- Provide the missing 64-bit variant of clock_getres()
This allows the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and
finally the removal of 32-bit time types from the kernel and UAPI.
- Remove the useless and broken getcpu_cache from the VDSO
The intention was to provide a trivial way to retrieve the CPU number from
the VDSO, but as the VDSO data is per process there is no way to make it
work.
- Switch get/put_unaligned() from packed struct to memcpy()
The packed struct violates strict aliasing rules which requires to pass
-fno-strict-aliasing to the compiler. As this are scalar values
__builtin_memcpy() turns them into simple loads and stores
- Use __typeof_unqual__() for __unqual_scalar_typeof()
The get/put_unaligned() changes triggered a new sparse warning when __beNN
types are used with get/put_unaligned() as sparse builds add a special
'bitwise' attribute to them which prevents sparse to evaluate the Generic
in __unqual_scalar_typeof().
Newer sparse versions support __typeof_unqual__() which avoids the problem,
but requires a recent sparse install. So this adds a sanity check to sparse
builds, which validates that sparse is available and capable of handling it.
- Force inline __cvdso_clock_getres_common()
Compilers sometimes un-inline agressively, which results in function call
overhead and problems with automatic stack variable initialization.
Interestingly enough the force inlining results in smaller code than the
un-inlined variant produced by GCC when optimizing for size.
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Merge tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull VDSO updates from Thomas Gleixner:
- Provide the missing 64-bit variant of clock_getres()
This allows the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and
finally the removal of 32-bit time types from the kernel and UAPI.
- Remove the useless and broken getcpu_cache from the VDSO
The intention was to provide a trivial way to retrieve the CPU number
from the VDSO, but as the VDSO data is per process there is no way to
make it work.
- Switch get/put_unaligned() from packed struct to memcpy()
The packed struct violates strict aliasing rules which requires to
pass -fno-strict-aliasing to the compiler. As this are scalar values
__builtin_memcpy() turns them into simple loads and stores
- Use __typeof_unqual__() for __unqual_scalar_typeof()
The get/put_unaligned() changes triggered a new sparse warning when
__beNN types are used with get/put_unaligned() as sparse builds add a
special 'bitwise' attribute to them which prevents sparse to evaluate
the Generic in __unqual_scalar_typeof().
Newer sparse versions support __typeof_unqual__() which avoids the
problem, but requires a recent sparse install. So this adds a sanity
check to sparse builds, which validates that sparse is available and
capable of handling it.
- Force inline __cvdso_clock_getres_common()
Compilers sometimes un-inline agressively, which results in function
call overhead and problems with automatic stack variable
initialization.
Interestingly enough the force inlining results in smaller code than
the un-inlined variant produced by GCC when optimizing for size.
* tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
vdso/gettimeofday: Force inlining of __cvdso_clock_getres_common()
x86/percpu: Make CONFIG_USE_X86_SEG_SUPPORT work with sparse
compiler: Use __typeof_unqual__() for __unqual_scalar_typeof()
powerpc/vdso: Provide clock_getres_time64()
tools headers: Remove unneeded ignoring of warnings in unaligned.h
tools headers: Update the linux/unaligned.h copy with the kernel sources
vdso: Switch get/put_unaligned() from packed struct to memcpy()
parisc: Inline a type punning version of get_unaligned_le32()
vdso: Remove struct getcpu_cache
MIPS: vdso: Provide getres_time64() for 32-bit ABIs
arm64: vdso32: Provide clock_getres_time64()
ARM: VDSO: Provide clock_getres_time64()
ARM: VDSO: Patch out __vdso_clock_getres() if unavailable
x86/vdso: Provide clock_getres_time64() for x86-32
selftests: vDSO: vdso_test_abi: Add test for clock_getres_time64()
selftests: vDSO: vdso_test_abi: Use UAPI system call numbers
selftests: vDSO: vdso_config: Add configurations for clock_getres_time64()
vdso: Add prototype for __vdso_clock_getres_time64()
For some reason gcc 8, 9, 10, and 11 generate a dynamic relocation in
vdso.so.dbg if CONFIG_KSTACK_ERASE is enabled:
>> arch/s390/kernel/vdso/vdso.so.dbg: dynamic relocations are not supported
make[3]: *** [arch/s390/kernel/vdso/Makefile:54: arch/s390/kernel/vdso/vdso.so.dbg] Error 1
$ readelf -rW arch/s390/kernel/vdso/vdso.so.dbg
Relocation section '.rela.dyn' at offset 0x15c0 contains 1 entry:
Offset Info Type Symbol's Value Symbol's Name + Addend
00000000000015f0 000000010000000b R_390_JMP_SLOT 0000000000000000 __sanitizer_cov_stack_depth + 0
Add $(DISABLE_KSTACK_ERASE) to vdso compile flags to fix this.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202601070505.xQcLr5KV-lkp@intel.com/
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The cache parameter of getcpu() is useless nowadays for various reasons.
* It is never passed by userspace for either the vDSO or syscalls.
* It is never used by the kernel.
* It could not be made to work on the current vDSO architecture.
* The structure definition is not part of the UAPI headers.
* vdso_getcpu() is superseded by restartable sequences in any case.
Remove the struct and its header.
As a side-effect this gets rid of an unwanted inclusion of the linux/
header namespace from vDSO code.
[ tglx: Adapt to s390 upstream changes */
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Link: https://patch.msgid.link/20251230-getcpu_cache-v3-1-fb9c5f880ebe@linutronix.de
The compiler/assembler flag -m64 is added and removed at two locations.
This pointless exercise is a leftover to keep the 31 and 64 bit vdso
Makefiles as symmetrical as possible. Given that the 31 bit vdso code
does not exist anymore, remove the -m64 flag handling.
Suggested-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Since compat is gone there is only a 64 bit vdso left.
Remove the superfluous "64" suffix everywhere.
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
