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8258479: Minor cleanups in VMError
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Reviewed-by: lfoltan, coleenp
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tstuefe committed Dec 17, 2020
1 parent c11525a commit 178c001
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Showing 8 changed files with 78 additions and 91 deletions.
3 changes: 2 additions & 1 deletion src/hotspot/os/posix/vmError_posix.cpp
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2018, 2020 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand Down Expand Up @@ -132,7 +133,7 @@ static void crash_handler(int sig, siginfo_t* info, void* ucVoid) {
VMError::report_and_die(NULL, sig, pc, info, ucVoid);
}

void VMError::reset_signal_handlers() {
void VMError::install_secondary_signal_handler() {
for (int i = 0; i < NUM_SIGNALS; i++) {
save_signal(i, SIGNALS[i]);
os::signal(SIGNALS[i], CAST_FROM_FN_PTR(void *, crash_handler));
Expand Down
4 changes: 2 additions & 2 deletions src/hotspot/os/windows/vmError_windows.cpp
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand Down Expand Up @@ -44,7 +44,7 @@ LONG WINAPI crash_handler(struct _EXCEPTION_POINTERS* exceptionInfo) {
return EXCEPTION_CONTINUE_SEARCH;
}

void VMError::reset_signal_handlers() {
void VMError::install_secondary_signal_handler() {
SetUnhandledExceptionFilter(crash_handler);
}

Expand Down
2 changes: 1 addition & 1 deletion src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp
Expand Up @@ -603,7 +603,7 @@ HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
assert(young_gen()->is_in(addr),
"addr should be in allocated part of young gen");
// called from os::print_location by find or VMError
if (Debugging || VMError::fatal_error_in_progress()) return NULL;
if (Debugging || VMError::is_error_reported()) return NULL;
Unimplemented();
} else if (old_gen()->is_in_reserved(addr)) {
assert(old_gen()->is_in(addr),
Expand Down
3 changes: 1 addition & 2 deletions src/hotspot/share/runtime/threadSMR.cpp
Expand Up @@ -540,8 +540,7 @@ void SafeThreadsListPtr::verify_hazard_ptr_scanned() {
return;
}

if (VMError::is_error_reported() &&
VMError::get_first_error_tid() == os::current_thread_id()) {
if (VMError::is_error_reported_in_current_thread()) {
// If there is an error reported by this thread it may use ThreadsList even
// if it's unsafe.
return;
Expand Down
15 changes: 5 additions & 10 deletions src/hotspot/share/utilities/decoder.cpp
@@ -1,5 +1,6 @@
/*
* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2017, 2020 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand All @@ -25,7 +26,6 @@
#include "precompiled.hpp"
#include "jvm.h"
#include "memory/allocation.inline.hpp"
#include "runtime/os.hpp"
#include "utilities/decoder.hpp"
#include "utilities/vmError.hpp"

Expand Down Expand Up @@ -84,30 +84,25 @@ Mutex* Decoder::shared_decoder_lock() {
}

bool Decoder::decode(address addr, char* buf, int buflen, int* offset, const char* modulepath, bool demangle) {
bool error_handling_thread = os::current_thread_id() == VMError::get_first_error_tid();
if (error_handling_thread) {
if (VMError::is_error_reported_in_current_thread()) {
return get_error_handler_instance()->decode(addr, buf, buflen, offset, modulepath, demangle);
} else {
MutexLocker locker(shared_decoder_lock(), Mutex::_no_safepoint_check_flag);
return get_shared_instance()->decode(addr, buf, buflen, offset, modulepath, demangle);
}

}

bool Decoder::decode(address addr, char* buf, int buflen, int* offset, const void* base) {
bool error_handling_thread = os::current_thread_id() == VMError::get_first_error_tid();
if (error_handling_thread) {
if (VMError::is_error_reported_in_current_thread()) {
return get_error_handler_instance()->decode(addr, buf, buflen, offset, base);
} else {
MutexLocker locker(shared_decoder_lock(), Mutex::_no_safepoint_check_flag);
return get_shared_instance()->decode(addr, buf, buflen, offset, base);
}
}


bool Decoder::demangle(const char* symbol, char* buf, int buflen) {
bool error_handling_thread = os::current_thread_id() == VMError::get_first_error_tid();
if (error_handling_thread) {
if (VMError::is_error_reported_in_current_thread()) {
return get_error_handler_instance()->demangle(symbol, buf, buflen);
} else {
MutexLocker locker(shared_decoder_lock(), Mutex::_no_safepoint_check_flag);
Expand Down
4 changes: 2 additions & 2 deletions src/hotspot/share/utilities/events.hpp
@@ -1,5 +1,5 @@
/*
* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand Down Expand Up @@ -127,7 +127,7 @@ template <class T> class EventLogBase : public EventLog {
bool should_log() {
// Don't bother adding new entries when we're crashing. This also
// avoids mutating the ring buffer when printing the log.
return !VMError::fatal_error_in_progress();
return !VMError::is_error_reported();
}

