runtime: impose stack size limit
The goal is to stop only those programs that would keep
going and run the machine out of memory, but before they do that.
1 GB on 64-bit, 250 MB on 32-bit.
That seems implausibly large, and it can be adjusted.
Fixes #2556.
Fixes #4494.
Fixes #5173.
R=khr, r, dvyukov
CC=golang-dev
https://golang.org/cl/12541052
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index b80e2ad..b87e64d 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -259,6 +259,7 @@
uintptr syscallguard; // if status==Gsyscall, syscallguard = stackguard to use during gc
uintptr stackguard; // same as stackguard0, but not set to StackPreempt
uintptr stack0;
+ uintptr stacksize;
G* alllink; // on allg
void* param; // passed parameter on wakeup
int16 status;
@@ -713,6 +714,7 @@
extern uint32 runtime·cpuid_ecx;
extern uint32 runtime·cpuid_edx;
extern DebugVars runtime·debug;
+extern uintptr runtime·maxstacksize;
/*
* common functions and data
