| /* |
| * 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 <jni.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <stddef.h> |
| #include <elf.h> |
| #include <link.h> |
| #include "libproc_impl.h" |
| #include "salibelf.h" |
| |
| // This file has the libproc implementation to read core files. |
| // For live processes, refer to ps_proc.c. Portions of this is adapted |
| // /modelled after Solaris libproc.so (in particular Pcore.c) |
| |
| //---------------------------------------------------------------------- |
| // ps_prochandle cleanup helper functions |
| |
| // close all file descriptors |
| static void close_files(struct ps_prochandle* ph) { |
| lib_info* lib = NULL; |
| |
| // close core file descriptor |
| if (ph->core->core_fd >= 0) |
| close(ph->core->core_fd); |
| |
| // close exec file descriptor |
| if (ph->core->exec_fd >= 0) |
| close(ph->core->exec_fd); |
| |
| // close interp file descriptor |
| if (ph->core->interp_fd >= 0) |
| close(ph->core->interp_fd); |
| |
| // close class share archive file |
| if (ph->core->classes_jsa_fd >= 0) |
| close(ph->core->classes_jsa_fd); |
| |
| // close all library file descriptors |
| lib = ph->libs; |
| while (lib) { |
| int fd = lib->fd; |
| if (fd >= 0 && fd != ph->core->exec_fd) { |
| close(fd); |
| } |
| lib = lib->next; |
| } |
| } |
| |
| // clean all map_info stuff |
| static void destroy_map_info(struct ps_prochandle* ph) { |
| map_info* map = ph->core->maps; |
| while (map) { |
| map_info* next = map->next; |
| free(map); |
| map = next; |
| } |
| |
| if (ph->core->map_array) { |
| free(ph->core->map_array); |
| } |
| |
| // Part of the class sharing workaround |
| map = ph->core->class_share_maps; |
| while (map) { |
| map_info* next = map->next; |
| free(map); |
| map = next; |
| } |
| } |
| |
| // ps_prochandle operations |
| static void core_release(struct ps_prochandle* ph) { |
| if (ph->core) { |
| close_files(ph); |
| destroy_map_info(ph); |
| free(ph->core); |
| } |
| } |
| |
| static map_info* allocate_init_map(int fd, off_t offset, uintptr_t vaddr, size_t memsz) { |
| map_info* map; |
| if ( (map = (map_info*) calloc(1, sizeof(map_info))) == NULL) { |
| print_debug("can't allocate memory for map_info\n"); |
| return NULL; |
| } |
| |
| // initialize map |
| map->fd = fd; |
| map->offset = offset; |
| map->vaddr = vaddr; |
| map->memsz = memsz; |
| return map; |
| } |
| |
| // add map info with given fd, offset, vaddr and memsz |
| static map_info* add_map_info(struct ps_prochandle* ph, int fd, off_t offset, |
| uintptr_t vaddr, size_t memsz) { |
| map_info* map; |
| if ((map = allocate_init_map(fd, offset, vaddr, memsz)) == NULL) { |
| return NULL; |
| } |
| |
| // add this to map list |
| map->next = ph->core->maps; |
| ph->core->maps = map; |
| ph->core->num_maps++; |
| |
| return map; |
| } |
| |
| // Part of the class sharing workaround |
| static map_info* add_class_share_map_info(struct ps_prochandle* ph, off_t offset, |
| uintptr_t vaddr, size_t memsz) { |
| map_info* map; |
| if ((map = allocate_init_map(ph->core->classes_jsa_fd, |
| offset, vaddr, memsz)) == NULL) { |
| return NULL; |
| } |
| |
| map->next = ph->core->class_share_maps; |
| ph->core->class_share_maps = map; |
| return map; |
| } |
| |
| // Return the map_info for the given virtual address. We keep a sorted |
| // array of pointers in ph->map_array, so we can binary search. |
| static map_info* core_lookup(struct ps_prochandle *ph, uintptr_t addr) { |
| int mid, lo = 0, hi = ph->core->num_maps - 1; |
| map_info *mp; |
| |
| while (hi - lo > 1) { |
| mid = (lo + hi) / 2; |
| if (addr >= ph->core->map_array[mid]->vaddr) { |
| lo = mid; |
| } else { |
| hi = mid; |
| } |
| } |
| |
| if (addr < ph->core->map_array[hi]->vaddr) { |
| mp = ph->core->map_array[lo]; |
| } else { |
| mp = ph->core->map_array[hi]; |
| } |
| |
| if (addr >= mp->vaddr && addr < mp->vaddr + mp->memsz) { |
| return (mp); |
| } |
| |
| |
| // Part of the class sharing workaround |
| // Unfortunately, we have no way of detecting -Xshare state. |
| // Check out the share maps atlast, if we don't find anywhere. |
| // This is done this way so to avoid reading share pages |
| // ahead of other normal maps. For eg. with -Xshare:off we don't |