// Print the contents of the log
Expand Down
116 changes: 56 additions & 60 deletions src/hotspot/share/utilities/vmError.cpp
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2017, 2020 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand Down Expand Up @@ -63,10 +64,25 @@
#include <signal.h>
#endif // PRODUCT

bool VMError::_error_reported = false;

// call this when the VM is dying--it might loosen some asserts
bool VMError::is_error_reported() { return _error_reported; }
bool VMError::coredump_status;
char VMError::coredump_message[O_BUFLEN];
int VMError::_current_step;
const char* VMError::_current_step_info;
volatile jlong VMError::_reporting_start_time = -1;
volatile bool VMError::_reporting_did_timeout = false;
volatile jlong VMError::_step_start_time = -1;
volatile bool VMError::_step_did_timeout = false;
volatile intptr_t VMError::_first_error_tid = -1;
int VMError::_id;
const char* VMError::_message;
char VMError::_detail_msg[1024];
Thread* VMError::_thread;
address VMError::_pc;
void* VMError::_siginfo;
void* VMError::_context;
const char* VMError::_filename;
int VMError::_lineno;
size_t VMError::_size;

// returns an address which is guaranteed to generate a SIGSEGV on read,
// for test purposes, which is not NULL and contains bits in every word
Expand All @@ -80,7 +96,7 @@ void* VMError::get_segfault_address() {
}

// List of environment variables that should be reported in error log file.
const char *env_list[] = {
static const char* env_list[] = {
// All platforms
"JAVA_HOME", "JAVA_TOOL_OPTIONS", "_JAVA_OPTIONS", "CLASSPATH",
"PATH", "USERNAME",
Expand Down Expand Up @@ -151,9 +167,6 @@ static void print_bug_submit_message(outputStream *out, Thread *thread) {
out->print_raw_cr("#");
}

bool VMError::coredump_status;
char VMError::coredump_message[O_BUFLEN];

void VMError::record_coredump_status(const char* message, bool status) {
coredump_status = status;
strncpy(coredump_message, message, sizeof(coredump_message));
Expand Down Expand Up @@ -358,40 +371,15 @@ static void report_vm_version(outputStream* st, char* buf, int buflen) {
);
}

// This is the main function to report a fatal error. Only one thread can
// call this function, so we don't need to worry about MT-safety. But it's
// possible that the error handler itself may crash or die on an internal
// error, for example, when the stack/heap is badly damaged. We must be
// able to handle recursive errors that happen inside error handler.
//
// Error reporting is done in several steps. If a crash or internal error
// occurred when reporting an error, the nested signal/exception handler
// can skip steps that are already (or partially) done. Error reporting will
// continue from the next step. This allows us to retrieve and print
// information that may be unsafe to get after a fatal error. If it happens,
// you may find nested report_and_die() frames when you look at the stack
// in a debugger.
//
// In general, a hang in error handler is much worse than a crash or internal
// error, as it's harder to recover from a hang. Deadlock can happen if we
// try to grab a lock that is already owned by current thread, or if the
// owner is blocked forever (e.g. in os::infinite_sleep()). If possible, the
// error handler and all the functions it called should avoid grabbing any
// lock. An important thing to notice is that memory allocation needs a lock.
//
// We should avoid using large stack allocated buffers. Many errors happen
// when stack space is already low. Making things even worse is that there
// could be nested report_and_die() calls on stack (see above). Only one
// thread can report error, so large buffers are statically allocated in data
// segment.

int VMError::_current_step;
const char* VMError::_current_step_info;
// Returns true if at least one thread reported a fatal error and fatal error handling is in process.
bool VMError::is_error_reported() {
return _first_error_tid != -1;
}

volatile jlong VMError::_reporting_start_time = -1;
volatile bool VMError::_reporting_did_timeout = false;
volatile jlong VMError::_step_start_time = -1;
volatile bool VMError::_step_did_timeout = false;
// Returns true if the current thread reported a fatal error.
bool VMError::is_error_reported_in_current_thread() {
return _first_error_tid == os::current_thread_id();
}

// Helper, return current timestamp for timeout handling.
jlong VMError::get_current_timestamp() {
Expand Down Expand Up @@ -422,6 +410,32 @@ void VMError::clear_step_start_time() {
return Atomic::store(&_step_start_time, (jlong)0);
}

