/* $OpenBSD: rtld.c,v 1.38 2003/08/15 23:13:06 deraadt Exp $ */ /* $NetBSD: rtld.c,v 1.43 1996/01/14 00:35:17 pk Exp $ */ /* * Copyright (c) 1993 Paul Kranenburg * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Paul Kranenburg. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #include #include #include #include #include #include #include #include #ifndef MAP_COPY #define MAP_COPY MAP_PRIVATE #endif #include #include #include #include #include #include #include #include #include #include #if __STDC__ #include #else #include #endif #include "ld.h" /* * Stack protector dummies. * Ideally, a scheme to compile these stubs from libc should be used, but * this would end up dragging too much code from libc here. */ long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; void __stack_smash_handler(char func[], int damaged) { _exit(127); } #ifndef MAP_ANON #define MAP_ANON 0 #define anon_open() do { \ if ((anon_fd = open("/dev/zero", O_RDWR, 0)) == -1) \ err("open: %s", "/dev/zero"); \ } while (0) #define anon_close() do { \ (void)close(anon_fd); \ anon_fd = -1; \ } while (0) #else #define anon_open() #define anon_close() #endif /* * Loader private data, hung off ->som_spd */ struct somap_private { int spd_version; struct so_map *spd_parent; int spd_refcount; int spd_flags; #define RTLD_MAIN 1 #define RTLD_RTLD 2 #define RTLD_DL 4 #define RTLD_INITED 8 size_t spd_size; #ifdef SUN_COMPAT long spd_offset; /* Correction for Sun main programs */ #endif struct dep_node *first_child; struct dep_node *last_child; }; struct dep_node { struct dep_node *next_sibling; struct so_map *data; }; #define LM_PRIVATE(smp) ((struct somap_private *)(smp)->som_spd) #ifdef SUN_COMPAT #define LM_OFFSET(smp) (LM_PRIVATE(smp)->spd_offset) #else #define LM_OFFSET(smp) (0) #endif /* Base address for section_dispatch_table entries */ #define LM_LDBASE(smp) (smp->som_addr + LM_OFFSET(smp)) /* Start of text segment */ #define LM_TXTADDR(smp) (smp->som_addr == (caddr_t)0 ? PAGSIZ : 0) /* Start of run-time relocation_info */ #define LM_REL(smp) ((struct relocation_info *) \ (smp->som_addr + LM_OFFSET(smp) + LD_REL((smp)->som_dynamic))) /* Start of symbols */ #define LM_SYMBOL(smp, i) ((struct nzlist *) \ (smp->som_addr + LM_OFFSET(smp) + LD_SYMBOL((smp)->som_dynamic) + \ i * (LD_VERSION_NZLIST_P(smp->som_dynamic->d_version) ? \ sizeof(struct nzlist) : sizeof(struct nlist)))) /* Start of hash table */ #define LM_HASH(smp) ((struct rrs_hash *) \ ((smp)->som_addr + LM_OFFSET(smp) + LD_HASH((smp)->som_dynamic))) /* Start of strings */ #define LM_STRINGS(smp) ((char *) \ ((smp)->som_addr + LM_OFFSET(smp) + LD_STRINGS((smp)->som_dynamic))) /* Start of search paths */ #define LM_PATHS(smp) ((char *) \ ((smp)->som_addr + LM_OFFSET(smp) + LD_PATHS((smp)->som_dynamic))) /* End of text */ #define LM_ETEXT(smp) ((char *) \ ((smp)->som_addr + LM_TXTADDR(smp) + LD_TEXTSZ((smp)->som_dynamic))) /* PLT is in data segment, so don't use LM_OFFSET here */ #define LM_PLT(smp) ((jmpslot_t *) \ ((smp)->som_addr + LD_PLT((smp)->som_dynamic))) /* Parent of link map */ #define LM_PARENT(smp) (LM_PRIVATE(smp)->spd_parent) static char __main_progname[] = "main"; static char *main_progname = __main_progname; static char us[] = "/usr/libexec/ld.so"; char **environ; char *__progname = us; int errno; static int careful; static int anon_fd = -1; struct so_map *link_map_head, *main_map; struct so_map **link_map_tail = &link_map_head; struct rt_symbol *rt_symbol_head; static char *ld_library_path; static char *ld_preload_path; static int no_intern_search; static int ld_suppress_warnings; static int ld_warn_non_pure_code; static int ld_tracing; static void *__dlopen(const char *, int); static int __dlclose(void *); static void *__dlsym(void *, const char *); static int __dlctl(void *, int, void *); static void __dlexit(void); static struct ld_entry ld_entry = { __dlopen, __dlclose, __dlsym, __dlctl, __dlexit }; void xprintf(char *, ...); int rtld(int, struct crt_ldso *, struct _dynamic *); void binder_entry(void); long binder(jmpslot_t *); static int load_subs(struct so_map *); static struct so_map *map_object(struct sod *, struct so_map *); static void unmap_object(struct so_map *); static struct so_map *alloc_link_map( char *, struct sod *, struct so_map *, caddr_t, size_t, struct _dynamic *); static void free_link_map(struct so_map *); static inline void check_text_reloc( struct relocation_info *, struct so_map *, caddr_t); static void init_maps(struct so_map *); static void reloc_map(struct so_map *); static void reloc_copy(struct so_map *); static void call_map(struct so_map *, char *); static char *rtfindlib(char *, int, int, int *, char *); static struct nzlist *lookup(const char *, struct so_map **, int); static inline struct rt_symbol *lookup_rts(const char *); static struct rt_symbol *enter_rts(const char *, long, int, caddr_t, long, struct so_map *); static void maphints(void); static void unmaphints(void); static void preload(char *); static void ld_trace(struct so_map *); static inline int strcmp (const char *s1, const char *s2) { while (*s1 == *s2++) if (*s1++ == 0) return (0); return (*(unsigned char *)s1 - *(unsigned char *)--s2); } #include "md-static-funcs.c" /* * Called from assembler stub that has set up crtp (passed from crt0) * and dp (our __DYNAMIC). */ int rtld(int version, struct crt_ldso *crtp, struct _dynamic *dp) { int n; int nreloc; /* # of ld.so relocations */ struct relocation_info *reloc; struct so_debug *ddp; struct so_map *smp; /* Check version */ if ( version != CRT_VERSION_BSD_2 && version != CRT_VERSION_BSD_3 && version != CRT_VERSION_BSD_4 && version != CRT_VERSION_SUN) return -1; /* Fixup __DYNAMIC structure */ (long)dp->d_un.d_sdt += crtp->crt_ba; /* Divide by hand to avoid possible use of library division routine */ for ( nreloc = 0, n = LD_RELSZ(dp); n > 0; n -= sizeof(struct relocation_info) ) nreloc++; /* Relocate ourselves */ for (reloc = (struct relocation_info *)(LD_REL(dp) + crtp->crt_ba); nreloc; nreloc--, reloc++) { long addr = reloc->r_address + crtp->crt_ba; md_relocate_simple(reloc, crtp->crt_ba, (char*)addr); } if (version >= CRT_VERSION_BSD_4) __progname = crtp->crt_ldso; if (version >= CRT_VERSION_BSD_3) main_progname = crtp->crt_prog; /* Setup out (private) environ variable */ environ = crtp->crt_ep; if (issetugid()) careful = 1; if (careful) { unsetenv("LD_LIBRARY_PATH"); unsetenv("LD_PRELOAD"); } /* Setup directory search */ ld_library_path = getenv("LD_LIBRARY_PATH"); add_search_path(ld_library_path); if (getenv("LD_NOSTD_PATH") == NULL) std_search_path(); ld_suppress_warnings = getenv("LD_SUPPRESS_WARNINGS") != NULL; ld_warn_non_pure_code = getenv("LD_WARN_NON_PURE_CODE") != NULL; no_intern_search = careful || getenv("LD_NO_INTERN_SEARCH") != 0; anon_open(); /* * Init object administration. We start off with a map description * for `main' and `rtld'. */ smp = alloc_link_map(main_progname, (struct sod *)0, (struct so_map *)0, (caddr_t)0, 0, crtp->crt_dp); LM_PRIVATE(smp)->spd_refcount++; LM_PRIVATE(smp)->spd_flags |= RTLD_MAIN; main_map = smp; smp = alloc_link_map(us, (struct sod *)0, (struct so_map *)0, (caddr_t)crtp->crt_ba, 0, dp); LM_PRIVATE(smp)->spd_refcount++; LM_PRIVATE(smp)->spd_flags |= RTLD_RTLD; /* Fill in some field in main's __DYNAMIC structure */ if (version >= CRT_VERSION_BSD_4) crtp->crt_ldentry = &ld_entry; else crtp->crt_dp->d_entry = &ld_entry; /* Handle LD_PRELOAD's here */ ld_preload_path = getenv("LD_PRELOAD"); if (ld_preload_path != NULL) preload(ld_preload_path); /* Load subsidiary objects into the process address space */ ld_tracing = (int)getenv("LD_TRACE_LOADED_OBJECTS"); load_subs(link_map_head); if (ld_tracing) { ld_trace(link_map_head); exit(0); } init_maps(link_map_head); crtp->crt_dp->d_un.d_sdt->sdt_loaded = link_map_head->som_next; ddp = crtp->crt_dp->d_debug; ddp->dd_cc = rt_symbol_head; if (ddp->dd_in_debugger) { caddr_t addr = (caddr_t)((long)crtp->crt_bp & (~(PAGSIZ - 1))); /* Set breakpoint for the benefit of debuggers */ if (mprotect(addr, PAGSIZ, PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { err(1, "Cannot set breakpoint (%s)", main_progname); } md_set_breakpoint((long)crtp->crt_bp, (long *)&ddp->dd_bpt_shadow); if (mprotect(addr, PAGSIZ, PROT_READ|PROT_EXEC) == -1) { err(1, "Cannot re-protect breakpoint (%s)", main_progname); } ddp->dd_bpt_addr = crtp->crt_bp; if (link_map_head) ddp->dd_sym_loaded = 1; } /* Close the hints file */ unmaphints(); /* Close our file descriptor */ (void)close(crtp->crt_ldfd); anon_close(); return 0; } static void link_sub(struct so_map *dep, struct so_map *p) { struct dep_node *n; struct somap_private *pp; n = xmalloc(sizeof *n); n->data = dep; n->next_sibling = NULL; pp = LM_PRIVATE(p); if (pp->first_child) { pp->last_child->next_sibling = n; pp->last_child = n; } else { pp->first_child = pp->last_child = n; } } static int load_subs(struct so_map *smp) { for (; smp; smp = smp->som_next) { struct sod *sodp; long next = 0; if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD) continue; if (smp->som_dynamic) next = LD_NEED(smp->som_dynamic); while (next) { struct so_map *newmap; sodp = (struct sod *)(LM_LDBASE(smp) + next); if ((newmap = map_object(sodp, smp)) == NULL) { if (!ld_tracing) { if (smp != main_map) if (sodp->sod_library) err(1, "%s(%s): lib%s.so.%d.%d", main_progname, smp->som_path, sodp->sod_name+LM_LDBASE(smp), sodp->sod_major, sodp->sod_minor); else err(1, "%s(%s): %s", main_progname, smp->som_path, sodp->sod_name+LM_LDBASE(smp)); else if (sodp->sod_library) err(1, "%s: lib%s.so.%d.%d", main_progname, sodp->sod_name+LM_LDBASE(smp), sodp->sod_major, sodp->sod_minor); else err(1, "%s: %s", main_progname, sodp->sod_name+LM_LDBASE(smp)); } newmap = alloc_link_map(NULL, sodp, smp, 0, 0, 0); } else { link_sub(newmap, smp); } LM_PRIVATE(newmap)->spd_refcount++; next = sodp->sod_next; } } return 0; } void ld_trace(struct so_map *smp) { char *fmt1, *fmt2, *fmt, *main_local; int c; if ((main_local = getenv("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) main_local = ""; if ((fmt1 = getenv("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL) fmt1 = "\t-l%o.%m => %p (%x)\n"; if ((fmt2 = getenv("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL) fmt2 = "\t%o (%x)\n"; for (; smp; smp = smp->som_next) { struct sod *sodp; char *name, *path; if ((sodp = smp->som_sod) == NULL) continue; name = (char *)sodp->sod_name; if (LM_PARENT(smp)) name += (long)LM_LDBASE(LM_PARENT(smp)); if ((path = smp->som_path) == NULL) path = "not found"; fmt = sodp->sod_library ? fmt1 : fmt2; while ((c = *fmt++) != '\0') { switch (c) { default: putchar(c); continue; case '\\': switch (c = *fmt) { case '\0': continue; case 'n': putchar('\n'); break; case 't': putchar('\t'); break; } break; case '%': switch (c = *fmt) { case '\0': continue; case '%': default: putchar(c); break; case 'A': printf("%s", main_local); break; case 'a': printf("%s", main_progname); break; case 'o': printf("%s", name); break; case 'm': printf("%d", sodp->sod_major); break; case 'n': printf("%d", sodp->sod_minor); break; case 'p': printf("%s", path); break; case 'x': printf("%p", smp->som_addr); break; } break; } ++fmt; } } } /* * Allocate a new link map for shared object NAME loaded at ADDR as a * result of the presence of link object LOP in the link map PARENT. */ static struct so_map * alloc_link_map(char *path, struct sod *sodp, struct so_map *parent, caddr_t addr, size_t size, struct _dynamic *dp) { struct so_map *smp; struct somap_private *smpp; smpp = (struct somap_private *)xmalloc(sizeof(struct somap_private)); smp = (struct so_map *)xmalloc(sizeof(struct so_map)); smp->som_next = NULL; *link_map_tail = smp; link_map_tail = &smp->som_next; /*smp->som_sodbase = 0; NOT USED */ smp->som_write = 0; smp->som_addr = addr; smp->som_path = path?strdup(path):NULL; smp->som_sod = sodp; smp->som_dynamic = dp; smp->som_spd = (caddr_t)smpp; smpp->spd_refcount = 0; smpp->spd_flags = 0; smpp->spd_parent = parent; smpp->spd_size = size; smpp->first_child = NULL; smpp->last_child = NULL; #ifdef SUN_COMPAT smpp->spd_offset = (addr==0 && dp && dp->d_version==LD_VERSION_SUN) ? PAGSIZ : 0; #endif return smp; } /* * Free the link map for an object being unmapped. The link map * has already been removed from the link map list, so it can't be used * after it's been unmapped. */ static void free_link_map(struct so_map *smp) { if ((LM_PRIVATE(smp)->spd_flags & RTLD_DL) != 0) { /* free synthetic sod structure allocated in __dlopen() */ free((char *)smp->som_sod->sod_name); free(smp->som_sod); } /* free the link map structure. */ free(smp->som_spd); if (smp->som_path != NULL) free(smp->som_path); free(smp); } /* * Map object identified by link object SODP which was found * in link map SMP. */ static struct so_map * map_object(struct sod *sodp, struct so_map *smp) { char *name; struct _dynamic *dp; char *path, *ipath; int fd, sverrno; caddr_t addr; struct exec hdr; int usehints = 0; struct so_map *p; name = (char *)sodp->sod_name; if (smp) name += (long)LM_LDBASE(smp); if (sodp->sod_library) { usehints = 1; again: if (smp == NULL || no_intern_search || LD_PATHS(smp->som_dynamic) == 0) { ipath = NULL; } else { ipath = LM_PATHS(smp); add_search_path(ipath); } path = rtfindlib(name, sodp->sod_major, sodp->sod_minor, &usehints, ipath); if (ipath) remove_search_path(ipath); if (path == NULL && smp != main_map && main_map != NULL && !no_intern_search && LD_PATHS(main_map->som_dynamic) != 0) { ipath = LM_PATHS(main_map); add_search_path(ipath); path = rtfindlib(name, sodp->sod_major, sodp->sod_minor, &usehints, ipath); remove_search_path(ipath); } if (path == NULL) { errno = ENOENT; return NULL; } } else { if (careful && *name != '/') { errno = EACCES; return NULL; } path = name; } /* Check if already loaded */ for (p = link_map_head; p; p = p->som_next) if (p->som_path && strcmp(p->som_path, path) == 0) break; if (p != NULL) return p; if ((fd = open(path, O_RDONLY, 0)) == -1) { if (usehints) { usehints = 0; goto again; } return NULL; } if (read(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) { sverrno = errno; (void)close(fd); errno = sverrno; return NULL; } if (N_BADMAG(hdr)) { (void)close(fd); errno = EFTYPE; return NULL; } if ((addr = mmap(0, hdr.a_text + hdr.a_data + hdr.a_bss, PROT_READ|PROT_EXEC, MAP_COPY, fd, 0)) == (caddr_t)MAP_FAILED) { sverrno = errno; (void)close(fd); errno = sverrno; return NULL; } #if DEBUG xprintf("map1: 0x%x for 0x%x\n", addr, hdr.a_text + hdr.a_data + hdr.a_bss); #endif if (mprotect(addr + hdr.a_text, hdr.a_data, PROT_READ|PROT_WRITE|PROT_EXEC) != 0) { sverrno = errno; (void)close(fd); errno = sverrno; return NULL; } if (mmap(addr + hdr.a_text + hdr.a_data, hdr.a_bss, PROT_READ|PROT_WRITE, MAP_ANON|MAP_COPY|MAP_FIXED, anon_fd, 0) == (caddr_t)MAP_FAILED) { sverrno = errno; (void)close(fd); errno = sverrno; return NULL; } (void)close(fd); /* Assume _DYNAMIC is the first data item */ dp = (struct _dynamic *)(addr+hdr.a_text); /* Fixup __DYNAMIC structure */ (long)dp->d_un.d_sdt += (long)addr; return alloc_link_map(path, sodp, smp, addr, hdr.a_text + hdr.a_data + hdr.a_bss, dp); } /* * Unmap a mapped object. */ static void unmap_object(struct so_map *smp) { struct so_map *p, **pp; /* remove from link map list */ pp = &link_map_head; while ((p = *pp) != NULL) { if (p == smp) break; pp = &p->som_next; } if (p == NULL) { warnx("warning: link map entry for %s not on link map list!", smp->som_path); return; } *pp = smp->som_next; /* make list skip it */ if (link_map_tail == &smp->som_next) /* and readjust tail pointer */ link_map_tail = pp; /* unmap from address space */ (void)munmap(smp->som_addr, LM_PRIVATE(smp)->spd_size); } void init_dependent_before_main(struct so_map *smp) { struct dep_node *n; LM_PRIVATE(smp)->spd_flags |= RTLD_INITED; for (n = LM_PRIVATE(smp)->first_child; n; n = n->next_sibling) { if (LM_PRIVATE(n->data)->spd_flags & RTLD_INITED) continue; init_dependent_before_main(n->data); } call_map(smp, ".init"); call_map(smp, "__init"); call_map(smp, "__GLOBAL__DI"); } void init_maps(struct so_map *head) { struct so_map *smp; /* Relocate all loaded objects according to their RRS segments */ for (smp = head; smp; smp = smp->som_next) { if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD) continue; reloc_map(smp); } /* Copy any relocated initialized data. */ for (smp = head; smp; smp = smp->som_next) { if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD) continue; reloc_copy(smp); } /* Call any object initialization routines. */ for (smp = head; smp; smp = smp->som_next) { if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD) continue; if (LM_PRIVATE(smp)->spd_flags & RTLD_INITED) continue; init_dependent_before_main(smp); } } static inline void check_text_reloc(struct relocation_info *r, struct so_map *smp, caddr_t addr) { char *sym; if (addr >= LM_ETEXT(smp)) return; if (RELOC_EXTERN_P(r)) sym = LM_STRINGS(smp) + LM_SYMBOL(smp, RELOC_SYMBOL(r))->nz_strx; else sym = ""; if (ld_warn_non_pure_code && !ld_suppress_warnings) warnx("warning: non pure code in %s at %x (%s)", smp->som_path, r->r_address, sym); if (smp->som_write == 0 && mprotect(smp->som_addr + LM_TXTADDR(smp), LD_TEXTSZ(smp->som_dynamic), PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { err(1, "Cannot enable writes to %s:%s", main_progname, smp->som_path); } smp->som_write = 1; } static void reloc_map(struct so_map *smp) { struct _dynamic *dp = smp->som_dynamic; struct relocation_info *r = LM_REL(smp); struct relocation_info *rend = r + LD_RELSZ(dp)/sizeof(*r); long symbolbase = (long)LM_SYMBOL(smp, 0); char *stringbase = LM_STRINGS(smp); int symsize = LD_VERSION_NZLIST_P(dp->d_version) ? sizeof(struct nzlist) : sizeof(struct nlist); if (LD_PLTSZ(dp)) md_fix_jmpslot(LM_PLT(smp), (long)LM_PLT(smp), (long)binder_entry); for (; r < rend; r++) { char *sym; caddr_t addr = smp->som_addr + r->r_address; check_text_reloc(r, smp, addr); if (RELOC_EXTERN_P(r)) { struct so_map *src_map = NULL; struct nzlist *p, *np; long relocation = md_get_addend(r, addr); if (RELOC_LAZY_P(r)) continue; p = (struct nzlist *) (symbolbase + symsize * RELOC_SYMBOL(r)); if (p->nz_type == (N_SETV + N_EXT)) src_map = smp; sym = stringbase + p->nz_strx; np = lookup(sym, &src_map, 0/*XXX-jumpslots!*/); if (np == NULL) errx(1, "Undefined symbol \"%s\" in %s:%s", sym, main_progname, smp->som_path); /* * Found symbol definition. * If it's in a link map, adjust value * according to the load address of that map. * Otherwise it's a run-time allocated common * whose value is already up-to-date. */ relocation += np->nz_value; if (src_map) relocation += (long)src_map->som_addr; if (RELOC_PCREL_P(r)) relocation -= (long)smp->som_addr; if (RELOC_COPY_P(r) && src_map) { (void)enter_rts(sym, (long)addr, N_DATA + N_EXT, src_map->som_addr + np->nz_value, np->nz_size, src_map); continue; } md_relocate(r, relocation, addr, 0); } else { md_relocate(r, #ifdef SUN_COMPAT md_get_rt_segment_addend(r, addr) #else md_get_addend(r, addr) #endif + (long)smp->som_addr, addr, 0); } } if (smp->som_write) { if (mprotect(smp->som_addr + LM_TXTADDR(smp), LD_TEXTSZ(smp->som_dynamic), PROT_READ|PROT_EXEC) == -1) { err(1, "Cannot disable writes to %s:%s", main_progname, smp->som_path); } smp->som_write = 0; } } static void reloc_copy(struct so_map *smp) { struct rt_symbol *rtsp; for (rtsp = rt_symbol_head; rtsp; rtsp = rtsp->rt_next) if ((rtsp->rt_smp == NULL || rtsp->rt_smp == smp) && rtsp->rt_sp->nz_type == N_DATA + N_EXT) { bcopy(rtsp->rt_srcaddr, (caddr_t)rtsp->rt_sp->nz_value, rtsp->rt_sp->nz_size); } } static void call_map(struct so_map *smp, char *sym) { struct so_map *src_map = smp; struct nzlist *np; np = lookup(sym, &src_map, 1); if (np) (*(void (*) (void))(src_map->som_addr + np->nz_value))(); } /* * Run-time common symbol table. */ #define RTC_TABSIZE 57 static struct rt_symbol *rt_symtab[RTC_TABSIZE]; /* * Compute hash value for run-time symbol table */ static inline int hash_string(const char *key) { const char *cp; int k; cp = key; k = 0; while (*cp) k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff; return k; } /* * Lookup KEY in the run-time common symbol table. */ static inline struct rt_symbol * lookup_rts(const char *key) { int hashval; struct rt_symbol *rtsp; /* Determine which bucket. */ hashval = hash_string(key) % RTC_TABSIZE; /* Search the bucket. */ for (rtsp = rt_symtab[hashval]; rtsp; rtsp = rtsp->rt_link) if (strcmp(key, rtsp->rt_sp->nz_name) == 0) return rtsp; return NULL; } static struct rt_symbol * enter_rts(const char *name, long value, int type, caddr_t srcaddr, long size, struct so_map *smp) { int hashval; struct rt_symbol *rtsp, **rpp; /* Determine which bucket */ hashval = hash_string(name) % RTC_TABSIZE; /* Find end of bucket */ for (rpp = &rt_symtab[hashval]; *rpp; rpp = &(*rpp)->rt_link) ; /* Allocate new common symbol */ rtsp = (struct rt_symbol *)malloc(sizeof(struct rt_symbol)); rtsp->rt_sp = (struct nzlist *)malloc(sizeof(struct nzlist)); rtsp->rt_sp->nz_name = strdup(name); rtsp->rt_sp->nz_value = value; rtsp->rt_sp->nz_type = type; rtsp->rt_sp->nz_size = size; rtsp->rt_srcaddr = srcaddr; rtsp->rt_smp = smp; rtsp->rt_link = NULL; /* Link onto linear list as well */ rtsp->rt_next = rt_symbol_head; rt_symbol_head = rtsp; *rpp = rtsp; return rtsp; } /* * Lookup NAME in the link maps. The link map producing a definition * is returned in SRC_MAP. If SRC_MAP is not NULL on entry the search is * confined to that map. If STRONG is set, the symbol returned must * have a proper type (used by binder()). */ static struct nzlist * lookup(const char *name, struct so_map **src_map, int strong) { long common_size = 0; struct so_map *smp, *weak_smp; struct rt_symbol *rtsp; struct nzlist *weak_np = 0; if ((rtsp = lookup_rts(name)) != NULL) { /* Common symbol is not a member of particular shlib. */ *src_map = NULL; return rtsp->rt_sp; } weak_smp = NULL; /* XXX - gcc! */ /* * Search all maps for a definition of NAME */ for (smp = link_map_head; smp; smp = smp->som_next) { int buckets; long hashval; struct rrs_hash *hp; const char *cp; struct nzlist *np; /* Some local caching */ long symbolbase; struct rrs_hash *hashbase; char *stringbase; int symsize; if (*src_map && smp != *src_map) continue; if ((buckets = LD_BUCKETS(smp->som_dynamic)) == 0) continue; if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD) continue; restart: /* * Compute bucket in which the symbol might be found. */ for (hashval = 0, cp = name; *cp; cp++) hashval = (hashval << 1) + *cp; hashval = (hashval & 0x7fffffff) % buckets; hashbase = LM_HASH(smp); hp = hashbase + hashval; if (hp->rh_symbolnum == -1) /* Nothing in this bucket */ continue; symbolbase = (long)LM_SYMBOL(smp, 0); stringbase = LM_STRINGS(smp); symsize = LD_VERSION_NZLIST_P(smp->som_dynamic->d_version)? sizeof(struct nzlist) : sizeof(struct nlist); while (hp) { np = (struct nzlist *) (symbolbase + hp->rh_symbolnum * symsize); cp = stringbase + np->nz_strx; if (strcmp(cp, name) == 0) break; if (hp->rh_next == 0) hp = NULL; else hp = hashbase + hp->rh_next; } if (hp == NULL) /* Nothing in this bucket */ continue; /* * We have a symbol with the name we're looking for. */ if (np->nz_type == N_INDR+N_EXT) { /* * Next symbol gives the aliased name. Restart * search with new name and confine to this map. */ name = stringbase + (++np)->nz_strx; *src_map = smp; goto restart; } if (np->nz_value == 0) /* It's not a definition */ continue; if (np->nz_type == N_UNDF+N_EXT && np->nz_value != 0) { if (np->nz_other == AUX_FUNC) { /* It's a weak function definition */ if (strong) continue; } else { /* It's a common, note value and continue search */ if (common_size < np->nz_value) common_size = np->nz_value; continue; } } if (N_BIND(&np->nlist) == BIND_WEAK && weak_np == 0) { weak_np = np; weak_smp = smp; continue; } *src_map = smp; return np; } if (weak_np) { *src_map = weak_smp; return weak_np; } if (common_size == 0) /* Not found */ return NULL; /* * It's a common, enter into run-time common symbol table. */ rtsp = enter_rts(name, (long)calloc(1, common_size), N_UNDF + N_EXT, 0, common_size, NULL); /* Common symbol is not a member of particular shlib. */ *src_map = NULL; #if DEBUG xprintf("Allocating common: %s size %d at %#x\n", name, common_size, rtsp->rt_sp->nz_value); #endif return rtsp->rt_sp; } /* * This routine is called from the jumptable to resolve * procedure calls to shared objects. */ long binder(jmpslot_t *jsp) { struct so_map *smp, *src_map = NULL; long addr; char *sym; struct nzlist *np; int index; /* * Find the PLT map that contains JSP. */ for (smp = link_map_head; smp; smp = smp->som_next) { if (LM_PLT(smp) < jsp && jsp < LM_PLT(smp) + LD_PLTSZ(smp->som_dynamic)/sizeof(*jsp)) break; } if (smp == NULL) errx(1, "Call to binder from unknown location: %p", jsp); index = jsp->reloc_index & JMPSLOT_RELOC_MASK; /* Get the local symbol this jmpslot refers to */ sym = LM_STRINGS(smp) + LM_SYMBOL(smp,RELOC_SYMBOL(&LM_REL(smp)[index]))->nz_strx; np = lookup(sym, &src_map, 1); if (np == NULL) errx(1, "Undefined symbol \"%s\" called from %s:%s at %p", sym, main_progname, smp->som_path, jsp); /* Fixup jmpslot so future calls transfer directly to target */ addr = np->nz_value; if (src_map) addr += (long)src_map->som_addr; md_fix_jmpslot(jsp, (long)jsp, addr); #if DEBUG xprintf(" BINDER: %s located at = %#x in %s\n", sym, addr, src_map->som_path); #endif return addr; } static int hfd; static long hsize; static struct hints_header *hheader; static struct hints_bucket *hbuckets; static char *hstrtab; static char *hint_search_path = ""; #define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1) static void maphints(void) { struct stat sb; caddr_t addr = MAP_FAILED; if ((hfd = open(_PATH_LD_HINTS, O_RDONLY, 0)) < 0) goto bad_hints; if (fstat(hfd, &sb) != 0 || !S_ISREG(sb.st_mode) || sb.st_size < sizeof(struct hints_header) || sb.st_size > LONG_MAX) goto bad_hints; hsize = (long)sb.st_size; addr = mmap(0, hsize, PROT_READ, MAP_COPY, hfd, 0); if (addr == MAP_FAILED) goto bad_hints; hheader = (struct hints_header *)addr; if (HH_BADMAG(*hheader) || hheader->hh_ehints > hsize) goto bad_hints; if (hheader->hh_version != LD_HINTS_VERSION_1 && hheader->hh_version != LD_HINTS_VERSION_2) goto bad_hints; hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab); hstrtab = (char *)(addr + hheader->hh_strtab); if (hheader->hh_version >= LD_HINTS_VERSION_2) hint_search_path = hstrtab + hheader->hh_dirlist; return; bad_hints: if (addr != MAP_FAILED) munmap(addr, hsize); if (hfd != -1) close(hfd); hheader = (struct hints_header *)-1; } static void unmaphints(void) { if (HINTS_VALID) { munmap((caddr_t)hheader, hsize); close(hfd); hheader = NULL; } } static int hinthash(char *cp, int vmajor, int vminor) { int k = 0; while (*cp) k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff; k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff; if (hheader->hh_version == LD_HINTS_VERSION_1) k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff; return k; } #undef major #undef minor static char * findhint(char *name, int major, int minor, char *prefered_path) { struct hints_bucket *bp; bp = hbuckets + (hinthash(name, major, minor) % hheader->hh_nbucket); while (1) { /* Sanity check */ if (bp->hi_namex >= hheader->hh_strtab_sz) { warnx("Bad name index: %#x", bp->hi_namex); break; } if (bp->hi_pathx >= hheader->hh_strtab_sz) { warnx("Bad path index: %#x", bp->hi_pathx); break; } if (strcmp(name, hstrtab + bp->hi_namex) == 0) { /* It's `name', check version numbers */ if (bp->hi_major == major && (bp->hi_ndewey < 2 || bp->hi_minor >= minor)) { if (prefered_path == NULL || strncmp(prefered_path, hstrtab + bp->hi_pathx, strlen(prefered_path)) == 0) { return hstrtab + bp->hi_pathx; } } } if (bp->hi_next == -1) break; /* Move on to next in bucket */ bp = &hbuckets[bp->hi_next]; } /* No hints available for name */ return NULL; } static char * rtfindlib(char *name, int major, int minor, int *usehints, char *ipath) { char *cp; int realminor; if (hheader == NULL) maphints(); if (!HINTS_VALID || !(*usehints)) goto lose; /* NOTE: `ipath' may reside in a piece of read-only memory */ if (ld_library_path || ipath) { /* Prefer paths from some explicit LD_LIBRARY_PATH */ char *lpath; char *dp; dp = lpath = concat(ld_library_path ? ld_library_path : "", (ld_library_path && ipath) ? ":" : "", ipath ? ipath : ""); while ((cp = strsep(&dp, ":")) != NULL) { if (*cp) { cp = findhint(name, major, minor, cp); if (cp) { free(lpath); return cp; } } } free(lpath); /* * Not found in hints; try directory search now, before * we get a spurious hint match below (i.e. a match not * on one of the paths we're supposed to search first. */ realminor = -1; cp = (char *)findshlib(name, &major, &realminor, 0); if (cp && realminor >= minor) return cp; } /* No LD_LIBRARY_PATH or lib not found in there; check default */ cp = findhint(name, major, minor, NULL); if (cp) return cp; lose: /* No hints available for name */ *usehints = 0; realminor = -1; add_search_path(hint_search_path); cp = (char *)findshlib(name, &major, &realminor, 0); remove_search_path(hint_search_path); if (cp) { if (realminor < minor && !ld_suppress_warnings) warnx("warning: lib%s.so.%d.