1 /*
   2  * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef _LIBPROC_H_
  26 #define _LIBPROC_H_
  27 
  28 #include <jni.h>
  29 #include <unistd.h>
  30 #include <stdint.h>
  31 #include "proc_service.h"
  32 
  33 #include <sys/ptrace.h>
  34 
  35 /************************************************************************************
  36 
  37 0. This is very minimal subset of Solaris libproc just enough for current application.
  38 Please note that the bulk of the functionality is from proc_service interface. This
  39 adds Pgrab__ and some missing stuff. We hide the difference b/w live process and core
  40 file by this interface.
  41 
  42 1. pthread_id unique in both NPTL & LinuxThreads. We store this in
  43 OSThread::_pthread_id in JVM code.
  44 
  45 2. All threads see the same pid when they call getpid() under NPTL.
  46 Threads receive different pid under LinuxThreads. We used to save the result of
  47 ::getpid() call in OSThread::_thread_id. This way uniqueness of OSThread::_thread_id
  48 was lost under NPTL. Now, we store the result of ::gettid() call in
  49 OSThread::_thread_id. Because gettid returns actual pid of thread (lwp id), this is
  50 unique again. We therefore use OSThread::_thread_id as unique identifier.
  51 
  52 3. There is a unique LWP id under both thread libraries. libthread_db  maps pthread_id
  53 to its underlying lwp_id under both the thread libraries. thread_info.lwp_id stores
  54 lwp_id of the thread. The lwp id is nothing but the actual pid of clone'd processes. But
  55 unfortunately libthread_db does not work very well for core dumps. So, we get pthread_id
  56 only for processes. For core dumps, we don't use libthread_db at all (like gdb).
  57 
  58 4. ptrace operates on this LWP id under both the thread libraries. When we say 'pid' for
  59 ptrace call, we refer to lwp_id of the thread.
  60 
  61 5. for core file, we parse ELF files and read data from them. For processes we  use
  62 combination of ptrace and /proc calls.
  63 
  64 *************************************************************************************/
  65 
  66 
  67 #if defined(sparc) || defined(sparcv9) || defined(ppc64) || defined(ppc64le)
  68 #include <asm/ptrace.h>
  69 #define user_regs_struct  pt_regs
  70 #endif
  71 #if defined(aarch64) || defined(arm64)
  72 #include <asm/ptrace.h>
  73 #define user_regs_struct user_pt_regs
  74 #elif defined(arm)
  75 #include <asm/ptrace.h>
  76 #define user_regs_struct  pt_regs
  77 #endif
  78 #if defined(s390x)
  79 #include <asm/ptrace.h>
  80 #endif
  81 
  82 // This C bool type must be int for compatibility with Linux calls and
  83 // it would be a mistake to equivalence it to C++ bool on many platforms
  84 
  85 typedef int bool;
  86 #define true  1
  87 #define false 0
  88 
  89 struct ps_prochandle;
  90 
  91 // attach to a process
  92 struct ps_prochandle* Pgrab(pid_t pid, char* err_buf, size_t err_buf_len);
  93 
  94 // attach to a core dump
  95 struct ps_prochandle* Pgrab_core(const char* execfile, const char* corefile);
  96 
  97 // release a process or core
  98 void Prelease(struct ps_prochandle* ph);
  99 
 100 // functions not directly available in Solaris libproc
 101 
 102 // initialize libproc (call this only once per app)
 103 // pass true to make library verbose
 104 bool init_libproc(bool verbose);
 105 
 106 // get number of threads
 107 int get_num_threads(struct ps_prochandle* ph);
 108 
 109 // get lwp_id of n'th thread
 110 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index);
 111 
 112 // get regs for a given lwp
 113 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lid, struct user_regs_struct* regs);
 114 
 115 // get number of shared objects
 116 int get_num_libs(struct ps_prochandle* ph);
 117 
 118 // get name of n'th lib
 119 const char* get_lib_name(struct ps_prochandle* ph, int index);
 120 
 121 // get base of lib
 122 uintptr_t get_lib_base(struct ps_prochandle* ph, int index);
 123 
 124 // returns true if given library is found in lib list
 125 bool find_lib(struct ps_prochandle* ph, const char *lib_name);
 126 
 127 // symbol lookup
 128 uintptr_t lookup_symbol(struct ps_prochandle* ph,  const char* object_name,
 129                        const char* sym_name);
 130 
 131 // address->nearest symbol lookup. return NULL for no symbol
 132 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset);
 133 
 134 struct ps_prochandle* get_proc_handle(JNIEnv* env, jobject this_obj);
 135 
 136 void throw_new_debugger_exception(JNIEnv* env, const char* errMsg);
 137 
 138 #endif //__LIBPROC_H_