--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/jdk.hotspot.agent/macosx/native/libsaproc/symtab.c Wed Dec 23 13:12:15 2015 +0300
@@ -0,0 +1,398 @@
+/*
+ * 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 <unistd.h>
+#include <search.h>
+#include <stdlib.h>
+#include <string.h>
+#include <db.h>
+#include <fcntl.h>
+
+#include "libproc_impl.h"
+#include "symtab.h"
+#ifndef __APPLE__
+#include "salibelf.h"
+#endif // __APPLE__
+
+
+// ----------------------------------------------------
+// functions for symbol lookups
+// ----------------------------------------------------
+
+typedef struct symtab_symbol {
+ char *name; // name like __ZThread_...
+ uintptr_t offset; // to loaded address
+ uintptr_t size; // size strlen
+} symtab_symbol;
+
+typedef struct symtab {
+ char *strs; // all symbols "__symbol1__'\0'__symbol2__...."
+ size_t num_symbols;
+ DB* hash_table;
+ symtab_symbol* symbols;
+} symtab_t;
+
+#ifdef __APPLE__
+
+void build_search_table(symtab_t *symtab) {
+ int i;
+ for (i = 0; i < symtab->num_symbols; i++) {
+ DBT key, value;
+ key.data = symtab->symbols[i].name;
+ key.size = strlen(key.data) + 1;
+ value.data = &(symtab->symbols[i]);
+ value.size = sizeof(symtab_symbol);
+ (*symtab->hash_table->put)(symtab->hash_table, &key, &value, 0);
+
+ // check result
+ if (is_debug()) {
+ DBT rkey, rvalue;
+ char* tmp = (char *)malloc(strlen(symtab->symbols[i].name) + 1);
+ strcpy(tmp, symtab->symbols[i].name);
+ rkey.data = tmp;
+ rkey.size = strlen(tmp) + 1;
+ (*symtab->hash_table->get)(symtab->hash_table, &rkey, &rvalue, 0);
+ // we may get a copy back so compare contents
+ symtab_symbol *res = (symtab_symbol *)rvalue.data;
+ if (strcmp(res->name, symtab->symbols[i].name) ||
+ res->offset != symtab->symbols[i].offset ||
+ res->size != symtab->symbols[i].size) {
+ print_debug("error to get hash_table value!\n");
+ }
+ free(tmp);
+ }
+ }
+}
+
+// read symbol table from given fd.
+struct symtab* build_symtab(int fd) {
+ symtab_t* symtab = NULL;
+ int i;
+ mach_header_64 header;
+ off_t image_start;
+
+ if (!get_arch_off(fd, CPU_TYPE_X86_64, &image_start)) {
+ print_debug("failed in get fat header\n");
+ return NULL;
+ }
+ lseek(fd, image_start, SEEK_SET);
+ if (read(fd, (void *)&header, sizeof(mach_header_64)) != sizeof(mach_header_64)) {
+ print_debug("reading header failed!\n");
+ return NULL;
+ }
+ // header
+ if (header.magic != MH_MAGIC_64) {
+ print_debug("not a valid .dylib file\n");
+ return NULL;
+ }
+
+ load_command lcmd;
+ symtab_command symtabcmd;
+ nlist_64 lentry;
+
+ bool lcsymtab_exist = false;
+
+ long filepos = ltell(fd);
+ for (i = 0; i < header.ncmds; i++) {
+ lseek(fd, filepos, SEEK_SET);
+ if (read(fd, (void *)&lcmd, sizeof(load_command)) != sizeof(load_command)) {
+ print_debug("read load_command failed for file\n");
+ return NULL;
+ }
+ filepos += lcmd.cmdsize; // next command position
+ if (lcmd.cmd == LC_SYMTAB) {
+ lseek(fd, -sizeof(load_command), SEEK_CUR);
+ lcsymtab_exist = true;
+ break;
+ }
+ }
+ if (!lcsymtab_exist) {
+ print_debug("No symtab command found!\n");
+ return NULL;
+ }
+ if (read(fd, (void *)&symtabcmd, sizeof(symtab_command)) != sizeof(symtab_command)) {
+ print_debug("read symtab_command failed for file");
+ return NULL;
+ }
+ symtab = (symtab_t *)malloc(sizeof(symtab_t));
+ if (symtab == NULL) {
+ print_debug("out of memory: allocating symtab\n");
+ return NULL;
+ }
+
+ // create hash table, we use berkeley db to
+ // manipulate the hash table.
