--- /dev/null Wed Sep 21 11:40:31 2011 +++ new/agent/src/os/bsd/ps_proc.c Wed Sep 21 11:41:01 2011 @@ -0,0 +1,444 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#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; +} + +// 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 { + int ret; + int status; + do { + // Wait for debuggee to stop. + ret = waitpid(pid, &status, 0); + 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 +// ------------------------------------------------------- + +// 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/.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; +}