate the VDSO storage
The VDSO data storage and data layout has been largely architecture
specific for historical reasons. That increases the maintenance
effort and causes inconsistencies over and over.
There is no real technical reason for architecture specific layouts
and implementations. The architecture specific details can easily be
integrated into a generic layout, which also reduces the amount of
duplicated code for managing the mappings.
Convert all architectures over to a unified layout and common mapping
infrastructure. This splits the VDSO data layout into subsystem
specific blocks, timekeeping, random and architecture parts, which
provides a better structure and allows to improve and update the
functionalities without conflict and interaction.
- Rework the timekeeping data storage
The current implementation is designed for exposing system
timekeeping accessors, which was good enough at the time when it was
designed.
PTP and Time Sensitive Networking (TSN) change that as there are
requirements to expose independent PTP clocks, which are not related
to system timekeeping.
Replace the monolithic data storage by a structured layout, which
allows to add support for independent PTP clocks on top while reusing
both the data structures and the time accessor implementations.
* tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits)
sparc/vdso: Always reject undefined references during linking
x86/vdso: Always reject undefined references during linking
vdso: Rework struct vdso_time_data and introduce struct vdso_clock
vdso: Move architecture related data before basetime data
powerpc/vdso: Prepare introduction of struct vdso_clock
arm64/vdso: Prepare introduction of struct vdso_clock
x86/vdso: Prepare introduction of struct vdso_clock
time/namespace: Prepare introduction of struct vdso_clock
vdso/namespace: Rename timens_setup_vdso_data() to reflect new vdso_clock struct
vdso/vsyscall: Prepare introduction of struct vdso_clock
vdso/gettimeofday: Prepare helper functions for introduction of struct vdso_clock
vdso/gettimeofday: Prepare do_coarse_timens() for introduction of struct vdso_clock
vdso/gettimeofday: Prepare do_coarse() for introduction of struct vdso_clock
vdso/gettimeofday: Prepare do_hres_timens() for introduction of struct vdso_clock
vdso/gettimeofday: Prepare do_hres() for introduction of struct vdso_clock
vdso/gettimeofday: Prepare introduction of struct vdso_clock
vdso/helpers: Prepare introduction of struct vdso_clock
vdso/datapage: Define vdso_clock to prepare for multiple PTP clocks
vdso: Make vdso_time_data cacheline aligned
arm64: Make asm/cache.h compatible with vDSO
...
The asm/ and asm-generic/ namespaces are implementation details of the UAPI
headers and not meant for direct usage.
Use the equivalent headers from the linux/ namespace instead.
While at it also drop the duplicate include of linux/signal.h from sys.h.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250307-nolibc-asm-headers-v2-1-e2a734f25d22@linutronix.de
openat is useful to avoid needing to construct relative paths, so expose
a wrapper for using it directly.
Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-1-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
limits.h is a widely used standard header. Missing it from nolibc requires
adoption effort to port applications.
Add a shim header which includes the global nolibc.h header.
It makes all nolibc symbols available.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/all/20250226-parse_vdso-nolibc-v2-9-28e14e031ed8@linutronix.de
These functions are used often, also in selftests.
sscanf() itself is also used by kselftest.h itself.
The implementation is limited and only supports numeric arguments.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250209-nolibc-scanf-v2-1-c29dea32f1cd@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
32-bit s390 is very close to the existing 64-bit implementation.
Some special handling is necessary as there is neither LLVM nor
QEMU support. Also the kernel itself can not build natively for 32-bit
s390, so instead the test program is executed with a 64-bit kernel.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250206-nolibc-s390-v2-2-991ad97e3d58@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Add an implementation for directory access operations.
To keep nolibc itself allocation-free, a "DIR *" does not point to any
data, but directly encodes a filedescriptor number, equivalent to "FILE *".
Without any per-directory storage it is not possible to implement
readdir() POSIX confirming. Instead only readdir_r() is provided.
While readdir_r() is deprecated in glibc, the reasons for that are
not applicable to nolibc.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250209-nolibc-dir-v2-2-57cc1da8558b@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Not all architectures have the old sys_lseek(), notably riscv32.
Implement lseek() in terms of sys_llseek() in that case.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250209-nolibc-dir-v2-1-57cc1da8558b@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
POSIX defines the signature of ioctl() as follows,
to allow passing a pointer or integer without casting:
int ioctl(int fildes, int request, ... /* arg */);
Nolibc ioctl() expects a pointer, forcing the user to manually cast.