+ symtab->hash_table = dbopen(NULL, O_CREAT | O_RDWR, 0600, DB_HASH, NULL);
+ if (symtab->hash_table == NULL)
+ goto quit;
+
+ symtab->num_symbols = symtabcmd.nsyms;
+ symtab->symbols = (symtab_symbol *)malloc(sizeof(symtab_symbol) * symtab->num_symbols);
+ symtab->strs = (char *)malloc(sizeof(char) * symtabcmd.strsize);
+ if (symtab->symbols == NULL || symtab->strs == NULL) {
+ print_debug("out of memory: allocating symtab.symbol or symtab.strs\n");
+ goto quit;
+ }
+ lseek(fd, image_start + symtabcmd.symoff, SEEK_SET);
+ for (i = 0; i < symtab->num_symbols; i++) {
+ if (read(fd, (void *)&lentry, sizeof(nlist_64)) != sizeof(nlist_64)) {
+ print_debug("read nlist_64 failed at %i\n", i);
+ goto quit;
+ }
+ symtab->symbols[i].offset = lentry.n_value;
+ symtab->symbols[i].size = lentry.n_un.n_strx; // index
+ }
+
+ // string table
+ lseek(fd, image_start + symtabcmd.stroff, SEEK_SET);
+ int size = read(fd, (void *)(symtab->strs), symtabcmd.strsize * sizeof(char));
+ if (size != symtabcmd.strsize * sizeof(char)) {
+ print_debug("reading string table failed\n");
+ goto quit;
+ }
+
+ for (i = 0; i < symtab->num_symbols; i++) {
+ symtab->symbols[i].name = symtab->strs + symtab->symbols[i].size;
+ if (i > 0) {
+ // fix size
+ symtab->symbols[i - 1].size = symtab->symbols[i].size - symtab->symbols[i - 1].size;
+ print_debug("%s size = %d\n", symtab->symbols[i - 1].name, symtab->symbols[i - 1].size);
+
+ }
+
+ if (i == symtab->num_symbols - 1) {
+ // last index
+ symtab->symbols[i].size =
+ symtabcmd.strsize - symtab->symbols[i].size;
+ print_debug("%s size = %d\n", symtab->symbols[i].name, symtab->symbols[i].size);
+ }
+ }
+
+ // build a hashtable for fast query
+ build_search_table(symtab);
+ return symtab;
+quit:
+ if (symtab) destroy_symtab(symtab);
+ return NULL;
+}
+
+#else // __APPLE__
+
+struct elf_section {
+ ELF_SHDR *c_shdr;
+ void *c_data;
+};
+
+// read symbol table from given fd.
+struct symtab* build_symtab(int fd) {
+ ELF_EHDR ehdr;
+ struct symtab* symtab = NULL;
+
+ // Reading of elf header
+ struct elf_section *scn_cache = NULL;
+ int cnt = 0;
+ ELF_SHDR* shbuf = NULL;
+ ELF_SHDR* cursct = NULL;
+ ELF_PHDR* phbuf = NULL;
+ int symtab_found = 0;
+ int dynsym_found = 0;
+ uint32_t symsection = SHT_SYMTAB;
+
+ uintptr_t baseaddr = (uintptr_t)-1;
+
+ lseek(fd, (off_t)0L, SEEK_SET);
+ if (! read_elf_header(fd, &ehdr)) {
+ // not an elf
+ return NULL;
+ }
+
+ // read ELF header
+ if ((shbuf = read_section_header_table(fd, &ehdr)) == NULL) {
+ goto quit;
+ }
+
+ baseaddr = find_base_address(fd, &ehdr);
+
+ scn_cache = calloc(ehdr.e_shnum, sizeof(*scn_cache));
+ if (scn_cache == NULL) {
+ goto quit;
+ }
+
+ for (cursct = shbuf, cnt = 0; cnt < ehdr.e_shnum; cnt++) {
+ scn_cache[cnt].c_shdr = cursct;
+ if (cursct->sh_type == SHT_SYMTAB ||
+ cursct->sh_type == SHT_STRTAB ||
+ cursct->sh_type == SHT_DYNSYM) {
+ if ( (scn_cache[cnt].c_data = read_section_data(fd, &ehdr, cursct)) == NULL) {
+ goto quit;
+ }
+ }
+
+ if (cursct->sh_type == SHT_SYMTAB)
+ symtab_found++;
+
+ if (cursct->sh_type == SHT_DYNSYM)
+ dynsym_found++;
+
+ cursct++;
+ }
+
+ if (!symtab_found && dynsym_found)
+ symsection = SHT_DYNSYM;
+
+ for (cnt = 1; cnt < ehdr.e_shnum; cnt++) {
+ ELF_SHDR *shdr = scn_cache[cnt].c_shdr;
+
+ if (shdr->sh_type == symsection) {
+ ELF_SYM *syms;
+ int j, n;
+ size_t size;
+
+ // FIXME: there could be multiple data buffers associated with the
+ // same ELF section. Here we can handle only one buffer. See man page
+ // for elf_getdata on Solaris.
