kernel/linux.git/arch/x86/include/asm/vdso, branch v6.12.80

random: vDSO: add __arch_get_k_vdso_rng_data() helper for data page access

2024-09-13T15:28:35+00:00

_vdso_data is specific to x86 and __arch_get_k_vdso_data() is provided so that all architectures can provide the requested pointer. Do the same with _vdso_rng_data, provide __arch_get_k_vdso_rng_data() and don't use x86 _vdso_rng_data directly. Until now vdso/vsyscall.h was only included by time/vsyscall.c but now it will also be included in char/random.c, leading to a duplicate declaration of _vdso_data and _vdso_rng_data. To fix this issue, move the declaration in a C file. vma.c looks like the most appropriate candidate. We don't need to replace the definitions in vsyscall.h by declarations as declarations are already in asm/vvar.h. Signed-off-by: Christophe Leroy Signed-off-by: Jason A. Donenfeld

random: vDSO: move prototype of arch chacha function to vdso/getrandom.h

2024-09-13T15:28:35+00:00

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 Signed-off-by: Jason A. Donenfeld

Merge tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

2024-07-24T17:29:50+00:00

Pull random number generator updates from Jason Donenfeld: "This adds getrandom() support to the vDSO. First, it adds a new kind of mapping to mmap(2), MAP_DROPPABLE, which lets the kernel zero out pages anytime under memory pressure, which enables allocating memory that never gets swapped to disk but also doesn't count as being mlocked. Then, the vDSO implementation of getrandom() is introduced in a generic manner and hooked into random.c. Next, this is implemented on x86. (Also, though it's not ready for this pull, somebody has begun an arm64 implementation already) Finally, two vDSO selftests are added. There are also two housekeeping cleanup commits" * tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: MAINTAINERS: add random.h headers to RNG subsection random: note that RNDGETPOOL was removed in 2.6.9-rc2 selftests/vDSO: add tests for vgetrandom x86: vdso: Wire up getrandom() vDSO implementation random: introduce generic vDSO getrandom() implementation mm: add MAP_DROPPABLE for designating always lazily freeable mappings

x86: vdso: Wire up getrandom() vDSO implementation

2024-07-19T18:22:12+00:00

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 Reviewed-by: Samuel Neves # for vgetrandom-chacha.S Signed-off-by: Jason A. Donenfeld

x86/vdso: Remove unused include

2024-07-03T19:27:04+00:00

Including hrtimer.h is not required and is probably a historical leftover. Remove it. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino Link: https://lore.kernel.org/r/20240701-vdso-cleanup-v1-5-36eb64e7ece2@linutronix.de

x86/vdso: Fix function reference in comment

2024-07-03T19:27:04+00:00

Replace the reference to the non-existent function arch_vdso_cycles_valid() by the proper function arch_vdso_cycles_ok(). Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino Link: https://lore.kernel.org/r/20240701-vdso-cleanup-v1-3-36eb64e7ece2@linutronix.de

x86/vdso: Make delta calculation overflow safe

2024-04-08T13:03:07+00:00

Kernel timekeeping is designed to keep the change in cycles (since the last timer interrupt) below max_cycles, which prevents multiplication overflow when converting cycles to nanoseconds. However, if timer interrupts stop, the calculation will eventually overflow. Add protection against that. Select GENERIC_VDSO_OVERFLOW_PROTECT so that max_cycles is made available in the VDSO data page. Check against max_cycles, falling back to a slower higher precision calculation. Take advantage of the opportunity to move masking and negative motion check into the slow path. The result is a calculation that has similar performance as before. Newer machines showed performance benefit, whereas older Skylake-based hardware such as Intel Kaby Lake was seen <1% worse. Suggested-by: Thomas Gleixner Signed-off-by: Adrian Hunter Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240325064023.2997-9-adrian.hunter@intel.com

vdso: Consolidate nanoseconds calculation

2024-04-08T13:03:06+00:00

Consolidate nanoseconds calculation to simplify and reduce code duplication. Suggested-by: Thomas Gleixner Signed-off-by: Adrian Hunter Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240325064023.2997-3-adrian.hunter@intel.com

Merge tag 'asm-generic-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2024-01-11T02:13:44+00:00

Pull asm-generic cleanups from Arnd Bergmann: "A series from Baoquan He cleans up the asm-generic/io.h to remove the ioremap_uc() definition from everything except x86, which still needs it for pre-PAT systems. This series notably contains a patch from Jiaxun Yang that converts MIPS to use asm-generic/io.h like every other architecture does, enabling future cleanups. Some of my own patches fix -Wmissing-prototype warnings in architecture specific code across several architectures. This is now needed as the warning is enabled by default. There are still some remaining warnings in minor platforms, but the series should catch most of the widely used ones make them more consistent with one another. David McKay fixes a bug in __generic_cmpxchg_local() when this is used on 64-bit architectures. This could currently only affect parisc64 and sparc64. Additional cleanups address from Linus Walleij, Uwe Kleine-König, Thomas Huth, and Kefeng Wang help reduce unnecessary inconsistencies between architectures" * tag 'asm-generic-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: asm-generic: Fix 32 bit __generic_cmpxchg_local Hexagon: Make pfn accessors statics inlines ARC: mm: Make virt_to_pfn() a static inline mips: remove extraneous asm-generic/iomap.h include sparc: Use $(kecho) to announce kernel images being ready arm64: vdso32: Define BUILD_VDSO32_64 to correct prototypes csky: fix arch_jump_label_transform_static override arch: add do_page_fault prototypes arch: add missing prepare_ftrace_return() prototypes arch: vdso: consolidate gettime prototypes arch: include linux/cpu.h for trap_init() prototype arch: fix asm-offsets.c building with -Wmissing-prototypes arch: consolidate arch_irq_work_raise prototypes hexagon: Remove CONFIG_HEXAGON_ARCH_VERSION from uapi header asm/io: remove unnecessary xlate_dev_mem_ptr() and unxlate_dev_mem_ptr() mips: io: remove duplicated codes arch/*/io.h: remove ioremap_uc in some architectures mips: add including

arch/x86: Fix typos

2024-01-03T10:46:22+00:00

Fix typos, most reported by "codespell arch/x86". Only touches comments, no code changes. Signed-off-by: Bjorn Helgaas Signed-off-by: Ingo Molnar Reviewed-by: Randy Dunlap Link: https://lore.kernel.org/r/20240103004011.1758650-1-helgaas@kernel.org