| /* |
| * Copyright (c) 2003, 2017, 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" |
| |
| #define SA_ALTROOT "SA_ALTROOT" |
| |
| int pathmap_open(const char* name) { |
| static const char *alt_root = NULL; |
| static int alt_root_initialized = 0; |
| |
| int fd; |
| char alt_path[PATH_MAX + 1], *alt_path_end; |
| const char *s; |
| int free_space; |
| |
| if (!alt_root_initialized) { |
| alt_root_initialized = -1; |
| alt_root = getenv(SA_ALTROOT); |
| } |
| |
| if (alt_root == NULL) { |
| return open(name, O_RDONLY); |
| } |
| |
| |
| if (strlen(alt_root) + strlen(name) > PATH_MAX) { |
| // Buffer too small. |
| return -1; |
| } |
| |
| strncpy(alt_path, alt_root, PATH_MAX); |
| alt_path[PATH_MAX] = '\0'; |
| alt_path_end = alt_path + strlen(alt_path); |
| free_space = PATH_MAX + 1 - (alt_path_end-alt_path); |
| |
| // Strip path items one by one and try to open file with alt_root prepended. |
| s = name; |
| while (1) { |
| strncat(alt_path, s, free_space); |
| s += 1; // Skip /. |
| |
| fd = open(alt_path, O_RDONLY); |
| if (fd >= 0) { |
| print_debug("path %s substituted for %s\n", alt_path, name); |
| return fd; |
| } |
| |
| // Linker always put full path to solib to process, so we can rely |
| // on presence of /. If slash is not present, it means, that SOlib doesn't |
| // physically exist (e.g. linux-gate.so) and we fail opening it anyway |
| if ((s = strchr(s, '/')) == NULL) { |
| break; |
| } |
| |
| // Cut off what we appended above. |
| *alt_path_end = '\0'; |
| } |
| |
| 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; |
| } |
| |
| if (strlen(libname) >= sizeof(newlib->name)) { |
| print_debug("libname %s too long\n", libname); |
| free(newlib); |
| return NULL; |
| } |
| strcpy(newlib->name, libname); |
| |
| 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; |
| } |