[PATCH v3 00/18] vDSO: Introduce generic data storage

Thomas Weißschuh
2025-02-04T12:06:07Z

Currently each architecture defines the setup of the vDSO data page on
its own, mostly through copy-and-paste from some other architecture.
Extend the existing generic vDSO implementation to also provide generic
data storage.
This removes duplicated code and paves the way for further changes to
the generic vDSO implementation without having to go through a lot of
per-architecture changes.

Based on v6.14-rc1 and intended to be merged through the tip tree.

This also provides the basis for some generic vDSO reworks.
The commits from this series and the upcoming reworks can be seen at:
https://git.kernel.org/pub/scm/linux/kernel/git/thomas.weissschuh/linux.git/log/?h=vdso/store

---
Changes in v3:
- Rebase on v6.14-rc1
- Fix build on riscv64-nommu
- Link to v2: https://lore.kernel.org/r/20250110-vdso-store-rng-v2-0-350c9179bbf1@linutronix.de

Changes in v2:
- Drop __arch_get_vdso_u_timens_data() (Christophe)
- Move to lib/vdso/ (Christophe)
- Rename __ppc_get_vdso_u_timens_data() to
__arch_get_vdso_u_timens_data(), same for other hooks
(Christophe)
- Fix build for architectures with time-less vDSO, like riscv32. (Conor)
- Explicitly fix bug around x86 vclock pages
- Link to v1: https://lore.kernel.org/r/20241216-vdso-store-rng-v1-0-f7aed1bdb3b2@linutronix.de

---
Thomas Weißschuh (18):
x86/vdso: Fix latent bug in vclock_pages calculation
parisc: Remove unused symbol vdso_data
vdso: Introduce vdso/align.h
vdso: Rename included Makefile
vdso: Add generic time data storage
vdso: Add generic random data storage
vdso: Add generic architecture-specific data storage
arm64: vdso: Switch to generic storage implementation
riscv: vdso: Switch to generic storage implementation
LoongArch: vDSO: Switch to generic storage implementation
arm: vdso: Switch to generic storage implementation
s390/vdso: Switch to generic storage implementation
MIPS: vdso: Switch to generic storage implementation
powerpc/vdso: Switch to generic storage implementation
x86/vdso: Switch to generic storage implementation
x86/vdso/vdso2c: Remove page handling
vdso: Remove remnants of architecture-specific random state storage
vdso: Remove remnants of architecture-specific time storage

