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Editing: sys_linux_amd64.s
// 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, Linux // #include "go_asm.h" #include "go_tls.h" #include "textflag.h" #include "cgo/abi_amd64.h" #define AT_FDCWD -100 #define SYS_read 0 #define SYS_write 1 #define SYS_close 3 #define SYS_mmap 9 #define SYS_munmap 11 #define SYS_brk 12 #define SYS_rt_sigaction 13 #define SYS_rt_sigprocmask 14 #define SYS_rt_sigreturn 15 #define SYS_sched_yield 24 #define SYS_mincore 27 #define SYS_madvise 28 #define SYS_nanosleep 35 #define SYS_setittimer 38 #define SYS_getpid 39 #define SYS_socket 41 #define SYS_connect 42 #define SYS_clone 56 #define SYS_exit 60 #define SYS_kill 62 #define SYS_sigaltstack 131 #define SYS_arch_prctl 158 #define SYS_gettid 186 #define SYS_futex 202 #define SYS_sched_getaffinity 204 #define SYS_timer_create 222 #define SYS_timer_settime 223 #define SYS_timer_delete 226 #define SYS_clock_gettime 228 #define SYS_exit_group 231 #define SYS_tgkill 234 #define SYS_openat 257 #define SYS_faccessat 269 #define SYS_pipe2 293 TEXT runtime·exit(SB),NOSPLIT,$0-4 MOVL code+0(FP), DI MOVL $SYS_exit_group, AX SYSCALL RET // func exitThread(wait *atomic.Uint32) TEXT runtime·exitThread(SB),NOSPLIT,$0-8 MOVQ wait+0(FP), AX // We're done using the stack. MOVL $0, (AX) MOVL $0, DI // exit code MOVL $SYS_exit, AX SYSCALL // We may not even have a stack any more. INT $3 JMP 0(PC) TEXT runtime·open(SB),NOSPLIT,$0-20 // This uses openat instead of open, because Android O blocks open. MOVL $AT_FDCWD, DI // AT_FDCWD, so this acts like open MOVQ name+0(FP), SI MOVL mode+8(FP), DX MOVL perm+12(FP), R10 MOVL $SYS_openat, AX SYSCALL CMPQ AX, $0xfffffffffffff001 JLS 2(PC) MOVL $-1, AX MOVL AX, ret+16(FP) RET TEXT runtime·closefd(SB),NOSPLIT,$0-12 MOVL fd+0(FP), DI MOVL $SYS_close, AX SYSCALL CMPQ AX, $0xfffffffffffff001 JLS 2(PC) MOVL $-1, AX MOVL AX, ret+8(FP) RET TEXT runtime·write1(SB),NOSPLIT,$0-28 MOVQ fd+0(FP), DI MOVQ p+8(FP), SI MOVL n+16(FP), DX MOVL $SYS_write, AX SYSCALL MOVL AX, ret+24(FP) RET TEXT runtime·read(SB),NOSPLIT,$0-28 MOVL fd+0(FP), DI MOVQ p+8(FP), SI MOVL n+16(FP), DX MOVL $SYS_read, AX SYSCALL MOVL AX, ret+24(FP) RET // func pipe2(flags int32) (r, w int32, errno int32) TEXT runtime·pipe2(SB),NOSPLIT,$0-20 LEAQ r+8(FP), DI MOVL flags+0(FP), SI MOVL $SYS_pipe2, AX SYSCALL MOVL AX, errno+16(FP) RET TEXT runtime·usleep(SB),NOSPLIT,$16 MOVL $0, DX MOVL usec+0(FP), AX MOVL $1000000, CX DIVL CX MOVQ AX, 0(SP) MOVL $1000, AX // usec to nsec MULL DX MOVQ AX, 8(SP) // nanosleep(&ts, 0) MOVQ SP, DI MOVL $0, SI MOVL $SYS_nanosleep, AX SYSCALL RET TEXT runtime·gettid(SB),NOSPLIT,$0-4 MOVL $SYS_gettid, AX SYSCALL MOVL AX, ret+0(FP) RET TEXT runtime·raise(SB),NOSPLIT,$0 MOVL $SYS_getpid, AX SYSCALL MOVL AX, R12 MOVL $SYS_gettid, AX SYSCALL MOVL AX, SI // arg 2 tid MOVL R12, DI // arg 1 pid MOVL sig+0(FP), DX // arg 3 MOVL $SYS_tgkill, AX SYSCALL RET TEXT runtime·raiseproc(SB),NOSPLIT,$0 MOVL $SYS_getpid, AX SYSCALL MOVL AX, DI // arg 1 pid MOVL sig+0(FP), SI // arg 2 MOVL $SYS_kill, AX