+
+ // guarantee(symtab == NULL, "multiple symtab");
+ symtab = calloc(1, sizeof(*symtab));
+ if (symtab == NULL) {
+ goto quit;
+ }
+ // the symbol table
+ syms = (ELF_SYM *)scn_cache[cnt].c_data;
+
+ // number of symbols
+ n = shdr->sh_size / shdr->sh_entsize;
+
+ // create hash table, we use berkeley db to
+ // manipulate the hash table.
+ symtab->hash_table = dbopen(NULL, O_CREAT | O_RDWR, 0600, DB_HASH, NULL);
+ // guarantee(symtab->hash_table, "unexpected failure: dbopen");
+ if (symtab->hash_table == NULL)
+ goto bad;
+
+ // shdr->sh_link points to the section that contains the actual strings
+ // for symbol names. the st_name field in ELF_SYM is just the
+ // string table index. we make a copy of the string table so the
+ // strings will not be destroyed by elf_end.
+ size = scn_cache[shdr->sh_link].c_shdr->sh_size;
+ symtab->strs = malloc(size);
+ if (symtab->strs == NULL)
+ goto bad;
+ memcpy(symtab->strs, scn_cache[shdr->sh_link].c_data, size);
+
+ // allocate memory for storing symbol offset and size;
+ symtab->num_symbols = n;
+ symtab->symbols = calloc(n , sizeof(*symtab->symbols));
+ if (symtab->symbols == NULL)
+ goto bad;
+
+ // copy symbols info our symtab and enter them info the hash table
+ for (j = 0; j < n; j++, syms++) {
+ DBT key, value;
+ char *sym_name = symtab->strs + syms->st_name;
+
+ // skip non-object and non-function symbols
+ int st_type = ELF_ST_TYPE(syms->st_info);
+ if ( st_type != STT_FUNC && st_type != STT_OBJECT)
+ continue;
+ // skip empty strings and undefined symbols
+ if (*sym_name == '\0' || syms->st_shndx == SHN_UNDEF) continue;
+
+ symtab->symbols[j].name = sym_name;
+ symtab->symbols[j].offset = syms->st_value - baseaddr;
+ symtab->symbols[j].size = syms->st_size;
+
+ key.data = sym_name;
+ key.size = strlen(sym_name) + 1;
+ value.data = &(symtab->symbols[j]);
+ value.size = sizeof(symtab_symbol);
+ (*symtab->hash_table->put)(symtab->hash_table, &key, &value, 0);
+ }
+ }
+ }
+ goto quit;
+
+bad:
+ destroy_symtab(symtab);
+ symtab = NULL;
+
+quit:
+ if (shbuf) free(shbuf);
+ if (phbuf) free(phbuf);
+ if (scn_cache) {
+ for (cnt = 0; cnt < ehdr.e_shnum; cnt++) {
+ if (scn_cache[cnt].c_data != NULL) {
+ free(scn_cache[cnt].c_data);
+ }
+ }
+ free(scn_cache);
+ }
+ return symtab;
+}
+
+#endif // __APPLE__
+
+void destroy_symtab(symtab_t* symtab) {
+ if (!symtab) return;
+ free(symtab->strs);
+ free(symtab->symbols);
+ free(symtab);
+}
+
+uintptr_t search_symbol(struct symtab* symtab, uintptr_t base, const char *sym_name, int *sym_size) {
+ DBT key, value;
+ int ret;
+
+ // library does not have symbol table
+ if (!symtab || !symtab->hash_table) {
+ return 0;
+ }
+
+ key.data = (char*)(uintptr_t)sym_name;
+ key.size = strlen(sym_name) + 1;
+ ret = (*symtab->hash_table->get)(symtab->hash_table, &key, &value, 0);
+ if (ret == 0) {
+ symtab_symbol *sym = value.data;
+ uintptr_t rslt = (uintptr_t) ((char*)base + sym->offset);
+ if (sym_size) *sym_size = sym->size;
+ return rslt;
+ }
+
+ return 0;
+}
+
+const char* nearest_symbol(struct symtab* symtab, uintptr_t offset,
+ uintptr_t* poffset) {
+ int n = 0;
+ if (!symtab) return NULL;
+ for (; n < symtab->num_symbols; n++) {
+ symtab_symbol* sym = &(symtab->symbols[n]);
+ if (sym->name != NULL &&
+ offset >= sym->offset && offset < sym->offset + sym->size) {
+ if (poffset) *poffset = (offset - sym->offset);
+ return sym->name;
+ }
+ }
+ return NULL;
+}