1
0
mirror of https://github.com/golang/go synced 2024-11-19 23:34:40 -07:00
go/src/runtime/rt0_darwin_arm.s
Elias Naur ea4b785ae0 runtime: preserve darwin/arm{,64} callee-save registers
CL 14603 attempted to preserve the callee-save registers for
the darwin/arm runtime initialization routine, but I believe it
wasn't sufficient and resulted in the crash reported in issue

Saving and restoring the registers on the stack the same way
linux/arm does seems more obvious and fixes #14778, so do that.

Even though #14778 is not reproducible on darwin/arm64, I applied
a similar change there, and to linux/arm64 which obeys the same
calling convention.

Finally, this CL is a candidate for a 1.6 minor release for the same
reason CL 14603 was in a 1.5 minor release (as CL 16968). It is
small and only touches the iOS platforms and gomobile on darwin/arm
is currently useless without it.

Fixes #14778
Fixes #12590 (again)

Change-Id: I7401daf0bbd7c579a7e84761384a7b763651752a
Reviewed-on: https://go-review.googlesource.com/20621
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-15 08:43:34 +00:00

81 lines
2.0 KiB
ArmAsm

// Copyright 2014 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.
#include "textflag.h"
TEXT _rt0_arm_darwin(SB),7,$-4
// prepare arguments for main (_rt0_go)
MOVW (R13), R0 // argc
MOVW $4(R13), R1 // argv
MOVW $main(SB), R4
B (R4)
// When linking with -buildmode=c-archive or -buildmode=c-shared,
// this symbol is called from a global initialization function.
//
// Note that all currently shipping darwin/arm platforms require
// cgo and do not support c-shared.
TEXT _rt0_arm_darwin_lib(SB),NOSPLIT,$32
// Preserve callee-save registers.
MOVW R4, 12(R13)
MOVW R5, 16(R13)
MOVW R6, 20(R13)
MOVW R7, 24(R13)
MOVW R8, 28(R13)
MOVW R11, 32(R13)
MOVW R0, _rt0_arm_darwin_lib_argc<>(SB)
MOVW R1, _rt0_arm_darwin_lib_argv<>(SB)
// Synchronous initialization.
MOVW $runtime·libpreinit(SB), R3
CALL (R3)
// Create a new thread to do the runtime initialization and return.
MOVW _cgo_sys_thread_create(SB), R3
CMP $0, R3
B.EQ nocgo
MOVW $_rt0_arm_darwin_lib_go(SB), R0
MOVW $0, R1
BL (R3)
B rr
nocgo:
MOVW $0x400000, R0
MOVW R0, (R13) // stacksize
MOVW $_rt0_arm_darwin_lib_go(SB), R0
MOVW R0, 4(R13) // fn
MOVW $0, R0
MOVW R0, 8(R13) // fnarg
MOVW $runtime·newosproc0(SB), R3
BL (R3)
rr:
// Restore callee-save registers and return.
MOVW 12(R13), R4
MOVW 16(R13), R5
MOVW 20(R13), R6
MOVW 24(R13), R7
MOVW 28(R13), R8
MOVW 32(R13), R11
RET
TEXT _rt0_arm_darwin_lib_go(SB),NOSPLIT,$0
MOVW _rt0_arm_darwin_lib_argc<>(SB), R0
MOVW _rt0_arm_darwin_lib_argv<>(SB), R1
MOVW R0, (R13)
MOVW R1, 4(R13)
MOVW $runtime·rt0_go(SB), R4
B (R4)
DATA _rt0_arm_darwin_lib_argc<>(SB)/4, $0
GLOBL _rt0_arm_darwin_lib_argc<>(SB),NOPTR, $4
DATA _rt0_arm_darwin_lib_argv<>(SB)/4, $0
GLOBL _rt0_arm_darwin_lib_argv<>(SB),NOPTR, $4
TEXT main(SB),NOSPLIT,$-8
// save argc and argv onto stack
MOVM.DB.W [R0-R1], (R13)
MOVW $runtime·rt0_go(SB), R4
B (R4)