SYSCALL RET TEXT ·getpid(SB),NOSPLIT,$0-8 MOVL $SYS_getpid, AX SYSCALL MOVQ AX, ret+0(FP) RET TEXT ·tgkill(SB),NOSPLIT,$0 MOVQ tgid+0(FP), DI MOVQ tid+8(FP), SI MOVQ sig+16(FP), DX MOVL $SYS_tgkill, AX SYSCALL RET TEXT runtime·setitimer(SB),NOSPLIT,$0-24 MOVL mode+0(FP), DI MOVQ new+8(FP), SI MOVQ old+16(FP), DX MOVL $SYS_setittimer, AX SYSCALL RET TEXT runtime·timer_create(SB),NOSPLIT,$0-28 MOVL clockid+0(FP), DI MOVQ sevp+8(FP), SI MOVQ timerid+16(FP), DX MOVL $SYS_timer_create, AX SYSCALL MOVL AX, ret+24(FP) RET TEXT runtime·timer_settime(SB),NOSPLIT,$0-28 MOVL timerid+0(FP), DI MOVL flags+4(FP), SI MOVQ new+8(FP), DX MOVQ old+16(FP), R10 MOVL $SYS_timer_settime, AX SYSCALL MOVL AX, ret+24(FP) RET TEXT runtime·timer_delete(SB),NOSPLIT,$0-12 MOVL timerid+0(FP), DI MOVL $SYS_timer_delete, AX SYSCALL MOVL AX, ret+8(FP) RET TEXT runtime·mincore(SB),NOSPLIT,$0-28 MOVQ addr+0(FP), DI MOVQ n+8(FP), SI MOVQ dst+16(FP), DX MOVL $SYS_mincore, AX SYSCALL MOVL AX, ret+24(FP) RET // func nanotime1() int64 TEXT runtime·nanotime1(SB),NOSPLIT,$16-8 // We don't know how much stack space the VDSO code will need, // so switch to g0. // In particular, a kernel configured with CONFIG_OPTIMIZE_INLINING=n // and hardening can use a full page of stack space in gettime_sym // due to stack probes inserted to avoid stack/heap collisions. // See issue #20427. MOVQ SP, R12 // Save old SP; R12 unchanged by C code. MOVQ g_m(R14), BX // BX unchanged by C code. // Set vdsoPC and vdsoSP for SIGPROF traceback. // Save the old values on stack and restore them on exit, // so this function is reentrant. MOVQ m_vdsoPC(BX), CX MOVQ m_vdsoSP(BX), DX MOVQ CX, 0(SP) MOVQ DX, 8(SP) LEAQ ret+0(FP), DX MOVQ -8(DX), CX MOVQ CX, m_vdsoPC(BX) MOVQ DX, m_vdsoSP(BX) CMPQ R14, m_curg(BX) // Only switch if on curg. JNE noswitch MOVQ m_g0(BX), DX MOVQ (g_sched+gobuf_sp)(DX), SP // Set SP to g0 stack noswitch: SUBQ $16, SP // Space for results ANDQ $~15, SP // Align for C code MOVL $1, DI // CLOCK_MONOTONIC LEAQ 0(SP), SI MOVQ runtime·vdsoClockgettimeSym(SB), AX CMPQ AX, $0 JEQ fallback CALL AX ret: MOVQ 0(SP), AX // sec MOVQ 8(SP), DX // nsec MOVQ R12, SP // Restore real SP // Restore vdsoPC, vdsoSP // We don't worry about being signaled between the two stores. // If we are not in a signal handler, we'll restore vdsoSP to 0, // and no one will care about vdsoPC. If we are in a signal handler, // we cannot receive another signal. MOVQ 8(SP), CX MOVQ CX, m_vdsoSP(BX) MOVQ 0(SP), CX MOVQ CX, m_vdsoPC(BX) // sec is in AX, nsec in DX // return nsec in AX IMULQ $1000000000, AX ADDQ DX, AX MOVQ AX, ret+0(FP) RET fallback: MOVQ $SYS_clock_gettime, AX SYSCALL JMP ret TEXT runtime·rtsigprocmask(SB),NOSPLIT,$0-28 MOVL how+0(FP), DI MOVQ new+8(FP), SI MOVQ old+16(FP), DX MOVL size+24(FP), R10 MOVL $SYS_rt_sigprocmask, AX SYSCALL CMPQ AX, $0xfffffffffffff001 JLS 2(PC) MOVL $0xf1, 0xf1 // crash RET TEXT runtime·rt_sigaction(SB),NOSPLIT,$0-36 MOVQ sig+0(FP), DI MOVQ new+8(FP), SI MOVQ old+16(FP), DX MOVQ size+24(FP), R10 MOVL $SYS_rt_sigaction, AX SYSCALL MOVL AX, ret+32(FP) RET // Call the