| // want to prefer class sharing data to data from core. |
| mp = ph->core->class_share_maps; |
| if (mp) { |
| print_debug("can't locate map_info at 0x%lx, trying class share maps\n", addr); |
| } |
| while (mp) { |
| if (addr >= mp->vaddr && addr < mp->vaddr + mp->memsz) { |
| print_debug("located map_info at 0x%lx from class share maps\n", addr); |
| return (mp); |
| } |
| mp = mp->next; |
| } |
| |
| print_debug("can't locate map_info at 0x%lx\n", addr); |
| return (NULL); |
| } |
| |
| //--------------------------------------------------------------- |
| // Part of the class sharing workaround: |
| // |
| // With class sharing, pages are mapped from classes.jsa file. |
| // The read-only class sharing pages are mapped as MAP_SHARED, |
| // PROT_READ pages. These pages are not dumped into core dump. |
| // With this workaround, these pages are read from classes.jsa. |
| |
| // FIXME: !HACK ALERT! |
| // The format of sharing achive file header is needed to read shared heap |
| // file mappings. For now, I am hard coding portion of FileMapHeader here. |
| // Refer to filemap.hpp. |
| |
| // FileMapHeader describes the shared space data in the file to be |
| // mapped. This structure gets written to a file. It is not a class, |
| // so that the compilers don't add any compiler-private data to it. |
| |
| #define NUM_SHARED_MAPS 4 |
| |
| // Refer to FileMapInfo::_current_version in filemap.hpp |
| #define CURRENT_ARCHIVE_VERSION 1 |
| |
| struct FileMapHeader { |
| int _magic; // identify file type. |
| int _version; // (from enum, above.) |
| size_t _alignment; // how shared archive should be aligned |
| |
| struct space_info { |
| int _file_offset; // sizeof(this) rounded to vm page size |
| char* _base; // copy-on-write base address |
| size_t _capacity; // for validity checking |
| size_t _used; // for setting space top on read |
| |
| // 4991491 NOTICE These are C++ bool's in filemap.hpp and must match up with |
| // the C type matching the C++ bool type on any given platform. |
| // We assume the corresponding C type is char but licensees |
| // may need to adjust the type of these fields. |
| char _read_only; // read only space? |
| char _allow_exec; // executable code in space? |
| |
| } _space[NUM_SHARED_MAPS]; |
| |
| // Ignore the rest of the FileMapHeader. We don't need those fields here. |
| }; |
| |
| static bool read_jboolean(struct ps_prochandle* ph, uintptr_t addr, jboolean* pvalue) { |
| jboolean i; |
| if (ps_pdread(ph, (psaddr_t) addr, &i, sizeof(i)) == PS_OK) { |
| *pvalue = i; |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| static bool read_pointer(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* pvalue) { |
| uintptr_t uip; |
| if (ps_pdread(ph, (psaddr_t) addr, (char *)&uip, sizeof(uip)) == PS_OK) { |
| *pvalue = uip; |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| // used to read strings from debuggee |
| static bool read_string(struct ps_prochandle* ph, uintptr_t addr, char* buf, size_t size) { |
| size_t i = 0; |
| char c = ' '; |
| |
| while (c != '\0') { |
| if (ps_pdread(ph, (psaddr_t) addr, &c, sizeof(char)) != PS_OK) { |
| return false; |
| } |
| if (i < size - 1) { |
| buf[i] = c; |
| } else { |
| // smaller buffer |
| return false; |
| } |
| i++; addr++; |
| } |
| |
| buf[i] = '\0'; |
| return true; |
| } |
| |
| #define USE_SHARED_SPACES_SYM "UseSharedSpaces" |
| // mangled name of Arguments::SharedArchivePath |
| #define SHARED_ARCHIVE_PATH_SYM "_ZN9Arguments17SharedArchivePathE" |
| #define LIBJVM_NAME "/libjvm.so" |
| |
| static bool init_classsharing_workaround(struct ps_prochandle* ph) { |
| lib_info* lib = ph->libs; |
| while (lib != NULL) { |
| // we are iterating over shared objects from the core dump. look for |
| // libjvm.so. |
| const char *jvm_name = 0; |
| if ((jvm_name = strstr(lib->name, LIBJVM_NAME)) != 0) { |
| char classes_jsa[PATH_MAX]; |
| struct FileMapHeader header; |
| int fd = -1; |
| int m = 0; |
| size_t n = 0; |
| uintptr_t base = 0, useSharedSpacesAddr = 0; |
| uintptr_t sharedArchivePathAddrAddr = 0, sharedArchivePathAddr = 0; |
| jboolean useSharedSpaces = 0; |
| map_info* mi = 0; |
| |
| memset(classes_jsa, 0, sizeof(classes_jsa)); |
| jvm_name = lib->name; |
| useSharedSpacesAddr = lookup_symbol(ph, jvm_name, USE_SHARED_SPACES_SYM); |