Using va_arg to make the signature more flexible would work but seems to
prevent inlining of the function. Instead use a macro. "fd" and "req"
will still be typechecked through sys_ioctl().
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
With -Wmissing-prototypes the compiler will warn about non-static
functions which don't have a prototype defined.
This warning doesn't make much sense for nolibc itself but for user code
it is still useful.
To pacify the compiler add prototypes next to the function definitions,
similar to how it is handled elsewhere in the kernel.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-prototype-v1-1-e1afc5c1999a@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
waitid() is the modern variant of the family of wait-like syscalls.
Some architectures have dropped support for wait(), wait4() and waitpid()
but all of them support waitid().
It is more flexible and easier to use than the older ones.
Link: https://lore.kernel.org/r/20241221-nolibc-rv32-v1-1-d9ef6dab7c63@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Recent version of GCC and clang gained -Wimplicit-fallthrough,
warning about implicit fall-through between switch labels.
As nolibc does not control the compilation flags, this can trigger
warnings for when built by the user.
Make use of the "fallthrough" attribute to explicitly annotate the
expected fall-throughs and silence the warning.
Link: https://lore.kernel.org/r/20240930-nolibc-fallthrough-v2-1-2e8d10fe3430@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
arch-s390.h uses types from std.h, but does not include it.
Depending on the inclusion order the compilation can fail.
Include std.h explicitly to avoid these errors.
Fixes: 404fa87c0e ("tools/nolibc: s390: provide custom implementation for sys_fork")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20240927-nolibc-s390-std-h-v1-1-30442339a6b9@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Compiling arch-x86_64.h with clang and binutils LD yields
duplicate label errors:
.../gcc-13.2.0-nolibc/x86_64-linux/bin/x86_64-linux-ld: error: LLVM gold plugin: <inline asm>:44:1: symbol '.Lbackward_copy' is already defined
.Lbackward_copy:leaq -1(%rdi, %rcx, 1), %rdi
Instead of a local symbol use a local label which can be defined
multiple times and therefore avoids the error.
Reviewed-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240812-nolibc-lto-v2-3-736af7bbefa8@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
During LTO the references from the compiler-generated prologue and
epilogues to the stack protector symbols are not visible and the symbols
are removed.
This will then lead to errors during linking.
As those symbols are already #ifdeffed-out if unused mark them as "used"
to prevent their removal.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240812-nolibc-lto-v2-2-736af7bbefa8@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
During LTO the reference from the asm startup code to the _start_c()
function is not visible and _start_c() is removed.
This will then lead to errors during linking.
As _start_c() is indeed always used, mark it as such.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240812-nolibc-lto-v2-1-736af7bbefa8@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
The current entrypoint attributes optimize("Os", "omit-frame-pointer")
are intended to avoid all compiler generated code, like function
porologue and epilogue.
This is the exact usecase implemented by the attribute "naked".
Unfortunately this is not implemented by GCC for all targets,
so only use it where available.
This also provides compatibility with clang, which recognizes the
"naked" attribute but not the previously used attribute "optimized".
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-6-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
The specific attributes for the _start entrypoint are duplicated for
each architecture.
Deduplicate it into a dedicated #define into compiler.h.
For clang compatibility, the epilogue will also need to be adapted, so
move that one, too.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-5-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Recent compilers support __has_attribute() to check if a certain
compiler attribute is supported.
Unfortunately we have to first check if __has_attribute is supported in
the first place and then if a specific attribute is present.
These two checks can't be folded into a single condition as that would
lead to errors.
Nesting the two conditions like below works, but becomes ugly as soon
as #else blocks are used as those need to be duplicated for both levels
of #if.
#if defined __has_attribute
# if __has_attribute (nonnull)
# define ATTR_NONNULL __attribute__ ((nonnull))
# endif
#endif
Introduce a new helper which makes the usage of __has_attribute() nicer
and migrate the current user to it.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-4-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
As mentioned in the comment, the workaround for
__attribute__((no_stack_protector)) is only necessary on GCC.
Avoid applying the workaround on clang, as clang does not recognize
__attribute__((__optimize__)) and would fail.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-3-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
The MIPS calling convention requires the address of the current function
to be available in $t9.