// This is the main function to report a fatal error. Only one thread can
// call this function, so we don't need to worry about MT-safety. But it's
// possible that the error handler itself may crash or die on an internal
// error, for example, when the stack/heap is badly damaged. We must be
// able to handle recursive errors that happen inside error handler.
//
// Error reporting is done in several steps. If a crash or internal error
// occurred when reporting an error, the nested signal/exception handler
// can skip steps that are already (or partially) done. Error reporting will
// continue from the next step. This allows us to retrieve and print
// information that may be unsafe to get after a fatal error. If it happens,
// you may find nested report_and_die() frames when you look at the stack
// in a debugger.
//
// In general, a hang in error handler is much worse than a crash or internal
// error, as it's harder to recover from a hang. Deadlock can happen if we
// try to grab a lock that is already owned by current thread, or if the
// owner is blocked forever (e.g. in os::infinite_sleep()). If possible, the
// error handler and all the functions it called should avoid grabbing any
// lock. An important thing to notice is that memory allocation needs a lock.
//
// We should avoid using large stack allocated buffers. Many errors happen
// when stack space is already low. Making things even worse is that there
// could be nested report_and_die() calls on stack (see above). Only one
// thread can report error, so large buffers are statically allocated in data
// segment.
void VMError::report(outputStream* st, bool _verbose) {

# define BEGIN if (_current_step == 0) { _current_step = __LINE__;
Expand Down Expand Up @@ -654,7 +668,6 @@ void VMError::report(outputStream* st, bool _verbose) {
os::print_summary_info(st, buf, sizeof(buf));
}


STEP("printing date and time")

if (_verbose) {
Expand Down Expand Up @@ -695,7 +708,6 @@ void VMError::report(outputStream* st, bool _verbose) {
}
}


STEP("printing stack bounds")

if (_verbose) {
Expand Down Expand Up @@ -1240,8 +1252,6 @@ void VMError::print_vm_info(outputStream* st) {
st->print_cr("END.");
}

volatile intptr_t VMError::_first_error_tid = -1;

/** Expand a pattern into a buffer starting at pos and open a file using constructed path */
static int expand_and_open(const char* pattern, bool overwrite_existing, char* buf, size_t buflen, size_t pos) {
int fd = -1;
Expand Down Expand Up @@ -1298,17 +1308,6 @@ static int prepare_log_file(const char* pattern, const char* default_pattern, bo
return fd;
}

int VMError::_id;
const char* VMError::_message;
char VMError::_detail_msg[1024];
Thread* VMError::_thread;
address VMError::_pc;
void* VMError::_siginfo;
void* VMError::_context;
const char* VMError::_filename;
int VMError::_lineno;
size_t VMError::_size;

void VMError::report_and_die(Thread* thread, unsigned int sig, address pc, void* siginfo,
void* context, const char* detail_fmt, ...)
{
Expand Down Expand Up @@ -1395,9 +1394,6 @@ void VMError::report_and_die(int id, const char* message, const char* detail_fmt
_size = size;
jio_vsnprintf(_detail_msg, sizeof(_detail_msg), detail_fmt, detail_args);

// first time
_error_reported = true;

reporting_started();
if (!TestUnresponsiveErrorHandler) {
// Record reporting_start_time unless we're running the
Expand All @@ -1420,7 +1416,7 @@ void VMError::report_and_die(int id, const char* message, const char* detail_fmt

// reset signal handlers or exception filter; make sure recursive crashes
// are handled properly.
reset_signal_handlers();
install_secondary_signal_handler();
} else {
#if defined(_WINDOWS)
// If UseOSErrorReporting we call this for each level of the call stack
Expand Down
22 changes: 9 additions & 13 deletions src/hotspot/share/utilities/vmError.hpp
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2017, 2020 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand Down Expand Up @@ -84,13 +85,9 @@ class VMError : public AllStatic {
// Whether or not the last error reporting step did timeout.
static volatile bool _step_did_timeout;

static bool _error_reported;

public:

// set signal handlers on Solaris/Linux or the default exception filter
// on Windows, to handle recursive crashes.
static void reset_signal_handlers();
// Install secondary signal handler to handle secondary faults during error reporting
// (see VMError::crash_handler)
static void install_secondary_signal_handler();

// handle -XX:+ShowMessageBoxOnError. buf is used to format the message string
static void show_message_box(char* buf, int buflen);
Expand Down Expand Up @@ -171,18 +168,17 @@ class VMError : public AllStatic {
// signal was not changed by error reporter
static address get_resetted_sighandler(int sig);

// check to see if fatal error reporting is in progress
static bool fatal_error_in_progress() { return _first_error_tid != -1; }

static intptr_t get_first_error_tid() { return _first_error_tid; }

// Called by the WatcherThread to check if error reporting has timed-out.
// Returns true if error reporting has not completed within the ErrorLogTimeout limit.
static bool check_timeout();

// Support for avoiding multiple asserts
// Returns true if at least one thread reported a fatal error and
// fatal error handling is in process.
static bool is_error_reported();

// Returns true if the current thread reported a fatal error.
static bool is_error_reported_in_current_thread();

DEBUG_ONLY(static void controlled_crash(int how);)

// returns an address which is guaranteed to generate a SIGSEGV on read,
Expand Down

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