| if (useSharedSpacesAddr == 0) { |
| print_debug("can't lookup 'UseSharedSpaces' flag\n"); |
| return false; |
| } |
| |
| // Hotspot vm types are not exported to build this library. So |
| // using equivalent type jboolean to read the value of |
| // UseSharedSpaces which is same as hotspot type "bool". |
| if (read_jboolean(ph, useSharedSpacesAddr, &useSharedSpaces) != true) { |
| print_debug("can't read the value of 'UseSharedSpaces' flag\n"); |
| return false; |
| } |
| |
| if ((int)useSharedSpaces == 0) { |
| print_debug("UseSharedSpaces is false, assuming -Xshare:off!\n"); |
| return true; |
| } |
| |
| sharedArchivePathAddrAddr = lookup_symbol(ph, jvm_name, SHARED_ARCHIVE_PATH_SYM); |
| if (sharedArchivePathAddrAddr == 0) { |
| print_debug("can't lookup shared archive path symbol\n"); |
| return false; |
| } |
| |
| if (read_pointer(ph, sharedArchivePathAddrAddr, &sharedArchivePathAddr) != true) { |
| print_debug("can't read shared archive path pointer\n"); |
| return false; |
| } |
| |
| if (read_string(ph, sharedArchivePathAddr, classes_jsa, sizeof(classes_jsa)) != true) { |
| print_debug("can't read shared archive path value\n"); |
| return false; |
| } |
| |
| print_debug("looking for %s\n", classes_jsa); |
| // open the class sharing archive file |
| fd = pathmap_open(classes_jsa); |
| if (fd < 0) { |
| print_debug("can't open %s!\n", classes_jsa); |
| ph->core->classes_jsa_fd = -1; |
| return false; |
| } else { |
| print_debug("opened %s\n", classes_jsa); |
| } |
| |
| // read FileMapHeader from the file |
| memset(&header, 0, sizeof(struct FileMapHeader)); |
| if ((n = read(fd, &header, sizeof(struct FileMapHeader))) |
| != sizeof(struct FileMapHeader)) { |
| print_debug("can't read shared archive file map header from %s\n", classes_jsa); |
| close(fd); |
| return false; |
| } |
| |
| // check file magic |
| if (header._magic != 0xf00baba2) { |
| print_debug("%s has bad shared archive file magic number 0x%x, expecing 0xf00baba2\n", |
| classes_jsa, header._magic); |
| close(fd); |
| return false; |
| } |
| |
| // check version |
| if (header._version != CURRENT_ARCHIVE_VERSION) { |
| print_debug("%s has wrong shared archive file version %d, expecting %d\n", |
| classes_jsa, header._version, CURRENT_ARCHIVE_VERSION); |
| close(fd); |
| return false; |
| } |
| |
| ph->core->classes_jsa_fd = fd; |
| // add read-only maps from classes.jsa to the list of maps |
| for (m = 0; m < NUM_SHARED_MAPS; m++) { |
| if (header._space[m]._read_only) { |
| base = (uintptr_t) header._space[m]._base; |
| // no need to worry about the fractional pages at-the-end. |
| // possible fractional pages are handled by core_read_data. |
| add_class_share_map_info(ph, (off_t) header._space[m]._file_offset, |
| base, (size_t) header._space[m]._used); |
| print_debug("added a share archive map at 0x%lx\n", base); |
| } |
| } |
| return true; |
| } |
| lib = lib->next; |
| } |
| return true; |
| } |
| |
| |
| //--------------------------------------------------------------------------- |
| // functions to handle map_info |
| |
| // Order mappings based on virtual address. We use this function as the |
| // callback for sorting the array of map_info pointers. |
| static int core_cmp_mapping(const void *lhsp, const void *rhsp) |
| { |
| const map_info *lhs = *((const map_info **)lhsp); |
| const map_info *rhs = *((const map_info **)rhsp); |
| |
| if (lhs->vaddr == rhs->vaddr) { |
| return (0); |
| } |
| |
| return (lhs->vaddr < rhs->vaddr ? -1 : 1); |
| } |
| |
| // we sort map_info by starting virtual address so that we can do |
| // binary search to read from an address. |
| static bool sort_map_array(struct ps_prochandle* ph) { |
| size_t num_maps = ph->core->num_maps; |
| map_info* map = ph->core->maps; |
| int i = 0; |
| |
| // allocate map_array |
| map_info** array; |
| if ( (array = (map_info**) malloc(sizeof(map_info*) * num_maps)) == NULL) { |
| print_debug("can't allocate memory for map array\n"); |
| return false; |
| } |
| |
| // add maps to array |
| while (map) { |
| array[i] = map; |
| i++; |
| map = map->next; |
| } |
| |
| // sort is called twice. If this is second time, clear map array |
| if (ph->core->map_array) { |
| free(ph->core->map_array); |
| } |
| |
| ph->core->map_array = array; |