This was not done so far.
For GCC this seems to have worked, but when compiled with clang the
executable segfault instantly.
Properly load the address of _start_c() into $t9 before calling it.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-2-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
string.h tests for the macros NOLIBC_ARCH_HAS_$FUNC to use the
architecture-optimized function variants.
However if string.h is included before arch.h header then that check
does not work, leading to duplicate function definitions.
Fixes: 553845eebd ("tools/nolibc: x86-64: Use `rep movsb` for `memcpy()` and `memmove()`")
Fixes: 12108aa8c1 ("tools/nolibc: x86-64: Use `rep stosb` for `memset()`")
Cc: stable@vger.kernel.org
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240725-arch-has-func-v1-1-5521ed354acd@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
strerror() is commonly used.
For example in kselftest which currently needs to do an #ifdef NOLIBC to
handle the lack of strerror().
Keep it simple and reuse the output format of perror() for strerror().
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
The implementation always works on uintmax_t values.
This is inefficient when only 32bit are needed.
However for all functions this only happens for strtol() on 32bit
platforms.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240425-nolibc-strtol-v1-2-bfeef7846902@weissschuh.net
All supported kernels are assumed to use struct new_utsname.
This is validated in test_uname().
uname(2) can for example be used in ksft_min_kernel_version() from the
kernels selftest framework.
Link: https://lore.kernel.org/lkml/20240412123536.GA32444@redhat.com/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
The return code should always be strlen(src), and we should copy at most
size-1 bytes.
While we are there, make sure to null-terminate the dst buffer if we
copied something.
Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
The return code should always be strlen(src) + strnlen(dst, size).
Let's make sure to copy at most size-1 bytes from src and null-terminate
the dst buffer if we did copied something.
While we can use strnlen() and strncpy() to implement strlcat(), this is
simple enough and results in shorter code when compiled.
Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
As with commit 8d304a3740, "tools/nolibc/string: export memset() and
memmove()", gcc -Os without -ffreestanding may fail to compile with:
cc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib -lgcc -static -o test test.c
/usr/bin/ld: /tmp/cccIasKL.o: in function `main':
test.c:(.text.startup+0x1e): undefined reference to `strlen'
collect2: error: ld returned 1 exit status
As on the aforementioned commit, this patch adds a section to export
this function so compilation works on those cases too.
Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Pass user_p_len to memcpy() instead of heap->len to prevent realloc()
from copying an extra sizeof(heap) bytes from beyond the allocated
region.
Signed-off-by: Brennan Xavier McManus <bxmcmanus@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Fixes: 0e0ff63840 ("tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`")
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
A future commit will include linux/resource.h, which will conflict with
the private definition of struct rusage in nolibc.
Avoid the conflict by dropping the private definition and use the one
from the UAPI headers.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20231123-nolibc-rlimit-v1-1-a428b131de2a@weissschuh.net/
Acked-by: Willy Tarreau <w@1wt.eu>
__attribute__(format(printf)) can also be used for functions that take a
va_list argument.
As per the GCC docs:
For functions where the arguments are not available to be checked
(such as vprintf), specify the third parameter as zero.
Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
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>
When installing nolibc to a sysroot arch.h is not used so its ABI check
is bypassed. This makes is possible to compile nolibc with a non O32 ABI
which may build but can not run.
Move the check into arch-mips.h so it will always be evaluated.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
When an architecture is unsupported arch.h would silently continue.
This leads to a lot of followup errors because my_syscallX() is not
defined and the startup code is missing.
Avoid these confusing errors and fail the build early with a clear
error message and location.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Linux defines a few custom flags for waitpid() which aren't currently
provided by nolibc, make them available to nolibc based programs by just
including linux/wait.h where they are defined instead of defining our
own copy of the flags.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
All symbols created by nolibc are also visible to user code.
Syscall constants are expected to come from the kernel headers and
should not be made up by nolibc.
Refactor the logic to avoid defining syscall numbers.
Also the new code is easier to understand.
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-v2-3-03863d509b9a@weissschuh.net
This function is only called by memcpy(), there is no real reason to
have this wrapper. Delete this function and move the code to memcpy()
directly.
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Reviewed-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
This nolibc internal function is not used. Delete it. It was probably
supposed to handle memmove(), but today the memmove() has its own
implementation.
