The generic vDSO installation logic used by 'make vdso_install' requires
that $(vdso-install-y) is defined by the top-level architecture Makefile
and that it contains a path relative to the root of the tree.
For UML neither of these is satisfied.

Move the definition of $(vdso-install-y) to a place which is included by
the arch/um/Makefile and use the full relative path.

Fixes: f1c2bb8b9964 ("um: implement a x86_64 vDSO")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260318-um-vdso-install-v1-1-26a4ca5c4210@weissschuh.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

We are going to support SMP on UML/x86, so we can't hard code
the CPU and NUMA node in __vdso_getcpu() anymore. Let's just
remove it and let applications fall back to the syscall.

Suggested-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20251027001815.1666872-7-tiwei.bie@linux.dev
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This symbol is unnecessary, remove it.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251013-uml-vdso-cleanup-v1-4-a079c7adcc69@weissschuh.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The vDSO address is added to the userspace auxiliary vectors even if the
vDSO was not allocated. When accessing the page, userspace processes
will crash.

Enforce that the allocation works.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251013-uml-vdso-cleanup-v1-3-a079c7adcc69@weissschuh.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The generic vDSO library provides a convenient header for the vDSO
function prototypes, use it.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251013-uml-vdso-cleanup-v1-2-a079c7adcc69@weissschuh.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The clock_gettime() system call takes a pointer to
'struct __kernel_timespec', not 'struct __kernel_old_timespec'.
Right now this is not an issue as the vDSO never works with the
actual struct but only passes it through to the kernel.

Fix the prototype for consistency with the system call.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251013-uml-vdso-cleanup-v1-1-a079c7adcc69@weissschuh.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Instead of dynamically allocating the pointer to the vdso page during
boot, we can just allocate it statically. Doing so will reduce error
handling and make the code slightly more readable.

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20250212045756.164977-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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>
Link: https://patch.msgid.link/20241011-vdso-checkundef-v1-2-1a46e0352d20@linutronix.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

All relevant architectures had already been converted to the new interface
(which just has an underscore in front of the name - not very imaginative
naming), this just force-converts the stragglers.

The modern interface is almost identical to the old one, except instead of
the page pointer it takes a "struct vm_special_mapping" that describes the
mapping (and contains the page pointer as one member), and it returns the
resulting 'vma' instead of just the error code.

Getting rid of the old interface also gets rid of some special casing,
which had caused problems with the mremap extensions to "struct
vm_special_mapping".

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/CAHk-=whvR+z=0=0gzgdfUiK70JTa-=+9vxD-4T=3BagXR6dciA@mail.gmail.comTested-by: Rob Landley <rob@landley.net> # arch/sh/
Link: https://lore.kernel.org/all/20240819195120.GA1113263@thelio-3990X/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Landley <rob@landley.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull UML updates from Richard Weinberger:

 - Fixes for -Wmissing-prototypes warnings and further cleanup

 - Remove callback returning void from rtc and virtio drivers

 - Fix bash location

* tag 'uml-for-linus-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (26 commits)
  um: virtio_uml: Convert to platform remove callback returning void
  um: rtc: Convert to platform remove callback returning void
  um: Remove unused do_get_thread_area function
  um: Fix -Wmissing-prototypes warnings for __vdso_*
  um: Add an internal header shared among the user code
  um: Fix the declaration of kasan_map_memory
  um: Fix the -Wmissing-prototypes warning for get_thread_reg
  um: Fix the -Wmissing-prototypes warning for __switch_mm
  um: Fix -Wmissing-prototypes warnings for (rt_)sigreturn
  um: Stop tracking host PID in cpu_tasks
  um: process: remove unused 'n' variable
  um: vector: remove unused len variable/calculation
  um: vector: fix bpfflash parameter evaluation
  um: slirp: remove set but unused variable 'pid'
  um: signal: move pid variable where needed
  um: Makefile: use bash from the environment
  um: Add winch to winch_handlers before registering winch IRQ
  um: Fix -Wmissing-prototypes warnings for __warp_* and foo
  um: Fix -Wmissing-prototypes warnings for text_poke*
  um: Move declarations to proper headers
  ...