| // sort the map_info array by base virtual address. |
| qsort(ph->core->map_array, ph->core->num_maps, sizeof (map_info*), |
| core_cmp_mapping); |
| |
| // print map |
| if (is_debug()) { |
| int j = 0; |
| print_debug("---- sorted virtual address map ----\n"); |
| for (j = 0; j < ph->core->num_maps; j++) { |
| print_debug("base = 0x%lx\tsize = %zu\n", ph->core->map_array[j]->vaddr, |
| ph->core->map_array[j]->memsz); |
| } |
| } |
| |
| return true; |
| } |
| |
| #ifndef MIN |
| #define MIN(x, y) (((x) < (y))? (x): (y)) |
| #endif |
| |
| static bool core_read_data(struct ps_prochandle* ph, uintptr_t addr, char *buf, size_t size) { |
| ssize_t resid = size; |
| int page_size=sysconf(_SC_PAGE_SIZE); |
| while (resid != 0) { |
| map_info *mp = core_lookup(ph, addr); |
| uintptr_t mapoff; |
| ssize_t len, rem; |
| off_t off; |
| int fd; |
| |
| if (mp == NULL) { |
| break; /* No mapping for this address */ |
| } |
| |
| fd = mp->fd; |
| mapoff = addr - mp->vaddr; |
| len = MIN(resid, mp->memsz - mapoff); |
| off = mp->offset + mapoff; |
| |
| if ((len = pread(fd, buf, len, off)) <= 0) { |
| break; |
| } |
| |
| resid -= len; |
| addr += len; |
| buf = (char *)buf + len; |
| |
| // mappings always start at page boundary. But, may end in fractional |
| // page. fill zeros for possible fractional page at the end of a mapping. |
| rem = mp->memsz % page_size; |
| if (rem > 0) { |
| rem = page_size - rem; |
| len = MIN(resid, rem); |
| resid -= len; |
| addr += len; |
| // we are not assuming 'buf' to be zero initialized. |
| memset(buf, 0, len); |
| buf += len; |
| } |
| } |
| |
| if (resid) { |
| print_debug("core read failed for %d byte(s) @ 0x%lx (%d more bytes)\n", |
| size, addr, resid); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| // null implementation for write |
| static bool core_write_data(struct ps_prochandle* ph, |
| uintptr_t addr, const char *buf , size_t size) { |
| return false; |
| } |
| |
| static bool core_get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, |
| struct user_regs_struct* regs) { |
| // for core we have cached the lwp regs from NOTE section |
| thread_info* thr = ph->threads; |
| while (thr) { |
| if (thr->lwp_id == lwp_id) { |
| memcpy(regs, &thr->regs, sizeof(struct user_regs_struct)); |
| return true; |
| } |
| thr = thr->next; |
| } |
| return false; |
| } |
| |
| static ps_prochandle_ops core_ops = { |
| .release= core_release, |
| .p_pread= core_read_data, |
| .p_pwrite= core_write_data, |
| .get_lwp_regs= core_get_lwp_regs |
| }; |
| |
| // read regs and create thread from NT_PRSTATUS entries from core file |
| static bool core_handle_prstatus(struct ps_prochandle* ph, const char* buf, size_t nbytes) { |
| // we have to read prstatus_t from buf |
| // assert(nbytes == sizeof(prstaus_t), "size mismatch on prstatus_t"); |
| prstatus_t* prstat = (prstatus_t*) buf; |
| thread_info* newthr; |
| print_debug("got integer regset for lwp %d\n", prstat->pr_pid); |
| // we set pthread_t to -1 for core dump |
| if((newthr = add_thread_info(ph, (pthread_t) -1, prstat->pr_pid)) == NULL) |
| return false; |
| |
| // copy regs |
| memcpy(&newthr->regs, prstat->pr_reg, sizeof(struct user_regs_struct)); |
| |
| if (is_debug()) { |
| print_debug("integer regset\n"); |
| #ifdef i386 |
| // print the regset |
| print_debug("\teax = 0x%x\n", newthr->regs.eax); |
| print_debug("\tebx = 0x%x\n", newthr->regs.ebx); |
| print_debug("\tecx = 0x%x\n", newthr->regs.ecx); |
| print_debug("\tedx = 0x%x\n", newthr->regs.edx); |
| print_debug("\tesp = 0x%x\n", newthr->regs.esp); |
| print_debug("\tebp = 0x%x\n", newthr->regs.ebp); |
| print_debug("\tesi = 0x%x\n", newthr->regs.esi); |
| print_debug("\tedi = 0x%x\n", newthr->regs.edi); |
| print_debug("\teip = 0x%x\n", newthr->regs.eip); |
| #endif |
| |
| #if defined(amd64) || defined(x86_64) |
| // print the regset |
| print_debug("\tr15 = 0x%lx\n", newthr->regs.r15); |
| print_debug("\tr14 = 0x%lx\n", newthr->regs.r14); |
| print_debug("\tr13 = 0x%lx\n", newthr->regs.r13); |
| print_debug("\tr12 = 0x%lx\n", newthr->regs.r12); |
| print_debug("\trbp = 0x%lx\n", newthr->regs.rbp); |
| print_debug("\trbx = 0x%lx\n", newthr->regs.rbx); |
| print_debug("\tr11 = 0x%lx\n", newthr->regs.r11); |
