kernel/arch/riscv/include/asm/vdso, branch linux-rolling-stable

riscv: hwprobe: Fix stale vDSO data for late-initialized keys at boot

2025-10-18T04:23:11Z

The hwprobe vDSO data for some keys, like MISALIGNED_VECTOR_PERF, is determined by an asynchronous kthread. This can create a race condition where the kthread finishes after the vDSO data has already been populated, causing userspace to read stale values. To fix this race, a new 'ready' flag is added to the vDSO data, initialized to 'false' during arch_initcall_sync. This flag is checked by both the vDSO's user-space code and the riscv_hwprobe syscall. The syscall serves as a one-time gate, using a completion to wait for any pending probes before populating the data and setting the flag to 'true', thus ensuring userspace reads fresh values on its first request. Reported-by: Tsukasa OI Closes: https://lore.kernel.org/linux-riscv/760d637b-b13b-4518-b6bf-883d55d44e7f@irq.a4lg.com/ Fixes: e7c9d66e313b ("RISC-V: Report vector unaligned access speed hwprobe") Cc: Palmer Dabbelt Cc: Alexandre Ghiti Cc: Olof Johansson Cc: stable@vger.kernel.org Reviewed-by: Alexandre Ghiti Co-developed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt Signed-off-by: Jingwei Wang Link: https://lore.kernel.org/r/20250811142035.105820-1-wangjingwei@iscas.ac.cn [pjw@kernel.org: fix checkpatch issues] Signed-off-by: Paul Walmsley

riscv: errata: Fix the PAUSE Opcode for MIPS P8700

2025-09-19T16:33:56Z

Add ERRATA_MIPS and ERRATA_MIPS_P8700_PAUSE_OPCODE configs. Handle errata for the MIPS PAUSE instruction. Signed-off-by: Djordje Todorovic Signed-off-by: Aleksandar Rikalo Signed-off-by: Raj Vishwanathan4 Signed-off-by: Aleksa Paunovic Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20250724-p8700-pause-v5-7-a6cbbe1c3412@htecgroup.com [pjw@kernel.org: updated to apply and compile; fixed a checkpatch issue] Signed-off-by: Paul Walmsley

riscv: Replace ASSEMBLY with ASSEMBLER in non-uapi headers

2025-09-16T22:25:30Z

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 originally was a completely mechanical patch (done with a simple "sed -i" statement), with some manual fixups during rebasing of the patch later. Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Alexandre Ghiti Cc: linux-riscv@lists.infradead.org Signed-off-by: Thomas Huth Link: https://lore.kernel.org/r/20250606070952.498274-3-thuth@redhat.com Signed-off-by: Paul Walmsley

RISC-V: vDSO: Correct inline assembly constraints in the getrandom syscall wrapper

2025-06-12T19:13:57Z

As recently pointed out by Thomas, if a register is forced for two different register variables, among them one is used as "+" (both input and output) and another is only used as input, Clang would treat the conflicting input parameters as undefined behaviour and optimize away the argument assignment. Instead use "=r" (only output) for the output parameter and "r" (only input) for the input parameter. While the example from the GCC documentation uses "0" for the input parameter, this is not necessary as confirmed by the GCC developers and "r" matches what the other architectures' vDSO implementations are using. [ alex: Update log to match v2 (Thomas) ] Link: https://lore.kernel.org/all/20250603-loongarch-vdso-syscall-v1-1-6d12d6dfbdd0@linutronix.de/ Link: https://gcc.gnu.org/onlinedocs/gcc-15.1.0/gcc/Local-Register-Variables.html Link: https://gcc.gnu.org/pipermail/gcc-help/2025-June/144266.html Cc: Thomas Weißschuh Cc: Nathan Chancellor Signed-off-by: Xi Ruoyao Reviewed-by: Thomas Weißschuh Fixes: ee0d03053e70 ("RISC-V: vDSO: Wire up getrandom() vDSO") Link: https://lore.kernel.org/r/20250606092443.73650-2-xry111@xry111.site Signed-off-by: Alexandre Ghiti Signed-off-by: Palmer Dabbelt

RISC-V: vDSO: Wire up getrandom() vDSO implementation

2025-06-05T21:03:09Z

Hook up the generic vDSO implementation to the generic vDSO getrandom implementation by providing the required __arch_chacha20_blocks_nostack and getrandom_syscall implementations. Also wire up the selftests. The benchmark result: vdso: 25000000 times in 2.466341333 seconds libc: 25000000 times in 41.447720005 seconds syscall: 25000000 times in 41.043926672 seconds vdso: 25000000 x 256 times in 162.286219353 seconds libc: 25000000 x 256 times in 2953.855018685 seconds syscall: 25000000 x 256 times in 2796.268546000 seconds [ alex: - Fix dynamic relocation - Squash Nathan's fix https://lore.kernel.org/all/20250423-riscv-fix-compat_vdso-lld-v2-1-b7bbbc244501@kernel.org/ - Add comment from Loongarch ] Signed-off-by: Xi Ruoyao Link: https://lore.kernel.org/r/20250411024600.16045-1-xry111@xry111.site Tested-by: Alexandre Ghiti Signed-off-by: Alexandre Ghiti Signed-off-by: Palmer Dabbelt

riscv: vdso: Switch to generic storage implementation

2025-02-21T08:54:02Z

The generic storage implementation provides the same features as the custom one. However it can be shared between architectures, making maintenance easier. Co-developed-by: Nam Cao Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-9-13a4669dfc8c@linutronix.de

vdso: Rename struct arch_vdso_data to arch_vdso_time_data

2024-11-02T11:37:36Z

The struct arch_vdso_data is only about vdso time data. So rename it to arch_vdso_time_data to make it obvious. Non time-related data will be migrated out of these structs soon. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Acked-by: Heiko Carstens # s390 Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-28-b64f0842d512@linutronix.de

riscv: vdso: Remove timekeeper include

2024-10-15T15:50:29Z

Since the generic VDSO clock mode storage is used, this header file is unused and can be removed. This avoids including a non-VDSO header while building the VDSO, which can lead to compilation errors. Also drop the comment which is out of date and in the wrong place. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20241010-vdso-generic-arch_update_vsyscall-v1-5-7fe5a3ea4382@linutronix.de

riscv: Provide a definition for 'pause'

2024-07-12T10:16:39Z

If we're going to provide the encoding for 'pause' in cpu_relax() anyway, then we can drop the toolchain checks and just always use it. The advantage of doing this is that other code that need pause don't need to also define it (yes, another use is coming). Add the definition to insn-def.h since it's an instruction definition and also because insn-def.h doesn't include much, so it's safe to include from asm/vdso/processor.h without concern for circular dependencies. Signed-off-by: Andrew Jones Link: https://lore.kernel.org/r/20240426100820.14762-9-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt

riscv: Using TOOLCHAIN_HAS_ZIHINTPAUSE marco replace zihintpause

2023-11-01T02:15:54Z

Actually it is a part of Conor's commit aae538cd03bc ("riscv: fix detection of toolchain Zihintpause support"). It is looks like a merge issue. Samuel's commit 0b1d60d6dd9e ("riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y") do not base on Conor's commit and revert to __riscv_zihintpause. So this patch can fix it. Signed-off-by: Minda Chen Fixes: 3c349eacc559 ("Merge patch "riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y"") Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230802064215.31111-1-minda.chen@starfivetech.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt