1
0
mirror of https://github.com/golang/go synced 2024-11-19 16:04:48 -07:00
go/src/runtime/sys_linux_mipsx.s
Austin Clements bb6309cd63 runtime: inform arena placement using sbrk(0)
On 32-bit architectures (or if we fail to map a 64-bit-style arena),
we try to map the heap arena just above the end of the process image.
While we can accept any address, using lower addresses is preferable
because lower addresses cause us to map less of the heap bitmap.

However, if a program is linked against C code that has global
constructors, those constructors may call brk/sbrk to allocate memory
(e.g., many C malloc implementations do this for small allocations).
The brk also starts just above the process image, so this may adjust
the brk past the beginning of where we want to put the heap arena. In
this case, the kernel will pick a different address for the arena and
it will usually be very high (at least, as these things go in a 32-bit
address space).

Fix this by consulting the current value of the brk and using this in
addition to the end of the process image to compute the initial arena
placement.

This is implemented only on Linux currently, since we have no evidence
that it's an issue on any other OSes.

Fixes #19831.

Change-Id: Id64b45d08d8c91e4f50d92d0339146250b04f2f8
Reviewed-on: https://go-review.googlesource.com/39810
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-21 14:34:10 +00:00

478 lines
9.2 KiB
ArmAsm

// Copyright 2016 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.
// +build linux
// +build mips mipsle
//
// System calls and other sys.stuff for mips, Linux
//
#include "go_asm.h"
#include "go_tls.h"
#include "textflag.h"
#define SYS_exit 4001
#define SYS_read 4003
#define SYS_write 4004
#define SYS_open 4005
#define SYS_close 4006
#define SYS_getpid 4020
#define SYS_kill 4037
#define SYS_fcntl 4055
#define SYS_gettimeofday 4078
#define SYS_mmap 4090
#define SYS_munmap 4091
#define SYS_setitimer 4104
#define SYS_clone 4120
#define SYS_newselect 4142
#define SYS_sched_yield 4162
#define SYS_rt_sigreturn 4193
#define SYS_rt_sigaction 4194
#define SYS_rt_sigprocmask 4195
#define SYS_sigaltstack 4206
#define SYS_getrlimit 4076
#define SYS_madvise 4218
#define SYS_mincore 4217
#define SYS_gettid 4222
#define SYS_tkill 4236
#define SYS_futex 4238
#define SYS_sched_getaffinity 4240
#define SYS_exit_group 4246
#define SYS_epoll_create 4248
#define SYS_epoll_ctl 4249
#define SYS_epoll_wait 4250
#define SYS_clock_gettime 4263
#define SYS_epoll_create1 4326
#define SYS_brk 4045
TEXT runtime·exit(SB),NOSPLIT,$0-4
MOVW code+0(FP), R4
MOVW $SYS_exit_group, R2
SYSCALL
UNDEF
RET
TEXT runtime·exit1(SB),NOSPLIT,$0-4
MOVW code+0(FP), R4
MOVW $SYS_exit, R2
SYSCALL
UNDEF
RET
TEXT runtime·open(SB),NOSPLIT,$0-16
MOVW name+0(FP), R4
MOVW mode+4(FP), R5
MOVW perm+8(FP), R6
MOVW $SYS_open, R2
SYSCALL
BEQ R7, 2(PC)
MOVW $-1, R2
MOVW R2, ret+12(FP)
RET
TEXT runtime·closefd(SB),NOSPLIT,$0-8
MOVW fd+0(FP), R4
MOVW $SYS_close, R2
SYSCALL
BEQ R7, 2(PC)
MOVW $-1, R2
MOVW R2, ret+4(FP)
RET
TEXT runtime·write(SB),NOSPLIT,$0-16
MOVW fd+0(FP), R4
MOVW p+4(FP), R5
MOVW n+8(FP), R6
MOVW $SYS_write, R2
SYSCALL
BEQ R7, 2(PC)
MOVW $-1, R2
MOVW R2, ret+12(FP)
RET
TEXT runtime·read(SB),NOSPLIT,$0-16
MOVW fd+0(FP), R4
MOVW p+4(FP), R5
MOVW n+8(FP), R6
MOVW $SYS_read, R2
SYSCALL
BEQ R7, 2(PC)
MOVW $-1, R2
MOVW R2, ret+12(FP)
RET
TEXT runtime·getrlimit(SB),NOSPLIT,$0-12
MOVW kind+0(FP), R4
MOVW limit+4(FP), R5
MOVW $SYS_getrlimit, R2
SYSCALL
MOVW R2, ret+8(FP)
RET
TEXT runtime·usleep(SB),NOSPLIT,$28-4
MOVW usec+0(FP), R3
MOVW R3, R5
MOVW $1000000, R4
DIVU R4, R3
MOVW LO, R3
MOVW R3, 24(R29)
MULU R3, R4
MOVW LO, R4
SUBU R4, R5
MOVW R5, 28(R29)
// select(0, 0, 0, 0, &tv)
MOVW $0, R4
MOVW $0, R5
MOVW $0, R6
MOVW $0, R7
ADDU $24, R29, R8
MOVW R8, 16(R29)
MOVW $SYS_newselect, R2
SYSCALL
RET
TEXT runtime·gettid(SB),NOSPLIT,$0-4
MOVW $SYS_gettid, R2
SYSCALL
MOVW R2, ret+0(FP)
RET
TEXT runtime·raise(SB),NOSPLIT,$0-4
MOVW $SYS_gettid, R2
SYSCALL
MOVW R2, R4 // arg 1 tid
MOVW sig+0(FP), R5 // arg 2
MOVW $SYS_tkill, R2
SYSCALL
RET
TEXT runtime·raiseproc(SB),NOSPLIT,$0
MOVW $SYS_getpid, R2
SYSCALL
MOVW R2, R4 // arg 1 pid
MOVW sig+0(FP), R5 // arg 2
MOVW $SYS_kill, R2
SYSCALL
RET
TEXT runtime·setitimer(SB),NOSPLIT,$0-12
MOVW mode+0(FP), R4
MOVW new+4(FP), R5
MOVW old+8(FP), R6
MOVW $SYS_setitimer, R2
SYSCALL
RET
TEXT runtime·mincore(SB),NOSPLIT,$0-16
MOVW addr+0(FP), R4
MOVW n+4(FP), R5
MOVW dst+8(FP), R6
MOVW $SYS_mincore, R2
SYSCALL
SUBU R2, R0, R2 // caller expects negative errno
MOVW R2, ret+12(FP)
RET
// func walltime() (sec int64, nsec int32)
TEXT runtime·walltime(SB),NOSPLIT,$8-12
MOVW $0, R4 // CLOCK_REALTIME
MOVW $4(R29), R5
MOVW $SYS_clock_gettime, R2
SYSCALL
MOVW 4(R29), R3 // sec
MOVW 8(R29), R5 // nsec
#ifdef GOARCH_mips
MOVW R3, sec_lo+4(FP)
MOVW R0, sec_hi+0(FP)
#else
MOVW R3, sec_lo+0(FP)
MOVW R0, sec_hi+4(FP)
#endif
MOVW R5, nsec+8(FP)
RET
TEXT runtime·nanotime(SB),NOSPLIT,$8-8
MOVW $1, R4 // CLOCK_MONOTONIC
MOVW $4(R29), R5
MOVW $SYS_clock_gettime, R2
SYSCALL
MOVW 4(R29), R3 // sec
