Le 12/08/2025 à 07:44, Thomas Weißschuh a écrit :
The compiler can emit absolute relocations in vDSO code,
which are invalid in vDSO code.
Detect them at compile-time.
I'm a bit puzzled with this series.
If I understand correctly, the check will be done only when you have
RUST available ?
I wouldn't expect having RUST to build a C kernel.
By the way, aren't relocations already detected by command
cmd_vdso_check in lib/vdso/Makefile.include , using readelf ? Why is a
new tool needed and why does it have to be written in RUST langage ?
Thanks
Christophe
libc elf.h is missing some of the relocation constants,
so make user of the kernels own UAPI headers instead.
Kbuild and Rust folks: This contains custom definitions of hostprog
bindgen and rust library commands.
These are currently only defined inside the subsystem directory.
Let me know if they should go into scripts/Makefile.host.
This will conflict with my SPARC64 generic vDSO patches [0].
If both end up being applied at the same time, please leave out commit
'vdso/vdsocheck: Drop the transitional kconfig option' from this series.
[0]
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flkml%2F20250724-vdso-sparc64-generic-2-v1-0-e376a3bd24d1%40linutronix.de%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C3f03f6747325451ee98808ddd9634f27%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638905742749561064%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=HacF%2FvlUoxA9P6fTiN1ytw49gwayX1wNE7IxfEkFutE%3D&reserved=0
Signed-off-by: Thomas Weißschuh <thomas.weisssc...@linutronix.de>
---
Changes in v4:
- Replace the inline shell logic with a dedicated build-time tool
- Link to v3:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fr%2F20250611-vdso-absolute-reloc-v3-0-47897d73784b%40linutronix.de&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C3f03f6747325451ee98808ddd9634f27%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638905742749584369%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=7NxAhutk6IXl%2B3fe1kkZEzhZz6CWye%2FVAcFO%2BgtS4uo%3D&reserved=0
Changes in v3:
- Drop already applied bugfix for arm64
- Disable LTO for the riscv vDSO, as it is incompatible
- Link to v2:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fr%2F20250430-vdso-absolute-reloc-v2-0-5efcc3bc4b26%40linutronix.de&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C3f03f6747325451ee98808ddd9634f27%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638905742749600546%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=uv0qMS5qq0DovLHtxfRvT42atbJEkztylpOS8zt6bJ4%3D&reserved=0
Changes in v2:
- Link to openend (invalid) GCC bug containing more explanations
- Refine commit messages
- Don't fail on commit absolute relocations in debug info
- Link to v1:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fr%2F20250429-vdso-absolute-reloc-v1-0-987a0afd10b5%40linutronix.de&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C3f03f6747325451ee98808ddd9634f27%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638905742749616057%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=K5iwoz0Xqc8kheotWEc4M2KrZ7UVMDObOyFfCPj4N8Q%3D&reserved=0
---
Thomas Weißschuh (24):
elf, uapi: Add a header for relocation constants
x86/elf, um/x86/elf: Move relocation constants to UAPI
ARM: elf: Move relocation constants to UAPI
arm64: elf: Move relocation constants to UAPI
powerpc/elf: Move relocation constants to UAPI
riscv: elf: Move relocation constants to UAPI
LoongArch: Move relocation constants to UAPI
s390/elf: Move relocation constants to UAPI
MIPS: ELF: Move relocation constants to UAPI
tools headers UAPI: Sync ELF headers with the kernel sources
vdso: Add the vdsocheck tool
x86/vdso: Enable the vdsocheck tool
ARM: vdso: Enable the vdsocheck tool
arm64: vdso: Enable the vdsocheck tool
powerpc/elf: Add 32-bit REL16 relocation definitions
powerpc/vdso: Enable the vdsocheck tool
riscv: vdso: Deduplicate CFLAGS_REMOVE_* variables
riscv: vdso: Disable LTO for the vDSO
riscv: vdso: Enable the vdsocheck tool
LoongArch: vDSO: Enable the vdsocheck tool
s390/vdso: Enable the vdsocheck tool
MIPS: ELF: Add more PC-relative relocation definitions
MIPS: vdso: Enable the vdsocheck tool
vdso/vdsocheck: Drop the transitional kconfig option
arch/arm/include/asm/elf.h | 24 --
arch/arm/vdso/Makefile | 4 +-
arch/arm64/include/asm/elf.h | 55 ----
arch/arm64/kernel/vdso/Makefile | 4 +-
arch/loongarch/include/asm/elf.h | 100 ------
arch/loongarch/vdso/Makefile | 4 +-
arch/mips/include/asm/elf.h | 53 ---
arch/mips/vdso/Makefile | 8 +-
arch/powerpc/include/uapi/asm/elf.h | 201 ------------
arch/powerpc/kernel/vdso/Makefile | 4 +-
arch/riscv/include/uapi/asm/elf.h | 66 ----
arch/riscv/kernel/vdso/Makefile | 11 +-
arch/s390/include/asm/elf.h | 83 -----
arch/s390/kernel/vdso32/Makefile | 4 +-
arch/s390/kernel/vdso64/Makefile | 4 +-
arch/x86/entry/vdso/Makefile | 6 +-
arch/x86/include/asm/elf.h | 34 --
arch/x86/um/asm/elf.h | 33 --
include/uapi/linux/elf-r.h | 631 ++++++++++++++++++++++++++++++++++++
include/uapi/linux/elf.h | 1 +
lib/vdso/Makefile | 2 +
lib/vdso/Makefile.include | 17 +
lib/vdso/check/.gitignore | 3 +
lib/vdso/check/Makefile | 28 ++
lib/vdso/check/elf.rs | 488 ++++++++++++++++++++++++++++
lib/vdso/check/vdsocheck.rs | 279 ++++++++++++++++
tools/include/uapi/linux/elf-em.h | 71 ++++
tools/include/uapi/linux/elf-r.h | 631 ++++++++++++++++++++++++++++++++++++
tools/include/uapi/linux/elf.h | 112 ++++++-
29 files changed, 2277 insertions(+), 684 deletions(-)
---
base-commit: 5180c6526acc9f1cb58f8b11fba67583c22e0854
change-id: 20250428-vdso-absolute-reloc-a226293c1761
Best regards,
