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39 lines
1,009 B
C
39 lines
1,009 B
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_VDSO_GETRANDOM_H
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#define __ASM_VDSO_GETRANDOM_H
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#ifndef __ASSEMBLY__
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#include <asm/unistd.h>
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#include <asm/vdso/vsyscall.h>
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#include <vdso/datapage.h>
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/**
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* getrandom_syscall - Invoke the getrandom() syscall.
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* @buffer: Destination buffer to fill with random bytes.
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* @len: Size of @buffer in bytes.
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* @flags: Zero or more GRND_* flags.
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* Returns: The number of random bytes written to @buffer, or a negative value indicating an error.
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*/
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static __always_inline ssize_t getrandom_syscall(void *_buffer, size_t _len, unsigned int _flags)
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{
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register void *buffer asm ("x0") = _buffer;
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register size_t len asm ("x1") = _len;
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register unsigned int flags asm ("x2") = _flags;
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register long ret asm ("x0");
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register long nr asm ("x8") = __NR_getrandom;
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asm volatile(
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" svc #0\n"
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: "=r" (ret)
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: "r" (buffer), "r" (len), "r" (flags), "r" (nr)
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: "memory");
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return ret;
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}
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#endif /* !__ASSEMBLY__ */
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#endif /* __ASM_VDSO_GETRANDOM_H */
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