runtime: correct caller PC/SP offsets in walltime1/nanotime1

In walltime1/nanotime1, we save the caller's PC and SP for stack
unwinding. The code does that assumed zero frame size. Now that
the frame size is not zero, correct the offset. Rewrite it in a
way that doesn't depend on hard-coded frame size.

May fix #37127.

Change-Id: I47d6d54fc3499d7d5946c3f6a2dbd24fbd679de1
Reviewed-on: https://go-review.googlesource.com/c/go/+/219118
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Author: cherrymui

src/runtime/sys_linux_386.s

@@ -233,9 +233,9 @@ TEXT runtime·walltime1(SB), NOSPLIT, $0-12
 	MOVL	g_m(AX), SI // SI unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVL	0(SP), DX
-	MOVL	DX, m_vdsoPC(SI)
-	LEAL	sec+0(SP), DX
+	LEAL	sec+0(FP), DX
+	MOVL	-4(DX), CX
+	MOVL	CX, m_vdsoPC(SI)
 	MOVL	DX, m_vdsoSP(SI)
 
 	CMPL	AX, m_curg(SI)	// Only switch if on curg.
@@ -296,9 +296,9 @@ TEXT runtime·nanotime1(SB), NOSPLIT, $0-8
 	MOVL	g_m(AX), SI // SI unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVL	0(SP), DX
-	MOVL	DX, m_vdsoPC(SI)
-	LEAL	ret+0(SP), DX
+	LEAL	ret+0(FP), DX
+	MOVL	-4(DX), CX
+	MOVL	CX, m_vdsoPC(SI)
 	MOVL	DX, m_vdsoSP(SI)
 
 	CMPL	AX, m_curg(SI)	// Only switch if on curg.

src/runtime/sys_linux_amd64.s

@@ -221,9 +221,9 @@ TEXT runtime·walltime1(SB),NOSPLIT,$8-12
 	MOVQ	g_m(AX), BX // BX unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVQ	0(SP), DX
-	MOVQ	DX, m_vdsoPC(BX)
-	LEAQ	sec+0(SP), DX
+	LEAQ	sec+0(FP), DX
+	MOVQ	-8(DX), CX
+	MOVQ	CX, m_vdsoPC(BX)
 	MOVQ	DX, m_vdsoSP(BX)
 
 	CMPQ	AX, m_curg(BX)	// Only switch if on curg.
@@ -275,9 +275,9 @@ TEXT runtime·nanotime1(SB),NOSPLIT,$8-8
 	MOVQ	g_m(AX), BX // BX unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVQ	0(SP), DX
-	MOVQ	DX, m_vdsoPC(BX)
-	LEAQ	ret+0(SP), DX
+	LEAQ	ret+0(FP), DX
+	MOVQ	-8(DX), CX
+	MOVQ	CX, m_vdsoPC(BX)
 	MOVQ	DX, m_vdsoSP(BX)
 
 	CMPQ	AX, m_curg(BX)	// Only switch if on curg.