runtime: use ABIInternal for most calls to sigtrampgo

sigtramp on openbsd-arm64 is teetering on the edge of the nosplit stack
limit. Add more headroom by calling sigtrampgo using ABIInternal, which
eliminates a 48-byte ABI wrapper frame.

openbsd-amd64 has slightly more space, but is also close to the limit,
so convert it as well.

Other operating systems don't have it as bad, but many have nearly
identical implementations of sigtramp, so I have converted them as well.

I've omitted darwin-arm64 and solaris, as those are quite different and
would benefit from not needing ifdef for both cases.

For #51485.

Change-Id: I70512645d4208b346a59d5e5d03836a45833b1d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/390814
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

10 files changed, 148 insertions, 56 deletions

diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index db4715d2b7..8e75a38bd2 100644
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -218,13 +218,21 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVL	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigtrampgo(SB)
+	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()
diff --git a/src/runtime/sys_dragonfly_amd64.s b/src/runtime/sys_dragonfly_amd64.s
index 684c9ab7f0..48b04ff979 100644
--- a/src/runtime/sys_dragonfly_amd64.s
+++ b/src/runtime/sys_dragonfly_amd64.s
@@ -226,13 +226,21 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVQ	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigtrampgo(SB)
+	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()
diff --git a/src/runtime/sys_freebsd_amd64.s b/src/runtime/sys_freebsd_amd64.s
index cc95da7e64..159f5c66ab 100644
--- a/src/runtime/sys_freebsd_amd64.s
+++ b/src/runtime/sys_freebsd_amd64.s
@@ -228,13 +228,21 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVQ	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigtrampgo(SB)
+	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()
@@ -245,13 +253,21 @@ TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVL	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigprofNonGo(SB)
+	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()
diff --git a/src/runtime/sys_freebsd_arm64.s b/src/runtime/sys_freebsd_arm64.s
index 7b05fb0900..a4f12eb3b9 100644
--- a/src/runtime/sys_freebsd_arm64.s
+++ b/src/runtime/sys_freebsd_arm64.s
@@ -295,10 +295,16 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$176
 	BEQ	2(PC)
 	BL	runtime·load_g(SB)
 
+#ifdef GOEXPERIMENT_regabiargs
+	// Restore signum to R0.
+	MOVW	8(RSP), R0
+	// R1 and R2 already contain info and ctx, respectively.
+#else
 	MOVD	R1, 16(RSP)
 	MOVD	R2, 24(RSP)
-	MOVD	$runtime·sigtrampgo(SB), R0
-	BL	(R0)
+#endif
+	MOVD	$runtime·sigtrampgo<ABIInternal>(SB), R3
+	BL	(R3)
 
 	// Restore callee-save registers.
 	RESTORE_R19_TO_R28(8*4)
diff --git a/src/runtime/sys_linux_amd64.s b/src/runtime/sys_linux_amd64.s
index 4be0801114..f2dfbbb70c 100644
--- a/src/runtime/sys_linux_amd64.s
+++ b/src/runtime/sys_linux_amd64.s
@@ -343,13 +343,21 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVQ	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigtrampgo(SB)
+	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()
@@ -360,13 +368,21 @@ TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVL	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigprofNonGo(SB)
+	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()
diff --git a/src/runtime/sys_linux_arm64.s b/src/runtime/sys_linux_arm64.s
index 36ac014f03..8e7cbf7d11 100644
--- a/src/runtime/sys_linux_arm64.s
+++ b/src/runtime/sys_linux_arm64.s
@@ -459,10 +459,16 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$176
 	CBZ	R0, 2(PC)
 	BL	runtime·load_g(SB)
 
+#ifdef GOEXPERIMENT_regabiargs
+	// Restore signum to R0.
+	MOVW	8(RSP), R0
+	// R1 and R2 already contain info and ctx, respectively.
+#else
 	MOVD	R1, 16(RSP)
 	MOVD	R2, 24(RSP)
-	MOVD	$runtime·sigtrampgo(SB), R0
-	BL	(R0)
+#endif
+	MOVD	$runtime·sigtrampgo<ABIInternal>(SB), R3
+	BL	(R3)
 
