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2025-03-25Merge tag 'timers-vdso-2025-03-23' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull VDSO infrastructure updates from Thomas Gleixner: - Consolidate the VDSO storage The VDSO data storage and data layout has been largely architecture specific for historical reasons. That increases the maintenance effort and causes inconsistencies over and over. There is no real technical reason for architecture specific layouts and implementations. The architecture specific details can easily be integrated into a generic layout, which also reduces the amount of duplicated code for managing the mappings. Convert all architectures over to a unified layout and common mapping infrastructure. This splits the VDSO data layout into subsystem specific blocks, timekeeping, random and architecture parts, which provides a better structure and allows to improve and update the functionalities without conflict and interaction. - Rework the timekeeping data storage The current implementation is designed for exposing system timekeeping accessors, which was good enough at the time when it was designed. PTP and Time Sensitive Networking (TSN) change that as there are requirements to expose independent PTP clocks, which are not related to system timekeeping. Replace the monolithic data storage by a structured layout, which allows to add support for independent PTP clocks on top while reusing both the data structures and the time accessor implementations. * tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) sparc/vdso: Always reject undefined references during linking x86/vdso: Always reject undefined references during linking vdso: Rework struct vdso_time_data and introduce struct vdso_clock vdso: Move architecture related data before basetime data powerpc/vdso: Prepare introduction of struct vdso_clock arm64/vdso: Prepare introduction of struct vdso_clock x86/vdso: Prepare introduction of struct vdso_clock time/namespace: Prepare introduction of struct vdso_clock vdso/namespace: Rename timens_setup_vdso_data() to reflect new vdso_clock struct vdso/vsyscall: Prepare introduction of struct vdso_clock vdso/gettimeofday: Prepare helper functions for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_coarse_timens() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_coarse() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_hres_timens() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_hres() for introduction of struct vdso_clock vdso/gettimeofday: Prepare introduction of struct vdso_clock vdso/helpers: Prepare introduction of struct vdso_clock vdso/datapage: Define vdso_clock to prepare for multiple PTP clocks vdso: Make vdso_time_data cacheline aligned arm64: Make asm/cache.h compatible with vDSO ...
2025-03-19x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headersThomas Huth
While the GCC and Clang compilers already define __ASSEMBLER__ automatically when compiling assembly code, __ASSEMBLY__ is a macro that only gets defined by the Makefiles in the kernel. This can be very confusing when switching between userspace and kernelspace coding, or when dealing with UAPI headers that rather should use __ASSEMBLER__ instead. So let's standardize on the __ASSEMBLER__ macro that is provided by the compilers now. This is mostly a mechanical patch (done with a simple "sed -i" statement), with some manual tweaks in <asm/frame.h>, <asm/hw_irq.h> and <asm/setup.h> that mentioned this macro in comments with some missing underscores. Signed-off-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250314071013.1575167-38-thuth@redhat.com
2025-02-21x86/vdso: Switch to generic storage implementationThomas Weißschuh
The generic storage implementation provides the same features as the custom one. However it can be shared between architectures, making maintenance easier. This switch also moves the random state data out of the time data page. The currently used hardcoded __VDSO_RND_DATA_OFFSET does not take into account changes to the time data page layout. Co-developed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-15-13a4669dfc8c@linutronix.de
2024-11-02x86/vdso: Access rng vdso data without vvar.hThomas Weißschuh
The vdso_rng_data is at a well-known offset in the vvar page. Make use of this invariant to remove the usage of vvar.h. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-16-b64f0842d512@linutronix.de
2024-11-02x86/vdso: Access timens vdso data without vvar.hThomas Weißschuh
The vdso_data is at the start of the timens page. Make use of this invariant to remove the usage of vvar.h. This also matches the logic for the pvclock and hvclock pages. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-15-b64f0842d512@linutronix.de
2024-11-02x86/vdso: Use __arch_get_vdso_data() to access vdso dataThomas Weißschuh
The implementation details of the vdso_data access will change. Prepare for that by using the existing helper function. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-11-b64f0842d512@linutronix.de
2024-09-13random: vDSO: move prototype of arch chacha function to vdso/getrandom.hJason A. Donenfeld
Having the prototype for __arch_chacha20_blocks_nostack in arch/x86/include/asm/vdso/getrandom.h meant that the prototype and large doc comment were cloned by every architecture, which has been causing unnecessary churn. Instead move it into include/vdso/getrandom.h, where it can be shared by all archs implementing it. As a side bonus, this then lets us use that prototype in the vdso_test_chacha self test, to ensure that it matches the source, and indeed doing so turned up some inconsistencies, which are rectified here. Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-07-19x86: vdso: Wire up getrandom() vDSO implementationJason A. Donenfeld
Hook up the generic vDSO implementation to the x86 vDSO data page. Since the existing vDSO infrastructure is heavily based on the timekeeping functionality, which works over arrays of bases, a new macro is introduced for vvars that are not arrays. The vDSO function requires a ChaCha20 implementation that does not write to the stack, yet can still do an entire ChaCha20 permutation, so provide this using SSE2, since this is userland code that must work on all x86-64 processors. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Samuel Neves <sneves@dei.uc.pt> # for vgetrandom-chacha.S Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>