| print_debug("\tr10 = 0x%lx\n", newthr->regs.r10); |
| print_debug("\tr9 = 0x%lx\n", newthr->regs.r9); |
| print_debug("\tr8 = 0x%lx\n", newthr->regs.r8); |
| print_debug("\trax = 0x%lx\n", newthr->regs.rax); |
| print_debug("\trcx = 0x%lx\n", newthr->regs.rcx); |
| print_debug("\trdx = 0x%lx\n", newthr->regs.rdx); |
| print_debug("\trsi = 0x%lx\n", newthr->regs.rsi); |
| print_debug("\trdi = 0x%lx\n", newthr->regs.rdi); |
| print_debug("\torig_rax = 0x%lx\n", newthr->regs.orig_rax); |
| print_debug("\trip = 0x%lx\n", newthr->regs.rip); |
| print_debug("\tcs = 0x%lx\n", newthr->regs.cs); |
| print_debug("\teflags = 0x%lx\n", newthr->regs.eflags); |
| print_debug("\trsp = 0x%lx\n", newthr->regs.rsp); |
| print_debug("\tss = 0x%lx\n", newthr->regs.ss); |
| print_debug("\tfs_base = 0x%lx\n", newthr->regs.fs_base); |
| print_debug("\tgs_base = 0x%lx\n", newthr->regs.gs_base); |
| print_debug("\tds = 0x%lx\n", newthr->regs.ds); |
| print_debug("\tes = 0x%lx\n", newthr->regs.es); |
| print_debug("\tfs = 0x%lx\n", newthr->regs.fs); |
| print_debug("\tgs = 0x%lx\n", newthr->regs.gs); |
| #endif |
| } |
| |
| return true; |
| } |
| |
| #define ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y)) |
| |
| // read NT_PRSTATUS entries from core NOTE segment |
| static bool core_handle_note(struct ps_prochandle* ph, ELF_PHDR* note_phdr) { |
| char* buf = NULL; |
| char* p = NULL; |
| size_t size = note_phdr->p_filesz; |
| |
| // we are interested in just prstatus entries. we will ignore the rest. |
| // Advance the seek pointer to the start of the PT_NOTE data |
| if (lseek(ph->core->core_fd, note_phdr->p_offset, SEEK_SET) == (off_t)-1) { |
| print_debug("failed to lseek to PT_NOTE data\n"); |
| return false; |
| } |
| |
| // Now process the PT_NOTE structures. Each one is preceded by |
| // an Elf{32/64}_Nhdr structure describing its type and size. |
| if ( (buf = (char*) malloc(size)) == NULL) { |
| print_debug("can't allocate memory for reading core notes\n"); |
| goto err; |
| } |
| |
| // read notes into buffer |
| if (read(ph->core->core_fd, buf, size) != size) { |
| print_debug("failed to read notes, core file must have been truncated\n"); |
| goto err; |
| } |
| |
| p = buf; |
| while (p < buf + size) { |
| ELF_NHDR* notep = (ELF_NHDR*) p; |
| char* descdata = p + sizeof(ELF_NHDR) + ROUNDUP(notep->n_namesz, 4); |
| print_debug("Note header with n_type = %d and n_descsz = %u\n", |
| notep->n_type, notep->n_descsz); |
| |
| if (notep->n_type == NT_PRSTATUS) { |
| if (core_handle_prstatus(ph, descdata, notep->n_descsz) != true) { |
| return false; |
| } |
| } else if (notep->n_type == NT_AUXV) { |
| // Get first segment from entry point |
| ELF_AUXV *auxv = (ELF_AUXV *)descdata; |
| while (auxv->a_type != AT_NULL) { |
| if (auxv->a_type == AT_ENTRY) { |
| // Set entry point address to address of dynamic section. |
| // We will adjust it in read_exec_segments(). |
| ph->core->dynamic_addr = auxv->a_un.a_val; |
| break; |
| } |
| auxv++; |
| } |
| } |
| p = descdata + ROUNDUP(notep->n_descsz, 4); |
| } |
| |
| free(buf); |
| return true; |
| |
| err: |
| if (buf) free(buf); |
| return false; |
| } |
| |
| // read all segments from core file |
| static bool read_core_segments(struct ps_prochandle* ph, ELF_EHDR* core_ehdr) { |
| int i = 0; |
| ELF_PHDR* phbuf = NULL; |
| ELF_PHDR* core_php = NULL; |
| |
| if ((phbuf = read_program_header_table(ph->core->core_fd, core_ehdr)) == NULL) |
| return false; |
| |
| /* |
| * Now iterate through the program headers in the core file. |
| * We're interested in two types of Phdrs: PT_NOTE (which |
| * contains a set of saved /proc structures), and PT_LOAD (which |
| * represents a memory mapping from the process's address space). |
| * |
| * Difference b/w Solaris PT_NOTE and Linux/BSD PT_NOTE: |
| * |
| * In Solaris there are two PT_NOTE segments the first PT_NOTE (if present) |
| * contains /proc structs in the pre-2.6 unstructured /proc format. the last |
| * PT_NOTE has data in new /proc format. |
| * |
| * In Solaris, there is only one pstatus (process status). pstatus contains |
| * integer register set among other stuff. For each LWP, we have one lwpstatus |
| * entry that has integer regset for that LWP. |
| * |
| * Linux threads are actually 'clone'd processes. To support core analysis |
