1 /* $NetBSD: kobj_rename.c,v 1.2 2014/04/25 18:31:35 pooka Exp $ */ 2 3 /*- 4 * Copyright (c) 2010 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: kobj_rename.c,v 1.2 2014/04/25 18:31:35 pooka Exp $"); 30 31 #define ELFSIZE ARCH_ELFSIZE 32 33 #include <sys/param.h> 34 #include <sys/exec_elf.h> 35 #include <sys/kmem.h> 36 #include <sys/kobj.h> 37 #include <sys/systm.h> 38 39 #include <rump/rump.h> 40 41 /* 42 * Mangle symbols into rump kernel namespace. This means 43 * putting "rumpns" in front of select symbols. 44 * See src/sys/rump/Makefile.rump for more details on the rump kernel 45 * namespace. 46 */ 47 const char *norentab[] = { 48 "RUMP", 49 "rump", 50 "__", 51 "_GLOBAL_OFFSET_TABLE", 52 }; 53 static int 54 norename(const char *name) 55 { 56 unsigned i; 57 58 for (i = 0; i < __arraycount(norentab); i++) { 59 if (strncmp(norentab[i], name, strlen(norentab[i])) == 0) 60 return 1; 61 } 62 return 0; 63 } 64 65 #define RUMPNS "rumpns_" 66 int 67 kobj_renamespace(Elf_Sym *symtab, size_t symcount, 68 char **strtab, size_t *strtabsz) 69 { 70 Elf_Sym *sym; 71 char *worktab, *newtab; 72 size_t worktabsz, worktabidx; 73 unsigned i; 74 const size_t prefixlen = strlen(RUMPNS); 75 static int warned; 76 77 if (!rump_nativeabi_p() && !warned) { 78 printf("warning: kernel ABI not supported on this arch\n"); 79 warned = 1; 80 } 81 82 /* allocate space for worst-case stringtab */ 83 worktabsz = *strtabsz + symcount * prefixlen; 84 worktab = kmem_alloc(worktabsz, KM_SLEEP); 85 86 /* now, adjust stringtab into temporary space */ 87 #define WORKTABP (worktab + worktabidx) 88 for (i = 0, worktabidx = 0; i < symcount; i++) { 89 const char *fromname; 90 91 sym = &symtab[i]; 92 if (sym->st_name == 0) { 93 continue; 94 } 95 96 fromname = *strtab + sym->st_name; 97 sym->st_name = worktabidx; 98 99 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL || 100 norename(fromname)) { 101 strcpy(WORKTABP, fromname); 102 worktabidx += strlen(fromname) + 1; 103 } else { 104 strcpy(WORKTABP, RUMPNS); 105 worktabidx += prefixlen; 106 strcpy(WORKTABP, fromname); 107 worktabidx += strlen(fromname) + 1; 108 } 109 KASSERT(worktabidx <= worktabsz); 110 } 111 #undef WORKTABP 112 113 /* 114 * Finally, free old strtab, allocate new one, and copy contents. 115 */ 116 kmem_free(*strtab, *strtabsz); 117 *strtab = NULL; /* marvin the paradroid 999 */ 118 newtab = kmem_alloc(worktabidx, KM_SLEEP); 119 memcpy(newtab, worktab, worktabidx); 120 121 kmem_free(worktab, worktabsz); 122 123 *strtab = newtab; 124 *strtabsz = worktabidx; 125 126 return 0; 127 } 128