aboutsummaryrefslogtreecommitdiff
path: root/agent/src/os/linux/libproc.h
blob: 4cde0c19d76cde28c18ff6c4978b9c2bf75f52da (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
/*
 * Copyright (c) 2003, 2012, 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
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef _LIBPROC_H_
#define _LIBPROC_H_

#include <jni.h>
#include <unistd.h>
#include <stdint.h>
#include "proc_service.h"

#if defined(arm) || defined(ppc)
#include "libproc_md.h"
#endif

#if defined(sparc) || defined(sparcv9)
/*
  If _LP64 is defined ptrace.h should be taken from /usr/include/asm-sparc64
  otherwise it should be from /usr/include/asm-sparc
  These two files define pt_regs structure differently
*/
#ifdef _LP64
#include "asm-sparc64/ptrace.h"
#else
#include "asm-sparc/ptrace.h"
#endif

#endif //sparc or sparcv9

/************************************************************************************

0. This is very minimal subset of Solaris libproc just enough for current application.
Please note that the bulk of the functionality is from proc_service interface. This
adds Pgrab__ and some missing stuff. We hide the difference b/w live process and core
file by this interface.

1. pthread_id unique in both NPTL & LinuxThreads. We store this in
OSThread::_pthread_id in JVM code.

2. All threads see the same pid when they call getpid() under NPTL.
Threads receive different pid under LinuxThreads. We used to save the result of
::getpid() call in OSThread::_thread_id. This way uniqueness of OSThread::_thread_id
was lost under NPTL. Now, we store the result of ::gettid() call in
OSThread::_thread_id. Because gettid returns actual pid of thread (lwp id), this is
unique again. We therefore use OSThread::_thread_id as unique identifier.

3. There is a unique LWP id under both thread libraries. libthread_db  maps pthread_id
to its underlying lwp_id under both the thread libraries. thread_info.lwp_id stores
lwp_id of the thread. The lwp id is nothing but the actual pid of clone'd processes. But
unfortunately libthread_db does not work very well for core dumps. So, we get pthread_id
only for processes. For core dumps, we don't use libthread_db at all (like gdb).

4. ptrace operates on this LWP id under both the thread libraries. When we say 'pid' for
ptrace call, we refer to lwp_id of the thread.

5. for core file, we parse ELF files and read data from them. For processes we  use
combination of ptrace and /proc calls.

*************************************************************************************/


#if defined(sparc)  || defined(sparcv9)
#define user_regs_struct  pt_regs
#endif

// This C bool type must be int for compatibility with Linux calls and
// it would be a mistake to equivalence it to C++ bool on many platforms

typedef int bool;
#define true  1
#define false 0

struct ps_prochandle;

// attach to a process
struct ps_prochandle* Pgrab(pid_t pid);

// attach to a core dump
struct ps_prochandle* Pgrab_core(const char* execfile, const char* corefile);

// release a process or core
void Prelease(struct ps_prochandle* ph);

// functions not directly available in Solaris libproc

// initialize libproc (call this only once per app)
// pass true to make library verbose
bool init_libproc(bool verbose);

// get number of threads
int get_num_threads(struct ps_prochandle* ph);

// get lwp_id of n'th thread
lwpid_t get_lwp_id(struct ps_prochandle* ph, int index);

// get regs for a given lwp
bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lid, struct user_regs_struct* regs);

// get number of shared objects
int get_num_libs(struct ps_prochandle* ph);

// get name of n'th lib
const char* get_lib_name(struct ps_prochandle* ph, int index);

// get base of lib
uintptr_t get_lib_base(struct ps_prochandle* ph, int index);

// returns true if given library is found in lib list
bool find_lib(struct ps_prochandle* ph, const char *lib_name);

// symbol lookup
uintptr_t lookup_symbol(struct ps_prochandle* ph,  const char* object_name,
                       const char* sym_name);

// address->nearest symbol lookup. return NULL for no symbol
const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset);

struct ps_prochandle* get_proc_handle(JNIEnv* env, jobject this_obj);

void throw_new_debugger_exception(JNIEnv* env, const char* errMsg);

#endif //__LIBPROC_H_