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kernel/arch/riscv/include/asm/vdso/getrandom.h
Xi Ruoyao ee0d03053e
RISC-V: vDSO: Wire up getrandom() vDSO implementation
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 <xry111@xry111.site>
Link: https://lore.kernel.org/r/20250411024600.16045-1-xry111@xry111.site
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-05 14:03:09 -07:00

30 lines
750 B
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2025 Xi Ruoyao <xry111@xry111.site>. All Rights Reserved.
*/
#ifndef __ASM_VDSO_GETRANDOM_H
#define __ASM_VDSO_GETRANDOM_H
#ifndef __ASSEMBLY__
#include <asm/unistd.h>
static __always_inline ssize_t getrandom_syscall(void *_buffer, size_t _len, unsigned int _flags)
{
register long ret asm("a0");
register long nr asm("a7") = __NR_getrandom;
register void *buffer asm("a0") = _buffer;
register size_t len asm("a1") = _len;
register unsigned int flags asm("a2") = _flags;
asm volatile ("ecall\n"
: "+r" (ret)
: "r" (nr), "r" (buffer), "r" (len), "r" (flags)
: "memory");
return ret;
}
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_GETRANDOM_H */