arch/Kconfig | 4 +
arch/arm/include/asm/vdso.h | 2 +
arch/arm/include/asm/vdso/gettimeofday.h | 7 +-
arch/arm/include/asm/vdso/vsyscall.h | 12 +-
arch/arm/kernel/asm-offsets.c | 4 -
arch/arm/kernel/vdso.c | 34 ++----
arch/arm/mm/Kconfig | 1 +
arch/arm/vdso/Makefile | 2 +-
arch/arm/vdso/vdso.lds.S | 4 +-
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/vdso.h | 2 +-
arch/arm64/include/asm/vdso/compat_gettimeofday.h | 36 ++----
arch/arm64/include/asm/vdso/getrandom.h | 12 --
arch/arm64/include/asm/vdso/gettimeofday.h | 16 +--
arch/arm64/include/asm/vdso/vsyscall.h | 25 +---
arch/arm64/kernel/vdso.c | 90 +-------------
arch/arm64/kernel/vdso/Makefile | 2 +-
arch/arm64/kernel/vdso/vdso.lds.S | 7 +-
arch/arm64/kernel/vdso32/Makefile | 2 +-
arch/arm64/kernel/vdso32/vdso.lds.S | 7 +-
arch/csky/kernel/vdso/Makefile | 2 +-
arch/loongarch/Kconfig | 2 +
arch/loongarch/include/asm/vdso.h | 1 -
arch/loongarch/include/asm/vdso/arch_data.h | 25 ++++
arch/loongarch/include/asm/vdso/getrandom.h | 5 -
arch/loongarch/include/asm/vdso/gettimeofday.h | 14 +--
arch/loongarch/include/asm/vdso/vdso.h | 38 +-----
arch/loongarch/include/asm/vdso/vsyscall.h | 17 ---
arch/loongarch/kernel/asm-offsets.c | 2 +-
arch/loongarch/kernel/vdso.c | 92 +--------------
arch/loongarch/vdso/Makefile | 2 +-
arch/loongarch/vdso/vdso.lds.S | 8 +-
arch/loongarch/vdso/vgetcpu.c | 12 +-
arch/mips/Kconfig | 1 +
arch/mips/include/asm/vdso/gettimeofday.h | 9 +-
arch/mips/include/asm/vdso/vdso.h | 19 ++-
arch/mips/include/asm/vdso/vsyscall.h | 14 +--
arch/mips/kernel/vdso.c | 47 +++-----
arch/mips/vdso/Makefile | 2 +-
arch/mips/vdso/vdso.lds.S | 5 +-
arch/parisc/include/asm/vdso.h | 2 -
arch/parisc/kernel/vdso32/Makefile | 2 +-
arch/parisc/kernel/vdso64/Makefile | 2 +-
arch/powerpc/Kconfig | 2 +
arch/powerpc/include/asm/vdso.h | 1 +
arch/powerpc/include/asm/vdso/arch_data.h | 37 ++++++
arch/powerpc/include/asm/vdso/getrandom.h | 11 +-
arch/powerpc/include/asm/vdso/gettimeofday.h | 29 ++---
arch/powerpc/include/asm/vdso/vsyscall.h | 13 ---
arch/powerpc/include/asm/vdso_datapage.h | 44 +------
arch/powerpc/kernel/asm-offsets.c | 1 -
arch/powerpc/kernel/time.c | 2 +-
arch/powerpc/kernel/vdso.c | 115 ++----------------
arch/powerpc/kernel/vdso/Makefile | 2 +-
arch/powerpc/kernel/vdso/cacheflush.S | 2 +-
arch/powerpc/kernel/vdso/datapage.S | 4 +-
arch/powerpc/kernel/vdso/gettimeofday.S | 4 +-
arch/powerpc/kernel/vdso/vdso32.lds.S | 4 +-
arch/powerpc/kernel/vdso/vdso64.lds.S | 4 +-
arch/powerpc/kernel/vdso/vgettimeofday.c | 14 +--
arch/riscv/Kconfig | 3 +-
arch/riscv/include/asm/vdso.h | 2 +-
.../include/asm/vdso/{time_data.h => arch_data.h} | 8 +-
arch/riscv/include/asm/vdso/gettimeofday.h | 14 +--
arch/riscv/include/asm/vdso/vsyscall.h | 9 --
arch/riscv/kernel/sys_hwprobe.c | 3 +-
arch/riscv/kernel/vdso.c | 90 +-------------
arch/riscv/kernel/vdso/Makefile | 2 +-
arch/riscv/kernel/vdso/hwprobe.c | 6 +-
arch/riscv/kernel/vdso/vdso.lds.S | 7 +-
arch/s390/Kconfig | 1 +
arch/s390/include/asm/vdso.h | 4 +-
arch/s390/include/asm/vdso/getrandom.h | 12 --
arch/s390/include/asm/vdso/gettimeofday.h | 15 +--
arch/s390/include/asm/vdso/vsyscall.h | 20 ----
arch/s390/kernel/time.c | 6 +-
arch/s390/kernel/vdso.c | 97 +---------------
arch/s390/kernel/vdso32/Makefile | 2 +-
arch/s390/kernel/vdso32/vdso32.lds.S | 7 +-
arch/s390/kernel/vdso64/Makefile | 2 +-
arch/s390/kernel/vdso64/vdso64.lds.S | 8 +-
arch/x86/Kconfig | 1 +
arch/x86/entry/vdso/Makefile | 2 +-
arch/x86/entry/vdso/vdso-layout.lds.S | 10 +-
arch/x86/entry/vdso/vdso2c.c | 21 ----
arch/x86/entry/vdso/vdso2c.h | 20 ----
arch/x86/entry/vdso/vma.c | 125 ++------------------
arch/x86/include/asm/vdso.h | 6 -
arch/x86/include/asm/vdso/getrandom.h | 10 --
arch/x86/include/asm/vdso/gettimeofday.h | 25 +---
arch/x86/include/asm/vdso/vsyscall.h | 23 +---
drivers/char/random.c | 6 +-
include/asm-generic/vdso/vsyscall.h | 27 +++--
include/linux/align.h | 10 +-
include/linux/time_namespace.h | 2 -
include/linux/vdso_datastore.h | 10 ++
include/vdso/align.h | 15 +++
include/vdso/datapage.h | 74 +++++++++---
include/vdso/helpers.h | 8 +-
kernel/time/namespace.c | 12 +-
kernel/time/vsyscall.c | 19 ++-
lib/Makefile | 2 +-
lib/vdso/Kconfig | 5 +
lib/vdso/Makefile | 19 +--
lib/vdso/Makefile.include | 18 +++
lib/vdso/datastore.c | 129 +++++++++++++++++++++
lib/vdso/getrandom.c | 8 +-
lib/vdso/gettimeofday.c | 74 +++++++-----
108 files changed, 604 insertions(+), 1277 deletions(-)
---
base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
change-id: 20240911-vdso-store-rng-607a3dc9e050

Best regards,
--
Thomas Weißschuh <thomas.weissschuh@linutronix.de>