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
...
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>
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>
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>
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>
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>
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>
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>
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 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>
__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>
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>
