agent/src/os/linux/libproc_impl.c

Fri, 25 Jan 2013 16:50:33 -0800

author
morris
date
Fri, 25 Jan 2013 16:50:33 -0800
changeset 4535
9fae07c31641
parent 3546
54d3535a6dd3
child 4599
2394a89e89f4
permissions
-rw-r--r--

6518907: cleanup IA64 specific code in Hotspot
Summary: removed unused IA64 specific code
Reviewed-by: twisti, kvn, dholmes

     1 /*
     2  * Copyright (c) 2003, 2012, 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 #include <stdarg.h>
    25 #include <stdio.h>
    26 #include <stdlib.h>
    27 #include <string.h>
    28 #include <fcntl.h>
    29 #include <thread_db.h>
    30 #include "libproc_impl.h"
    32 static const char* alt_root = NULL;
    33 static int alt_root_len = -1;
    35 #define SA_ALTROOT "SA_ALTROOT"
    37 static void init_alt_root() {
    38    if (alt_root_len == -1) {
    39       alt_root = getenv(SA_ALTROOT);
    40       if (alt_root) {
    41          alt_root_len = strlen(alt_root);
    42       } else {
    43          alt_root_len = 0;
    44       }
    45    }
    46 }
    48 int pathmap_open(const char* name) {
    49    int fd;
    50    char alt_path[PATH_MAX + 1];
    52    init_alt_root();
    54    if (alt_root_len > 0) {
    55       strcpy(alt_path, alt_root);
    56       strcat(alt_path, name);
    57       fd = open(alt_path, O_RDONLY);
    58       if (fd >= 0) {
    59          print_debug("path %s substituted for %s\n", alt_path, name);
    60          return fd;
    61       }
    63       if (strrchr(name, '/')) {
    64          strcpy(alt_path, alt_root);
    65          strcat(alt_path, strrchr(name, '/'));
    66          fd = open(alt_path, O_RDONLY);
    67          if (fd >= 0) {
    68             print_debug("path %s substituted for %s\n", alt_path, name);
    69             return fd;
    70          }
    71       }
    72    } else {
    73       fd = open(name, O_RDONLY);
    74       if (fd >= 0) {
    75          return fd;
    76       }
    77    }
    79    return -1;
    80 }
    82 static bool _libsaproc_debug;
    84 void print_debug(const char* format,...) {
    85    if (_libsaproc_debug) {
    86      va_list alist;
    88      va_start(alist, format);
    89      fputs("libsaproc DEBUG: ", stderr);
    90      vfprintf(stderr, format, alist);
    91      va_end(alist);
    92    }
    93 }
    95 bool is_debug() {
    96    return _libsaproc_debug;
    97 }
    99 // initialize libproc
   100 bool init_libproc(bool debug) {
   101    // init debug mode
   102    _libsaproc_debug = debug;
   104    // initialize the thread_db library
   105    if (td_init() != TD_OK) {
   106      print_debug("libthread_db's td_init failed\n");
   107      return false;
   108    }
   110    return true;
   111 }
   113 static void destroy_lib_info(struct ps_prochandle* ph) {
   114    lib_info* lib = ph->libs;
   115    while (lib) {
   116      lib_info *next = lib->next;
   117      if (lib->symtab) {
   118         destroy_symtab(lib->symtab);
   119      }
   120      free(lib);
   121      lib = next;
   122    }
   123 }
   125 static void destroy_thread_info(struct ps_prochandle* ph) {
   126    thread_info* thr = ph->threads;
   127    while (thr) {
   128      thread_info *next = thr->next;
   129      free(thr);
   130      thr = next;
   131    }
   132 }
   134 // ps_prochandle cleanup
   136 // ps_prochandle cleanup
   137 void Prelease(struct ps_prochandle* ph) {
   138    // do the "derived class" clean-up first
   139    ph->ops->release(ph);
   140    destroy_lib_info(ph);
   141    destroy_thread_info(ph);
   142    free(ph);
   143 }
   145 lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) {
   146    return add_lib_info_fd(ph, libname, -1, base);
   147 }
   149 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
   150    lib_info* newlib;
   152    if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
   153       print_debug("can't allocate memory for lib_info\n");
   154       return NULL;
   155    }
   157    strncpy(newlib->name, libname, sizeof(newlib->name));
   158    newlib->base = base;
   160    if (fd == -1) {
   161       if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
   162          print_debug("can't open shared object %s\n", newlib->name);
   163          free(newlib);
   164          return NULL;
   165       }
   166    } else {
   167       newlib->fd = fd;
   168    }
   170    // check whether we have got an ELF file. /proc/<pid>/map
