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

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>

diff --git a/src/runtime/cgo/abi_loong64.h b/src/runtime/cgo/abi_loong64.h
new file mode 100644 (file)
index 0000000..b10d837
--- /dev/null
+++ b/src/runtime/cgo/abi_loong64.h
@@ -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

diff --git a/src/runtime/cgo/asm_loong64.s b/src/runtime/cgo/asm_loong64.s
index 1eb5b3ea37c090092d0bcf50325b82558e8bed13..3b514ffc4a195345087621abb5c92e47e9475653 100644 (file)
--- a/src/runtime/cgo/asm_loong64.s
+++ b/src/runtime/cgo/asm_loong64.s
@@ -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

diff --git a/src/runtime/sys_linux_loong64.s b/src/runtime/sys_linux_loong64.s
index 9ce5e722565f0433aefb8d82c1e9070230c739ad..f1dcef4233862c546a4cf315da6ccdc30af0aaf8 100644 (file)
--- a/src/runtime/sys_linux_loong64.s
+++ b/src/runtime/sys_linux_loong64.s
@@ -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