The generic vDSO provides a lot common functionality shared between different architectures. SPARC is the last architecture not using it, preventing some necessary code cleanup.
Make use of the generic infrastructure.
Follow-up to and replacement for Arnd's SPARC vDSO removal patches: https://lore.kernel.org/lkml/20250707144726.4008707-1-arnd@kernel.org/
SPARC64 can not map .bss into userspace, so the vDSO datapages are switched over to be allocated dynamically. This requires changes to the s390 and random subsystem vDSO initialization as preparation. The random subsystem changes in turn require some cleanup of the vDSO headers to not end up as ugly #ifdef mess.
Tested on a Niagara T4 and QEMU.
This has a semantic conflict with my series "vdso: Reject absolute relocations during build" [0]. The last patch of this series expects all users of the generic vDSO library to use the vdsocheck tool. This is not the case (yet) for SPARC64. I do have the patches for the integration, the specifics will depend on which series is applied first.
Based on v6.18-rc1.
[0] https://lore.kernel.org/lkml/20250812-vdso-absolute-reloc-v4-0-61a8b615e5ec@...
Signed-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de --- Changes in v4: - Rebase on v6.18-rc1. - Keep inclusion of asm/clocksource.h from linux/clocksource.h - Reword description of "s390/time: Set up vDSO datapage later" - Link to v3: https://lore.kernel.org/r/20250917-vdso-sparc64-generic-2-v3-0-3679b1bc8ee8@...
Changes in v3: - Allocate vDSO data pages dynamically (and lots of preparations for that) - Drop clock_getres() - Fix 32bit clock_gettime() syscall fallback - Link to v2: https://lore.kernel.org/r/20250815-vdso-sparc64-generic-2-v2-0-b5ff80672347@...
Changes in v2: - Rebase on v6.17-rc1 - Drop RFC state - Fix typo in commit message - Drop duplicate 'select GENERIC_TIME_VSYSCALL' - Merge "sparc64: time: Remove architecture-specific clocksource data" into the main conversion patch. It violated the check in __clocksource_register_scale() - Link to v1: https://lore.kernel.org/r/20250724-vdso-sparc64-generic-2-v1-0-e376a3bd24d1@...
--- Arnd Bergmann (1): clocksource: remove ARCH_CLOCKSOURCE_DATA
Thomas Weißschuh (34): selftests: vDSO: vdso_test_correctness: Handle different tv_usec types arm64: vDSO: getrandom: Explicitly include asm/alternative.h arm64: vDSO: gettimeofday: Explicitly include vdso/clocksource.h arm64: vDSO: compat_gettimeofday: Add explicit includes ARM: vdso: gettimeofday: Add explicit includes powerpc/vdso/gettimeofday: Explicitly include vdso/time32.h powerpc/vdso: Explicitly include asm/cputable.h and asm/feature-fixups.h LoongArch: vDSO: Explicitly include asm/vdso/vdso.h MIPS: vdso: Add include guard to asm/vdso/vdso.h MIPS: vdso: Explicitly include asm/vdso/vdso.h random: vDSO: Add explicit includes vdso/gettimeofday: Add explicit includes vdso/helpers: Explicitly include vdso/processor.h vdso/datapage: Remove inclusion of gettimeofday.h vdso/datapage: Trim down unnecessary includes random: vDSO: trim vDSO includes random: vDSO: remove ifdeffery random: vDSO: split out datapage update into helper functions random: vDSO: only access vDSO datapage after random_init() s390/time: Set up vDSO datapage later vdso/datastore: Reduce scope of some variables in vvar_fault() vdso/datastore: Drop inclusion of linux/mmap_lock.h vdso/datastore: Map pages through struct page vdso/datastore: Allocate data pages dynamically sparc64: vdso: Link with -z noexecstack sparc64: vdso: Remove obsolete "fake section table" reservation sparc64: vdso: Replace code patching with runtime conditional sparc64: vdso: Move hardware counter read into header sparc64: vdso: Move syscall fallbacks into header sparc64: vdso: Introduce vdso/processor.h sparc64: vdso: Switch to the generic vDSO library sparc64: vdso2c: Drop sym_vvar_start handling sparc64: vdso2c: Remove symbol handling sparc64: vdso: Implement clock_gettime64()
arch/arm/include/asm/vdso/gettimeofday.h | 2 + arch/arm64/include/asm/vdso/compat_gettimeofday.h | 3 + arch/arm64/include/asm/vdso/gettimeofday.h | 2 + arch/arm64/kernel/vdso/vgetrandom.c | 2 + arch/loongarch/kernel/process.c | 1 + arch/loongarch/kernel/vdso.c | 1 + arch/mips/include/asm/vdso/vdso.h | 5 + arch/mips/kernel/vdso.c | 1 + arch/powerpc/include/asm/vdso/gettimeofday.h | 1 + arch/powerpc/include/asm/vdso/processor.h | 3 + arch/s390/kernel/time.c | 4 +- arch/sparc/Kconfig | 3 +- arch/sparc/include/asm/clocksource.h | 9 - arch/sparc/include/asm/processor.h | 3 + arch/sparc/include/asm/processor_32.h | 2 - arch/sparc/include/asm/processor_64.h | 25 -- arch/sparc/include/asm/vdso.h | 2 - arch/sparc/include/asm/vdso/clocksource.h | 10 + arch/sparc/include/asm/vdso/gettimeofday.h | 184 ++++++++++ arch/sparc/include/asm/vdso/processor.h | 41 +++ arch/sparc/include/asm/vdso/vsyscall.h | 10 + arch/sparc/include/asm/vvar.h | 75 ---- arch/sparc/kernel/Makefile | 1 - arch/sparc/kernel/time_64.c | 6 +- arch/sparc/kernel/vdso.c | 69 ---- arch/sparc/vdso/Makefile | 8 +- arch/sparc/vdso/vclock_gettime.c | 380 ++------------------- arch/sparc/vdso/vdso-layout.lds.S | 26 +- arch/sparc/vdso/vdso.lds.S | 2 - arch/sparc/vdso/vdso2c.c | 24 -- arch/sparc/vdso/vdso2c.h | 45 +-- arch/sparc/vdso/vdso32/vdso32.lds.S | 4 +- arch/sparc/vdso/vma.c | 274 +-------------- drivers/char/random.c | 71 ++-- include/linux/clocksource.h | 6 +- include/linux/vdso_datastore.h | 6 + include/vdso/datapage.h | 23 +- include/vdso/helpers.h | 1 + init/main.c | 2 + kernel/time/Kconfig | 4 - lib/vdso/datastore.c | 73 ++-- lib/vdso/getrandom.c | 3 + lib/vdso/gettimeofday.c | 17 + .../testing/selftests/vDSO/vdso_test_correctness.c | 8 +- 44 files changed, 448 insertions(+), 994 deletions(-) --- base-commit: 28b1ac5ccd8d4900a8f53f0e6e84d517a7ccc71f change-id: 20250722-vdso-sparc64-generic-2-25f2e058e92c
Best regards,