Commit Graph

338 Commits

Author SHA1 Message Date
Thomas Weißschuh 0c89abf5ab tools/nolibc: implement waitpid() in terms of waitid()
The old wait4() syscall used by waitpid() before is not available everywhere.
Switch to the waitid() syscall which is the new replacement.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:58:18 +02:00
Thomas Weißschuh 67fe525e34 tools/nolibc: add setpgrp()
setpgrp() is defined to be identical to setpgid(0, 0).

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:56:27 +02:00
Thomas Weißschuh 7b11531ed1 tools/nolibc: add _exit()
_exit() is the faster variant of exit(), skipping all cleanup actions.
As nolibc does not perform any cleanup anyways, the implementation is
trivial.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:56:27 +02:00
Thomas Weißschuh 9b070d97d9 tools/nolibc: add tolower() and toupper()
The kselftest harness uses these functions.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:56:26 +02:00
Thomas Weißschuh 4de88a88bc tools/nolibc: use ppoll_time64 if available
riscv32 does not have any of the older poll systemcalls.
Use ppoll_time64 instead.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:56:25 +02:00
Thomas Weißschuh 248ddc80b1 tools/nolibc: use pselect6_time64 if available
riscv32 does not have any of the older select systemcalls.
Use pselect6_time64 instead.
poll() is also used to implement sleep().

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:56:25 +02:00
Thomas Weißschuh e5407c0820 tools/nolibc: use intmax definitions from compiler
The printf format checking in the compiler uses the intmax types from
the compiler, not libc. This can lead to compiler errors.

Instead use the types already provided by the compiler.

Example issue with clang 19 for arm64:

nolibc-test.c:30:2: error: format specifies type 'uintmax_t' (aka 'unsigned long') but the argument has type 'uintmax_t' (aka 'unsigned long long') [-Werror,-Wformat]

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:56:24 +02:00
Thomas Weißschuh 4c99fbc6a0 tools/nolibc: handle intmax_t/uintmax_t in printf
In nolibc intmax_t and uintmax_t are always the same as
(unsigned) long long/uint64_t as 128bit numbers are not supported.
Even libcs that do support 128bit numbers often fix intmax_t to 64bit
as it is used in ABIs and any change would break those.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22 10:56:23 +02:00
Thomas Weißschuh 6d1724ec86 tools/nolibc: move wait() and friends to sys/wait.h
This is the location regular userspace expects these definitions.

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-v1-10-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:30 +02:00
Thomas Weißschuh ffb94910c3 tools/nolibc: add sys/types.h shim
This is the location regular userspace expects the header.

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-v1-9-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:29 +02:00
Thomas Weißschuh face777a44 tools/nolibc: move gettimeofday() to sys/time.h
This is the location regular userspace expects this definition.

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-v1-8-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:28 +02:00
Thomas Weißschuh 0fd55773f4 tools/nolibc: move syscall() to sys/syscall.h
This is the location regular userspace expects the definition.

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-v1-7-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:26 +02:00
Thomas Weißschuh c6e6c2c4d7 tools/nolibc: move stat() and friends to sys/stat.h
This is the location regular userspace expects these definitions.

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-v1-6-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:25 +02:00
Thomas Weißschuh cce273161e tools/nolibc: move mmap() and friends to sys/mman.h
This is the location regular userspace expects these definitions.

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-v1-5-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:23 +02:00
Thomas Weißschuh 9e67941dde tools/nolibc: move getauxval() to sys/auxv.h
This is the location regular userspace expects the definition.

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-v1-4-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:22 +02:00
Thomas Weißschuh ecc091d93a tools/nolibc: move open() and friends to fcntl.h
This is the location regular userspace expects these definitions.

