kernel/linux.git/include/linux/kernel.h, branch v6.6.132

kernel.h: Move ARRAY_SIZE() to a separate header

2025-12-01T10:41:47+00:00

[ Upstream commit 3cd39bc3b11b8d34b7d7c961a35fdfd18b0ebf75 ] Touching files so used for the kernel, forces 'make' to recompile most of the kernel. Having those definitions in more granular files helps avoid recompiling so much of the kernel. Signed-off-by: Alejandro Colomar Reviewed-by: Giovanni Cabiddu Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230817143352.132583-2-lucas.segarra.fernandez@intel.com [andy: reduced to cover only string.h for now] Signed-off-by: Andy Shevchenko Stable-dep-of: 896f1a2493b5 ("net: qlogic/qede: fix potential out-of-bounds read in qede_tpa_cont() and qede_tpa_end()") Signed-off-by: Sasha Levin

lib/vsprintf: split out sprintf() and friends

2023-08-21T20:46:24+00:00

Patch series "lib/vsprintf: Rework header inclusions", v3. Some patches that reduce the mess with the header inclusions related to vsprintf.c module. Each patch has its own description, and has no dependencies to each other, except the collisions over modifications of the same places. Hence the series. This patch (of 2): kernel.h is being used as a dump for all kinds of stuff for a long time. sprintf() and friends are used in many drivers without need of the full kernel.h dependency train with it. Here is the attempt on cleaning it up by splitting out sprintf() and friends. Link: https://lkml.kernel.org/r/20230814163344.17429-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20230814163344.17429-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Reviewed-by: Petr Mladek Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Marco Elver Cc: Rasmus Villemoes Cc: Sergey Senozhatsky Cc: Steven Rostedt (Google) Signed-off-by: Andrew Morton

kernel.h: split out COUNT_ARGS() and CONCATENATE() to args.h

2023-08-18T17:18:56+00:00

Patch series "kernel.h: Split out a couple of macros to args.h", v4. There are macros in kernel.h that can be used outside of that header. Split them to args.h and replace open coded variants. This patch (of 4): kernel.h is being used as a dump for all kinds of stuff for a long time. The COUNT_ARGS() and CONCATENATE() macros may be used in some places without need of the full kernel.h dependency train with it. Here is the attempt on cleaning it up by splitting out these macros(). While at it, include new header where it's being used. Link: https://lkml.kernel.org/r/20230718211147.18647-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20230718211147.18647-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Acked-by: Steven Rostedt (Google) Cc: Bjorn Helgaas Acked-by: Bjorn Helgaas [PCI] Cc: Brendan Higgins Cc: Daniel Latypov Cc: Dave Hansen Cc: David Gow Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Lorenzo Pieralisi Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Shuah Khan Cc: Sudeep Holla Cc: Thomas Gleixner Signed-off-by: Andrew Morton

kernel.h: split the hexadecimal related helpers to hex.h

2023-04-08T20:45:38+00:00

For the sake of cleaning up the kernel.h split the hexadecimal related helpers to own header called 'hex.h'. Link: https://lkml.kernel.org/r/20230323155029.40000-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Cc: Rasmus Villemoes Signed-off-by: Andrew Morton

tracing: Always use canonical ftrace path

2023-02-18T19:34:09+00:00

The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many comments and Kconfig help messages in the tracing code still refer to this older debugfs path, so let's update them to avoid confusion. Link: https://lore.kernel.org/linux-trace-kernel/20230215223350.2658616-2-zwisler@google.com Acked-by: Masami Hiramatsu (Google) Reviewed-by: Mukesh Ojha Signed-off-by: Ross Zwisler Signed-off-by: Steven Rostedt (Google)

hex2bin: make the function hex_to_bin constant-time

2022-04-27T17:57:33+00:00

The function hex2bin is used to load cryptographic keys into device mapper targets dm-crypt and dm-integrity. It should take constant time independent on the processed data, so that concurrently running unprivileged code can't infer any information about the keys via microarchitectural convert channels. This patch changes the function hex_to_bin so that it contains no branches and no memory accesses. Note that this shouldn't cause performance degradation because the size of the new function is the same as the size of the old function (on x86-64) - and the new function causes no branch misprediction penalties. I compile-tested this function with gcc on aarch64 alpha arm hppa hppa64 i386 ia64 m68k mips32 mips64 powerpc powerpc64 riscv sh4 s390x sparc32 sparc64 x86_64 and with clang on aarch64 arm hexagon i386 mips32 mips64 powerpc powerpc64 s390x sparc32 sparc64 x86_64 to verify that there are no branches in the generated code. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds

block: move lower_48_bits() to block

2022-04-12T01:18:27+00:00

The function is not generally applicable enough to be included in the core kernel header. Move it to block since it's the only subsystem using it. Suggested-by: Linus Torvalds Signed-off-by: Keith Busch Link: https://lore.kernel.org/r/20220327173316.315-1-kbusch@kernel.org Signed-off-by: Jens Axboe

