[ Upstream commit acc4f131d5d57c2aa89db914aeb6f7bb0ab4eb4a ]

The vDSO stack does not need to be executable. Prevent the linker from
creating executable. For more background see commit ffcf9c5700e4 ("x86:
link vdso and boot with -z noexecstack --no-warn-rwx-segments").

Also prevent the following warning from the linker:
sparc64-linux-ld: warning: arch/sparc/vdso/vdso-note.o: missing .note.GNU-stack section implies executable stack
sparc64-linux-ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker

Fixes: 9a08862a5d2e ("vDSO for sparc")
Suggested-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Andreas Larsson <andreas@gaisler.com>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/lkml/20250707144726.4008707-1-arnd@kernel.org/
Link: https://patch.msgid.link/20260304-vdso-sparc64-generic-2-v6-4-d8eb3b0e1410@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>

This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>

In preparation for Clang stack depth tracking for KSTACK_ERASE,
split the stackleak-specific cflags out of GCC_PLUGINS_CFLAGS into
KSTACK_ERASE_CFLAGS.

Link: https://lore.kernel.org/r/20250717232519.2984886-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>

Instead of using a custom script to detect and fail on undefined
references, use --no-undefined for all VDSO linker invocations.

Drop the now unused checkundef.sh script.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20250306-vdso-checkundef-v2-2-a26cc315fd73@linutronix.de

Add helper function for 64-bit right shift on 32-bit target so that
clang does not emit a runtime library call.

Signed-off-by: Koakuma <koachan@protonmail.com>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20240808-sparc-shr64-v2-1-fd18f1b2cea9@protonmail.com
Signed-off-by: Andreas Larsson <andreas@gaisler.com>

Place -fcall-used* flags behind cc-option so that clang (which doesn't
support them) can still compile the kernel.

This is a safe change, the reasoning is as follows:

In the (normal) 32-bit ABI, %g5 and %g7 is normally reserved, and in
the 64-bit ABI, %g7 is the reserved one.
Linux turns them into volatile registers by the way of -fcall-used-*,
but on the other hand, omitting the flags shouldn't be harmful;
compilers will now simply refuse to touch them, and any assembly
code that happens to touch them would still work like usual (because
Linux' conventions already treats them as volatile anyway).

Signed-off-by: Koakuma <koachan@protonmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20241029-sparc-cflags-v3-1-b28745a6bd71@protonmail.com
Signed-off-by: Andreas Larsson <andreas@gaisler.com>

Pull sparc updates from Andreas Larsson:

 - Avoid on-stack cpumask variables in a number of places

 - Move struct termio to asm/termios.h, matching other architectures and
   allowing certain user space applications to build also for sparc

 - Fix missing prototype warnings for sparc64

 - Fix version generation warnings for sparc32

 - Fix bug where non-consecutive CPU IDs lead to some CPUs not starting

 - Simplification using swap and cleanup using NULL for pointer

 - Convert sparc parport and chmc drivers to use remove callbacks
   returning void

* tag 'sparc-for-6.10-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/alarsson/linux-sparc:
  sparc/leon: Remove on-stack cpumask var
  sparc/pci_msi: Remove on-stack cpumask var
  sparc/of: Remove on-stack cpumask var
  sparc/irq: Remove on-stack cpumask var
  sparc/srmmu: Remove on-stack cpumask var
  sparc: chmc: Convert to platform remove callback returning void
  sparc: parport: Convert to platform remove callback returning void
  sparc: Compare pointers to NULL instead of 0
  sparc: Use swap() to fix Coccinelle warning
  sparc32: Fix version generation failed warnings
  sparc64: Fix number of online CPUs
  sparc64: Fix prototype warning for sched_clock
  sparc64: Fix prototype warnings in adi_64.c
  sparc64: Fix prototype warning for dma_4v_iotsb_bind
  sparc64: Fix prototype warning for uprobe_trap
  sparc64: Fix prototype warning for alloc_irqstack_bootmem
  sparc64: Fix prototype warning for vmemmap_free
  sparc64: Fix prototype warnings in traps_64.c
  sparc64: Fix prototype warning for init_vdso_image
  sparc: move struct termio to asm/termios.h

Now Kbuild provides reasonable defaults for objtool, sanitizers, and
profilers.

Remove redundant variables.

Note:

This commit changes the coverage for some objects:

  - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV
  - include arch/sparc/vdso/vdso-image-*.o into UBSAN
  - include arch/sparc/vdso/vma.o into UBSAN
  - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vma.o into GCOV, KCOV
  - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV

I believe these are positive effects because all of them are kernel
space objects.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Roberto Sassu <roberto.sassu@huawei.com>

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>