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-v1-3-a069a3f1d145@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-04-19 14:22:21 +02:00
Thomas Weißschuh 2b45ceb915 tools/nolibc: add elf.h
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>
2025-04-19 14:22:20 +02:00
Thomas Weißschuh 060525302b tools/nolibc: prepare for headers in subdirectories
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>
2025-04-19 14:22:19 +02:00
Thomas Weißschuh 4d231a7df1 tools/nolibc: fix integer overflow in i{64,}toa_r() and
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
2025-04-19 14:18:05 +02:00
Thomas Weißschuh 0e75768ba2 tools/nolibc: properly align dirent buffer
As byte buffer is overlaid with a 'struct dirent64'.
it has to satisfy the structs alignment requirements.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Fixes: 665fa8dea9 ("tools/nolibc: add support for directory access")
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-4-060b8a016917@weissschuh.net
2025-04-19 14:18:01 +02:00
Thomas Weißschuh 9fca5554af tools/nolibc: disable function sanitizer for _start_c()
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
2025-04-19 14:17:56 +02:00
Thomas Weißschuh f4152715dc tools/nolibc: add __nolibc_aligned() and __nolibc_aligned_as()
Provide a convenience macro around __attribute__((aligned)).

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-2-060b8a016917@weissschuh.net
2025-04-19 14:17:52 +02:00
Thomas Weißschuh 8399f14666 tools/nolibc: add __nolibc_has_feature()
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
2025-04-19 14:17:46 +02:00
Thomas Weißschuh 60ccc16f53 tools/nolibc: drop manual stack pointer alignment
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
2025-04-14 07:51:25 +02:00
Thomas Weißschuh 8e1930296f tools/nolibc: Add support for SPARC
Add support for 32bit and 64bit SPARC to nolibc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Tested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> # UltraSparc T4 (Niagara4)
Link: https://lore.kernel.org/lkml/20250322-nolibc-sparc-v2-1-89af018c6296@weissschuh.net/
2025-04-11 20:00:20 +02:00
Jemmy Wong 9c138ac939 tools/nolibc/types.h: fix mismatched parenthesis in minor()
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>
2025-04-11 20:00:18 +02:00
Linus Torvalds 317a76a996 Updates for the VDSO infrastructure:
- 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
  ...
2025-03-25 11:30:42 -07:00
Thomas Weißschuh bceb73904c tools/nolibc: don't use asm/ UAPI headers
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
2025-03-08 13:18:27 +01:00
Louis Taylor 00e03fea96 tools/nolibc: drop outdated example from overview comment
This behaviour was changed in commit a7604ba149 ("tools/nolibc/sys:
make open() take a vararg on the 3rd argument").

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-4-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-03-06 22:30:21 +01:00
Louis Taylor 90e1f9f744 tools/nolibc: process open() vararg as mode_t
openat() uses mode_t for this, so also update open() to be consistent.

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-3-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-03-06 22:30:21 +01:00
Louis Taylor fbd4f52f5b tools/nolibc: always use openat(2) instead of open(2)
All architectures support openat, so we don't need to make its use
conditional.

