/*
* 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;
}