RFR(S): 8058345: Refactor native stack printing from vmError.cpp to debug.cpp to make it available in gdb as well

Tue Sep 16 18:11:37 UTC 2014

Thank you for fixing frame walk.
I don't see where make_frame() is used.

Thanks,
Vladimir

On 9/16/14 9:35 AM, Volker Simonis wrote:
> Hi,
>
> while testing my change, I found two other small problems with native
> stack traces:
>
> 1. we can not walk native wrappers on (at least not on Linux/amd64)
> because they are treated as native "C" frames. However, if the native
> wrapper was called from a compiled frame which had no valid frame
> pointer (i.e. %rbp) os::get_sender_for_C_frame(&fr) will produce a bad
> frame. This can be easily fixed by treating native wrappers like java
> frames.
>
> 2. the fix for "8035983: Fix "Native frames:" in crash report (hs_err
> file)" introduced a similar problem. If we walk tha stack from a
> native wrapper down to a compiled frame, we will have a frame with an
> invalid frame pointer. In that case, the newly introduced check from
> change 8035983 will fail, because fr.sender_sp() depends on a valid
> fp. I'll propose to replace fr.sender_sp() by fr.real_fp() which
> should do the same but also works for compiled frames with invalid fp.
>
> Here's the new webrev:
>
> http://cr.openjdk.java.net/~simonis/webrevs/8058345.v1/
>
> What dou you think?
>
> Thank you and best regards,
> Volker
>
>
> On Tue, Sep 16, 2014 at 3:48 PM, Volker Simonis
> <volker.simonis at gmail.com> wrote:
>> 'print_native_stack()' must be visible in both vmError.cpp and
>> debug.cpp. Initially I saw that vmError.cpp already included debug.hpp
>> so I decided to declare it in debug.hpp. But now I realized that also
>> debug.cpp includes vmError.hpp so I could just as well declare
>> 'print_native_stack()' in vmError.hpp and leave the implementation in
>> vmError.cpp. Do you want me to change that?
>>
>> Thank you and best regards,
>> Volker
>>
>>
>> On Tue, Sep 16, 2014 at 8:51 AM, David Holmes <david.holmes at oracle.com> wrote:
>>> Hi Volker,
>>>
>>> On 13/09/2014 5:15 AM, Volker Simonis wrote:
>>>>
>>>> Hi,
>>>>
>>>> could you please review and sponsor the following small change which
>>>> should make debugging a little more comfortabel (at least on Linux for
>>>> now):
>>>>
>>>> http://cr.openjdk.java.net/~simonis/webrevs/8058345/
>>>> https://bugs.openjdk.java.net/browse/JDK-8058345
>>>>
>>>> In the hs_err files we have a nice mixed stack trace which contains
>>>> both, Java and native frames.
>>>> It would be nice if we could make this functionality available from
>>>> within gdb during debugging sessions (until now we can only print the
>>>> pure Java stack with the "ps()" helper function from debug.cpp).
>>>>
>>>> This new feature can be easily achieved by refactoring the
>>>> corresponding stack printing code from VMError::report() in
>>>> vmError.cpp into its own method in debug.cpp. This change extracts
>>>> that code into the new function 'print_native_stack()' in debug.cpp
>>>> without changing anything of the functionality.
>>>
>>>
>>> Why does it need to move to debug.cpp to allow this ?
>>>
>>> David
>>> -----
>>>
>>>
>>>> It also adds some helper functions which make it easy to call the new
>>>> 'print_native_stack()' method from within gdb. There's the new helper
>>>> function 'pns(frame f)'  which takes a frame argument and calls
>>>> 'print_native_stack()'. We need the frame argument because gdb inserts
>>>> a dummy frame for every call and we can't easily walk over this dummy
>>>> frame from our stack printing routine.
>>>>
>>>> To simplify the creation of the frame object, I've added the helper
>>>> functions:
>>>>