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-2-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-03-06 22:30:20 +01:00
Louis Taylor b2edaad7f5 tools/nolibc: add support for openat(2)
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>
2025-03-06 22:30:20 +01:00
Thomas Weißschuh 5caaa0aa7c tools/nolibc: add limits.h shim header
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
2025-03-03 20:00:12 +01:00
Thomas Weißschuh 22edf1f8d4 tools/nolibc: add support for [v]sscanf()
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>
2025-02-26 22:13:48 +01:00
Thomas Weißschuh 9c812b01f1 tools/nolibc: add support for 32-bit s390
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>
2025-02-20 22:06:32 +01:00
Thomas Weißschuh 665fa8dea9 tools/nolibc: add support for directory access
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>
2025-02-09 16:46:50 +01:00
Thomas Weißschuh dde5625d4d tools/nolibc: add support for sys_llseek()
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>
2025-02-09 16:46:50 +01:00
Thomas Weißschuh cfb1bfe953 tools/nolibc: make signature of ioctl() more flexible
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>
2025-02-03 20:57:39 +01:00
Thomas Weißschuh 0de64754a5 tools/nolibc: add prototypes for non-static functions
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>
2025-02-03 20:57:37 +01:00
Thomas Weißschuh 7f89bc5110 tools/nolibc: add support for waitid()
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>
2025-01-13 22:21:34 +01:00
Thomas Weißschuh 079ec6a3cf tools/nolibc: compiler: add macro __nolibc_fallthrough
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>
2024-10-07 21:56:18 +02:00
Thomas Weißschuh 711b587581 tools/nolibc: s390: include std.h
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>
2024-10-07 21:56:08 +02:00
Thomas Weißschuh 25fb329a23 tools/nolibc: x86_64: use local label in memcpy/memmove
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>
2024-08-16 17:23:13 +02:00
Thomas Weißschuh ff7b9abbfc tools/nolibc: stackprotector: mark implicitly used symbols as used
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>
2024-08-16 17:23:13 +02:00
Thomas Weißschuh 0021d6670d tools/nolibc: crt: mark _start_c() as used
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>
2024-08-16 17:23:13 +02:00
Thomas Weißschuh e098eebb63 tools/nolibc: compiler: use attribute((naked)) if available
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>
2024-08-12 22:22:03 +02:00
Thomas Weißschuh ef32e9b6a3 tools/nolibc: move entrypoint specifics to compiler.h
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>
2024-08-12 22:21:00 +02:00
Thomas Weißschuh 02a62b551c tools/nolibc: compiler: introduce __nolibc_has_attribute()
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>
2024-08-10 17:08:19 +02:00
Thomas Weißschuh 1daea158d0 tools/nolibc: powerpc: limit stack-protector workaround to GCC
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>
2024-08-10 17:08:15 +02:00
Thomas Weißschuh 0daf8c86a4 tools/nolibc: mips: load current function to $t9
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>
2024-08-10 17:08:10 +02:00
Thomas Weißschuh 55850eb4e5 tools/nolibc: arm: use clang-compatible asm syntax
The clang assembler rejects the current syntax.
Switch to a syntax accepted by both GCC and clang.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-1-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2024-08-10 17:08:04 +02:00
Thomas Weißschuh 754283ce83 tools/nolibc: pass argc, argv and envp to constructors
Since 2005 glibc has passed argc, argv, and envp to all constructors.
As it is cheap and easy to do so, mirror that behaviour in nolibc.
This makes it easier to migrate applications to nolibc.

Link: https://lore.kernel.org/r/20240728-nolibc-constructor-args-v1-1-36d0bf5cd4c0@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2024-08-09 07:40:18 +02:00
Thomas Weißschuh ae1f550efc tools/nolibc: add stdbool.h header
stdbool.h is very simple.
Provide an implementation for the user convenience.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240725-nolibc-stdbool-v1-1-a6ee2c80bcde@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2024-07-29 07:52:57 +02:00
Thomas Weißschuh 6ea2987c9a tools/nolibc: include arch.h from string.h
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>
2024-07-29 07:52:56 +02:00
Thomas Weißschuh d20d0b10f8 tools/nolibc: implement strerror()
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>
2024-06-29 09:44:57 +02:00
Thomas Weißschuh 0cf24d36bb tools/nolibc: implement strtol() and friends
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
2024-06-29 09:44:55 +02:00
Thomas Weißschuh 8c3bd8bc40 tools/nolibc: add limits for {u,}intmax_t, ulong and {u,}llong
They are useful for users and necessary for strtol() and friends.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240425-nolibc-strtol-v1-1-bfeef7846902@weissschuh.net
2024-06-29 09:44:54 +02:00
Thomas Weißschuh 0adab2b6b7 tools/nolibc: add support for uname(2)
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>
2024-04-14 20:28:54 +02:00
Thomas Weißschuh e93b912ecf tools/nolibc/string: remove open-coded strnlen()
The same header already defines an implementation of strnlen(),
so use it.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2024-04-10 23:27:06 +02:00
Rodrigo Campos fbffce819e tools/nolibc: Fix strlcpy() return code and size usage
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>
2024-04-10 23:19:02 +02:00
Rodrigo Campos 34d232c39a tools/nolibc: Fix strlcat() return code and size usage
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>
2024-04-10 23:19:01 +02:00
Rodrigo Campos 689230b674 tools/nolibc/string: export strlen()
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>
2024-04-10 23:19:01 +02:00
Brennan Xavier McManus 791f464114 tools/nolibc/stdlib: fix memory error in realloc()
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>
2024-04-10 23:19:00 +02:00
Thomas Weißschuh a0bb5f88fc tools/nolibc: add support for getrlimit/setrlimit
The implementation uses the prlimit64 systemcall as that is available on
all architectures.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20231123-nolibc-rlimit-v1-2-a428b131de2a@weissschuh.net/
Acked-by: Willy Tarreau <w@1wt.eu>
2023-12-11 22:38:35 +01:00
Thomas Weißschuh 7b20478b77 tools/nolibc: drop custom definition of struct rusage
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>
2023-12-11 22:38:34 +01:00
Thomas Weißschuh dece8476d6 tools/nolibc: annotate va_list printf formats
__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>
2023-12-11 22:38:32 +01:00
Thomas Weißschuh 544102458a 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>
2023-12-11 22:38:30 +01:00
Thomas Weißschuh aa68a5a83a tools/nolibc: move MIPS ABI validation into arch-mips.h
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>
2023-12-11 22:38:21 +01:00
Thomas Weißschuh 48946c5aa7 tools/nolibc: error out on unsupported architecture
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>
2023-12-11 22:38:20 +01:00
Mark Brown bb6ec2e9fd tools/nolibc: Use linux/wait.h rather than duplicating it
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>
2023-12-11 22:38:08 +01:00
Thomas Weißschuh 63aa531716 tools/nolibc: add support for constructors and destructors
With the startup code moved to C, implementing support for
constructors and deconstructors is fairly easy to implement.

