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runtime: save/restore callee-saved registers in loong64's sigtramp

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Loong64's R22-R31 and F24-F31 are callee saved registers, which
should be saved in the beginning of sigtramp, and restored at
the end.

In reviewing comments about sigtramp in sys_linux_arm64 it was
noted that a previous issue in arm64 due to missing callee save
registers could also be a problem on loong64, so code was added
to save and restore those.

Updates #31827

Change-Id: I3ae58fe8a64ddb052d0a89b63e82c01ad328dd15
Reviewed-on: https://go-review.googlesource.com/c/go/+/426356
Reviewed-by: Meidan Li <limeidan@loongson.cn>
Auto-Submit: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: xiaodong liu <teaofmoli@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This commit is contained in:
Guoqi Chen 2022-08-26 14:05:31 +08:00 committed by Gopher Robot
parent 579109789f
commit 5fa65d8c93
3 changed files with 94 additions and 49 deletions
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60
src/runtime/cgo/abi_loong64.h Normal file
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@ -0,0 +1,60 @@
// Copyright 2022 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.
// Macros for transitioning from the host ABI to Go ABI0.
//
// These macros save and restore the callee-saved registers
// from the stack, but they don't adjust stack pointer, so
// the user should prepare stack space in advance.
// SAVE_R22_TO_R31(offset) saves R22 ~ R31 to the stack space
// of ((offset)+0*8)(R3) ~ ((offset)+9*8)(R3).
//
// SAVE_F24_TO_F31(offset) saves F24 ~ F31 to the stack space
// of ((offset)+0*8)(R3) ~ ((offset)+7*8)(R3).
//
// Note: g is R22
#define SAVE_R22_TO_R31(offset) \
MOVV g, ((offset)+(0*8))(R3) \
MOVV R23, ((offset)+(1*8))(R3) \
MOVV R24, ((offset)+(2*8))(R3) \
MOVV R25, ((offset)+(3*8))(R3) \
MOVV R26, ((offset)+(4*8))(R3) \
MOVV R27, ((offset)+(5*8))(R3) \
MOVV R28, ((offset)+(6*8))(R3) \
MOVV R29, ((offset)+(7*8))(R3) \
MOVV R30, ((offset)+(8*8))(R3) \
MOVV R31, ((offset)+(9*8))(R3)
#define SAVE_F24_TO_F31(offset) \
MOVD F24, ((offset)+(0*8))(R3) \
MOVD F25, ((offset)+(1*8))(R3) \
MOVD F26, ((offset)+(2*8))(R3) \
MOVD F27, ((offset)+(3*8))(R3) \
MOVD F28, ((offset)+(4*8))(R3) \
MOVD F29, ((offset)+(5*8))(R3) \
MOVD F30, ((offset)+(6*8))(R3) \
MOVD F31, ((offset)+(7*8))(R3)
#define RESTORE_R22_TO_R31(offset) \
MOVV ((offset)+(0*8))(R3), g \
MOVV ((offset)+(1*8))(R3), R23 \
MOVV ((offset)+(2*8))(R3), R24 \
MOVV ((offset)+(3*8))(R3), R25 \
MOVV ((offset)+(4*8))(R3), R26 \
MOVV ((offset)+(5*8))(R3), R27 \
MOVV ((offset)+(6*8))(R3), R28 \
MOVV ((offset)+(7*8))(R3), R29 \
MOVV ((offset)+(8*8))(R3), R30 \
MOVV ((offset)+(9*8))(R3), R31
#define RESTORE_F24_TO_F31(offset) \
MOVD ((offset)+(0*8))(R3), F24 \
MOVD ((offset)+(1*8))(R3), F25 \
MOVD ((offset)+(2*8))(R3), F26 \
MOVD ((offset)+(3*8))(R3), F27 \
MOVD ((offset)+(4*8))(R3), F28 \
MOVD ((offset)+(5*8))(R3), F29 \
MOVD ((offset)+(6*8))(R3), F30 \
MOVD ((offset)+(7*8))(R3), F31

