runtime: fix windows cpu profiler
Currently it periodically fails with the following message.
The immediate cause is the wrong base register when obtaining g
in sys_windows_amd64/386.s.
But there are several secondary problems as well.
runtime: unknown pc 0x0 after stack split
panic: invalid memory address or nil pointer dereference
fatal error: panic during malloc
[signal 0xc0000005 code=0x0 addr=0x60 pc=0x42267a]
runtime stack:
runtime.panic(0x7914c0, 0xc862af)
c:/src/perfer/work/windows-amd64-a15f344a9efa/go/src/pkg/runtime/panic.c:217 +0x2c
runtime: unexpected return pc for runtime.externalthreadhandler called from 0x0
R=rsc, alex.brainman
CC=golang-codereviews
https://golang.org/cl/63310043
diff --git a/src/pkg/runtime/os_windows.c b/src/pkg/runtime/os_windows.c
index 6c9d687..8815aee 100644
--- a/src/pkg/runtime/os_windows.c
+++ b/src/pkg/runtime/os_windows.c
@@ -71,6 +71,9 @@
void *runtime·GetQueuedCompletionStatusEx;
+extern uintptr runtime·externalthreadhandlerp;
+void runtime·externalthreadhandler(void);
+
static int32
getproccount(void)
{
@@ -86,6 +89,8 @@
void *kernel32;
void *SetProcessPriorityBoost;
+ runtime·externalthreadhandlerp = (uintptr)runtime·externalthreadhandler;
+
runtime·stdcall(runtime·SetConsoleCtrlHandler, 2, runtime·ctrlhandler, (uintptr)1);
runtime·stdcall(runtime·timeBeginPeriod, 1, (uintptr)1);
runtime·ncpu = getproccount();
@@ -293,9 +298,11 @@
m->libcall.args = (uintptr*)&count + 1;
if(m->profilehz != 0) {
// leave pc/sp for cpu profiler
- m->libcallpc = (uintptr)runtime·getcallerpc(&fn);
- m->libcallsp = (uintptr)runtime·getcallersp(&fn);
m->libcallg = g;
+ m->libcallpc = (uintptr)runtime·getcallerpc(&fn);
+ // sp must be the last, because once async cpu profiler finds
+ // all three values to be non-zero, it will use them
+ m->libcallsp = (uintptr)runtime·getcallersp(&fn);
}
runtime·asmcgocall(runtime·asmstdcall, &m->libcall);
m->libcallsp = 0;
diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index 88d6ace..47cb304 100644
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -3029,6 +3029,7 @@
}
extern void runtime·morestack(void);
+uintptr runtime·externalthreadhandlerp;
// Does f mark the top of a goroutine stack?
bool
@@ -3039,7 +3040,8 @@
f->entry == (uintptr)runtime·mcall ||
f->entry == (uintptr)runtime·morestack ||
f->entry == (uintptr)runtime·lessstack ||
- f->entry == (uintptr)_rt0_go;
+ f->entry == (uintptr)_rt0_go ||
+ (runtime·externalthreadhandlerp != 0 && f->entry == runtime·externalthreadhandlerp);
}
void
diff --git a/src/pkg/runtime/sys_windows_386.s b/src/pkg/runtime/sys_windows_386.s
index af10ca8..2755d50 100644
--- a/src/pkg/runtime/sys_windows_386.s
+++ b/src/pkg/runtime/sys_windows_386.s
@@ -347,10 +347,12 @@
// leave pc/sp for cpu profiler
MOVL (SP), SI
MOVL SI, m_libcallpc(BP)
+ MOVL g(CX), SI
+ MOVL SI, m_libcallg(BP)
+ // sp must be the last, because once async cpu profiler finds
+ // all three values to be non-zero, it will use them
LEAL 4(SP), SI
MOVL SI, m_libcallsp(BP)
- MOVL g(BP), SI
- MOVL SI, m_libcallg(BP)
MOVL m_g0(BP), SI
CMPL g(CX), SI
diff --git a/src/pkg/runtime/sys_windows_amd64.s b/src/pkg/runtime/sys_windows_amd64.s
index 6576c42..288cd77 100644
--- a/src/pkg/runtime/sys_windows_amd64.s
+++ b/src/pkg/runtime/sys_windows_amd64.s
@@ -342,10 +342,12 @@
// leave pc/sp for cpu profiler
MOVQ (SP), R12
MOVQ R12, m_libcallpc(R13)
+ MOVQ g(R15), R12
+ MOVQ R12, m_libcallg(R13)
+ // sp must be the last, because once async cpu profiler finds
+ // all three values to be non-zero, it will use them
LEAQ 8(SP), R12
MOVQ R12, m_libcallsp(R13)
- MOVQ g(R13), R12
- MOVQ R12, m_libcallg(R13)
MOVQ m_g0(R13), R14
CMPQ g(R15), R14