Examples for code size impact:

   text	   data	    bss	    dec	    hex	filename
  21837	    104	     88	  22029	   560d	nolibc-test.before
  22135	    120	     88	  22343	   5747	nolibc-test.after
  21970	    104	     88	  22162	   5692 nolibc-test.after-only-crt.h-changes

The sections are defined by [0].

[0] https://refspecs.linuxfoundation.org/elf/gabi4+/ch5.dynamic.html

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20231007-nolibc-constructors-v2-1-ef84693efbc1@weissschuh.net/
2023-10-12 21:14:16 +02:00
Thomas Weißschuh eaa8c9a8b4 tools/nolibc: automatically detect necessity to use pselect6
We can automatically detect if pselect6 is needed or not from the kernel
headers. This removes the need to manually specify it.

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-v2-4-03863d509b9a@weissschuh.net
2023-10-12 21:14:13 +02:00
Thomas Weißschuh e7b28f2516 tools/nolibc: don't define new syscall number
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
2023-10-12 21:14:12 +02:00
Thomas Weißschuh 535b70c143 tools/nolibc: avoid unused parameter warnings for ENOSYS fallbacks
The ENOSYS fallback code does not use its functions parameters.
This can lead to compiler warnings about unused parameters.

Explicitly avoid these warnings.

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-v2-2-03863d509b9a@weissschuh.net
2023-10-12 21:14:10 +02:00
Ammar Faizi bc61614de0 tools/nolibc: string: Remove the `_nolibc_memcpy_up()` function
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>
2023-10-12 21:14:03 +02:00
Ammar Faizi 5dfc79b20e tools/nolibc: string: Remove the `_nolibc_memcpy_down()` function
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>
2023-10-12 21:14:02 +02:00
Ammar Faizi 12108aa8c1 tools/nolibc: x86-64: Use `rep stosb` for `memset()`
Simplify memset() on the x86-64 arch.

The x86-64 arch has a 'rep stosb' instruction, which can perform
memset() using only a single instruction, given:

    %al  = value (just like the second argument of memset())
    %rdi = destination
    %rcx = length

Before this patch:
```
  00000000000010c9 <memset>:
    10c9: 48 89 f8              mov    %rdi,%rax
    10cc: 48 85 d2              test   %rdx,%rdx
    10cf: 74 0e                 je     10df <memset+0x16>
    10d1: 31 c9                 xor    %ecx,%ecx
    10d3: 40 88 34 08           mov    %sil,(%rax,%rcx,1)
    10d7: 48 ff c1              inc    %rcx
    10da: 48 39 ca              cmp    %rcx,%rdx
    10dd: 75 f4                 jne    10d3 <memset+0xa>
    10df: c3                    ret
```

After this patch:
```
  0000000000001511 <memset>:
    1511: 96                    xchg   %eax,%esi
    1512: 48 89 d1              mov    %rdx,%rcx
    1515: 57                    push   %rdi
    1516: f3 aa                 rep stos %al,%es:(%rdi)
    1518: 58                    pop    %rax
    1519: c3                    ret
```

v2:
  - Use pushq %rdi / popq %rax (Alviro).
  - Use xchg %eax, %esi (Willy).