%d: " "minor version >= %d expected, using it anyway", name, major, realminor, minor); return cp; } return NULL; } void preload(char *paths) { struct so_map *nsmp; struct sod *sodp; char *cp, *dp; dp = paths = strdup(paths); if (dp == NULL) { errx(1, "preload: out of memory"); } while ((cp = strsep(&dp, ":")) != NULL) { if ((sodp = (struct sod *)malloc(sizeof(struct sod))) == NULL) { errx(1, "preload: %s: out of memory", cp); return; } sodp->sod_name = (long)strdup(cp); sodp->sod_library = 0; sodp->sod_major = sodp->sod_minor = 0; if ((nsmp = map_object(sodp, 0)) == NULL) { errx(1, "preload: %s: cannot map object", cp); } LM_PRIVATE(nsmp)->spd_refcount++; } free(paths); return; } static int dlerrno; /* * Populate sod struct for dlopen's call to map_object */ static void build_sod(const char *name, struct sod *sodp) { unsigned int tuplet; int major, minor; char *realname, *tok, *etok, *cp; /* default is an absolute or relative path */ sodp->sod_name = (long)strdup(name); /* strtok is destructive */ sodp->sod_library = 0; sodp->sod_major = sodp->sod_minor = 0; /* does it look like /^lib/ ? */ if (strncmp((char *)sodp->sod_name, "lib", 3) != 0) return; /* is this a filename? */ if (strchr((char *)sodp->sod_name, '/')) return; /* skip over 'lib' */ cp = (char *)sodp->sod_name + 3; /* dot guardian */ if ((strchr(cp, '.') == NULL) || (*(cp+strlen(cp)-1) == '.')) return; /* default */ major = minor = -1; /* loop through name - parse skipping name */ for (tuplet = 0; (tok = strsep(&cp, ".")) != NULL; tuplet++) { switch (tuplet) { case 0: /* removed 'lib' and extensions from name */ realname = tok; break; case 1: /* 'so' extension */ if (strcmp(tok, "so") != 0) goto backout; break; case 2: /* major version extension */ major = strtol(tok, &etok, 10); if (*tok == '\0' || *etok != '\0') goto backout; break; case 3: /* minor version extension */ minor = strtol(tok, &etok, 10); if (*tok == '\0' || *etok != '\0') goto backout; break; /* if we get here, it must be weird */ default: goto backout; } } cp = (char *)sodp->sod_name; sodp->sod_name = (long)strdup(realname); free(cp); sodp->sod_library = 1; sodp->sod_major = major; sodp->sod_minor = minor; return; backout: free((char *)sodp->sod_name); sodp->sod_name = (long)strdup(name); } static void * __dlopen(const char *name, int mode) { struct sod *sodp; struct so_map *smp; /* * A NULL argument returns the current set of mapped objects. */ if (name == NULL) { LM_PRIVATE(link_map_head)->spd_refcount++; return link_map_head; } if ((sodp = (struct sod *)malloc(sizeof(struct sod))) == NULL) { dlerrno = ENOMEM; return NULL; } build_sod(name, sodp); if ((smp = map_object(sodp, main_map)) == NULL) { #ifdef DEBUG xprintf("%s: %s\n", name, strerror(errno)); #endif dlerrno = errno; free((char *)sodp->sod_name); free(sodp); return NULL; } LM_PRIVATE(smp)->spd_flags |= RTLD_DL; if (LM_PRIVATE(smp)->spd_refcount++ > 0) { free((char *)sodp->sod_name); free(sodp); return smp; } if (load_subs(smp) != 0) { if (--LM_PRIVATE(smp)->spd_refcount == 0) { unmap_object(smp); free_link_map(smp); } return NULL; } init_maps(smp); return smp; } static int __dlclose(void *fd) { struct so_map *smp = (struct so_map *)fd; #ifdef DEBUG xprintf("dlclose(%s): refcount = %d\n", smp->som_path, LM_PRIVATE(smp)->spd_refcount); #endif if (--LM_PRIVATE(smp)->spd_refcount != 0) return 0; if ((LM_PRIVATE(smp)->spd_flags & RTLD_DL) == 0) return 0; /* Dismantle shared object map and descriptor */ call_map(smp, "__fini"); call_map(smp, "__GLOBAL__DD"); #if 0 unload_subs(smp); /* XXX should unload implied objects */ #endif unmap_object(smp); free_link_map(smp); return 0; } static void * __dlsym(void *fd, const char *sym) { struct so_map *smp, *src_map = NULL; struct nzlist *np; long addr; /* * Restrict search to passed map if dlopen()ed. */ if (fd == NULL) smp = link_map_head; else src_map = smp = (struct so_map *)fd; np = lookup(sym, &src_map, 1); if (np == NULL) { dlerrno = ENOENT; return NULL; } /* Fixup jmpslot so future calls transfer directly to target */ addr = np->nz_value; if (src_map) addr += (long)src_map->som_addr; return (void *)addr; } static int __dlctl(void *fd, int cmd, void *arg) { switch (cmd) { case DL_GETERRNO: *(int *)arg = dlerrno; dlerrno = 0; return 0; default: dlerrno = EOPNOTSUPP; return -1; } return 0; } static void __dlexit(void) { struct so_map *smp; /* Call any object initialization routines. */ for (smp = link_map_head; smp; smp = smp->som_next) { if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD) continue; call_map(smp, ".fini"); call_map(smp, "__GLOBAL__DD"); } } void #if __STDC__ xprintf(char *fmt, ...) #else xprintf(fmt, va_alist) char *fmt; #endif { char buf[256]; va_list ap; #if __STDC__ va_start(ap, fmt); #else va_start(ap); #endif vsprintf(buf, fmt, ap); (void)write(1, buf, strlen(buf)); va_end(ap); }