jdk8-mips64-public/hotspot: agent/src/os/linux/libproc

agent/src/os/linux/libproc_impl.c@2394a89e89f4 (annotated)

agent/src/os/linux/libproc_impl.c

Wed, 13 Feb 2013 09:46:19 +0100

author: rbackman
date: Wed, 13 Feb 2013 09:46:19 +0100
changeset 4599: 2394a89e89f4
parent 3546: 54d3535a6dd3
child 6876: 710a3c8b516e
child 9627: d626acee4654
permissions: -rw-r--r--

8008088: SA can hang the VM
Reviewed-by: mgronlun, sla, dholmes

 /*
  * Copyright (c) 2003, 2013, 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.
  *
  */
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <fcntl.h>
 #include <thread_db.h>
 #include "libproc_impl.h"
 static const char* alt_root = NULL;
 static int alt_root_len = -1;
 #define SA_ALTROOT "SA_ALTROOT"
 static void init_alt_root() {
    if (alt_root_len == -1) {
       alt_root = getenv(SA_ALTROOT);
       if (alt_root) {
          alt_root_len = strlen(alt_root);
       } else {
          alt_root_len = 0;
       }
    }
 }
 int pathmap_open(const char* name) {
    int fd;
    char alt_path[PATH_MAX + 1];
    init_alt_root();
    if (alt_root_len > 0) {
       strcpy(alt_path, alt_root);
       strcat(alt_path, name);
       fd = open(alt_path, O_RDONLY);
       if (fd >= 0) {
          print_debug("path %s substituted for %s\n", alt_path, name);
          return fd;
       }
       if (strrchr(name, '/')) {
          strcpy(alt_path, alt_root);
          strcat(alt_path, strrchr(name, '/'));
          fd = open(alt_path, O_RDONLY);
          if (fd >= 0) {
             print_debug("path %s substituted for %s\n", alt_path, name);
             return fd;
          }
       }
    } else {
       fd = open(name, O_RDONLY);
       if (fd >= 0) {
          return fd;
       }
    }
    return -1;
 }
 static bool _libsaproc_debug;
 void print_debug(const char* format,...) {
    if (_libsaproc_debug) {
      va_list alist;
      va_start(alist, format);
      fputs("libsaproc DEBUG: ", stderr);
      vfprintf(stderr, format, alist);
      va_end(alist);
    }
 }
 void print_error(const char* format,...) {
   va_list alist;
   va_start(alist, format);
   fputs("ERROR: ", stderr);
   vfprintf(stderr, format, alist);
   va_end(alist);
 }
 bool is_debug() {
    return _libsaproc_debug;
 }
 // initialize libproc
 bool init_libproc(bool debug) {
    // init debug mode
    _libsaproc_debug = debug;
    // initialize the thread_db library
    if (td_init() != TD_OK) {
      print_debug("libthread_db's td_init failed\n");
      return false;
    }
    return true;
 }
 static void destroy_lib_info(struct ps_prochandle* ph) {
    lib_info* lib = ph->libs;
    while (lib) {
      lib_info *next = lib->next;
      if (lib->symtab) {
         destroy_symtab(lib->symtab);
      }
      free(lib);
      lib = next;
    }
 }
 static void destroy_thread_info(struct ps_prochandle* ph) {
    thread_info* thr = ph->threads;
    while (thr) {
      thread_info *next = thr->next;
      free(thr);
      thr = next;
    }
 }
 // ps_prochandle cleanup
 // ps_prochandle cleanup
 void Prelease(struct ps_prochandle* ph) {
    // do the "derived class" clean-up first
    ph->ops->release(ph);
    destroy_lib_info(ph);
    destroy_thread_info(ph);
    free(ph);
 }
 lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) {
    return add_lib_info_fd(ph, libname, -1, base);
 }
 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
    lib_info* newlib;
    if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
       print_debug("can't allocate memory for lib_info\n");
       return NULL;
    }
    strncpy(newlib->name, libname, sizeof(newlib->name));
    newlib->base = base;
    if (fd == -1) {
       if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
          print_debug("can't open shared object %s\n", newlib->name);
          free(newlib);
          return NULL;
       }
    } else {
       newlib->fd = fd;
    }
    // check whether we have got an ELF file. /proc/<pid>/map
    // gives out all file mappings and not just shared objects
    if (is_elf_file(newlib->fd) == false) {
       close(newlib->fd);
       free(newlib);
       return NULL;
    }
    newlib->symtab = build_symtab(newlib->fd, libname);
    if (newlib->symtab == NULL) {
       print_debug("symbol table build failed for %s\n", newlib->name);
    }
    // even if symbol table building fails, we add the lib_info.
    // This is because we may need to read from the ELF file for core file
    // address read functionality. lookup_symbol checks for NULL symtab.
    if (ph->libs) {
       ph->lib_tail->next = newlib;
       ph->lib_tail = newlib;
    }  else {
       ph->libs = ph->lib_tail = newlib;
    }
    ph->num_libs++;
    return newlib;
 }
 // lookup for a specific symbol
 uintptr_t lookup_symbol(struct ps_prochandle* ph,  const char* object_name,
                        const char* sym_name) {
    // ignore object_name. search in all libraries
    // FIXME: what should we do with object_name?? The library names are obtained
    // by parsing /proc/<pid>/maps, which may not be the same as object_name.
    // What we need is a utility to map object_name to real file name, something
    // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
    // now, we just ignore object_name and do a global search for the symbol.
    lib_info* lib = ph->libs;
    while (lib) {
       if (lib->symtab) {
          uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
          if (res) return res;
       }
       lib = lib->next;
    }
    print_debug("lookup failed for symbol '%s' in obj '%s'\n",
                           sym_name, object_name);
    return (uintptr_t) NULL;
 }
 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
    const char* res = NULL;
    lib_info* lib = ph->libs;
    while (lib) {
       if (lib->symtab && addr >= lib->base) {