function stored in _cgo_sigaction using the GCC calling convention. TEXT runtime·callCgoSigaction(SB),NOSPLIT,$16 MOVQ sig+0(FP), DI MOVQ new+8(FP), SI MOVQ old+16(FP), DX MOVQ _cgo_sigaction(SB), AX MOVQ SP, BX // callee-saved ANDQ $~15, SP // alignment as per amd64 psABI CALL AX MOVQ BX, SP MOVL AX, ret+24(FP) RET TEXT runtime·sigfwd(SB),NOSPLIT,$0-32 MOVQ fn+0(FP), AX MOVL sig+8(FP), DI MOVQ info+16(FP), SI MOVQ ctx+24(FP), DX MOVQ SP, BX // callee-saved ANDQ $~15, SP // alignment for x86_64 ABI CALL AX MOVQ BX, SP RET // Called using C ABI. TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME|NOFRAME,$0 // Transition from C ABI to Go ABI. PUSH_REGS_HOST_TO_ABI0() // Set up ABIInternal environment: g in R14, cleared X15. get_tls(R12) MOVQ g(R12), R14 PXOR X15, X15 // Reserve space for spill slots. NOP SP // disable vet stack checking ADJSP $24 // Call into the Go signal handler MOVQ DI, AX // sig MOVQ SI, BX // info MOVQ DX, CX // ctx CALL ·sigtrampgo<ABIInternal>(SB) ADJSP $-24 POP_REGS_HOST_TO_ABI0() RET // Called using C ABI. TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT|NOFRAME,$0 // Transition from C ABI to Go ABI. PUSH_REGS_HOST_TO_ABI0() // Set up ABIInternal environment: g in R14, cleared X15. get_tls(R12) MOVQ g(R12), R14 PXOR X15, X15 // Reserve space for spill slots. NOP SP // disable vet stack checking ADJSP $24 // Call into the Go signal handler MOVQ DI, AX // sig MOVQ SI, BX // info MOVQ DX, CX // ctx CALL ·sigprofNonGo<ABIInternal>(SB) ADJSP $-24 POP_REGS_HOST_TO_ABI0() RET // Used instead of sigtramp in programs that use cgo. // Arguments from kernel are in DI, SI, DX. TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0 // If no traceback function, do usual sigtramp. MOVQ runtime·cgoTraceback(SB), AX TESTQ AX, AX JZ sigtramp // If no traceback support function, which means that // runtime/cgo was not linked in, do usual sigtramp. MOVQ _cgo_callers(SB), AX TESTQ AX, AX JZ sigtramp // Figure out if we are currently in a cgo call. // If not, just do usual sigtramp. get_tls(CX) MOVQ g(CX),AX TESTQ AX, AX JZ sigtrampnog // g == nil MOVQ g_m(AX), AX TESTQ AX, AX JZ sigtramp // g.m == nil MOVL m_ncgo(AX), CX TESTL CX, CX JZ sigtramp // g.m.ncgo == 0 MOVQ m_curg(AX), CX TESTQ CX, CX JZ sigtramp // g.m.curg == nil MOVQ g_syscallsp(CX), CX TESTQ CX, CX JZ sigtramp // g.m.curg.syscallsp == 0 MOVQ m_cgoCallers(AX), R8 TESTQ R8, R8 JZ sigtramp // g.m.cgoCallers == nil MOVL m_cgoCallersUse(AX), CX TESTL CX, CX JNZ sigtramp // g.m.cgoCallersUse != 0 // Jump to a function in runtime/cgo. // That function, written in C, will call the user's traceback // function with proper unwind info, and will then call back here. // The first three arguments, and the fifth, are already in registers. // Set the two remaining arguments now. MOVQ runtime·cgoTraceback(SB), CX MOVQ $runtime·sigtramp(SB), R9 MOVQ _cgo_callers(SB), AX JMP AX sigtramp: JMP runtime·sigtramp(SB) sigtrampnog: // Signal arrived on a non-Go thread. If this is SIGPROF, get a // stack trace. CMPL DI, $27 // 27 == SIGPROF JNZ sigtramp // Lock