| * of "multithreaded" process, Linux creates more than one pstatus (called |
| * "prstatus") entry in PT_NOTE. Each prstatus entry has integer regset for one |
| * "thread". Please refer to Linux kernel src file 'fs/binfmt_elf.c', in particular |
| * function "elf_core_dump". |
| */ |
| |
| for (core_php = phbuf, i = 0; i < core_ehdr->e_phnum; i++) { |
| switch (core_php->p_type) { |
| case PT_NOTE: |
| if (core_handle_note(ph, core_php) != true) { |
| goto err; |
| } |
| break; |
| |
| case PT_LOAD: { |
| if (core_php->p_filesz != 0) { |
| if (add_map_info(ph, ph->core->core_fd, core_php->p_offset, |
| core_php->p_vaddr, core_php->p_filesz) == NULL) goto err; |
| } |
| break; |
| } |
| } |
| |
| core_php++; |
| } |
| |
| free(phbuf); |
| return true; |
| err: |
| free(phbuf); |
| return false; |
| } |
| |
| // read segments of a shared object |
| static bool read_lib_segments(struct ps_prochandle* ph, int lib_fd, ELF_EHDR* lib_ehdr, uintptr_t lib_base) { |
| int i = 0; |
| ELF_PHDR* phbuf; |
| ELF_PHDR* lib_php = NULL; |
| |
| int page_size = sysconf(_SC_PAGE_SIZE); |
| |
| if ((phbuf = read_program_header_table(lib_fd, lib_ehdr)) == NULL) { |
| return false; |
| } |
| |
| // we want to process only PT_LOAD segments that are not writable. |
| // i.e., text segments. The read/write/exec (data) segments would |
| // have been already added from core file segments. |
| for (lib_php = phbuf, i = 0; i < lib_ehdr->e_phnum; i++) { |
| if ((lib_php->p_type == PT_LOAD) && !(lib_php->p_flags & PF_W) && (lib_php->p_filesz != 0)) { |
| |
| uintptr_t target_vaddr = lib_php->p_vaddr + lib_base; |
| map_info *existing_map = core_lookup(ph, target_vaddr); |
| |
| if (existing_map == NULL){ |
| if (add_map_info(ph, lib_fd, lib_php->p_offset, |
| target_vaddr, lib_php->p_memsz) == NULL) { |
| goto err; |
| } |
| } else { |
| // Coredump stores value of p_memsz elf field |
| // rounded up to page boundary. |
| |
| if ((existing_map->memsz != page_size) && |
| (existing_map->fd != lib_fd) && |
| (ROUNDUP(existing_map->memsz, page_size) != ROUNDUP(lib_php->p_memsz, page_size))) { |
| |
| print_debug("address conflict @ 0x%lx (existing map size = %ld, size = %ld, flags = %d)\n", |
| target_vaddr, existing_map->memsz, lib_php->p_memsz, lib_php->p_flags); |
| goto err; |
| } |
| |
| /* replace PT_LOAD segment with library segment */ |
| print_debug("overwrote with new address mapping (memsz %ld -> %ld)\n", |
| existing_map->memsz, ROUNDUP(lib_php->p_memsz, page_size)); |
| |
| existing_map->fd = lib_fd; |
| existing_map->offset = lib_php->p_offset; |
| existing_map->memsz = ROUNDUP(lib_php->p_memsz, page_size); |
| } |
| } |
| |
| lib_php++; |
| } |
| |
| free(phbuf); |
| return true; |
| err: |
| free(phbuf); |
| return false; |
| } |
| |
| // process segments from interpreter (ld.so or ld-linux.so) |
| static bool read_interp_segments(struct ps_prochandle* ph) { |
| ELF_EHDR interp_ehdr; |
| |
| if (read_elf_header(ph->core->interp_fd, &interp_ehdr) != true) { |
| print_debug("interpreter is not a valid ELF file\n"); |
| return false; |
| } |
| |
| if (read_lib_segments(ph, ph->core->interp_fd, &interp_ehdr, ph->core->ld_base_addr) != true) { |
| print_debug("can't read segments of interpreter\n"); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // process segments of a a.out |
| static bool read_exec_segments(struct ps_prochandle* ph, ELF_EHDR* exec_ehdr) { |
| int i = 0; |
| ELF_PHDR* phbuf = NULL; |
| ELF_PHDR* exec_php = NULL; |
| |
| if ((phbuf = read_program_header_table(ph->core->exec_fd, exec_ehdr)) == NULL) { |
| return false; |
| } |
| |
| for (exec_php = phbuf, i = 0; i < exec_ehdr->e_phnum; i++) { |
| switch (exec_php->p_type) { |
| |
| // add mappings for PT_LOAD segments |
| case PT_LOAD: { |
| // add only non-writable segments of non-zero filesz |
| if (!(exec_php->p_flags & PF_W) && exec_php->p_filesz != 0) { |
| if (add_map_info(ph, ph->core->exec_fd, exec_php->p_offset, exec_php->p_vaddr, exec_php->p_filesz) == NULL) goto err; |
| } |
| break; |
| } |
| |
| // read the interpreter and it's segments |
| case PT_INTERP: { |
| char interp_name[BUF_SIZE + 1]; |
| |
| // BUF_SIZE is PATH_MAX + NAME_MAX + 1. |
| if (exec_php->p_filesz > BUF_SIZE) { |
| goto err; |
| } |