   171    // gives out all file mappings and not just shared objects
   172    if (is_elf_file(newlib->fd) == false) {
   173       close(newlib->fd);
   174       free(newlib);
   175       return NULL;
   176    }
   178    newlib->symtab = build_symtab(newlib->fd, libname);
   179    if (newlib->symtab == NULL) {
   180       print_debug("symbol table build failed for %s\n", newlib->name);
   181    }
   183    // even if symbol table building fails, we add the lib_info.
   184    // This is because we may need to read from the ELF file for core file
   185    // address read functionality. lookup_symbol checks for NULL symtab.
   186    if (ph->libs) {
   187       ph->lib_tail->next = newlib;
   188       ph->lib_tail = newlib;
   189    }  else {
   190       ph->libs = ph->lib_tail = newlib;
   191    }
   192    ph->num_libs++;
   194    return newlib;
   195 }
   197 // lookup for a specific symbol
   198 uintptr_t lookup_symbol(struct ps_prochandle* ph,  const char* object_name,
   199                        const char* sym_name) {
   200    // ignore object_name. search in all libraries
   201    // FIXME: what should we do with object_name?? The library names are obtained
   202    // by parsing /proc/<pid>/maps, which may not be the same as object_name.
   203    // What we need is a utility to map object_name to real file name, something
   204    // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
   205    // now, we just ignore object_name and do a global search for the symbol.
   207    lib_info* lib = ph->libs;
   208    while (lib) {
   209       if (lib->symtab) {
   210          uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
   211          if (res) return res;
   212       }
   213       lib = lib->next;
   214    }
   216    print_debug("lookup failed for symbol '%s' in obj '%s'\n",
   217                           sym_name, object_name);
   218    return (uintptr_t) NULL;
   219 }
   222 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
   223    const char* res = NULL;
   224    lib_info* lib = ph->libs;
   225    while (lib) {
   226       if (lib->symtab && addr >= lib->base) {
   227          res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
   228          if (res) return res;
   229       }
   230       lib = lib->next;
   231    }
   232    return NULL;
   233 }
   235 // add a thread to ps_prochandle
   236 thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
   237    thread_info* newthr;
   238    if ( (newthr = (thread_info*) calloc(1, sizeof(thread_info))) == NULL) {
   239       print_debug("can't allocate memory for thread_info\n");
   240       return NULL;
   241    }
   243    // initialize thread info
   244    newthr->pthread_id = pthread_id;
   245    newthr->lwp_id = lwp_id;
   247    // add new thread to the list
   248    newthr->next = ph->threads;
   249    ph->threads = newthr;
   250    ph->num_threads++;
   251    return newthr;
   252 }
   255 // struct used for client data from thread_db callback
   256 struct thread_db_client_data {
   257    struct ps_prochandle* ph;
   258    thread_info_callback callback;
   259 };
   261 // callback function for libthread_db
   262 static int thread_db_callback(const td_thrhandle_t *th_p, void *data) {
   263   struct thread_db_client_data* ptr = (struct thread_db_client_data*) data;
   264   td_thrinfo_t ti;
   265   td_err_e err;
   267   memset(&ti, 0, sizeof(ti));
   268   err = td_thr_get_info(th_p, &ti);
   269   if (err != TD_OK) {
   270     print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n");
   271     return err;
   272   }
   274   print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid);
   276   if (ptr->callback(ptr->ph, ti.ti_tid, ti.ti_lid) != true)
   277     return TD_ERR;
   279   return TD_OK;
   280 }
   282 // read thread_info using libthread_db
   283 bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) {
   284   struct thread_db_client_data mydata;
   285   td_thragent_t* thread_agent = NULL;
   286   if (td_ta_new(ph, &thread_agent) != TD_OK) {
   287      print_debug("can't create libthread_db agent\n");
   288      return false;
   289   }
   291   mydata.ph = ph;
   292   mydata.callback = cb;
   294   // we use libthread_db iterator to iterate thru list of threads.
   295   if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata,
   296                  TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
