platform_system_core/include/backtrace/BacktraceMap.h
Christopher Ferris 12385e3ad0 Move map data into backtrace data proper.
The backtrace structure used to include a pointer to a backtrace_map_t
that represented the map data for a particular pc. This introduced a
race condition where the pointer could be discarded, but the backtrace
structure still contained a pointer to garbage memory. Now all of the map
information is right in the structure.

Bug: 19028453
Change-Id: If7088a73f3c6bf1f3bc8cdd2bb4b62e7cab831c0
2015-02-06 15:00:09 -08:00

94 lines
2.6 KiB
C++

/*
* Copyright (C) 2014 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 _BACKTRACE_BACKTRACE_MAP_H
#define _BACKTRACE_BACKTRACE_MAP_H
#include <stdint.h>
#include <sys/types.h>
#ifdef USE_MINGW
// MINGW does not define these constants.
#define PROT_NONE 0
#define PROT_READ 0x1
#define PROT_WRITE 0x2
#define PROT_EXEC 0x4
#else
#include <sys/mman.h>
#endif
#include <deque>
#include <string>
struct backtrace_map_t {
backtrace_map_t(): start(0), end(0), flags(0) {}
uintptr_t start;
uintptr_t end;
int flags;
std::string name;
};
class BacktraceMap {
public:
// If uncached is true, then parse the current process map as of the call.
// Passing a map created with uncached set to true to Backtrace::Create()
// is unsupported.
static BacktraceMap* Create(pid_t pid, bool uncached = false);
virtual ~BacktraceMap();
// Fill in the map data structure for the given address.
virtual void FillIn(uintptr_t addr, backtrace_map_t* map);
// The flags returned are the same flags as used by the mmap call.
// The values are PROT_*.
int GetFlags(uintptr_t pc) {
backtrace_map_t map;
FillIn(pc, &map);
if (IsValid(map)) {
return map.flags;
}
return PROT_NONE;
}
bool IsReadable(uintptr_t pc) { return GetFlags(pc) & PROT_READ; }
bool IsWritable(uintptr_t pc) { return GetFlags(pc) & PROT_WRITE; }
bool IsExecutable(uintptr_t pc) { return GetFlags(pc) & PROT_EXEC; }
typedef std::deque<backtrace_map_t>::iterator iterator;
iterator begin() { return maps_.begin(); }
iterator end() { return maps_.end(); }
typedef std::deque<backtrace_map_t>::const_iterator const_iterator;
const_iterator begin() const { return maps_.begin(); }
const_iterator end() const { return maps_.end(); }
virtual bool Build();
static inline bool IsValid(const backtrace_map_t& map) {
return map.end > 0;
}
protected:
BacktraceMap(pid_t pid);
virtual bool ParseLine(const char* line, backtrace_map_t* map);
std::deque<backtrace_map_t> maps_;
pid_t pid_;
};
#endif // _BACKTRACE_BACKTRACE_MAP_H