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Reviewed-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
This allows nolic to work with `-nostdinc` avoiding any reliance on
system headers.
The implementation has been lifted from musl libc 1.2.4.
There is already an implementation of stdarg.h in include/linux/stdarg.h
but that is GPL licensed and therefore not suitable for nolibc.
The used compiler builtins have been validated to be at least available
since GCC 4.1.2 and clang 3.0.0.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
The ABI mandates that the %esp register must be a multiple of 16 when
executing a 'call' instruction.
Commit 2ab446336b ("tools/nolibc: i386: shrink _start with _start_c")
simplified the _start function, but it didn't take care of the %esp
alignment, causing SIGSEGV on SSE and AVX programs that use aligned move
instruction (e.g., movdqa, movaps, and vmovdqa).
The 'and $-16, %esp' aligns the %esp at a multiple of 16. Then 'push
%eax' will subtract the %esp by 4; thus, it breaks the 16-byte
alignment. Make sure the %esp is correctly aligned after the push by
subtracting 12 before the push.
Extra:
Add 'add $12, %esp' before the 'and $-16, %esp' to avoid over-estimating
for particular cases as suggested by Willy.
A test program to validate the %esp alignment on _start can be found at:
https://lore.kernel.org/lkml/ZOoindMFj1UKqo+s@biznet-home.integral.gnuweeb.org
[ Thomas: trim Fixes tag commit id ]
Cc: Zhangjin Wu <falcon@tinylab.org>
Fixes: 2ab446336b ("tools/nolibc: i386: shrink _start with _start_c")
Reported-by: Nicholas Rosenberg <inori@vnlx.org>
Acked-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Reviewed-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Having __sysret() as an inline function has the unfortunate effect of
adding casts and large constants comparisons after the syscall returns
that significantly inflate some light code that's otherwise syscall-
heavy. Even nolibc-test grew by ~1%.
Let's switch back to a macro for this, and use it only with signed
arguments. Note that it is also possible to design a slightly more
complex macro covering unsigned and pointers but we only have 3 such
syscalls so it is pointless, and these were just addressed not to use
this macro anymore. Now for the argument (the local variable containing
the syscall return value), any negative value is an error, that results
in -1 being returned and errno to be assigned the opposite value.
This may be revisited again in the future if really needed but for now
let's get back to something sane.
Fixes: 428905da6e ("tools/nolibc: sys.h: add a syscall return helper")
Link: https://lore.kernel.org/lkml/20230806095846.GB10627@1wt.eu/
Link: https://lore.kernel.org/lkml/ZNKOJY+g66nkIyvv@1wt.eu/
Cc: Zhangjin Wu <falcon@tinylab.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Thomas Weißschuh <thomas@t-8ch.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
The __sysret() function causes some undesirable casts so we'll revert
it. In order to keep it simple it will now only support integer return
values like in the past, so we must basically revert the changes that
were made to these 3 syscalls which return a pointer so that they
simply rely on their own test and the SET_ERRNO() macro.
Fixes: 4201cfce15 ("tools/nolibc: clean up sbrk() routine")
Fixes: 924e9539ae ("tools/nolibc: clean up mmap() routine")
Fixes: d27447bc2e ("tools/nolibc: sys.h: apply __sysret() helper")
Link: https://lore.kernel.org/lkml/20230806095846.GB10627@1wt.eu/
Link: https://lore.kernel.org/lkml/ZNKOJY+g66nkIyvv@1wt.eu/
Cc: Zhangjin Wu <falcon@tinylab.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Thomas Weißschuh <thomas@t-8ch.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Silence the following warnings reported by the new -Wall -Wextra options
with pure assembly code.
In file included from sysroot/powerpc/include/stdio.h:13,
from nolibc-test.c:13:
sysroot/powerpc/include/arch.h: In function '_start':
sysroot/powerpc/include/arch.h:192:32: warning: unused variable 'r2' [-Wunused-variable]
192 | register volatile long r2 __asm__ ("r2") = (void *)&TOC - (void *)_start;
| ^~
sysroot/powerpc/include/arch.h:187:97: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var]
187 | void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
| ^~~~~~
Since only elfv2 ABI requires to save the TOC/GOT pointer to r2
register, when using elfv1 ABI, the old C code is simply ignored by the
compiler, but the compiler can not ignore the inline assembly code and
will introduce build failure or running segfaults. So, let's further
only add the new assembly code for elfv2 ABI with the checking of
_CALL_ELF == 2.