>>>> extern "C" frame make_frame(intptr_t* sp, intptr_t* fp, address pc) {
>>>>     return frame(sp, fp, pc);
>>>> }
>>>>
>>>> for x86 (in frame_x86.cpp) and
>>>>
>>>> extern "C" frame make_frame(intptr_t* sp, address pc) {
>>>>     return frame(sp, pc);
>>>> }
>>>>
>>>> for ppc64 in frame_ppc.cpp. With these helper functions we can now
>>>> easily get a mixed stack trace of a Java thread in gdb (see below).
>>>>
>>>> All the helper functions are protected by '#ifndef PRODUCT'
>>>>
>>>> Thank you and best regards,
>>>> Volker
>>>>
>>>>
>>>> (gdb) call pns(make_frame($sp, $rbp, $pc))
>>>>
>>>> "Executing pns"
>>>> Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native
>>>> code)
>>>> C  [libpthread.so.0+0xc0fe]  pthread_cond_timedwait+0x13e
>>>> V  [libjvm.so+0x96c4c1]  os::sleep(Thread*, long, bool)+0x1a1
>>>> V  [libjvm.so+0x75f442]  JVM_Sleep+0x312
>>>> j  java.lang.Thread.sleep(J)V+0
>>>> j  CrashNative.crashIt(Lsun/misc/Unsafe;I)V+10
>>>> j  CrashNative.doIt()V+45
>>>> v  ~StubRoutines::call_stub
>>>> V  [libjvm.so+0x71599f]  JavaCalls::call_helper(JavaValue*,
>>>> methodHandle*, JavaCallArguments*, Thread*)+0xf8f
>>>> V  [libjvm.so+0x9eab75]  Reflection::invoke(instanceKlassHandle,
>>>> methodHandle, Handle, bool, objArrayHandle, BasicType, objArrayHandle,
>>>> bool, Thread*) [clone .constprop.218]+0xa25
>>>> V  [libjvm.so+0x9eb838]  Reflection::invoke_method(oopDesc*, Handle,
>>>> objArrayHandle, Thread*)+0x1c8
>>>> V  [libjvm.so+0x7637ae]  JVM_InvokeMethod+0xfe
>>>> j
>>>> sun.reflect.NativeMethodAccessorImpl.invoke0(Ljava/lang/reflect/Method;Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+0
>>>> j
>>>> sun.reflect.NativeMethodAccessorImpl.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+100
>>>> j
>>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+6
>>>> j
>>>> java.lang.reflect.Method.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+56
>>>> j  CrashNative.mainJava()V+32
>>>> v  ~StubRoutines::call_stub
>>>> V  [libjvm.so+0x71599f]  JavaCalls::call_helper(JavaValue*,
>>>> methodHandle*, JavaCallArguments*, Thread*)+0xf8f
>>>> V  [libjvm.so+0x7384f5]  jni_invoke_static(JNIEnv_*, JavaValue*,
>>>> _jobject*, JNICallType, _jmethodID*, JNI_ArgumentPusher*, Thread*)
>>>> [clone .isra.238] [clone .constprop.250]+0x385
>>>> V  [libjvm.so+0x73b3d7]  jni_CallStaticVoidMethodV+0xe7
>>>> C  [libCrashNative.so+0x9a9]  JNIEnv_::CallStaticVoidMethod(_jclass*,
>>>> _jmethodID*, ...)+0xb9
>>>> C  [libCrashNative.so+0xa10]  step3(JNIEnv_*, _jobject*)+0x65
>>>> C  [libCrashNative.so+0xa69]  step2(JNIEnv_*, _jobject*)+0x57
>>>> C  [libCrashNative.so+0xa37]  step2(JNIEnv_*, _jobject*)+0x25
>>>> C  [libCrashNative.so+0xa37]  step2(JNIEnv_*, _jobject*)+0x25
>>>> C  [libCrashNative.so+0xa37]  step2(JNIEnv_*, _jobject*)+0x25
>>>> C  [libCrashNative.so+0xa37]  step2(JNIEnv_*, _jobject*)+0x25
>>>> C  [libCrashNative.so+0xa37]  step2(JNIEnv_*, _jobject*)+0x25
>>>> C  [libCrashNative.so+0xa8e]  step1(JNIEnv_*, _jobject*)+0x23
>>>> C  [libCrashNative.so+0x87f]  Java_CrashNative_nativeMethod+0x23
>>>> j  CrashNative.nativeMethod()V+0
>>>> j  CrashNative.main([Ljava/lang/String;)V+9
>>>> v  ~StubRoutines::call_stub
>>>> V  [libjvm.so+0x71599f]  JavaCalls::call_helper(JavaValue*,
>>>> methodHandle*, JavaCallArguments*, Thread*)+0xf8f
>>>> V  [libjvm.so+0x7384f5]  jni_invoke_static(JNIEnv_*, JavaValue*,
>>>> _jobject*, JNICallType, _jmethodID*, JNI_ArgumentPusher*, Thread*)
>>>> [clone .isra.238] [clone .constprop.250]+0x385
>>>> V  [libjvm.so+0x73b2b0]  jni_CallStaticVoidMethod+0x170
>>>> C  [libjli.so+0x742a]  JavaMain+0x65a
>>>> C  [libpthread.so.0+0x7e9a]  start_thread+0xda
>>>>
>>>