   297                  TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) {
   298      td_ta_delete(thread_agent);
   299      return false;
   300   }
   302   // delete thread agent
   303   td_ta_delete(thread_agent);
   304   return true;
   305 }
   308 // get number of threads
   309 int get_num_threads(struct ps_prochandle* ph) {
   310    return ph->num_threads;
   311 }
   313 // get lwp_id of n'th thread
   314 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
   315    int count = 0;
   316    thread_info* thr = ph->threads;
   317    while (thr) {
   318       if (count == index) {
   319          return thr->lwp_id;
   320       }
   321       count++;
   322       thr = thr->next;
   323    }
   324    return -1;
   325 }
   327 // get regs for a given lwp
   328 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct user_regs_struct* regs) {
   329   return ph->ops->get_lwp_regs(ph, lwp_id, regs);
   330 }
   332 // get number of shared objects
   333 int get_num_libs(struct ps_prochandle* ph) {
   334    return ph->num_libs;
   335 }
   337 // get name of n'th solib
   338 const char* get_lib_name(struct ps_prochandle* ph, int index) {
   339    int count = 0;
   340    lib_info* lib = ph->libs;
   341    while (lib) {
   342       if (count == index) {
   343          return lib->name;
   344       }
   345       count++;
   346       lib = lib->next;
   347    }
   348    return NULL;
   349 }
   351 // get base address of a lib
   352 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
   353    int count = 0;
   354    lib_info* lib = ph->libs;
   355    while (lib) {
   356       if (count == index) {
   357          return lib->base;
   358       }
   359       count++;
   360       lib = lib->next;
   361    }
   362    return (uintptr_t)NULL;
   363 }
   365 bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
   366   lib_info *p = ph->libs;
   367   while (p) {
   368     if (strcmp(p->name, lib_name) == 0) {
   369       return true;
   370     }
   371     p = p->next;
   372   }
   373   return false;
   374 }
   376 //--------------------------------------------------------------------------
   377 // proc service functions
   379 // get process id
   380 pid_t ps_getpid(struct ps_prochandle *ph) {
   381    return ph->pid;
   382 }
   384 // ps_pglobal_lookup() looks up the symbol sym_name in the symbol table
   385 // of the load object object_name in the target process identified by ph.
   386 // It returns the symbol's value as an address in the target process in
   387 // *sym_addr.
   389 ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name,
   390                     const char *sym_name, psaddr_t *sym_addr) {
   391   *sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name);
   392   return (*sym_addr ? PS_OK : PS_NOSYM);
   393 }
   395 // read "size" bytes info "buf" from address "addr"
   396 ps_err_e ps_pdread(struct ps_prochandle *ph, psaddr_t  addr,
   397                    void *buf, size_t size) {
   398   return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR;
   399 }
   401 // write "size" bytes of data to debuggee at address "addr"
   402 ps_err_e ps_pdwrite(struct ps_prochandle *ph, psaddr_t addr,
   403                     const void *buf, size_t size) {
   404   return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR;
   405 }
   407 // ------------------------------------------------------------------------
   408 // Functions below this point are not yet implemented. They are here only
   409 // to make the linker happy.
   411 ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) {
   412   print_debug("ps_lsetfpregs not implemented\n");
   413   return PS_OK;
   414 }
   416 ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) {
   417   print_debug("ps_lsetregs not implemented\n");
   418   return PS_OK;
   419 }
   421 ps_err_e  ps_lgetfpregs(struct  ps_prochandle  *ph,  lwpid_t lid, prfpregset_t *fpregs) {
   422   print_debug("ps_lgetfpregs not implemented\n");
   423   return PS_OK;
   424 }
   426 ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) {
   427   print_debug("ps_lgetfpregs not implemented\n");
   428   return PS_OK;
   429 }
   431 // new libthread_db of NPTL seem to require this symbol
   432 ps_err_e ps_get_thread_area() {
   433   print_debug("ps_get_thread_area not implemented\n");
   434   return PS_OK;
   435 }

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