Link: https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.pdf
Link: https://www.llvm.org/devmtg/2014-04/PDFs/Talks/Euro-LLVM-2014-Weigand.pdf
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This allows to generate smaller text/data/dec size.
As the _start_c() function added by crt.h, __stack_chk_init() is called
from _start_c() instead of the assembly _start. So, it is able to mark
it with static now.
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This follows the 64-bit PowerPC ABI [1], refers to the slides: "A new
ABI for little-endian PowerPC64 Design & Implementation" [2] and the
musl code in arch/powerpc64/crt_arch.h.
First, stdu and clrrdi are used instead of stwu and clrrwi for
powerpc64.
Second, the stack frame size is increased to 32 bytes for powerpc64, 32
bytes is the minimal stack frame size supported described in [2].
Besides, the TOC pointer (GOT pointer) must be saved to r2.
This works on both little endian and big endian 64-bit PowerPC.
[1]: https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.pdf
[2]: https://www.llvm.org/devmtg/2014-04/PDFs/Talks/Euro-LLVM-2014-Weigand.pdf
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Both syscall declarations and _start code definition are added for
powerpc to nolibc.
Like mips, powerpc uses a register (exactly, the summary overflow bit)
to record the error occurred, and uses another register to return the
value [1]. So, the return value of every syscall declaration must be
normalized to match the __sysret() helper, return -value when there is
an error, otheriwse, return value directly.
Glibc and musl use different methods to check the summary overflow bit,
glibc (sysdeps/unix/sysv/linux/powerpc/sysdep.h) saves the cr register
to r0 at first, and then check the summary overflow bit in cr0:
mfcr r0
r0 & (1 << 28) ? -r3 : r3
-->
10003c14: 7c 00 00 26 mfcr r0
10003c18: 74 09 10 00 andis. r9,r0,4096
10003c1c: 41 82 00 08 beq 0x10003c24
10003c20: 7c 63 00 d0 neg r3,r3
Musl (arch/powerpc/syscall_arch.h) directly checks the summary overflow
bit with the 'bns' instruction, it is smaller:
/* no summary overflow bit means no error, return value directly */
bns+ 1f
/* otherwise, return negated value */
neg r3, r3
1:
-->
10000418: 40 a3 00 08 bns 0x10000420
1000041c: 7c 63 00 d0 neg r3,r3
Like musl, Linux (arch/powerpc/include/asm/vdso/gettimeofday.h) uses the
same method for do_syscall_2() too.
Here applies the second method to get smaller size.
[1]: https://man7.org/linux/man-pages/man2/syscall.2.html
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Otherwise both gcc and clang may generate warnings about type
mismatches:
sysroot/mips/include/string.h:12:14: warning: mismatch in argument 1 type of built-in function 'malloc'; expected 'unsigned int' [-Wbuiltin-declaration-mismatch]
12 | static void *malloc(size_t len);
| ^~~~~~
The compiler provides __SIZE_TYPE__ as the type that corresponds to size_t
(typically "long unsigned int" or "unsigned int"). It was verified to be
available at least since gcc-3.4 and clang-3.8, so from now on we'll use
this definition for size_t.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20230805161929.GA15284@1wt.eu/
Signed-off-by: Willy Tarreau <w@1wt.eu>
getauxval() returns an unsigned long but the overall type of the ternary
operator needs to be signed.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This warning will be enabled later so avoid triggering it.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
It's documented as returning int which is also implemented by glibc and
musl, so adopt that return type.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
According to manual page [1], posix spec [2] and source code like
arch/mips/kernel/syscall.c, for historic reasons, the sys_pipe() syscall
on some architectures has an unusual calling convention. It returns
results in two registers which means there is no need for it to do
verify the validity of a userspace pointer argument. Historically that
used to be expensive in Linux. These days the performance advantage is
negligible.
Nolibc doesn't support the unusual calling convention above, luckily
Linux provides a generic sys_pipe2() with an additional flags argument
from 2.6.27. If flags is 0, then pipe2() is the same as pipe(). So here
we use sys_pipe2() to implement the pipe().
pipe2() is also provided to allow users to use flags argument on demand.
