Mercurial > hg > truffle
view agent/src/os/linux/ps_proc.c @ 8246:3862508afe2f
Updated @NodeClass tests.
author | Christian Humer <christian.humer@gmail.com> |
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date | Wed, 06 Mar 2013 18:33:05 +0100 |
parents | 0a8e0d4345b3 |
children | 2394a89e89f4 |
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/* * Copyright (c) 2003, 2010, 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 <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <sys/ptrace.h> #include "libproc_impl.h" #if defined(x86_64) && !defined(amd64) #define amd64 1 #endif #ifndef __WALL #define __WALL 0x40000000 // Copied from /usr/include/linux/wait.h #endif // This file has the libproc implementation specific to live process // For core files, refer to ps_core.c static inline uintptr_t align(uintptr_t ptr, size_t size) { return (ptr & ~(size - 1)); } // --------------------------------------------- // ptrace functions // --------------------------------------------- // read "size" bytes of data from "addr" within the target process. // unlike the standard ptrace() function, process_read_data() can handle // unaligned address - alignment check, if required, should be done // before calling process_read_data. static bool process_read_data(struct ps_prochandle* ph, uintptr_t addr, char *buf, size_t size) { long rslt; size_t i, words; uintptr_t end_addr = addr + size; uintptr_t aligned_addr = align(addr, sizeof(long)); if (aligned_addr != addr) { char *ptr = (char *)&rslt; errno = 0; rslt = ptrace(PTRACE_PEEKDATA, ph->pid, aligned_addr, 0); if (errno) { print_debug("ptrace(PTRACE_PEEKDATA, ..) failed for %d bytes @ %lx\n", size, addr); return false; } for (; aligned_addr != addr; aligned_addr++, ptr++); for (; ((intptr_t)aligned_addr % sizeof(long)) && aligned_addr < end_addr; aligned_addr++) *(buf++) = *(ptr++); } words = (end_addr - aligned_addr) / sizeof(long); // assert((intptr_t)aligned_addr % sizeof(long) == 0); for (i = 0; i < words; i++) { errno = 0; rslt = ptrace(PTRACE_PEEKDATA, ph->pid, aligned_addr, 0); if (errno) { print_debug("ptrace(PTRACE_PEEKDATA, ..) failed for %d bytes @ %lx\n", size, addr); return false; } *(long *)buf = rslt; buf += sizeof(long); aligned_addr += sizeof(long); } if (aligned_addr != end_addr) { char *ptr = (char *)&rslt; errno = 0; rslt = ptrace(PTRACE_PEEKDATA, ph->pid, aligned_addr, 0); if (errno) { print_debug("ptrace(PTRACE_PEEKDATA, ..) failed for %d bytes @ %lx\n", size, addr); return false; } for (; aligned_addr != end_addr; aligned_addr++) *(buf++) = *(ptr++); } return true; } // null implementation for write static bool process_write_data(struct ps_prochandle* ph, uintptr_t addr, const char *buf , size_t size) { return false; } // "user" should be a pointer to a user_regs_struct static bool process_get_lwp_regs(struct ps_prochandle* ph, pid_t pid, struct user_regs_struct *user) { // we have already attached to all thread 'pid's, just use ptrace call // to get regset now. Note that we don't cache regset upfront for processes. // Linux on x86 and sparc are different. On x86 ptrace(PTRACE_GETREGS, ...) // uses pointer from 4th argument and ignores 3rd argument. On sparc it uses // pointer from 3rd argument and ignores 4th argument #if defined(sparc) || defined(sparcv9) #define ptrace_getregs(request, pid, addr, data) ptrace(request, pid, addr, data) #else #define ptrace_getregs(request, pid, addr, data) ptrace(request, pid, data, addr) #endif #if defined(_LP64) && defined(PTRACE_GETREGS64) #define PTRACE_GETREGS_REQ PTRACE_GETREGS64 #elif defined(PTRACE_GETREGS) #define PTRACE_GETREGS_REQ PTRACE_GETREGS #elif defined(PT_GETREGS) #define PTRACE_GETREGS_REQ PT_GETREGS #endif #ifdef PTRACE_GETREGS_REQ if (ptrace_getregs(PTRACE_GETREGS_REQ, pid, user, NULL) < 0) { print_debug("ptrace(PTRACE_GETREGS, ...) failed for lwp %d\n", pid); return false; } return true; #else print_debug("ptrace(PTRACE_GETREGS, ...) not supported\n"); return false; #endif } // attach to a process/thread specified by "pid" static bool ptrace_attach(pid_t pid) { if (ptrace(PTRACE_ATTACH, pid, NULL, NULL) < 0) { print_debug("ptrace(PTRACE_ATTACH, ..) failed for %d\n", pid); return false; } else { int ret; int status; do { // Wait for debuggee to stop. ret = waitpid(pid, &status, 0); if (ret == -1 && errno == ECHILD) { // try cloned process. ret = waitpid(pid, &status, __WALL); } if (ret >= 0) { if (WIFSTOPPED(status)) { // Debuggee stopped. return true; } else { print_debug("waitpid(): Child process exited/terminated (status = 0x%x)\n", status); return false; } } else { switch (errno) { case EINTR: continue; break; case ECHILD: print_debug("waitpid() failed. Child process pid (%d) does not exist \n", pid); break; case EINVAL: print_debug("waitpid() failed. Invalid options argument.