linux-stable.git/tools/include/nolibc, branch v6.6.76

tools/nolibc: s390: include std.h

2024-12-09T09:32:45+00:00

commit 711b5875814b2a0e9a5aaf7a85ba7c80f5a389b1 upstream.

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: 404fa87c0eaf ("tools/nolibc: s390: provide custom implementation for sys_fork")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20240927-nolibc-s390-std-h-v1-1-30442339a6b9@linutronix.de
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Greg Kroah-Hartman

tools/nolibc: powerpc: limit stack-protector workaround to GCC

2024-10-10T09:57:30+00:00

[ Upstream commit 1daea158d0aae0770371f3079305a29fdb66829e ]

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 
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-3-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc/stdlib: fix memory error in realloc()

2024-06-12T09:11:19+00:00

commit 791f4641142e2aced85de082e5783b4fb0b977c2 upstream.

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 
Cc: stable@vger.kernel.org
Reviewed-by: Ammar Faizi 
Fixes: 0e0ff638400be8f497a35b51a4751fd823f6bd6a ("tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`")
Signed-off-by: Willy Tarreau 
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Greg Kroah-Hartman

tools/nolibc: mark start_c as weak

2023-10-12T19:13:51+00:00

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: 17336755150b ("tools/nolibc: add new crt.h with _start_c")
Signed-off-by: Thomas Weißschuh 
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

tools/nolibc: i386: Fix a stack misalign bug on _start

2023-10-12T19:10:37+00:00

The ABI mandates that the %esp register must be a multiple of 16 when
executing a 'call' instruction.

Commit 2ab446336b17 ("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 
Fixes: 2ab446336b17 ("tools/nolibc: i386: shrink _start with _start_c")
Reported-by: Nicholas Rosenberg 
Acked-by: Thomas Weißschuh 
Signed-off-by: Ammar Faizi 
Reviewed-by: Alviro Iskandar Setiawan 
Signed-off-by: Willy Tarreau 
Signed-off-by: Thomas Weißschuh

tools/nolibc: avoid undesired casts in the __sysret() macro

2023-08-23T03:17:07+00:00

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: 428905da6ec4 ("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 
Cc: David Laight 
Cc: Thomas Weißschuh 
Signed-off-by: Willy Tarreau

tools/nolibc: keep brk(), sbrk(), mmap() away from __sysret()

2023-08-23T03:19:22+00:00

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: 4201cfce15fe ("tools/nolibc: clean up sbrk() routine")
Fixes: 924e9539aeaa ("tools/nolibc: clean up mmap() routine")
Fixes: d27447bc2e0a ("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 
Cc: David Laight 
Cc: Thomas Weißschuh 
Signed-off-by: Willy Tarreau

tools/nolibc: silence ppc64 compile warnings

2023-08-23T03:17:07+00:00

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 
Signed-off-by: Willy Tarreau

tools/nolibc: stackprotector.h: make __stack_chk_init static

2023-08-23T03:17:07+00:00

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 
Signed-off-by: Zhangjin Wu 
Signed-off-by: Willy Tarreau

tools/nolibc: add support for powerpc64

2023-08-23T03:17:07+00:00

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 
Signed-off-by: Zhangjin Wu 
Signed-off-by: Willy Tarreau