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Diffstat (limited to 'libexec/rtld-aout/rtld.c')
-rw-r--r-- | libexec/rtld-aout/rtld.c | 2120 |
1 files changed, 2120 insertions, 0 deletions
diff --git a/libexec/rtld-aout/rtld.c b/libexec/rtld-aout/rtld.c new file mode 100644 index 0000000..ea33fe8 --- /dev/null +++ b/libexec/rtld-aout/rtld.c @@ -0,0 +1,2120 @@ +/* + * 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. + * + * $Id: rtld.c,v 1.46 1997/02/22 15:46:48 peter Exp $ + */ + +#include <sys/param.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/file.h> +#include <sys/time.h> +#include <sys/resource.h> +#include <sys/errno.h> +#include <sys/mman.h> +#ifndef MAP_COPY +#define MAP_COPY MAP_PRIVATE +#endif +#include <dlfcn.h> +#include <err.h> +#include <fcntl.h> +#include <a.out.h> +#include <stab.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#if __STDC__ +#include <stdarg.h> +#else +#include <varargs.h> +#endif + +#include <link.h> + +#include "md.h" +#include "shlib.h" +#include "support.h" +#include "dynamic.h" + +#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 + +/* + * Structure for building a list of shared objects. + */ +struct so_list { + struct so_map *sol_map; /* Link map for shared object */ + struct so_list *sol_next; /* Next entry in the list */ +}; + +/* + * Loader private data, hung off <so_map>->som_spd + */ +struct somap_private { + int spd_version; + struct so_map *spd_parent; + struct so_list *spd_children; + struct so_map *spd_prev; + dev_t spd_dev; + ino_t spd_ino; + int spd_refcount; + int spd_flags; +#define RTLD_MAIN 0x01 +#define RTLD_RTLD 0x02 +#define RTLD_DL 0x04 +#define RTLD_INIT 0x08 + unsigned long a_text; /* text size, if known */ + unsigned long a_data; /* initialized data size */ + unsigned long a_bss; /* uninitialized data size */ + +#ifdef SUN_COMPAT + long spd_offset; /* Correction for Sun main programs */ +#endif +}; + +#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))) + +/* Needed shared objects */ +#define LM_NEED(smp) ((struct sod *) \ + ((smp)->som_addr + LM_TXTADDR(smp) + LD_NEED((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) + +#ifndef RELOC_EXTERN_P +#define RELOC_EXTERN_P(s) ((s)->r_extern) +#endif + +#ifndef RELOC_SYMBOL +#define RELOC_SYMBOL(s) ((s)->r_symbolnum) +#endif + +#ifndef RELOC_PCREL_P +#define RELOC_PCREL_P(s) ((s)->r_pcrel) +#endif + +static char __main_progname[] = "main"; +static char *main_progname = __main_progname; +static char us[] = "/usr/libexec/ld.so"; + +char **environ; +char *__progname; +int errno; + +static uid_t uid, euid; +static gid_t gid, egid; +static int careful; +static int anon_fd = -1; + +static char *ld_bind_now; +static char *ld_ignore_missing_objects; +static char *ld_library_path; +static char *ld_preload; +static char *ld_tracing; +static char *ld_suppress_warnings; +static char *ld_warn_non_pure_code; + +struct so_map *link_map_head; +struct so_map *link_map_tail; +struct rt_symbol *rt_symbol_head; + +static void *__dlopen __P((char *, int)); +static int __dlclose __P((void *)); +static void *__dlsym __P((void *, char *)); +static char *__dlerror __P((void)); +static void __dlexit __P((void)); +static void *__dlsym3 __P((void *, char *, void *)); + +static struct ld_entry ld_entry = { + __dlopen, __dlclose, __dlsym, __dlerror, __dlexit, __dlsym3 +}; + + void xprintf __P((char *, ...)); +static struct so_map *map_object __P(( char *, + struct sod *, + struct so_map *)); +static int map_preload __P((void)); +static int map_sods __P((struct so_map *)); +static int reloc_and_init __P((struct so_map *, int)); +static void unmap_object __P((struct so_map *, int)); +static struct so_map *alloc_link_map __P(( char *, struct sod *, + struct so_map *, caddr_t, + struct _dynamic *)); +static void free_link_map __P((struct so_map *)); +static inline int check_text_reloc __P(( struct relocation_info *, + struct so_map *, + caddr_t)); +static int reloc_map __P((struct so_map *, int)); +static void reloc_copy __P((struct so_map *)); +static void init_object __P((struct so_map *)); +static void init_sods __P((struct so_list *)); +static int call_map __P((struct so_map *, char *)); +static char *findhint __P((char *, int, int *)); +static char *rtfindlib __P((char *, int, int)); +static char *rtfindfile __P((char *)); +void binder_entry __P((void)); +long binder __P((jmpslot_t *)); +static struct nzlist *lookup __P((char *, struct so_map **, int)); +static inline struct rt_symbol *lookup_rts __P((char *)); +static struct rt_symbol *enter_rts __P((char *, long, int, caddr_t, + long, struct so_map *)); +static void die __P((void)); +static void generror __P((char *, ...)); +static int maphints __P((void)); +static void unmaphints __P((void)); +static void ld_trace __P((struct so_map *)); +static void rt_readenv __P((void)); +static int hinthash __P((char *, int)); +int rtld __P((int, struct crt_ldso *, struct _dynamic *)); + +static inline int +strcmp (register const char *s1, register 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(version, crtp, dp) +int version; +struct crt_ldso *crtp; +struct _dynamic *dp; +{ + struct relocation_info *reloc; + struct relocation_info *reloc_limit; /* End+1 of relocation */ + struct so_debug *ddp; + struct so_map *main_map; + struct so_map *smp; + char *add_paths; + + /* 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; + + /* Relocate ourselves */ + reloc = (struct relocation_info *) (LD_REL(dp) + crtp->crt_ba); + reloc_limit = + (struct relocation_info *) ((char *) reloc + LD_RELSZ(dp)); + while(reloc < reloc_limit) { + /* + * Objects linked with "-Bsymbolic" (in particular, ld.so + * itself) can end up having unused relocation entries at + * the end. These can be detected by the fact that they + * have an address of 0. + */ + if(reloc->r_address == 0) /* We're done */ + break; + md_relocate_simple(reloc, crtp->crt_ba, + reloc->r_address + crtp->crt_ba); + ++reloc; + } + + if (version >= CRT_VERSION_BSD_4) + __progname = crtp->crt_ldso; + if (version >= CRT_VERSION_BSD_3) + main_progname = crtp->crt_prog; + + /* Some buggy versions of crt0.o have crt_ldso filled in as NULL. */ + if (__progname == NULL) + __progname = us; + + /* Fill in some fields in _DYNAMIC or crt structure */ + if (version >= CRT_VERSION_BSD_4) + crtp->crt_ldentry = &ld_entry; /* crt */ + else + crtp->crt_dp->d_entry = &ld_entry; /* _DYNAMIC */ + + /* Setup out (private) environ variable */ + environ = crtp->crt_ep; + + /* Get user and group identifiers */ + uid = getuid(); euid = geteuid(); + gid = getgid(); egid = getegid(); + + careful = (uid != euid) || (gid != egid); + + rt_readenv(); + + anon_open(); + + /* Make a link map entry for the main program */ + main_map = alloc_link_map(main_progname, + (struct sod *) NULL, (struct so_map *) NULL, + (caddr_t) 0, crtp->crt_dp); + LM_PRIVATE(main_map)->spd_refcount++; + LM_PRIVATE(main_map)->spd_flags |= RTLD_MAIN; + + /* Make a link map entry for ourselves */ + smp = alloc_link_map(us, + (struct sod *) NULL, (struct so_map *) NULL, + (caddr_t) crtp->crt_ba, dp); + LM_PRIVATE(smp)->spd_refcount++; + LM_PRIVATE(smp)->spd_flags |= RTLD_RTLD; + + /* + * Setup the executable's run path + */ + if (version >= CRT_VERSION_BSD_4) { + add_paths = LM_PATHS(main_map); + if (add_paths) + add_search_path(add_paths); + } + + /* + * Setup the directory search list for findshlib. We use only + * the standard search path. Any extra directories from + * LD_LIBRARY_PATH are searched explicitly, in rtfindlib. + */ + std_search_path(); + + /* Map in LD_PRELOADs before the main program's shared objects so we + can intercept those calls */ + if (ld_preload != NULL) { + if(map_preload() == -1) /* Failed */ + die(); + } + + /* Map all the shared objects that the main program depends upon */ + if(map_sods(main_map) == -1) + die(); + + if(ld_tracing) { /* We're done */ + ld_trace(link_map_head); + exit(0); + } + + crtp->crt_dp->d_un.d_sdt->sdt_loaded = link_map_head->som_next; + + /* Relocate and initialize all mapped objects */ + if(reloc_and_init(main_map, ld_bind_now != NULL) == -1) /* Failed */ + die(); + + 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 LDSO_VERSION_HAS_DLSYM3; +} + +void +ld_trace(smp) + 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 and return a pointer to it. + * + * PATH is the pathname of the shared object. + * + * SODP is a pointer to the shared object dependency structure responsible + * for causing the new object to be loaded. PARENT is the shared object + * into which SODP points. Both can be NULL if the new object is not + * being loaded as a result of a shared object dependency. + * + * ADDR is the address at which the object has been mapped. DP is a pointer + * to its _dynamic structure. + */ + static struct so_map * +alloc_link_map(path, sodp, parent, addr, dp) + char *path; + struct sod *sodp; + struct so_map *parent; + caddr_t addr; + struct _dynamic *dp; +{ + struct so_map *smp; + struct somap_private *smpp; + size_t smp_size; + +#ifdef DEBUG /* { */ + xprintf("alloc_link_map: \"%s\" at %p\n", path, addr); +#endif /* } */ + + /* + * Allocate so_map and private area with a single malloc. Round + * up the size of so_map so the private area is aligned. + */ + smp_size = ((((sizeof(struct so_map)) + sizeof (void *) - 1) / + sizeof (void *)) * sizeof (void *)); + + smp = (struct so_map *)xmalloc(smp_size + + sizeof (struct somap_private)); + smpp = (struct somap_private *) (((caddr_t) smp) + smp_size); + + /* Link the new entry into the list of link maps */ + smp->som_next = NULL; + smpp->spd_prev = link_map_tail; + if(link_map_tail == NULL) /* First link map entered into list */ + link_map_head = link_map_tail = smp; + else { /* Append to end of list */ + link_map_tail->som_next = smp; + link_map_tail = smp; + } + + 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_children = NULL; + smpp->a_text = 0; + smpp->a_data = 0; + smpp->a_bss = 0; +#ifdef SUN_COMPAT + smpp->spd_offset = + (addr==0 && dp && dp->d_version==LD_VERSION_SUN) ? PAGSIZ : 0; +#endif + return smp; +} + +/* + * Remove the specified link map entry from the list of link maps, and free + * the associated storage. + */ + static void +free_link_map(smp) + struct so_map *smp; +{ + struct somap_private *smpp = LM_PRIVATE(smp); + +#ifdef DEBUG /* { */ + xprintf("free_link_map: \"%s\"\n", smp->som_path); +#endif /* } */ + + if(smpp->spd_prev == NULL) /* Removing first entry in list */ + link_map_head = smp->som_next; + else /* Update link of previous entry */ + smpp->spd_prev->som_next = smp->som_next; + + if(smp->som_next == NULL) /* Removing last entry in list */ + link_map_tail = smpp->spd_prev; + else /* Update back link of next entry */ + LM_PRIVATE(smp->som_next)->spd_prev = smpp->spd_prev; + + free(smp->som_path); + free(smp); +} + +/* + * Map the shared object specified by PATH into memory, if it is not + * already mapped. Increment the object's reference count, and return a + * pointer to its link map. + * + * As a special case, if PATH is NULL, it is taken to refer to the main + * program. + * + * SODP is a pointer to the shared object dependency structure that caused + * this object to be requested. PARENT is a pointer to the link map of + * the shared object containing that structure. For a shared object not + * being mapped as a result of a shared object dependency, these pointers + * should be NULL. An example of this is a shared