platform_system_core/libbacktrace/BacktraceThread.h
Christopher Ferris e484607622 Only copy mcontext data from sigcontext.
The ucontext_t data structure could be bigger than the kernel data
structure. Since the unwinder only cares about the mcontext data, only
copy that out of the structure. The mcontext data is the same size in
the kernel and in the ucontext_t structure.

Bug: 15189014
Change-Id: I5978169c4425b8212e11db85a57eb319cd0e264b
2014-05-23 15:11:26 -07:00

88 lines
2.2 KiB
C++

/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _LIBBACKTRACE_BACKTRACE_THREAD_H
#define _LIBBACKTRACE_BACKTRACE_THREAD_H
#include <inttypes.h>
#include <pthread.h>
#include <signal.h>
#include <string.h>
#include <sys/types.h>
#include <ucontext.h>
#include "BacktraceImpl.h"
// The signal used to cause a thread to dump the stack.
#if defined(__GLIBC__)
// GLIBC reserves __SIGRTMIN signals, so use SIGRTMIN to avoid errors.
#define THREAD_SIGNAL SIGRTMIN
#else
#define THREAD_SIGNAL (__SIGRTMIN+1)
#endif
class ThreadEntry {
public:
static ThreadEntry* Get(pid_t pid, pid_t tid, bool create = true);
static void Remove(ThreadEntry* entry);
void Wake();
void Wait(int);
void CopyUcontextFromSigcontext(void*);
inline void Lock() {
pthread_mutex_lock(&mutex_);
// Reset the futex value in case of multiple unwinds of the same thread.
futex_ = 0;
}
inline void Unlock() {
pthread_mutex_unlock(&mutex_);
}
inline ucontext_t* GetUcontext() { return &ucontext_; }
private:
ThreadEntry(pid_t pid, pid_t tid);
~ThreadEntry();
bool Match(pid_t chk_pid, pid_t chk_tid) { return (chk_pid == pid_ && chk_tid == tid_); }
pid_t pid_;
pid_t tid_;
int futex_;
int ref_count_;
pthread_mutex_t mutex_;
ThreadEntry* next_;
ThreadEntry* prev_;
ucontext_t ucontext_;
static ThreadEntry* list_;
static pthread_mutex_t list_mutex_;
};
class BacktraceThread : public BacktraceCurrent {
public:
BacktraceThread(BacktraceImpl* impl, pid_t tid, BacktraceMap* map);
virtual ~BacktraceThread();
virtual bool Unwind(size_t num_ignore_frames, ucontext_t* ucontext);
};
#endif // _LIBBACKTRACE_BACKTRACE_THREAD_H