| pread(ph->core->exec_fd, interp_name, exec_php->p_filesz, exec_php->p_offset); |
| interp_name[exec_php->p_filesz] = '\0'; |
| print_debug("ELF interpreter %s\n", interp_name); |
| // read interpreter segments as well |
| if ((ph->core->interp_fd = pathmap_open(interp_name)) < 0) { |
| print_debug("can't open runtime loader\n"); |
| goto err; |
| } |
| break; |
| } |
| |
| // from PT_DYNAMIC we want to read address of first link_map addr |
| case PT_DYNAMIC: { |
| if (exec_ehdr->e_type == ET_EXEC) { |
| ph->core->dynamic_addr = exec_php->p_vaddr; |
| } else { // ET_DYN |
| // dynamic_addr has entry point of executable. |
| // Thus we should substract it. |
| ph->core->dynamic_addr += exec_php->p_vaddr - exec_ehdr->e_entry; |
| } |
| print_debug("address of _DYNAMIC is 0x%lx\n", ph->core->dynamic_addr); |
| break; |
| } |
| |
| } // switch |
| exec_php++; |
| } // for |
| |
| free(phbuf); |
| return true; |
| err: |
| free(phbuf); |
| return false; |
| } |
| |
| |
| #define FIRST_LINK_MAP_OFFSET offsetof(struct r_debug, r_map) |
| #define LD_BASE_OFFSET offsetof(struct r_debug, r_ldbase) |
| #define LINK_MAP_ADDR_OFFSET offsetof(struct link_map, l_addr) |
| #define LINK_MAP_NAME_OFFSET offsetof(struct link_map, l_name) |
| #define LINK_MAP_NEXT_OFFSET offsetof(struct link_map, l_next) |
| |
| // read shared library info from runtime linker's data structures. |
| // This work is done by librtlb_db in Solaris |
| static bool read_shared_lib_info(struct ps_prochandle* ph) { |
| uintptr_t addr = ph->core->dynamic_addr; |
| uintptr_t debug_base; |
| uintptr_t first_link_map_addr; |
| uintptr_t ld_base_addr; |
| uintptr_t link_map_addr; |
| uintptr_t lib_base_diff; |
| uintptr_t lib_base; |
| uintptr_t lib_name_addr; |
| char lib_name[BUF_SIZE]; |
| ELF_DYN dyn; |
| ELF_EHDR elf_ehdr; |
| int lib_fd; |
| |
| // _DYNAMIC has information of the form |
| // [tag] [data] [tag] [data] ..... |
| // Both tag and data are pointer sized. |
| // We look for dynamic info with DT_DEBUG. This has shared object info. |
| // refer to struct r_debug in link.h |
| |
| dyn.d_tag = DT_NULL; |
| while (dyn.d_tag != DT_DEBUG) { |
| if (ps_pdread(ph, (psaddr_t) addr, &dyn, sizeof(ELF_DYN)) != PS_OK) { |
| print_debug("can't read debug info from _DYNAMIC\n"); |
| return false; |
| } |
| addr += sizeof(ELF_DYN); |
| } |
| |
| // we have got Dyn entry with DT_DEBUG |
| debug_base = dyn.d_un.d_ptr; |
| // at debug_base we have struct r_debug. This has first link map in r_map field |
| if (ps_pdread(ph, (psaddr_t) debug_base + FIRST_LINK_MAP_OFFSET, |
| &first_link_map_addr, sizeof(uintptr_t)) != PS_OK) { |
| print_debug("can't read first link map address\n"); |
| return false; |
| } |
| |
| // read ld_base address from struct r_debug |
| if (ps_pdread(ph, (psaddr_t) debug_base + LD_BASE_OFFSET, &ld_base_addr, |
| sizeof(uintptr_t)) != PS_OK) { |
| print_debug("can't read ld base address\n"); |
| return false; |
| } |
| ph->core->ld_base_addr = ld_base_addr; |
| |
| print_debug("interpreter base address is 0x%lx\n", ld_base_addr); |
| |
| // now read segments from interp (i.e ld.so or ld-linux.so or ld-elf.so) |
| if (read_interp_segments(ph) != true) { |
| return false; |
| } |
| |
| // after adding interpreter (ld.so) mappings sort again |
| if (sort_map_array(ph) != true) { |
| return false; |
| } |
| |
| print_debug("first link map is at 0x%lx\n", first_link_map_addr); |
| |
| link_map_addr = first_link_map_addr; |
| while (link_map_addr != 0) { |
| // read library base address of the .so. Note that even though <sys/link.h> calls |
| // link_map->l_addr as "base address", this is * not * really base virtual |
| // address of the shared object. This is actually the difference b/w the virtual |
| // address mentioned in shared object and the actual virtual base where runtime |
| // linker loaded it. We use "base diff" in read_lib_segments call below. |
| |
| if (ps_pdread(ph, (psaddr_t) link_map_addr + LINK_MAP_ADDR_OFFSET, |
| &lib_base_diff, sizeof(uintptr_t)) != PS_OK) { |
| print_debug("can't read shared object base address diff\n"); |
| return false; |
| } |
| |
| // read address of the name |
| if (ps_pdread(ph, (psaddr_t) link_map_addr + LINK_MAP_NAME_OFFSET, |
| &lib_name_addr, sizeof(uintptr_t)) != PS_OK) { |