MOVW 8(R29), R5 // nsec
// sec is in R3, nsec in R5
// return nsec in R3
MOVW $1000000000, R4
MULU R4, R3
MOVW LO, R3
ADDU R5, R3
SGTU R5, R3, R4
#ifdef GOARCH_mips
MOVW R3, ret_lo+4(FP)
#else
MOVW R3, ret_lo+0(FP)
#endif
MOVW HI, R3
ADDU R4, R3
#ifdef GOARCH_mips
MOVW R3, ret_hi+0(FP)
#else
MOVW R3, ret_hi+4(FP)
#endif
RET
TEXT runtime·rtsigprocmask(SB),NOSPLIT,$0-16
MOVW how+0(FP), R4
MOVW new+4(FP), R5
MOVW old+8(FP), R6
MOVW size+12(FP), R7
MOVW $SYS_rt_sigprocmask, R2
SYSCALL
BEQ R7, 2(PC)
UNDEF // crash
RET
TEXT runtime·rt_sigaction(SB),NOSPLIT,$0-20
MOVW sig+0(FP), R4
MOVW new+4(FP), R5
MOVW old+8(FP), R6
MOVW size+12(FP), R7
MOVW $SYS_rt_sigaction, R2
SYSCALL
MOVW R2, ret+16(FP)
RET
TEXT runtime·sigfwd(SB),NOSPLIT,$0-16
MOVW sig+4(FP), R4
MOVW info+8(FP), R5
MOVW ctx+12(FP), R6
MOVW fn+0(FP), R25
MOVW R29, R22
SUBU $16, R29
AND $~7, R29 // shadow space for 4 args aligned to 8 bytes as per O32 ABI
JAL (R25)
MOVW R22, R29
RET
TEXT runtime·sigtramp(SB),NOSPLIT,$12
// this might be called in external code context,
// where g is not set.
MOVB runtime·iscgo(SB), R1
BEQ R1, 2(PC)
JAL runtime·load_g(SB)
MOVW R4, 4(R29)
MOVW R5, 8(R29)
MOVW R6, 12(R29)
MOVW $runtime·sigtrampgo(SB), R1
JAL (R1)
RET
TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0
JMP runtime·sigtramp(SB)
TEXT runtime·mmap(SB),NOSPLIT,$20-28
MOVW addr+0(FP), R4
MOVW n+4(FP), R5
MOVW prot+8(FP), R6
MOVW flags+12(FP), R7
MOVW fd+16(FP), R8
MOVW off+20(FP), R9
MOVW R8, 16(R29)
MOVW R9, 20(R29)
MOVW $SYS_mmap, R2
SYSCALL
MOVW R2, ret+24(FP)
RET
TEXT runtime·munmap(SB),NOSPLIT,$0-8
MOVW addr+0(FP), R4
MOVW n+4(FP), R5
MOVW $SYS_munmap, R2
SYSCALL
BEQ R7, 2(PC)
UNDEF // crash
RET
TEXT runtime·madvise(SB),NOSPLIT,$0-12
MOVW addr+0(FP), R4
MOVW n+4(FP), R5
MOVW flags+8(FP), R6
MOVW $SYS_madvise, R2
SYSCALL
// ignore failure - maybe pages are locked
RET
// int32 futex(int32 *uaddr, int32 op, int32 val, struct timespec *timeout, int32 *uaddr2, int32 val2);
TEXT runtime·futex(SB),NOSPLIT,$20-28
MOVW addr+0(FP), R4
MOVW op+4(FP), R5
MOVW val+8(FP), R6
MOVW ts+12(FP), R7
MOVW addr2+16(FP), R8
MOVW val3+20(FP), R9
MOVW R8, 16(R29)
MOVW R9, 20(R29)
MOVW $SYS_futex, R2
SYSCALL
MOVW R2, ret+24(FP)
RET
// int32 clone(int32 flags, void *stk, M *mp, G *gp, void (*fn)(void));
TEXT runtime·clone(SB),NOSPLIT,$-4-24
MOVW flags+0(FP), R4
MOVW stk+4(FP), R5
MOVW R0, R6 // ptid
MOVW R0, R7 // tls
// O32 syscall handler unconditionally copies arguments 5-8 from stack,
// even for syscalls with less than 8 arguments. Reserve 32 bytes of new
