Mercurial > hg > truffle
view agent/src/os/bsd/ps_proc.c @ 9219:1964871a642d
Enabled execute evaluated methods in typed node.
author | Christian Humer <christian.humer@gmail.com> |
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date | Tue, 16 Apr 2013 11:03:40 +0200 |
parents | 2394a89e89f4 |
children | 1a04de1aaedb |
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/* * 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 <limits.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <sys/types.h> #include <sys/wait.h> #include <sys/ptrace.h> #include <sys/param.h> #include <sys/user.h> #include <elf.h> #include <sys/elf_common.h> #include <sys/link_elf.h> #include <libutil.h> #include "libproc_impl.h" #include "elfmacros.h" // 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) { int rslt; size_t i, words; uintptr_t end_addr = addr + size; uintptr_t aligned_addr = align(addr, sizeof(int)); if (aligned_addr != addr) { char *ptr = (char *)&rslt; errno = 0; rslt = ptrace(PT_READ_D, ph->pid, (caddr_t) aligned_addr, 0); if (errno) { print_debug("ptrace(PT_READ_D, ..) failed for %d bytes @ %lx\n", size, addr); return false; } for (; aligned_addr != addr; aligned_addr++, ptr++); for (; ((intptr_t)aligned_addr % sizeof(int)) && aligned_addr < end_addr; aligned_addr++) *(buf++) = *(ptr++); } words = (end_addr - aligned_addr) / sizeof(int); // assert((intptr_t)aligned_addr % sizeof(int) == 0); for (i = 0; i < words; i++) { errno = 0; rslt = ptrace(PT_READ_D, ph->pid, (caddr_t) aligned_addr, 0); if (errno) { print_debug("ptrace(PT_READ_D, ..) failed for %d bytes @ %lx\n", size, addr); return false; } *(int *)buf = rslt; buf += sizeof(int); aligned_addr += sizeof(int); } if (aligned_addr != end_addr) { char *ptr = (char *)&rslt; errno = 0; rslt = ptrace(PT_READ_D, ph->pid, (caddr_t) aligned_addr, 0); if (errno) { print_debug("ptrace(PT_READ_D, ..) 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 reg static bool process_get_lwp_regs(struct ps_prochandle* ph, pid_t pid, struct reg *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. if (ptrace(PT_GETREGS, pid, (caddr_t) user, 0) < 0) { print_debug("ptrace(PTRACE_GETREGS, ...) failed for lwp %d\n", pid); return false; } return true; } // fill in ptrace_lwpinfo for lid static bool process_get_lwp_info(struct ps_prochandle *ph, lwpid_t lwp_id, void *linfo) { errno = 0; ptrace(PT_LWPINFO, lwp_id, linfo, sizeof(struct ptrace_lwpinfo)); return (errno == 0)? true: false; } static bool ptrace_continue(pid_t pid, int signal) { // pass the signal to the process so we don't swallow it if (ptrace(PTRACE_CONT, pid, NULL, signal) < 0) { print_debug("ptrace(PTRACE_CONT, ..) failed for %d\n", pid); return false; } return true; } // waits until the ATTACH has stopped the process // by signal SIGSTOP static bool ptrace_waitpid(pid_t pid) { int ret; int status; do { // Wait for debuggee to stop. ret = waitpid(pid, &status, 0); if (ret >= 0) { if (WIFSTOPPED(status)) { // Any signal will stop the thread, make sure it is SIGSTOP. Otherwise SIGSTOP // will still be pending and delivered when the process is DETACHED and the process // will go to sleep. if (WSTOPSIG(status) == SIGSTOP) { // Debuggee stopped by SIGSTOP. return true; } if (!ptrace_continue(pid, WSTOPSIG(status))) { print_error("Failed to correctly attach to VM. VM might HANG! [PTRACE_CONT failed, stopped by %d]\n", WSTOPSIG(status)); return false; } } 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); } // attach to a process/thread specified by "pid" static bool ptrace_attach(pid_t pid) { if (ptrace(PT_ATTACH, pid, NULL, 0) < 0) { print_debug("ptrace(PTRACE_ATTACH, ..) failed for %d\n", pid); return false; } else { return ptrace_waitpid(pid); } } // ------------------------------------------------------- // functions for obtaining library information // ------------------------------------------------------- // 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; } #if defined(__FreeBSD__) && __FreeBSD_version < 701000 /* * TEXT_START_ADDR from binutils/ld/emulparams/<arch_spec>.sh * Not the most robust but good enough. */ #if defined(amd64) || defined(x86_64) #define TEXT_START_ADDR 0x400000 #elif defined(i386) #define TEXT_START_ADDR 0x8048000 #else #error TEXT_START_ADDR not defined #endif #define BUF_SIZE (PATH_MAX + NAME_MAX + 1) uintptr_t linkmap_addr(struct ps_prochandle *ph) { uintptr_t