// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//
// System calls and other sys.stuff for AMD64, FreeBSD
// /usr/src/sys/kern/syscalls.master for syscall numbers.
//
#include "zasm_GOOS_GOARCH.h"
#include "../../cmd/ld/textflag.h"
// FreeBSD 8, FreeBSD 9, and older versions that I have checked
// do not restore R10 on exit from a "restarted" system call
// if you use the SYSCALL instruction. This means that, for example,
// if a signal arrives while the wait4 system call is executing,
// the wait4 internally returns ERESTART, which makes the kernel
// back up the PC to execute the SYSCALL instruction a second time.
// However, since the kernel does not restore R10, the fourth
// argument to the system call has been lost. (FreeBSD 9 also fails
// to restore the fifth and sixth arguments, R8 and R9, although
// some earlier versions did restore those correctly.)
// The broken code is in fast_syscall in FreeBSD's amd64/amd64/exception.S.
// It restores only DI, SI, DX, AX, and RFLAGS on system call return.
// http://fxr.watson.org/fxr/source/amd64/amd64/exception.S?v=FREEBSD91#L399
//
// The INT $0x80 system call path (int0x80_syscall in FreeBSD's
// amd64/ia32/ia32_exception.S) does not have this problem,
// but it expects the third argument in R10. Instead of rewriting
// all the assembly in this file, #define SYSCALL to a safe simulation
// using INT $0x80.
//
// INT $0x80 is a little slower than SYSCALL, but correctness wins.
//
// See golang.org/issue/6372.
#define SYSCALL MOVQ R10, CX; INT $0x80
TEXT runtime·sys_umtx_op(SB),NOSPLIT,$0
MOVQ 8(SP), DI
MOVL 16(SP), SI
MOVL 20(SP), DX
MOVQ 24(SP), R10
MOVQ 32(SP), R8
MOVL $454, AX
SYSCALL
RET
TEXT runtime·thr_new(SB),NOSPLIT,$0
MOVQ 8(SP), DI
MOVQ 16(SP), SI
MOVL $455, AX
SYSCALL
RET
TEXT runtime·thr_start(SB),NOSPLIT,$0
MOVQ DI, R13 // m
// set up FS to point at m->tls
LEAQ m_tls(R13), DI
CALL runtime·settls(SB) // smashes DI
// set up m, g
get_tls(CX)
MOVQ R13, m(CX)
MOVQ m_g0(R13), DI
MOVQ DI, g(CX)
CALL runtime·stackcheck(SB)
CALL runtime·mstart(SB)
MOVQ 0, AX // crash (not reached)
// Exit the entire program (like C exit)
TEXT runtime·exit(SB),NOSPLIT,$-8
MOVL 8(SP), DI // arg 1 exit status
MOVL $1, AX
SYSCALL
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·exit1(SB),NOSPLIT,$-8
MOVQ 8(SP), DI // arg 1 exit status
MOVL $431, AX
SYSCALL
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·open(SB),NOSPLIT,$-8
MOVQ 8(SP), DI // arg 1 pathname
MOVL 16(SP), SI // arg 2 flags
MOVL 20(SP), DX // arg 3 mode
MOVL $5, AX
SYSCALL
RET
TEXT runtime·close(SB),NOSPLIT,$-8
MOVL 8(SP), DI // arg 1 fd
MOVL $6, AX
SYSCALL
RET
TEXT runtime·read(SB),NOSPLIT,$-8
MOVL 8(SP), DI // arg 1 fd
MOVQ 16(SP), SI // arg 2 buf
MOVL 24(SP), DX // arg 3 count
MOVL $3, AX
SYSCALL
RET
TEXT runtime·write(SB),NOSPLIT,$-8
MOVL 8(SP), DI // arg 1 fd
MOVQ 16(SP), SI // arg 2 buf
MOVL 24(SP), DX // arg 3 count
MOVL $4, AX
SYSCALL
RET
TEXT runtime·getrlimit(SB),NOSPLIT,$-8
MOVL 8(SP), DI
MOVQ 16(SP), SI
MOVL $194, AX
SYSCALL
RET
TEXT runtime·raise(SB),NOSPLIT,$16
// thr_self(&8(SP))
LEAQ 8(SP), DI // arg 1 &8(SP)
MOVL $432, AX
SYSCALL
// thr_kill(self, SIGPIPE)
MOVQ 8(SP), DI // arg 1 id
MOVL sig+0(FP), SI // arg 2
MOVL $433, AX
SYSCALL
RET
TEXT runtime·setitimer(SB), NOSPLIT, $-8
MOVL 8(SP), DI
MOVQ 16(SP), SI
MOVQ 24(SP), DX
MOVL $83, AX
SYSCALL
RET
// func now() (sec int64, nsec int32)
TEXT time·now(SB), NOSPLIT, $32
MOVL $232, AX
MOVQ $0, DI // CLOCK_REALTIME
LEAQ 8(SP), SI
SYSCALL
MOVQ 8(SP), AX // sec
MOVQ 16(SP), DX // nsec
// sec is in AX, nsec in DX
MOVQ AX, sec+0(FP)
MOVL DX, nsec+8(FP)
RET
TEXT runtime·nanotime(SB), NOSPLIT, $32
MOVL $232, AX
// We can use CLOCK_MONOTONIC_FAST here when we drop
// support for FreeBSD 8-STABLE.