Link: https://lore.kernel.org/lkml/ZO9e6h2jjVIMpBJP@1wt.eu
Suggested-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Suggested-by: Willy Tarreau <w@1wt.eu>
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>
2023-10-12 21:14:00 +02:00
Ammar Faizi 553845eebd tools/nolibc: x86-64: Use `rep movsb` for `memcpy()` and `memmove()`
Simplify memcpy() and memmove() on the x86-64 arch.

The x86-64 arch has a 'rep movsb' instruction, which can perform
memcpy() using only a single instruction, given:

    %rdi = destination
    %rsi = source
    %rcx = length

Additionally, it can also handle the overlapping case by setting DF=1
(backward copy), which can be used as the memmove() implementation.

Before this patch:
```
  00000000000010ab <memmove>:
    10ab: 48 89 f8              mov    %rdi,%rax
    10ae: 31 c9                 xor    %ecx,%ecx
    10b0: 48 39 f7              cmp    %rsi,%rdi
    10b3: 48 83 d1 ff           adc    $0xffffffffffffffff,%rcx
    10b7: 48 85 d2              test   %rdx,%rdx
    10ba: 74 25                 je     10e1 <memmove+0x36>
    10bc: 48 83 c9 01           or     $0x1,%rcx
    10c0: 48 39 f0              cmp    %rsi,%rax
    10c3: 48 c7 c7 ff ff ff ff  mov    $0xffffffffffffffff,%rdi
    10ca: 48 0f 43 fa           cmovae %rdx,%rdi
    10ce: 48 01 cf              add    %rcx,%rdi
    10d1: 44 8a 04 3e           mov    (%rsi,%rdi,1),%r8b
    10d5: 44 88 04 38           mov    %r8b,(%rax,%rdi,1)
    10d9: 48 01 cf              add    %rcx,%rdi
    10dc: 48 ff ca              dec    %rdx
    10df: 75 f0                 jne    10d1 <memmove+0x26>
    10e1: c3                    ret

  00000000000010e2 <memcpy>:
    10e2: 48 89 f8              mov    %rdi,%rax
    10e5: 48 85 d2              test   %rdx,%rdx
    10e8: 74 12                 je     10fc <memcpy+0x1a>
    10ea: 31 c9                 xor    %ecx,%ecx
    10ec: 40 8a 3c 0e           mov    (%rsi,%rcx,1),%dil
    10f0: 40 88 3c 08           mov    %dil,(%rax,%rcx,1)
    10f4: 48 ff c1              inc    %rcx
    10f7: 48 39 ca              cmp    %rcx,%rdx
    10fa: 75 f0                 jne    10ec <memcpy+0xa>
    10fc: c3                    ret
```

After this patch:
```
  // memmove is an alias for memcpy
  000000000040133b <memcpy>:
    40133b: 48 89 d1              mov    %rdx,%rcx
    40133e: 48 89 f8              mov    %rdi,%rax
    401341: 48 89 fa              mov    %rdi,%rdx
    401344: 48 29 f2              sub    %rsi,%rdx
    401347: 48 39 ca              cmp    %rcx,%rdx
    40134a: 72 03                 jb     40134f <memcpy+0x14>
    40134c: f3 a4                 rep movsb %ds:(%rsi),%es:(%rdi)
    40134e: c3                    ret
    40134f: 48 8d 7c 0f ff        lea    -0x1(%rdi,%rcx,1),%rdi
    401354: 48 8d 74 0e ff        lea    -0x1(%rsi,%rcx,1),%rsi
    401359: fd                    std
    40135a: f3 a4                 rep movsb %ds:(%rsi),%es:(%rdi)
    40135c: fc                    cld
    40135d: c3                    ret
```

v3:
  - Make memmove as an alias for memcpy (Willy).
  - Make the forward copy the likely case (Alviro).

v2:
  - Fix the broken memmove implementation (David).