ehdr_addr, phdr_addr, dyn_addr, dmap_addr, lmap_addr; ELF_EHDR ehdr; ELF_PHDR *phdrs, *phdr; ELF_DYN *dyns, *dyn; struct r_debug dmap; unsigned long hdrs_size; unsigned int i; /* read ELF_EHDR at TEXT_START_ADDR and validate */ ehdr_addr = (uintptr_t)TEXT_START_ADDR; if (process_read_data(ph, ehdr_addr, (char *)&ehdr, sizeof(ehdr)) != true) { print_debug("process_read_data failed for ehdr_addr %p\n", ehdr_addr); return (0); } if (!IS_ELF(ehdr) || ehdr.e_ident[EI_CLASS] != ELF_TARG_CLASS || ehdr.e_ident[EI_DATA] != ELF_TARG_DATA || ehdr.e_ident[EI_VERSION] != EV_CURRENT || ehdr.e_phentsize != sizeof(ELF_PHDR) || ehdr.e_version != ELF_TARG_VER || ehdr.e_machine != ELF_TARG_MACH) { print_debug("not an ELF_EHDR at %p\n", ehdr_addr); return (0); } /* allocate space for all ELF_PHDR's and read */ phdr_addr = ehdr_addr + ehdr.e_phoff; hdrs_size = ehdr.e_phnum * sizeof(ELF_PHDR); if ((phdrs = malloc(hdrs_size)) == NULL) return (0); if (process_read_data(ph, phdr_addr, (char *)phdrs, hdrs_size) != true) { print_debug("process_read_data failed for phdr_addr %p\n", phdr_addr); return (0); } /* find PT_DYNAMIC section */ for (i = 0, phdr = phdrs; i < ehdr.e_phnum; i++, phdr++) { if (phdr->p_type == PT_DYNAMIC) break; } if (i >= ehdr.e_phnum) { print_debug("PT_DYNAMIC section not found!\n"); free(phdrs); return (0); } /* allocate space and read in ELF_DYN headers */ dyn_addr = phdr->p_vaddr; hdrs_size = phdr->p_memsz; free(phdrs); if ((dyns = malloc(hdrs_size)) == NULL) return (0); if (process_read_data(ph, dyn_addr, (char *)dyns, hdrs_size) != true) { print_debug("process_read_data failed for dyn_addr %p\n", dyn_addr); free(dyns); return (0); } /* find DT_DEBUG */ dyn = dyns; while (dyn->d_tag != DT_DEBUG && dyn->d_tag != DT_NULL) { dyn++; } if (dyn->d_tag != DT_DEBUG) { print_debug("failed to find DT_DEBUG\n"); free(dyns); return (0); } /* read struct r_debug into dmap */ dmap_addr = (uintptr_t)dyn->d_un.d_ptr; free(dyns); if (process_read_data(ph, dmap_addr, (char *)&dmap, sizeof(dmap)) != true) { print_debug("process_read_data failed for dmap_addr %p\n", dmap_addr); return (0); } lmap_addr = (uintptr_t)dmap.r_map; return (lmap_addr); } #endif // __FreeBSD__ && __FreeBSD_version < 701000 static bool read_lib_info(struct ps_prochandle* ph) { #if defined(__FreeBSD__) && __FreeBSD_version >= 701000 struct kinfo_vmentry *freep, *kve; int i, cnt; freep = kinfo_getvmmap(ph->pid, &cnt); if (freep == NULL) { print_debug("can't get vm map for pid\n", ph->pid); return false; } for (i = 0; i < cnt; i++) { kve = &freep[i]; if ((kve->kve_flags & KVME_FLAG_COW) && kve->kve_path != NULL && strlen(kve->kve_path) > 0) { if (find_lib(ph, kve->kve_path) == false) { lib_info* lib; if ((lib = add_lib_info(ph, kve->kve_path, (uintptr_t) kve->kve_start)) == 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; } } } free(freep); return true; #else char *l_name; struct link_map *lmap; uintptr_t lmap_addr; if ((l_name = malloc(BUF_SIZE)) == NULL) return false; if ((lmap = malloc(sizeof(*lmap))) == NULL) { free(l_name); return false; } lmap_addr = linkmap_addr(ph); if (lmap_addr == 0) { free(l_name); free(lmap); return false; } do { if (process_read_data(ph, lmap_addr, (char *)lmap, sizeof(*lmap)) != true) { print_debug("process_read_data failed for lmap_addr %p\n", lmap_addr); free (l_name); free (lmap); return false; } if (process_read_data(ph, (uintptr_t)lmap->l_name, l_name, BUF_SIZE) != true) { print_debug("process_read_data failed for lmap->l_name %p\n", lmap->l_name); free (l_name); free (lmap); return false; } if (find_lib(ph, l_name) == false) { lib_info* lib; if ((lib = add_lib_info(ph, l_name, (uintptr_t) lmap->l_addr)) == 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; } lmap_addr = (uintptr_t)lmap->l_next; } while (lmap->l_next != NULL); free (l_name); free (lmap); return true; #endif } // detach a given pid static bool ptrace_detach(pid_t pid) { if (pid && ptrace(PT_DETACH, pid, (caddr_t)1, 0) < 0) { print_debug("ptrace(PTRACE_DETACH, ..) failed for %d\n", pid); return false; } else { return true; } } static void process_cleanup(struct ps_prochandle* ph) { ptrace_detach(ph->pid); } 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, .get_lwp_info= process_get_lwp_info }; // 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. if (read_lib_info(ph) != true) { ptrace_detach(pid); free(ph); return NULL; } // read thread info read_thread_info(ph, add_new_thread); return ph; }