From: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Date: Fri, 23 Feb 2024 01:06:40 +0000 (+0000)
Subject: runtime: add crash stack support for arm
X-Git-Tag: go1.23rc1~1144
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=727e8d3863f45789e559d4a9d20286026cb5bb07;p=gostls13.git

runtime: add crash stack support for arm

Change-Id: Ide4002d1cf82f2daaf7261b367c391dedbbf7719
GitHub-Last-Rev: 80ee248c3e34529e7a522acc97db9fb69c82dffb
GitHub-Pull-Request: golang/go#65308
Reviewed-on: https://go-review.googlesource.com/c/go/+/558699
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
---

diff --git a/src/runtime/asm.s b/src/runtime/asm.s
index 4833fae5e9..64b9e420b6 100644
--- a/src/runtime/asm.s
+++ b/src/runtime/asm.s
@@ -13,6 +13,7 @@ TEXT ·sigpanic0(SB),NOSPLIT,$0-0
 TEXT ·mapinitnoop<ABIInternal>(SB),NOSPLIT,$0-0
 	RET
 
+#ifndef GOARCH_arm
 #ifndef GOARCH_amd64
 #ifndef GOARCH_arm64
 #ifndef GOARCH_loong64
@@ -36,3 +37,4 @@ TEXT ·switchToCrashStack0<ABIInternal>(SB),NOSPLIT,$0-0
 #endif
 #endif
 #endif
+#endif
diff --git a/src/runtime/asm_arm.s b/src/runtime/asm_arm.s
index 31a0584fb5..4d57ec6062 100644
--- a/src/runtime/asm_arm.s
+++ b/src/runtime/asm_arm.s
@@ -333,6 +333,30 @@ noswitch:
 	MOVW.P	4(R13), R14	// restore LR
 	B	(R0)
 
+// func switchToCrashStack0(fn func())
+TEXT runtime·switchToCrashStack0(SB), NOSPLIT, $0-4
+	MOVW	fn+0(FP), R7 // context register
+	MOVW	g_m(g), R1 // curm
+
+	// set g to gcrash
+	MOVW	$runtime·gcrash(SB), R0
+	BL	setg<>(SB)	// g = &gcrash
+	MOVW	R1, g_m(g)	// g.m = curm
+	MOVW	g, m_g0(R1)	// curm.g0 = g
+
+	// switch to crashstack
+	MOVW	(g_stack+stack_hi)(g), R1
+	SUB	$(4*8), R1
+	MOVW	R1, R13
+
+	// call target function
+	MOVW	0(R7), R0
+	BL	(R0)
+
+	// should never return
+	CALL	runtime·abort(SB)
+	UNDEF
+
 /*
  * support for morestack
  */
@@ -349,6 +373,14 @@ TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0
 	// Cannot grow scheduler stack (m->g0).
 	MOVW	g_m(g), R8
 	MOVW	m_g0(R8), R4
+
+	// Called from f.
+	// Set g->sched to context in f.
+	MOVW	R13, (g_sched+gobuf_sp)(g)
+	MOVW	LR, (g_sched+gobuf_pc)(g)
+	MOVW	R3, (g_sched+gobuf_lr)(g)
+	MOVW	R7, (g_sched+gobuf_ctxt)(g)
+
 	CMP	g, R4
 	BNE	3(PC)
 	BL	runtime·badmorestackg0(SB)
@@ -361,13 +393,6 @@ TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0
 	BL	runtime·badmorestackgsignal(SB)
 	B	runtime·abort(SB)
 
-	// Called from f.
-	// Set g->sched to context in f.
-	MOVW	R13, (g_sched+gobuf_sp)(g)
-	MOVW	LR, (g_sched+gobuf_pc)(g)
-	MOVW	R3, (g_sched+gobuf_lr)(g)
-	MOVW	R7, (g_sched+gobuf_ctxt)(g)
-
 	// Called from f.
 	// Set m->morebuf to f's caller.
 	MOVW	R3, (m_morebuf+gobuf_pc)(R8)	// f's caller's PC
diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index 538ed0a282..dc26cda992 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -579,7 +579,7 @@ func switchToCrashStack(fn func()) {
 // Disable crash stack on Windows for now. Apparently, throwing an exception
 // on a non-system-allocated crash stack causes EXCEPTION_STACK_OVERFLOW and
 // hangs the process (see issue 63938).
-const crashStackImplemented = (GOARCH == "amd64" || GOARCH == "arm64" || GOARCH == "loong64" || GOARCH == "mips64" || GOARCH == "mips64le" || GOARCH == "ppc64" || GOARCH == "ppc64le" || GOARCH == "riscv64" || GOARCH == "s390x" || GOARCH == "wasm") && GOOS != "windows"
+const crashStackImplemented = (GOARCH == "amd64" || GOARCH == "arm" || GOARCH == "arm64" || GOARCH == "loong64" || GOARCH == "mips64" || GOARCH == "mips64le" || GOARCH == "ppc64" || GOARCH == "ppc64le" || GOARCH == "riscv64" || GOARCH == "s390x" || GOARCH == "wasm") && GOOS != "windows"
 
 //go:noescape
 func switchToCrashStack0(fn func()) // in assembly