\n"); break; default: print_debug("waitpid() failed. Unexpected error %d\n",errno); } return false; } } while(true); } } // ------------------------------------------------------- // functions for obtaining library information // ------------------------------------------------------- /* * splits a string _str_ into substrings with delimiter _delim_ by replacing old * delimiters with _new_delim_ (ideally, '\0'). the address of each substring * is stored in array _ptrs_ as the return value. the maximum capacity of _ptrs_ * array is specified by parameter _n_. * RETURN VALUE: total number of substrings (always <= _n_) * NOTE: string _str_ is modified if _delim_!=_new_delim_ */ static int split_n_str(char * str, int n, char ** ptrs, char delim, char new_delim) { int i; for(i = 0; i < n; i++) ptrs[i] = NULL; if (str == NULL || n < 1 ) return 0; i = 0; // skipping leading blanks while(*str&&*str==delim) str++; while(*str&&i<n){ ptrs[i++] = str; while(*str&&*str!=delim) str++; while(*str&&*str==delim) *(str++) = new_delim; } return i; } /* * fgets without storing '\n' at the end of the string */ static char * fgets_no_cr(char * buf, int n, FILE *fp) { char * rslt = fgets(buf, n, fp); if (rslt && buf && *buf){ char *p = strchr(buf, '\0'); if (*--p=='\n') *p='\0'; } return rslt; } // callback for read_thread_info static bool add_new_thread(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) { return add_thread_info(ph, pthread_id, lwp_id) != NULL; } static bool read_lib_info(struct ps_prochandle* ph) { char fname[32]; char buf[256]; FILE *fp = NULL; sprintf(fname, "/proc/%d/maps", ph->pid); fp = fopen(fname, "r"); if (fp == NULL) { print_debug("can't open /proc/%d/maps file\n", ph->pid); return false; } while(fgets_no_cr(buf, 256, fp)){ char * word[6]; int nwords = split_n_str(buf, 6, word, ' ', '\0'); if (nwords > 5 && find_lib(ph, word[5]) == false) { intptr_t base; lib_info* lib; #ifdef _LP64 sscanf(word[0], "%lx", &base); #else sscanf(word[0], "%x", &base); #endif if ((lib = add_lib_info(ph, word[5], (uintptr_t)base)) == NULL) continue; // ignore, add_lib_info prints error // we don't need to keep the library open, symtab is already // built. Only for core dump we need to keep the fd open. close(lib->fd); lib->fd = -1; } } fclose(fp); return true; } // detach a given pid static bool ptrace_detach(pid_t pid) { if (pid && ptrace(PTRACE_DETACH, pid, NULL, NULL) < 0) { print_debug("ptrace(PTRACE_DETACH, ..) failed for %d\n", pid); return false; } else { return true; } } // detach all pids of a ps_prochandle static void detach_all_pids(struct ps_prochandle* ph) { thread_info* thr = ph->threads; while (thr) { ptrace_detach(thr->lwp_id); thr = thr->next; } } static void process_cleanup(struct ps_prochandle* ph) { detach_all_pids(ph); } static ps_prochandle_ops process_ops = { .release= process_cleanup, .p_pread= process_read_data, .p_pwrite= process_write_data, .get_lwp_regs= process_get_lwp_regs }; // attach to the process. One and only one exposed stuff struct ps_prochandle* Pgrab(pid_t pid) { struct ps_prochandle* ph = NULL; thread_info* thr = NULL; if ( (ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle))) == NULL) { print_debug("can't allocate memory for ps_prochandle\n"); return NULL; } if (ptrace_attach(pid) != true) { free(ph); return NULL; } // initialize ps_prochandle ph->pid = pid; // initialize vtable ph->ops = &process_ops; // read library info and symbol tables, must do this before attaching threads, // as the symbols in the pthread library will be used to figure out // the list of threads within the same process. read_lib_info(ph); // read thread info read_thread_info(ph, add_new_thread); // attach to the threads thr = ph->threads; while (thr) { // don't attach to the main thread again if (ph->pid != thr->lwp_id && ptrace_attach(thr->lwp_id) != true) { // even if one attach fails, we get return NULL Prelease(ph); return NULL; } thr = thr->next; } return ph; }