// stack so that any syscall invoked immediately in the new thread won't fail.
ADD $-32, R5
// Copy mp, gp, fn off parent stack for use by child.
MOVW mp+8(FP), R16
MOVW gp+12(FP), R17
MOVW fn+16(FP), R18
MOVW $1234, R1
MOVW R16, 0(R5)
MOVW R17, 4(R5)
MOVW R18, 8(R5)
MOVW R1, 12(R5)
MOVW $SYS_clone, R2
SYSCALL
// In parent, return.
BEQ R2, 5(PC)
SUBU R2, R0, R3
CMOVN R7, R3, R2
MOVW R2, ret+20(FP)
RET
// In child, on new stack.
// Check that SP is as we expect
MOVW 12(R29), R16
MOVW $1234, R1
BEQ R16, R1, 2(PC)
MOVW (R0), R0
// Initialize m->procid to Linux tid
MOVW $SYS_gettid, R2
SYSCALL
MOVW 0(R29), R16 // m
MOVW 4(R29), R17 // g
MOVW 8(R29), R18 // fn
BEQ R16, nog
BEQ R17, nog
MOVW R2, m_procid(R16)
// In child, set up new stack
MOVW R16, g_m(R17)
MOVW R17, g
// TODO(mips32): doesn't have runtime·stackcheck(SB)
nog:
// Call fn
ADDU $32, R29
JAL (R18)
// It shouldn't return. If it does, exit that thread.
ADDU $-32, R29
MOVW $0xf4, R4
MOVW $SYS_exit, R2
SYSCALL
UNDEF
TEXT runtime·sigaltstack(SB),NOSPLIT,$0
MOVW new+0(FP), R4
MOVW old+4(FP), R5
MOVW $SYS_sigaltstack, R2
SYSCALL
BEQ R7, 2(PC)
UNDEF // crash
RET
TEXT runtime·osyield(SB),NOSPLIT,$0
MOVW $SYS_sched_yield, R2
SYSCALL
RET
TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0-16
MOVW pid+0(FP), R4
MOVW len+4(FP), R5
MOVW buf+8(FP), R6
MOVW $SYS_sched_getaffinity, R2
SYSCALL
MOVW R2, ret+12(FP)
RET
// int32 runtime·epollcreate(int32 size);
TEXT runtime·epollcreate(SB),NOSPLIT,$0-8
MOVW size+0(FP), R4
MOVW $SYS_epoll_create, R2
SYSCALL
MOVW R2, ret+4(FP)
RET
// int32 runtime·epollcreate1(int32 flags);
TEXT runtime·epollcreate1(SB),NOSPLIT,$0-8
MOVW flags+0(FP), R4
MOVW $SYS_epoll_create1, R2
SYSCALL
MOVW R2, ret+4(FP)
RET
// func epollctl(epfd, op, fd int32, ev *epollEvent) int
TEXT runtime·epollctl(SB),NOSPLIT,$0-20
MOVW epfd+0(FP), R4
MOVW op+4(FP), R5
MOVW fd+8(FP), R6
MOVW ev+12(FP), R7
MOVW $SYS_epoll_ctl, R2
SYSCALL
MOVW R2, ret+16(FP)
RET
// int32 runtime·epollwait(int32 epfd, EpollEvent *ev, int32 nev, int32 timeout);
TEXT runtime·epollwait(SB),NOSPLIT,$0-20
MOVW epfd+0(FP), R4
MOVW ev+4(FP), R5
MOVW nev+8(FP), R6
MOVW timeout+12(FP), R7
MOVW $SYS_epoll_wait, R2
SYSCALL
MOVW R2, ret+16(FP)
RET
// void runtime·closeonexec(int32 fd);
TEXT runtime·closeonexec(SB),NOSPLIT,$0-4
MOVW fd+0(FP), R4 // fd
MOVW $2, R5 // F_SETFD
MOVW $1, R6 // FD_CLOEXEC
MOVW $SYS_fcntl, R2
SYSCALL
RET
// func sbrk0() uintptr
TEXT runtime·sbrk0(SB),NOSPLIT,$0-4
// Implemented as brk(NULL).
MOVW $0, R4
MOVW $SYS_brk, R2
SYSCALL
MOVW R2, ret+0(FP)
RET