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

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

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

riscv: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-uapi headers

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

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

riscv: Replace ASSEMBLY with ASSEMBLER in non-uapi headers