1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include "misc.h" 27 28 #define UMEM_OBJNAME "libumem.so.1" 29 30 int umem_debug_level = 0; 31 int umem_is_standalone = 0; 32 33 /*ARGSUSED*/ 34 int 35 umem_debug(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv) 36 { 37 umem_debug_level ^= 1; 38 39 mdb_printf("umem: debugging is now %s\n", 40 umem_debug_level ? "on" : "off"); 41 42 return (DCMD_OK); 43 } 44 45 /* 46 * To further confuse the issue, this dmod can run against either 47 * libumem.so.1 *or* the libstandumem.so linked into kmdb(1M). To figure 48 * out which one we are working against, we look up "umem_alloc" in both 49 * libumem.so and the executable. 50 * 51 * A further wrinkle is that libumem.so may not yet be loaded into the 52 * process' address space. That can lead to either the lookup failing, or 53 * being unable to read from the data segment. We treat either case as 54 * an error. 55 */ 56 int 57 umem_set_standalone(void) 58 { 59 GElf_Sym sym; 60 int ready; 61 62 if (mdb_lookup_by_obj(UMEM_OBJNAME, "umem_alloc", &sym) == 0) 63 umem_is_standalone = 0; 64 else if (mdb_lookup_by_obj(MDB_OBJ_EXEC, "umem_alloc", &sym) == 0) 65 umem_is_standalone = 1; 66 else 67 return (-1); 68 69 /* 70 * now that we know where things should be, make sure we can actually 71 * read things out. 72 */ 73 if (umem_readvar(&ready, "umem_ready") == -1) 74 return (-1); 75 return (0); 76 } 77 78 ssize_t 79 umem_lookup_by_name(const char *name, GElf_Sym *sym) 80 { 81 return (mdb_lookup_by_obj((umem_is_standalone ? MDB_OBJ_EXEC : 82 UMEM_OBJNAME), name, sym)); 83 } 84 85 /* This is like mdb_readvar, only for libumem.so's symbols */ 86 ssize_t 87 umem_readvar(void *buf, const char *name) 88 { 89 GElf_Sym sym; 90 91 if (umem_lookup_by_name(name, &sym)) 92 return (-1); 93 94 if (mdb_vread(buf, sym.st_size, (uintptr_t)sym.st_value) 95 == sym.st_size) 96 return ((ssize_t)sym.st_size); 97 98 return (-1); 99 } 100 101 int 102 is_umem_sym(const char *sym, const char *prefix) 103 { 104 char *tick_p = strrchr(sym, '`'); 105 106 return (strncmp(sym, "libumem", 7) == 0 && tick_p != NULL && 107 strncmp(tick_p + 1, prefix, strlen(prefix)) == 0); 108 } 109