Link: https://lore.kernel.org/lkml/20230902062237.GA23141@1wt.eu
Link: https://lore.kernel.org/lkml/5a821292d96a4dbc84c96ccdc6b5b666@AcuMS.aculab.com
Suggested-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2023-10-12 21:13:56 +02:00
Thomas Weißschuh b56a9492d0 tools/nolibc: add stdarg.h header
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>
2023-10-12 21:13:52 +02:00
Thomas Weißschuh 921992229b tools/nolibc: mark start_c as weak
Otherwise the different instances of _start_c from each compilation unit
will lead to linker errors:

/usr/bin/ld: /tmp/ccSNvRqs.o: in function `_start_c':
nolibc-test-foo.c:(.text.nolibc_memset+0x9): multiple definition of `_start_c'; /tmp/ccG25101.o:nolibc-test.c:(.text+0x1ea3): first defined here

Fixes: 1733675515 ("tools/nolibc: add new crt.h with _start_c")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20231012-nolibc-start_c-multiple-v1-1-fbfc73e0283f@weissschuh.net/
Link: https://lore.kernel.org/lkml/20231012-nolibc-linkage-test-v1-1-315e682768b4@weissschuh.net/
Acked-by: Willy Tarreau <w@1wt.eu>
2023-10-12 21:13:51 +02:00
Ammar Faizi d873a364ef tools/nolibc: i386: Fix a stack misalign bug on _start
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>
2023-10-12 21:10:37 +02:00
Willy Tarreau 556fb7131e tools/nolibc: avoid undesired casts in the __sysret() macro
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>
2023-08-23 05:17:07 +02:00
Willy Tarreau fb01ff635e tools/nolibc: keep brk(), sbrk(), mmap() away from __sysret()
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>
2023-08-23 05:19:22 +02:00
Zhangjin Wu 872dbfa032 tools/nolibc: silence ppc64 compile warnings
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>
2023-08-23 05:17:07 +02:00
Zhangjin Wu dcb677c3d3 tools/nolibc: stackprotector.h: make __stack_chk_init static
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>
2023-08-23 05:17:07 +02:00
Zhangjin Wu e45ce88e65 tools/nolibc: add support for powerpc64
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>
2023-08-23 05:17:07 +02:00
Zhangjin Wu 0cb0675ec3 tools/nolibc: add support for powerpc
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>
2023-08-23 05:17:07 +02:00
Thomas Weißschuh 202a0bd12f tools/nolibc: stdint: use __SIZE_TYPE__ for size_t
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>
2023-08-23 05:17:07 +02:00
Thomas Weißschuh 04694658ad tools/nolibc: sys: avoid implicit sign cast
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>
2023-08-23 05:17:07 +02:00
Thomas Weißschuh 809145f842 tools/nolibc: setvbuf: avoid unused parameter warnings
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>
2023-08-23 05:17:07 +02:00
Thomas Weißschuh 6407750225 tools/nolibc: fix return type of getpagesize()
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>
2023-08-23 05:17:07 +02:00
Thomas Weißschuh f2f5eaefa1 tools/nolibc: drop unused variables
Nobody needs it, get rid of it.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 05:17:07 +02:00
Yuan Tan 3ec38af6ee tools/nolibc: add pipe() and pipe2() support
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>
2023-08-23 05:17:07 +02:00
Ryan Roberts 4893c22eb2 tools/nolibc/stdio: add setvbuf() to set buffering mode
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>
2023-08-23 04:40:22 +02:00
Zhangjin Wu c48d8af2fa tools/nolibc: s390: shrink _start with _start_c
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>
2023-08-23 04:40:22 +02:00
Zhangjin Wu eea70cdac6 tools/nolibc: riscv: shrink _start with _start_c
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>
2023-08-23 04:40:22 +02:00
Zhangjin Wu 61bd4621c0 tools/nolibc: loongarch: shrink _start with _start_c
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>
2023-08-23 04:40:22 +02:00
Zhangjin Wu 431b806b9b tools/nolibc: mips: shrink _start with _start_c
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>
2023-08-23 04:40:22 +02:00
Zhangjin Wu 539287d751 tools/nolibc: x86_64: shrink _start with _start_c
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>
2023-08-23 04:40:22 +02:00
Zhangjin Wu 2ab446336b tools/nolibc: i386: shrink _start with _start_c
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>
2023-08-23 04:40:22 +02:00