[1]: https://man7.org/linux/man-pages/man2/pipe.2.html
[2]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/pipe.html
Suggested-by: Zhangjin Wu <falcon@tinylab.org>
Link: https://lore.kernel.org/all/20230729100401.GA4577@1wt.eu/
Signed-off-by: Yuan Tan <tanyuan@tinylab.org>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Add a minimal implementation of setvbuf(), which error checks the mode
argument (as required by spec) and returns. Since nolibc never buffers
output, nothing needs to be done.
The kselftest framework recently added a call to setvbuf(). As a result,
any tests that use the kselftest framework and nolibc cause a compiler
error due to missing function. This provides an urgent fix for the
problem which is preventing arm64 testing on linux-next.
Example:
clang --target=aarch64-linux-gnu -fintegrated-as
-Werror=unknown-warning-option -Werror=ignored-optimization-argument
-Werror=option-ignored -Werror=unused-command-line-argument
--target=aarch64-linux-gnu -fintegrated-as
-fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \
-include ../../../../include/nolibc/nolibc.h -I../..\
-static -ffreestanding -Wall za-fork.c
build/kselftest/arm64/fp/za-fork-asm.o
-o build/kselftest/arm64/fp/za-fork
In file included from <built-in>:1:
In file included from ./../../../../include/nolibc/nolibc.h:97:
In file included from ./../../../../include/nolibc/arch.h:25:
./../../../../include/nolibc/arch-aarch64.h:178:35: warning: unknown
attribute 'optimize' ignored [-Wunknown-attributes]
void __attribute__((weak,noreturn,optimize("omit-frame-pointer")))
__no_stack_protector _start(void)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from za-fork.c:12:
../../kselftest.h:123:2: error: call to undeclared function 'setvbuf';
ISO C99 and later do not support implicit function declarations
[-Wimplicit-function-declaration]
setvbuf(stdout, NULL, _IOLBF, 0);
^
../../kselftest.h:123:24: error: use of undeclared identifier '_IOLBF'
setvbuf(stdout, NULL, _IOLBF, 0);
^
1 warning and 2 errors generated.
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Link: https://lore.kernel.org/linux-kselftest/CA+G9fYus3Z8r2cg3zLv8uH8MRrzLFVWdnor02SNr=rCz+_WGVg@mail.gmail.com/
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Also clean up the instructions in delayed slots.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
move most of the _start operations to _start_c(), include the
stackprotector initialization.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
As suggested by Thomas, It is able to move the stackprotector
initialization from the assembly _start to the beginning of the new
_start_c(). Let's call __stack_chk_init() in _start_c() as a
preparation.
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/a00284a6-54b1-498c-92aa-44997fa78403@t-8ch.de/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Let's define an empty __stack_chk_init for the !_NOLIBC_STACKPROTECTOR
branch.
This allows to remove #ifdef around every call of __stack_chk_init().
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
As the environ and _auxv support added for nolibc, the assembly _start
function becomes more and more complex and therefore makes the porting
of nolibc to new architectures harder and harder.
To simplify portability, this C version of _start_c() is added to do
most of the assembly start operations in C, which reduces the complexity
a lot and will eventually simplify the porting of nolibc to the new
architectures.
The new _start_c() only requires a stack pointer argument, it will find
argc, argv, envp/environ and _auxv for us, and then call main(),
finally, it exit() with main's return status. With this new _start_c(),
the future new architectures only require to add very few assembly
instructions.
As suggested by Thomas, users may use a different signature of main
(e.g. void main(void)), a _nolibc_main alias is added for main to
silence the warning about potential conflicting types.
As suggested by Willy, the code is carefully polished for both smaller
size and better readability with local variables and the right types.
Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230715095729.GC24086@1wt.eu/
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/90fdd255-32f4-4caf-90ff-06456b53dac3@t-8ch.de/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
The statx manpage [1] shows that it has been supported from Linux 4.11
and glibc 2.28, the Linux support can be checked for all of the
architectures with this command:
$ git grep -r statx v4.11 arch/ include/uapi/asm-generic/unistd.h \
| grep -E "aarch64|arm|mips|s390|x86|:include/uapi"
Besides riscv and loongarch, all of the nolibc supported architectures
have added sys_statx from Linux v4.11. riscv is mainlined to v4.15,
loongarch is mainlined to v5.19, both of them use the generic unistd.h,
so, they have added sys_statx from their first mainline versions.