 	// Restore callee-save registers.
 	RESTORE_R19_TO_R28(8*4)
@@ -476,10 +482,14 @@ TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT,$176
 	SAVE_R19_TO_R28(8*4)
 	SAVE_F8_TO_F15(8*14)
 
+#ifdef GOEXPERIMENT_regabiargs
+	// R0, R1 and R2 already contain sig, info and ctx, respectively.
+#else
 	MOVW	R0, 8(RSP)	// sig
 	MOVD	R1, 16(RSP)	// info
 	MOVD	R2, 24(RSP)	// ctx
-	CALL	runtime·sigprofNonGo(SB)
+#endif
+	CALL	runtime·sigprofNonGo<ABIInternal>(SB)
 
 	// Restore callee-save registers.
 	RESTORE_R19_TO_R28(8*4)
diff --git a/src/runtime/sys_netbsd_amd64.s b/src/runtime/sys_netbsd_amd64.s
index 41eddf3735..ade11366e5 100644
--- a/src/runtime/sys_netbsd_amd64.s
+++ b/src/runtime/sys_netbsd_amd64.s
@@ -309,13 +309,21 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVQ	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigtrampgo(SB)
+	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()
diff --git a/src/runtime/sys_netbsd_arm64.s b/src/runtime/sys_netbsd_arm64.s
index 32e6740c52..6bcd3445d3 100644
--- a/src/runtime/sys_netbsd_arm64.s
+++ b/src/runtime/sys_netbsd_arm64.s
@@ -317,9 +317,15 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$176
 	BEQ	2(PC)
 	BL	runtime·load_g(SB)
 
+#ifdef GOEXPERIMENT_regabiargs
+	// Restore signum to R0.
+	MOVW	8(RSP), R0
+	// R1 and R2 already contain info and ctx, respectively.
+#else
 	MOVD	R1, 16(RSP)
 	MOVD	R2, 24(RSP)
-	BL	runtime·sigtrampgo(SB)
+#endif
+	BL	runtime·sigtrampgo<ABIInternal>(SB)
 
 	// Restore callee-save registers.
 	RESTORE_R19_TO_R28(8*4)
diff --git a/src/runtime/sys_openbsd_amd64.s b/src/runtime/sys_openbsd_amd64.s
index fc6d5dc387..f71f5ccead 100644
--- a/src/runtime/sys_openbsd_amd64.s
+++ b/src/runtime/sys_openbsd_amd64.s
@@ -62,16 +62,24 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
-	// Call into the Go signal handler
+	// 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
-	MOVQ	DI, 0(SP)	// sig
-	MOVQ	SI, 8(SP)	// info
-	MOVQ	DX, 16(SP)	// ctx
-	CALL	·sigtrampgo(SB)
+	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()
+	POP_REGS_HOST_TO_ABI0()
 	RET
 
 //
diff --git a/src/runtime/sys_openbsd_arm64.s b/src/runtime/sys_openbsd_arm64.s
index 7c1886e0a0..4a3f2fc3a2 100644
--- a/src/runtime/sys_openbsd_arm64.s
+++ b/src/runtime/sys_openbsd_arm64.s
@@ -62,9 +62,15 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$192
 	MOVW	R0, 8(RSP)		// signum
 	BL	runtime·load_g(SB)
 
+#ifdef GOEXPERIMENT_regabiargs
+	// Restore signum to R0.
+	MOVW	8(RSP), R0
+	// R1 and R2 already contain info and ctx, respectively.
+#else
 	MOVD	R1, 16(RSP)
 	MOVD	R2, 24(RSP)
-	BL	runtime·sigtrampgo(SB)
+#endif
+	BL	runtime·sigtrampgo<ABIInternal>(SB)
 
 	// Restore callee-save registers.
 	RESTORE_R19_TO_R28(8*4)