          res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
          if (res) return res;
       }
       lib = lib->next;
    }
    return NULL;
 }
 // add a thread to ps_prochandle
 thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
    thread_info* newthr;
    if ( (newthr = (thread_info*) calloc(1, sizeof(thread_info))) == NULL) {
       print_debug("can't allocate memory for thread_info\n");
       return NULL;
    }
    // initialize thread info
    newthr->pthread_id = pthread_id;
    newthr->lwp_id = lwp_id;
    // add new thread to the list
    newthr->next = ph->threads;
    ph->threads = newthr;
    ph->num_threads++;
    return newthr;
 }
 // struct used for client data from thread_db callback
 struct thread_db_client_data {
    struct ps_prochandle* ph;
    thread_info_callback callback;
 };
 // callback function for libthread_db
 static int thread_db_callback(const td_thrhandle_t *th_p, void *data) {
   struct thread_db_client_data* ptr = (struct thread_db_client_data*) data;
   td_thrinfo_t ti;
   td_err_e err;
   memset(&ti, 0, sizeof(ti));
   err = td_thr_get_info(th_p, &ti);
   if (err != TD_OK) {
     print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n");
     return err;
   }
   print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid);
   if (ptr->callback(ptr->ph, ti.ti_tid, ti.ti_lid) != true)
     return TD_ERR;
   return TD_OK;
 }
 // read thread_info using libthread_db
 bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) {
   struct thread_db_client_data mydata;
   td_thragent_t* thread_agent = NULL;
   if (td_ta_new(ph, &thread_agent) != TD_OK) {
      print_debug("can't create libthread_db agent\n");
      return false;
   }
   mydata.ph = ph;
   mydata.callback = cb;
   // we use libthread_db iterator to iterate thru list of threads.
   if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata,
                  TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
                  TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) {
      td_ta_delete(thread_agent);
      return false;
   }
   // delete thread agent
   td_ta_delete(thread_agent);
   return true;
 }
 // get number of threads
 int get_num_threads(struct ps_prochandle* ph) {
    return ph->num_threads;
 }
 // get lwp_id of n'th thread
 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
    int count = 0;
    thread_info* thr = ph->threads;
    while (thr) {
       if (count == index) {
          return thr->lwp_id;
       }
       count++;
       thr = thr->next;
    }
    return -1;
 }
 // get regs for a given lwp
 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct user_regs_struct* regs) {
   return ph->ops->get_lwp_regs(ph, lwp_id, regs);
 }
 // get number of shared objects
 int get_num_libs(struct ps_prochandle* ph) {
    return ph->num_libs;
 }
 // get name of n'th solib
 const char* get_lib_name(struct ps_prochandle* ph, int index) {
    int count = 0;
    lib_info* lib = ph->libs;
    while (lib) {
       if (count == index) {
          return lib->name;
       }
       count++;
       lib = lib->next;
    }
    return NULL;
 }
 // get base address of a lib
 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
    int count = 0;
    lib_info* lib = ph->libs;
    while (lib) {
       if (count == index) {
          return lib->base;
       }
       count++;
       lib = lib->next;
    }
    return (uintptr_t)NULL;
 }
 bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
   lib_info *p = ph->libs;
   while (p) {
     if (strcmp(p->name, lib_name) == 0) {
       return true;
     }
     p = p->next;
   }
   return false;
 }
 //--------------------------------------------------------------------------
 // proc service functions
 // get process id
 pid_t ps_getpid(struct ps_prochandle *ph) {
    return ph->pid;
 }
 // ps_pglobal_lookup() looks up the symbol sym_name in the symbol table
 // of the load object object_name in the target process identified by ph.
 // It returns the symbol's value as an address in the target process in
 // *sym_addr.
 ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name,
                     const char *sym_name, psaddr_t *sym_addr) {
   *sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name);
   return (*sym_addr ? PS_OK : PS_NOSYM);
 }
 // read "size" bytes info "buf" from address "addr"
 ps_err_e ps_pdread(struct ps_prochandle *ph, psaddr_t  addr,
                    void *buf, size_t size) {
   return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR;
 }
 // write "size" bytes of data to debuggee at address "addr"
 ps_err_e ps_pdwrite(struct ps_prochandle *ph, psaddr_t addr,
                     const void *buf, size_t size) {
   return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR;
 }
 // ------------------------------------------------------------------------
 // Functions below this point are not yet implemented. They are here only
 // to make the linker happy.
 ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) {
   print_debug("ps_lsetfpregs not implemented\n");
   return PS_OK;
 }
 ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) {
   print_debug("ps_lsetregs not implemented\n");
   return PS_OK;
 }
 ps_err_e  ps_lgetfpregs(struct  ps_prochandle  *ph,  lwpid_t lid, prfpregset_t *fpregs) {
   print_debug("ps_lgetfpregs not implemented\n");
   return PS_OK;
 }
 ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) {
   print_debug("ps_lgetfpregs not implemented\n");
   return PS_OK;
 }
 // new libthread_db of NPTL seem to require this symbol
 ps_err_e ps_get_thread_area() {
   print_debug("ps_get_thread_area not implemented\n");
   return PS_OK;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

agent/src/os/linux/libproc_impl.c@2394a89e89f4 (annotated)

agent/src/os/linux/libproc_impl.c