The current oldest stable branch is v4.14, only reserving sys_statx
still preserves compatibility with all of the supported stable branches,
So, let's remove the old arch related and dependent sys_stat support
completely.
This is friendly to the future new architecture porting.
[1]: https://man7.org/linux/man-pages/man2/statx.2.html
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
As gcc doc [1] shows:
Most optimizations are completely disabled at -O0 or if an -O level is
not set on the command line, even if individual optimization flags are
specified.
Test result [2] shows, gcc>=11.1.0 deviates from the above description,
but before gcc 11.1.0, "-O0" still forcely uses frame pointer in the
_start function even if the individual optimize("omit-frame-pointer")
flag is specified.
The frame pointer related operations will change the stack pointer (e.g.
In x86_64, an extra "push %rbp" will be inserted at the beginning of
_start) and make it differs from the one we expected, as a result, break
the whole startup function.
To fix up this issue, as suggested by Thomas, the individual "Os" and
"omit-frame-pointer" optimize flags are used together on _start function
to disable frame pointer completely even if the -O0 is set on the
command line.
[1]: https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
[2]: https://lore.kernel.org/lkml/20230714094723.140603-1-falcon@tinylab.org/
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/34b21ba5-7b59-4b3b-9ed6-ef9a3a5e06f7@t-8ch.de/
Fixes: 7f85485896 ("tools/nolibc: make compiler and assembler agree on the section around _start")
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Fix up such errors reported by scripts/checkpatch.pl:
ERROR: space required after that ',' (ctx:VxV)
#148: FILE: tools/include/nolibc/arch-aarch64.h:148:
+void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void)
^
ERROR: space required after that ',' (ctx:VxV)
#148: FILE: tools/include/nolibc/arch-aarch64.h:148:
+void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void)
^
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
In commit 52e423f5b9 ("tools/nolibc: export environ as a weak symbol on i386")
and friends the asm startup logic was extended to directly populate the
"environ" array.
This makes it impossible for "environ" to be dropped by the linker.
Therefore also drop the other logic to handle non-present "environ".
Also add a testcase to validate the initialization of environ.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
a reverse operation of mkdir() is meaningful, add rmdir() here.
required by nolibc-test to remove /proc while CONFIG_PROC_FS is not
enabled.
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Both glibc and musl provide RB_ flags via <sys/reboot.h> for reboot(),
they don't need to include <linux/reboot.h>, let nolibc provide RB_
flags too.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Fix up the error reported by scripts/checkpatch.pl:
ERROR: do not use assignment in if condition
#95: FILE: tools/include/nolibc/sys.h:95:
+ if ((ret = sys_brk(0)) && (sys_brk(ret + inc) == ret + inc))
Apply the new generic __sysret() to merge the SET_ERRNO() and return
lines.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Do several cleanups together:
- Since all supported architectures have my_syscall6() now, remove the
#ifdef check.
- Move the mmap() related macros to tools/include/nolibc/types.h and
reuse most of them from <linux/mman.h>
- Apply the new generic __sysret() to convert the calling of sys_map()
to oneline code
Note, since MAP_FAILED is -1 on Linux, so we can use the generic
__sysret() which returns -1 upon error and still satisfy user land that
checks for MAP_FAILED.
Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230702192347.GJ16233@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
No official reference states the errno range, here aligns with musl and
glibc and uses [-MAX_ERRNO, -1] instead of all negative ones.
- musl: src/internal/syscall_ret.c
- glibc: sysdeps/unix/sysv/linux/sysdep.h
The MAX_ERRNO used by musl and glibc is 4095, just like the one nolibc
defined in tools/include/nolibc/errno.h.
Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/ZKKdD%2Fp4UkEavru6@1wt.eu/
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Link: https://lore.kernel.org/linux-riscv/94dd5170929f454fbc0a10a2eb3b108d@AcuMS.aculab.com/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
It is able to pass the 6th argument like the 5th argument via the stack
for mips, let's add a new my_syscall6() now, see [1] for details:
The mips/o32 system call convention passes arguments 5 through 8 on
the user stack.
Both mmap() and pselect6() require my_syscall6().
[1]: https://man7.org/linux/man-pages/man2/syscall.2.html
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
my_syscall<N> share the same long clobber list, define a macro for them.
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