sigprofCallersUse. MOVL $0, AX MOVL $1, CX MOVQ $runtime·sigprofCallersUse(SB), R11 LOCK CMPXCHGL CX, 0(R11) JNZ sigtramp // Skip stack trace if already locked. // Jump to the traceback function in runtime/cgo. // It will call back to sigprofNonGo, via sigprofNonGoWrapper, to convert // the arguments to the Go calling convention. // First three arguments to traceback function are in registers already. MOVQ runtime·cgoTraceback(SB), CX MOVQ $runtime·sigprofCallers(SB), R8 MOVQ $runtime·sigprofNonGoWrapper<>(SB), R9 MOVQ _cgo_callers(SB), AX JMP AX // For cgo unwinding to work, this function must look precisely like // the one in glibc. The glibc source code is: // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c;h=afdce87381228f0cf32fa9fa6c8c4efa5179065c#l80 // The code that cares about the precise instructions used is: // https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libgcc/config/i386/linux-unwind.h;h=5486223d60272c73d5103b29ae592d2ee998e1cf#l49 // // For gdb unwinding to work, this function must look precisely like the one in // glibc and must be named "__restore_rt" or contain the string "sigaction" in // the name. The gdb source code is: // https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gdb/amd64-linux-tdep.c;h=cbbac1a0c64e1deb8181b9d0ff6404e328e2979d#l178 TEXT runtime·sigreturn__sigaction(SB),NOSPLIT,$0 MOVQ $SYS_rt_sigreturn, AX SYSCALL INT $3 // not reached TEXT runtime·sysMmap(SB),NOSPLIT,$0 MOVQ addr+0(FP), DI MOVQ n+8(FP), SI MOVL prot+16(FP), DX MOVL flags+20(FP), R10 MOVL fd+24(FP), R8 MOVL off+28(FP), R9 MOVL $SYS_mmap, AX SYSCALL CMPQ AX, $0xfffffffffffff001 JLS ok NOTQ AX INCQ AX MOVQ $0, p+32(FP) MOVQ AX, err+40(FP) RET ok: MOVQ AX, p+32(FP) MOVQ $0, err+40(FP) RET // Call the function stored in _cgo_mmap using the GCC calling convention. // This must be called on the system stack. TEXT runtime·callCgoMmap(SB),NOSPLIT,$16 MOVQ addr+0(FP), DI MOVQ n+8(FP), SI MOVL prot+16(FP), DX MOVL flags+20(FP), CX MOVL fd+24(FP), R8 MOVL off+28(FP), R9 MOVQ _cgo_mmap(SB), AX MOVQ SP, BX ANDQ $~15, SP // alignment as per amd64 psABI MOVQ BX, 0(SP) CALL AX MOVQ 0(SP), SP MOVQ AX, ret+32(FP) RET TEXT runtime·sysMunmap(SB),NOSPLIT,$0 MOVQ addr+0(FP), DI MOVQ n+8(FP), SI MOVQ $SYS_munmap, AX SYSCALL CMPQ AX, $0xfffffffffffff001 JLS 2(PC) MOVL $0xf1, 0xf1 // crash RET // Call the function stored in _cgo_munmap using the GCC calling convention. // This must be called on the system stack. TEXT runtime·callCgoMunmap(SB),NOSPLIT,$16-16 MOVQ addr+0(FP), DI MOVQ n+8(FP), SI MOVQ _cgo_munmap(SB), AX MOVQ SP, BX ANDQ $~15, SP // alignment as per amd64 psABI MOVQ BX, 0(SP) CALL AX MOVQ 0(SP), SP RET TEXT runtime·madvise(SB),NOSPLIT,$0 MOVQ addr+0(FP), DI MOVQ n+8(FP), SI MOVL flags+16(FP), DX MOVQ $SYS_madvise, AX SYSCALL MOVL AX, ret+24(FP) RET // int64 futex(int32 *uaddr, int32 op, int32 val, // struct timespec *timeout, int32 *uaddr2, int32 val2); TEXT runtime·futex(SB),NOSPLIT,$0 MOVQ addr+0(FP), DI MOVL op+8(FP), SI MOVL val+12(FP), DX MOVQ ts+16(FP), R10 MOVQ addr2+24(FP), R8 MOVL val3+32(FP), R9 MOVL $SYS_futex, AX