object that is explicitly + * loaded via dlopen(). + * + * The return value is a pointer to the link map for the requested object. + * If the operation failed, the return value is NULL. In that case, an + * error message can be retrieved by calling dlerror(). + */ + static struct so_map * +map_object(path, sodp, parent) + char *path; + struct sod *sodp; + struct so_map *parent; +{ + struct so_map *smp; + struct stat statbuf; + + if(path == NULL) /* Special case for the main program itself */ + smp = link_map_head; + else { + /* + * Check whether the shared object is already mapped. + * We check first for an exact match by pathname. That + * will detect the usual case. If no match is found by + * pathname, then stat the file, and check for a match by + * device and inode. That will detect the less common case + * involving multiple links to the same library. + */ + for(smp = link_map_head; smp != NULL; smp = smp->som_next) { + if(!(LM_PRIVATE(smp)->spd_flags & (RTLD_MAIN|RTLD_RTLD)) + && smp->som_path != NULL + && strcmp(smp->som_path, path) == 0) + break; + } + if(smp == NULL) { /* Check for a match by device and inode */ + if (stat(path, &statbuf) == -1) { + generror ("cannot stat \"%s\" : %s", + path, strerror(errno)); + return NULL; + } + for (smp = link_map_head; smp != NULL; + smp = smp->som_next) { + struct somap_private *smpp = LM_PRIVATE(smp); + + if (!(smpp->spd_flags & (RTLD_MAIN | RTLD_RTLD)) + && smpp->spd_ino == statbuf.st_ino + && smpp->spd_dev == statbuf.st_dev) + break; + } + } + } + + if (smp == NULL) { /* We must map the object */ + struct _dynamic *dp; + int fd; + caddr_t addr; + struct exec hdr; + struct somap_private *smpp; + + if ((fd = open(path, O_RDONLY, 0)) == -1) { + generror ("open failed for \"%s\" : %s", + path, strerror (errno)); + return NULL; + } + + if (read(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) { + generror ("header read failed for \"%s\"", path); + (void)close(fd); + return NULL; + } + + if (N_BADMAG(hdr)) { + generror ("bad magic number in \"%s\"", path); + (void)close(fd); + return NULL; + } + + /* + * Map the entire address space of the object. It is + * tempting to map just the text segment at first, in + * order to avoid having to use mprotect to change the + * protections of the data segment. But that would not + * be correct. Mmap might find a group of free pages + * large enough to hold the text segment, but not large + * enough for the entire object. When we then mapped + * in the data and BSS segments, they would either be + * non-contiguous with the text segment (if we didn't + * specify MAP_FIXED), or they would map over some + * previously mapped region (if we did use MAP_FIXED). + * The only way we can be sure of getting a contigous + * region that is large enough is to map the entire + * region at once. + */ + if ((addr = mmap(0, hdr.a_text + hdr.a_data + hdr.a_bss, + PROT_READ|PROT_EXEC, + MAP_COPY, fd, 0)) == (caddr_t)-1) { + generror ("mmap failed for \"%s\" : %s", + path, strerror (errno)); + (void)close(fd); + return NULL; + } + + (void)close(fd); + + /* Change the data segment to writable */ + if (mprotect(addr + hdr.a_text, hdr.a_data, + PROT_READ|PROT_WRITE|PROT_EXEC) != 0) { + generror ("mprotect failed for \"%s\" : %s", + path, strerror (errno)); + (void)munmap(addr, hdr.a_text + hdr.a_data + hdr.a_bss); + return NULL; + } + + /* Map in pages of zeros for the BSS segment */ + if (mmap(addr + hdr.a_text + hdr.a_data, hdr.a_bss, + PROT_READ|PROT_WRITE|PROT_EXEC, + MAP_ANON|MAP_COPY|MAP_FIXED, + anon_fd, 0) == (caddr_t)-1) { + generror ("mmap failed for \"%s\" : %s", + path, strerror (errno)); + (void)munmap(addr, hdr.a_text + hdr.a_data + hdr.a_bss); + return NULL; + } + + /* 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; + + smp = alloc_link_map(path, sodp, parent, addr, dp); + + /* save segment sizes for unmap. */ + smpp = LM_PRIVATE(smp); + smpp->a_text = hdr.a_text; + smpp->a_data = hdr.a_data; + smpp->a_bss = hdr.a_bss; + + /* + * Save the device and inode, so we can detect multiple links + * to the same library. Note, if we reach this point, then + * statbuf is guaranteed to have been filled in. + */ + smpp->spd_dev = statbuf.st_dev; + smpp->spd_ino = statbuf.st_ino; + } + + LM_PRIVATE(smp)->spd_refcount++; + if(LM_PRIVATE(smp)->spd_refcount == 1) { /* First use of object */ + /* + * Recursively map all of the shared objects that this + * one depends upon. + */ + if(map_sods(smp) == -1) { /* Failed */ + unmap_object(smp, 0); /* Clean up */ + return NULL; + } + } + + return smp; +} + +/* + * Map all the shared libraries named in the LD_PRELOAD environment + * variable. + * + * Returns 0 on success, -1 on failure. On failure, an error message can + * be gotten via dlerror(). + */ + static int +map_preload __P((void)) { + char *ld_name = ld_preload; + char *name; + + while ((name = strsep(&ld_name, ":")) != NULL) { + char *path = NULL; + struct so_map *smp = NULL; + + if (*name != '\0') { + path = (strchr(name, '/') != NULL) ? strdup(name) : + rtfindfile(name); + } + if (path == NULL) { + generror("Can't find LD_PRELOAD shared" + " library \"%s\"", name); + } else { + smp = map_object(path, (struct sod *) NULL, + (struct so_map *) NULL); + free(path); + } + if (ld_name != NULL) + *(ld_name - 1) = ':'; + if (smp == NULL) { + /* + * We don't bother to unmap already-loaded libraries + * on failure, because in that case the program is + * about to die anyway. + */ + return -1; + } + } + return 0; +} + +/* + * Map all of the shared objects that a given object depends upon. PARENT is + * a pointer to the link map for the shared object whose dependencies are + * to be mapped. + * + * Returns 0 on success. Returns -1 on failure. In that case, an error + * message can be retrieved by calling dlerror(). + */ + static int +map_sods(parent) + struct so_map *parent; +{ + struct somap_private *parpp = LM_PRIVATE(parent); + struct so_list **soltail = &parpp->spd_children; + long next = LD_NEED(parent->som_dynamic); + + while(next != 0) { + struct sod *sodp = + (struct sod *) (LM_LDBASE(parent) + next); + char *name = + (char *) (LM_LDBASE(parent) + sodp->sod_name); + char *path = NULL; + struct so_map *smp = NULL; + + if(sodp->sod_library) { + path = rtfindlib(name, sodp->sod_major, + sodp->sod_minor); + if(path == NULL && !ld_tracing) { + generror ("Can't find shared library" + " \"lib%s.so.%d.%d\"", name, + sodp->sod_major, sodp->sod_minor); + } + } else { + if(careful && name[0] != '/') { + generror("Shared library path must start" + " with \"/\" for \"%s\"", name); + } else + path = strdup(name); + } + + if(path != NULL) { + smp = map_object(path, sodp, parent); + free(path); + } + + if(smp != NULL) { + struct so_list *solp = (struct so_list *) + xmalloc(sizeof(struct so_list)); + solp->sol_map = smp; + solp->sol_next = NULL; + *soltail = solp; + soltail = &solp->sol_next; + } else if(ld_tracing) { + /* + * Allocate a dummy map entry so that we will get the + * "not found" message. + */ + (void)alloc_link_map(NULL, sodp, parent, 0, 0); + } else if (ld_ignore_missing_objects) { + char *msg; + /* + * Call __dlerror() even it we're not going to use + * the message, in order to clear the saved message. + */ + msg = __dlerror(); /* Should never be NULL */ + if (!ld_suppress_warnings) + warnx("warning: %s", msg); + } else /* Give up */ + break; + + next = sodp->sod_next; + } + + if(next != 0) { + /* + * Oh drat, we have to clean up a mess. + * + * We failed to load a shared object that we depend upon. + * So now we have to unload any dependencies that we had + * already successfully loaded prior to the