55
src/runtime/cgo/asm_loong64.s
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@ -3,6 +3,7 @@
// license that can be found in the LICENSE file.
#include "textflag.h"
#include "abi_loong64.h"
// Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2
@ -24,52 +25,24 @@ TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
* first arg.
*/
ADDV $(-8*22), R3
MOVV R4, (8*1)(R3) // fn unsafe.Pointer
MOVV R5, (8*2)(R3) // a unsafe.Pointer
MOVV R7, (8*3)(R3) // ctxt uintptr
MOVV R23, (8*4)(R3)
MOVV R24, (8*5)(R3)
MOVV R25, (8*6)(R3)
MOVV R26, (8*7)(R3)
MOVV R27, (8*8)(R3)
MOVV R28, (8*9)(R3)
MOVV R29, (8*10)(R3)
MOVV R30, (8*11)(R3)
MOVV g, (8*12)(R3)
MOVV R1, (8*13)(R3)
MOVD F24, (8*14)(R3)
MOVD F25, (8*15)(R3)
MOVD F26, (8*16)(R3)
MOVD F27, (8*17)(R3)
MOVD F28, (8*18)(R3)
MOVD F29, (8*19)(R3)
MOVD F30, (8*20)(R3)
MOVD F31, (8*21)(R3)
ADDV $(-23*8), R3
MOVV R4, (1*8)(R3) // fn unsafe.Pointer
MOVV R5, (2*8)(R3) // a unsafe.Pointer
MOVV R7, (3*8)(R3) // ctxt uintptr
SAVE_R22_TO_R31((4*8))
SAVE_F24_TO_F31((14*8))
MOVV R1, (22*8)(R3)
// Initialize Go ABI environment
JAL runtime·load_g(SB)
JAL runtime·cgocallback(SB)
MOVV (8*4)(R3), R23
MOVV (8*5)(R3), R24
MOVV (8*6)(R3), R25
MOVV (8*7)(R3), R26
MOVV (8*8)(R3), R27
MOVV (8*9)(R3), R28
MOVV (8*10)(R3), R29
MOVV (8*11)(R3), R30
MOVV (8*12)(R3), g
MOVV (8*13)(R3), R1
MOVD (8*14)(R3), F24
MOVD (8*15)(R3), F25
MOVD (8*16)(R3), F26
MOVD (8*17)(R3), F27
MOVD (8*18)(R3), F28
MOVD (8*19)(R3), F29
MOVD (8*20)(R3), F30
MOVD (8*21)(R3), F31
ADDV $(8*22), R3
RESTORE_R22_TO_R31((4*8))
RESTORE_F24_TO_F31((14*8))
MOVV (22*8)(R3), R1
ADDV $(23*8), R3
RET

28
src/runtime/sys_linux_loong64.s
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@ -9,6 +9,7 @@
#include "go_asm.h"
#include "go_tls.h"
#include "textflag.h"
#include "cgo/abi_loong64.h"
#define AT_FDCWD -100
@ -374,18 +375,29 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
JAL (R20)
RET
TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$64
TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$168
MOVW R4, (1*8)(R3)
MOVV R5, (2*8)(R3)
MOVV R6, (3*8)(R3)
// Save callee-save registers in the case of signal forwarding.
// Please refer to https://golang.org/issue/31827 .
SAVE_R22_TO_R31((4*8))
SAVE_F24_TO_F31((14*8))
// this might be called in external code context,
// where g is not set.
MOVB runtime·iscgo(SB), R19
BEQ R19, 2(PC)
MOVB runtime·iscgo(SB), R4
BEQ R4, 2(PC)
JAL runtime·load_g(SB)
MOVW R4, 8(R3)
MOVV R5, 16(R3)
MOVV R6, 24(R3)
MOVV $runtime·sigtrampgo(SB), R19
JAL (R19)
MOVV $runtime·sigtrampgo(SB), R4
JAL (R4)
// Restore callee-save registers.
RESTORE_R22_TO_R31((4*8))
RESTORE_F24_TO_F31((14*8))
RET
TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0