| print_debug("can't read address of shared object name\n"); |
| return false; |
| } |
| |
| // read name of the shared object |
| lib_name[0] = '\0'; |
| if (lib_name_addr != 0 && |
| read_string(ph, (uintptr_t) lib_name_addr, lib_name, sizeof(lib_name)) != true) { |
| print_debug("can't read shared object name\n"); |
| // don't let failure to read the name stop opening the file. If something is really wrong |
| // it will fail later. |
| } |
| |
| if (lib_name[0] != '\0') { |
| // ignore empty lib names |
| lib_fd = pathmap_open(lib_name); |
| |
| if (lib_fd < 0) { |
| print_debug("can't open shared object %s\n", lib_name); |
| // continue with other libraries... |
| } else { |
| if (read_elf_header(lib_fd, &elf_ehdr)) { |
| lib_base = lib_base_diff + find_base_address(lib_fd, &elf_ehdr); |
| print_debug("reading library %s @ 0x%lx [ 0x%lx ]\n", |
| lib_name, lib_base, lib_base_diff); |
| // while adding library mappings we need to use "base difference". |
| if (! read_lib_segments(ph, lib_fd, &elf_ehdr, lib_base_diff)) { |
| print_debug("can't read shared object's segments\n"); |
| close(lib_fd); |
| return false; |
| } |
| add_lib_info_fd(ph, lib_name, lib_fd, lib_base); |
| // Map info is added for the library (lib_name) so |
| // we need to re-sort it before calling the p_pdread. |
| if (sort_map_array(ph) != true) |
| return false; |
| } else { |
| print_debug("can't read ELF header for shared object %s\n", lib_name); |
| close(lib_fd); |
| // continue with other libraries... |
| } |
| } |
| } |
| |
| // read next link_map address |
| if (ps_pdread(ph, (psaddr_t) link_map_addr + LINK_MAP_NEXT_OFFSET, |
| &link_map_addr, sizeof(uintptr_t)) != PS_OK) { |
| print_debug("can't read next link in link_map\n"); |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| // the one and only one exposed stuff from this file |
| struct ps_prochandle* Pgrab_core(const char* exec_file, const char* core_file) { |
| ELF_EHDR core_ehdr; |
| ELF_EHDR exec_ehdr; |
| ELF_EHDR lib_ehdr; |
| |
| struct ps_prochandle* ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle)); |
| if (ph == NULL) { |
| print_debug("can't allocate ps_prochandle\n"); |
| return NULL; |
| } |
| |
| if ((ph->core = (struct core_data*) calloc(1, sizeof(struct core_data))) == NULL) { |
| free(ph); |
| print_debug("can't allocate ps_prochandle\n"); |
| return NULL; |
| } |
| |
| // initialize ph |
| ph->ops = &core_ops; |
| ph->core->core_fd = -1; |
| ph->core->exec_fd = -1; |
| ph->core->interp_fd = -1; |
| |
| // open the core file |
| if ((ph->core->core_fd = open(core_file, O_RDONLY)) < 0) { |
| print_debug("can't open core file\n"); |
| goto err; |
| } |
| |
| // read core file ELF header |
| if (read_elf_header(ph->core->core_fd, &core_ehdr) != true || core_ehdr.e_type != ET_CORE) { |
| print_debug("core file is not a valid ELF ET_CORE file\n"); |
| goto err; |
| } |
| |
| if ((ph->core->exec_fd = open(exec_file, O_RDONLY)) < 0) { |
| print_debug("can't open executable file\n"); |
| goto err; |
| } |
| |
| if (read_elf_header(ph->core->exec_fd, &exec_ehdr) != true || |
| ((exec_ehdr.e_type != ET_EXEC) && (exec_ehdr.e_type != ET_DYN))) { |
| print_debug("executable file is not a valid ELF file\n"); |
| goto err; |
| } |
| |
| // process core file segments |
| if (read_core_segments(ph, &core_ehdr) != true) { |
| goto err; |
| } |
| |
| // process exec file segments |
| if (read_exec_segments(ph, &exec_ehdr) != true) { |
| goto err; |
| } |
| |
| // exec file is also treated like a shared object for symbol search |
| if (add_lib_info_fd(ph, exec_file, ph->core->exec_fd, |
| (uintptr_t)0 + find_base_address(ph->core->exec_fd, &exec_ehdr)) == NULL) { |
| goto err; |
| } |
| |
| // allocate and sort maps into map_array, we need to do this |
| // here because read_shared_lib_info needs to read from debuggee |
| // address space |
| if (sort_map_array(ph) != true) { |
| goto err; |
| } |
| |
| if (read_shared_lib_info(ph) != true) { |
| goto err; |
| } |
| |
| // sort again because we have added more mappings from shared objects |
| if (sort_map_array(ph) != true) { |
| goto err; |
| } |
| |
| if (init_classsharing_workaround(ph) != true) { |
| goto err; |
| } |
| |
| return ph; |
| |
| err: |
| Prelease(ph); |
| return NULL; |
| } |