Merge tag 'for-5.18/64bit-pi-2022-03-25' of git://git.kernel.dk/linux-block

2022-03-26T19:01:35+00:00

Pull block layer 64-bit data integrity support from Jens Axboe: "This adds support for 64-bit data integrity in the block layer and in NVMe" * tag 'for-5.18/64bit-pi-2022-03-25' of git://git.kernel.dk/linux-block: crypto: fix crc64 testmgr digest byte order nvme: add support for enhanced metadata block: add pi for extended integrity crypto: add rocksoft 64b crc guard tag framework lib: add rocksoft model crc64 linux/kernel: introduce lower_48_bits function asm-generic: introduce be48 unaligned accessors nvme: allow integrity on extended metadata formats block: support pi with extended metadata

linux/kernel: introduce lower_48_bits function

2022-03-07T19:48:35+00:00

Recent data integrity field enhancements allow reference tags to be up to 48 bits. Introduce an inline helper function since this will be a repeated operation. Suggested-by: Bart Van Assche Signed-off-by: Keith Busch Reviewed-by: Bart Van Assche Link: https://lore.kernel.org/r/20220303201312.3255347-5-kbusch@kernel.org Signed-off-by: Jens Axboe

sched/preempt: Add PREEMPT_DYNAMIC using static keys

2022-02-19T10:11:08+00:00

Where an architecture selects HAVE_STATIC_CALL but not HAVE_STATIC_CALL_INLINE, each static call has an out-of-line trampoline which will either branch to a callee or return to the caller. On such architectures, a number of constraints can conspire to make those trampolines more complicated and potentially less useful than we'd like. For example: * Hardware and software control flow integrity schemes can require the addition of "landing pad" instructions (e.g. `BTI` for arm64), which will also be present at the "real" callee. * Limited branch ranges can require that trampolines generate or load an address into a register and perform an indirect branch (or at least have a slow path that does so). This loses some of the benefits of having a direct branch. * Interaction with SW CFI schemes can be complicated and fragile, e.g. requiring that we can recognise idiomatic codegen and remove indirections understand, at least until clang proves more helpful mechanisms for dealing with this. For PREEMPT_DYNAMIC, we don't need the full power of static calls, as we really only need to enable/disable specific preemption functions. We can achieve the same effect without a number of the pain points above by using static keys to fold early returns into the preemption functions themselves rather than in an out-of-line trampoline, effectively inlining the trampoline into the start of the function. For arm64, this results in good code generation. For example, the dynamic_cond_resched() wrapper looks as follows when enabled. When disabled, the first `B` is replaced with a `NOP`, resulting in an early return. | : | bti c | b // or `nop` | mov w0, #0x0 | ret | mrs x0, sp_el0 | ldr x0, [x0, #8] | cbnz x0, | paciasp | stp x29, x30, [sp, #-16]! | mov x29, sp | bl | mov w0, #0x1 | ldp x29, x30, [sp], #16 | autiasp | ret ... compared to the regular form of the function: | <__cond_resched>: | bti c | mrs x0, sp_el0 | ldr x1, [x0, #8] | cbz x1, <__cond_resched+0x18> | mov w0, #0x0 | ret | paciasp | stp x29, x30, [sp, #-16]! | mov x29, sp | bl | mov w0, #0x1 | ldp x29, x30, [sp], #16 | autiasp | ret Any architecture which implements static keys should be able to use this to implement PREEMPT_DYNAMIC with similar cost to non-inlined static calls. Since this is likely to have greater overhead than (inlined) static calls, PREEMPT_DYNAMIC is only defaulted to enabled when HAVE_PREEMPT_DYNAMIC_CALL is selected. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Acked-by: Ard Biesheuvel Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20220214165216.2231574-6-mark.rutland@arm.com