SYSCALL MOVL AX, ret+40(FP) RET // int32 clone(int32 flags, void *stk, M *mp, G *gp, void (*fn)(void)); TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0 MOVL flags+0(FP), DI MOVQ stk+8(FP), SI MOVQ $0, DX MOVQ $0, R10 MOVQ $0, R8 // Copy mp, gp, fn off parent stack for use by child. // Careful: Linux system call clobbers CX and R11. MOVQ mp+16(FP), R13 MOVQ gp+24(FP), R9 MOVQ fn+32(FP), R12 CMPQ R13, $0 // m JEQ nog1 CMPQ R9, $0 // g JEQ nog1 LEAQ m_tls(R13), R8 #ifdef GOOS_android // Android stores the TLS offset in runtime·tls_g. SUBQ runtime·tls_g(SB), R8 #else ADDQ $8, R8 // ELF wants to use -8(FS) #endif ORQ $0x00080000, DI //add flag CLONE_SETTLS(0x00080000) to call clone nog1: MOVL $SYS_clone, AX SYSCALL // In parent, return. CMPQ AX, $0 JEQ 3(PC) MOVL AX, ret+40(FP) RET // In child, on new stack. MOVQ SI, SP // If g or m are nil, skip Go-related setup. CMPQ R13, $0 // m JEQ nog2 CMPQ R9, $0 // g JEQ nog2 // Initialize m->procid to Linux tid MOVL $SYS_gettid, AX SYSCALL MOVQ AX, m_procid(R13) // In child, set up new stack get_tls(CX) MOVQ R13, g_m(R9) MOVQ R9, g(CX) MOVQ R9, R14 // set g register CALL runtime·stackcheck(SB) nog2: // Call fn. This is the PC of an ABI0 function. CALL R12 // It shouldn't return. If it does, exit that thread. MOVL $111, DI MOVL $SYS_exit, AX SYSCALL JMP -3(PC) // keep exiting TEXT runtime·sigaltstack(SB),NOSPLIT,$0 MOVQ new+0(FP), DI MOVQ old+8(FP), SI MOVQ $SYS_sigaltstack, AX SYSCALL CMPQ AX, $0xfffffffffffff001 JLS 2(PC) MOVL $0xf1, 0xf1 // crash RET // set tls base to DI TEXT runtime·settls(SB),NOSPLIT,$32 #ifdef GOOS_android // Android stores the TLS offset in runtime·tls_g. SUBQ runtime·tls_g(SB), DI #else ADDQ $8, DI // ELF wants to use -8(FS) #endif MOVQ DI, SI MOVQ $0x1002, DI // ARCH_SET_FS MOVQ $SYS_arch_prctl, AX SYSCALL CMPQ AX, $0xfffffffffffff001 JLS 2(PC) MOVL $0xf1, 0xf1 // crash RET TEXT runtime·osyield(SB),NOSPLIT,$0 MOVL $SYS_sched_yield, AX SYSCALL RET TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0 MOVQ pid+0(FP), DI MOVQ len+8(FP), SI MOVQ buf+16(FP), DX MOVL $SYS_sched_getaffinity, AX SYSCALL MOVL AX, ret+24(FP) RET // int access(const char *name, int mode) TEXT runtime·access(SB),NOSPLIT,$0 // This uses faccessat instead of access, because Android O blocks access. MOVL $AT_FDCWD, DI // AT_FDCWD, so this acts like access MOVQ name+0(FP), SI MOVL mode+8(FP), DX MOVL $0, R10 MOVL $SYS_faccessat, AX SYSCALL MOVL AX, ret+16(FP) RET // int connect(int fd, const struct sockaddr *addr, socklen_t addrlen) TEXT runtime·connect(SB),NOSPLIT,$0-28 MOVL fd+0(FP), DI MOVQ addr+8(FP), SI MOVL len+16(FP), DX MOVL $SYS_connect, AX SYSCALL MOVL AX, ret+24(FP) RET // int socket(int domain, int type, int protocol) TEXT runtime·socket(SB),NOSPLIT,$0-20 MOVL domain+0(FP), DI MOVL typ+4(FP), SI MOVL prot+8(FP), DX MOVL $SYS_socket, AX SYSCALL MOVL AX, ret+16(FP) RET // func sbrk0() uintptr TEXT runtime·sbrk0(SB),NOSPLIT,$0-8 // Implemented as brk(NULL). MOVQ $0, DI MOVL $SYS_brk, AX SYSCALL MOVQ AX, ret+0(FP) RET
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