MOVQ $4, DI // CLOCK_MONOTONIC
LEAQ 8(SP), SI
SYSCALL
MOVQ 8(SP), AX // sec
MOVQ 16(SP), DX // nsec
// sec is in AX, nsec in DX
// return nsec in AX
IMULQ $1000000000, AX
ADDQ DX, AX
RET
TEXT runtime·sigaction(SB),NOSPLIT,$-8
MOVL 8(SP), DI // arg 1 sig
MOVQ 16(SP), SI // arg 2 act
MOVQ 24(SP), DX // arg 3 oact
MOVL $416, AX
SYSCALL
JCC 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·sigtramp(SB),NOSPLIT,$64
get_tls(BX)
// check that m exists
MOVQ m(BX), BP
CMPQ BP, $0
JNE 5(PC)
MOVQ DI, 0(SP)
MOVQ $runtime·badsignal(SB), AX
CALL AX
RET
// save g
MOVQ g(BX), R10
MOVQ R10, 40(SP)
// g = m->signal
MOVQ m_gsignal(BP), BP
MOVQ BP, g(BX)
MOVQ DI, 0(SP)
MOVQ SI, 8(SP)
MOVQ DX, 16(SP)
MOVQ R10, 24(SP)
CALL runtime·sighandler(SB)
// restore g
get_tls(BX)
MOVQ 40(SP), R10
MOVQ R10, g(BX)
RET
TEXT runtime·mmap(SB),NOSPLIT,$0
MOVQ 8(SP), DI // arg 1 addr
MOVQ 16(SP), SI // arg 2 len
MOVL 24(SP), DX // arg 3 prot
MOVL 28(SP), R10 // arg 4 flags
MOVL 32(SP), R8 // arg 5 fid
MOVL 36(SP), R9 // arg 6 offset
MOVL $477, AX
SYSCALL
RET
TEXT runtime·munmap(SB),NOSPLIT,$0
MOVQ 8(SP), DI // arg 1 addr
MOVQ 16(SP), SI // arg 2 len
MOVL $73, AX
SYSCALL
JCC 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·madvise(SB),NOSPLIT,$0
MOVQ 8(SP), DI
MOVQ 16(SP), SI
MOVQ 24(SP), DX
MOVQ $75, AX // madvise
SYSCALL
// ignore failure - maybe pages are locked
RET
TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
MOVQ new+8(SP), DI
MOVQ old+16(SP), SI
MOVQ $53, AX
SYSCALL
JCC 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·usleep(SB),NOSPLIT,$16
MOVL $0, DX
MOVL usec+0(FP), AX
MOVL $1000000, CX
DIVL CX
MOVQ AX, 0(SP) // tv_sec
MOVL $1000, AX
MULL DX
MOVQ AX, 8(SP) // tv_nsec
MOVQ SP, DI // arg 1 - rqtp
MOVQ $0, SI // arg 2 - rmtp
MOVL $240, AX // sys_nanosleep
SYSCALL
RET
// set tls base to DI
TEXT runtime·settls(SB),NOSPLIT,$8
ADDQ $16, DI // adjust for ELF: wants to use -16(FS) and -8(FS) for g and m
MOVQ DI, 0(SP)
MOVQ SP, SI
MOVQ $129, DI // AMD64_SET_FSBASE
MOVQ $165, AX // sysarch
SYSCALL
JCC 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·sysctl(SB),NOSPLIT,$0
MOVQ 8(SP), DI // arg 1 - name
MOVL 16(SP), SI // arg 2 - namelen
MOVQ 24(SP), DX // arg 3 - oldp
MOVQ 32(SP), R10 // arg 4 - oldlenp
MOVQ 40(SP), R8 // arg 5 - newp
MOVQ 48(SP), R9 // arg 6 - newlen
MOVQ $202, AX // sys___sysctl
SYSCALL
JCC 3(PC)
NEGQ AX
RET
MOVL $0, AX
RET
TEXT runtime·osyield(SB),NOSPLIT,$-4
MOVL $331, AX // sys_sched_yield
SYSCALL
RET
TEXT runtime·sigprocmask(SB),NOSPLIT,$0
MOVL $3, DI // arg 1 - how (SIG_SETMASK)
MOVQ 8(SP), SI // arg 2 - set
MOVQ 16(SP), DX // arg 3 - oset
MOVL $340, AX // sys_sigprocmask
SYSCALL
JAE 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
// int32 runtime·kqueue(void);
TEXT runtime·kqueue(SB),NOSPLIT,$0
MOVQ $0, DI
MOVQ $0, SI
MOVQ $0, DX
MOVL $362, AX
SYSCALL
JCC 2(PC)
NEGQ AX
RET
// int32 runtime·kevent(int kq, Kevent *changelist, int nchanges, Kevent *eventlist, int nevents, Timespec *timeout);
TEXT runtime·kevent(SB),NOSPLIT,$0
MOVL 8(SP), DI
MOVQ 16(SP), SI
MOVL 24(SP), DX
MOVQ 32(SP), R10
MOVL 40(SP), R8
MOVQ 48(SP), R9
MOVL $363, AX
SYSCALL
JCC 2(PC)
NEGQ AX
RET
// void runtime·closeonexec(int32 fd);
TEXT runtime·closeonexec(SB),NOSPLIT,$0
MOVL 8(SP), DI // fd
MOVQ $2, SI // F_SETFD
MOVQ $1, DX // FD_CLOEXEC
MOVL $92, AX // fcntl
SYSCALL
RET