Merge tag 'v6.6.56' into for/openbmc/dev-6.6

This is the 6.6.56 stable release

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

[ Upstream commit 1daea158d0aae0770371f3079305a29fdb66829e ]

As mentioned in the comment, the workaround for
__attribute__((no_stack_p

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

[ 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 <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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'linux-kselftest-nolibc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull nolibc updates from Shuah Khan:
"Nolibc:
- improved portability by removing

Merge tag 'linux-kselftest-nolibc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull nolibc updates from Shuah Khan:
"Nolibc:
- improved portability by removing build errors with -ENOSYS
- added syscall6() on MIPS to support pselect6() and mmap()
- added setvbuf(), rmdir(), pipe(), pipe2()
- add support for ppc/ppc64
- environ is no longer optional
- fixed frame pointer issues at -O0
- dropped sys_stat() in favor of sys_statx()
- centralized _start_c() to remove lots of asm code
- switched size_t to __SIZE_TYPE__

Selftests:
- improved status reporting (success/warning/failure counts, path to
log file)
- various code cleanups (indent, unused variables, ...)
- more consistent test numbering
- enabled compiler warnings
- dropped unreliable chmod_net test
- improved reliability (create /dev/zero & /tmp, rely less on /proc)
- new tests (brk/sbrk/mmap/munmap)
- improved compatibility with musl
- new run-nolibc-test target to build and run natively
- new run-libc-test target to build and run against native libc
- made the cmdline parser more reliable against boolean arguments
- dropped dependency on memfd for vfprintf() test
- nolibc-test is no longer stripped
- added support for extending ARCH via XARCH

Other:
- add Thomas as co-maintainer"

* tag 'linux-kselftest-nolibc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (103 commits)
tools/nolibc: avoid undesired casts in the __sysret() macro
tools/nolibc: keep brk(), sbrk(), mmap() away from __sysret()
tools/nolibc: silence ppc64 compile warnings
selftests/nolibc: libc-test: use HOSTCC instead of CC
tools/nolibc: stackprotector.h: make __stack_chk_init static
selftests/nolibc: allow report with existing test log
selftests/nolibc: add test support for ppc64
selftests/nolibc: add test support for ppc64le
selftests/nolibc: add test support for ppc
selftests/nolibc: add XARCH and ARCH mapping support
tools/nolibc: add support for powerpc64
tools/nolibc: add support for powerpc
MAINTAINERS: nolibc: add myself as co-maintainer
selftests/nolibc: enable compiler warnings
selftests/nolibc: don't strip nolibc-test
selftests/nolibc: prevent out of bounds access in expect_vfprintf
selftests/nolibc: use correct return type for read() and write()
selftests/nolibc: avoid sign-compare warnings
selftests/nolibc: avoid unused parameter warnings
selftests/nolibc: make functions static if possible
...

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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/stdi

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>

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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/p

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>

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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

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>

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