f5b4057074
- getcpu() is not implemented. It will cause SIGILL. - gettimeofday() and time() are implemented with syscall.
61 lines
1.3 KiB
C
61 lines
1.3 KiB
C
/**
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* \file vsyscall.c
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* License details are found in the file LICENSE.
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* \brief
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* implements x86's vsyscall
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* \author Gou Nakamura <go.nakamura.yw@hitachi-solutions.com> \par
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* Copyright (C) 2014 Hitachi, Ltd.
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*/
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/*
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* HISTORY:
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*/
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/*
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* .vsyscall.* section's LMAs are different from their VMA.
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* make sure that these are position-independent codes.
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*/
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#include <syscall.h>
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extern int vsyscall_gettimeofday(void *tv, void *tz)
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__attribute__ ((section (".vsyscall.gettimeofday")));
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int vsyscall_gettimeofday(void *tv, void *tz)
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{
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int error;
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asm ("syscall" : "=a" (error)
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: "a" (__NR_gettimeofday), "D" (tv), "S" (tz)
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: "%rcx", "%r11", "memory");
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return error;
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}
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extern long vsyscall_time(void *tp)
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__attribute__ ((section (".vsyscall.time")));
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long vsyscall_time(void *tp)
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{
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long t;
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asm ( "syscall ;"
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/*
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* This vsyscall_time() cannot fail, because glibc's
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* vsyscall_time() does not set the errno.
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*
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* Because a possible error is only a memory access error,
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* in order that this function generates SIGSEGV
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* rather than returns error when a memory access error occurs,
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* this function accesses memory in user mode.
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*/
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"test %%rdx,%%rdx;"
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"jz 1f;"
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"mov %%rax,(%%rdx);"
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"1:"
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: "=a" (t)
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: "a" (__NR_time), "d" (tp), "D" (0)
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: "%rcx", "%r11", "memory");
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return t;
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}
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