error. + * + * Cleaning up doesn't matter so much for the initial + * loading of the program, since any failure is going to + * terminate the program anyway. But it is very important + * to clean up properly when something is being loaded + * via dlopen(). + */ + struct so_list *solp; + + while((solp = parpp->spd_children) != NULL) { + unmap_object(solp->sol_map, 0); + parpp->spd_children = solp->sol_next; + free(solp); + } + + return -1; + } + + return 0; +} + +/* + * Relocate and initialize the tree of shared objects rooted at the given + * link map entry. Returns 0 on success, or -1 on failure. On failure, + * an error message can be retrieved via dlerror(). + */ + static int +reloc_and_init(root, bind_now) + struct so_map *root; + int bind_now; +{ + struct so_map *smp; + + /* + * Relocate all newly-loaded objects. We avoid recursion for this + * step by taking advantage of a few facts. This function is called + * only when there are in fact some newly-loaded objects to process. + * Furthermore, all newly-loaded objects will have their link map + * entries at the end of the link map list. And, the root of the + * tree of objects just loaded will have been the first to be loaded + * and therefore the first new object in the link map list. Finally, + * we take advantage of the fact that we can relocate the newly-loaded + * objects in any order. + * + * All these facts conspire to let us simply loop over the tail + * portion of the link map list, relocating each object so + * encountered. + */ + for(smp = root; smp != NULL; smp = smp->som_next) { + if(!(LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)) { + if(reloc_map(smp, bind_now) < 0) + return -1; + } + } + + /* + * Copy any relocated initialized data. Again, we can just loop + * over the appropriate portion of the link map list. + */ + for(smp = root; smp != NULL; smp = smp->som_next) { + if(!(LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)) + reloc_copy(smp); + } + + /* + * Call any object initialization routines. + * + * Here, the order is very important, and we cannot simply loop + * over the newly-loaded objects as we did before. Rather, we + * have to initialize the tree of new objects depth-first, and + * process the sibling objects at each level in reverse order + * relative to the dependency list. + * + * Here is the reason we initialize depth-first. If an object + * depends on one or more other objects, then the objects it + * depends on should be initialized first, before the parent + * object itself. For it is possible that the parent's + * initialization routine will need the services provided by the + * objects it depends on -- and those objects had better already + * be initialized. + * + * We initialize the objects at each level of the tree in reverse + * order for a similar reason. When an object is linked with + * several libraries, it is common for routines in the earlier + * libraries to call routines in the later libraries. So, again, + * the later libraries need to be initialized first. + * + * The upshot of these rules is that we have to use recursion to + * get the libraries initialized in the best order. But the + * recursion is never likely to be very deep. + */ + init_object(root); + + return 0; +} + +/* + * Remove a reference to the shared object specified by SMP. If no + * references remain, unmap the object and, recursively, its descendents. + * This function also takes care of calling the finalization routines for + * objects that are removed. + * + * If KEEP is true, then the actual calls to munmap() are skipped, + * and the object is kept in memory. That is used only for finalization, + * from dlexit(), when the program is exiting. There are two reasons + * for it. First, the program is exiting and there is no point in + * spending the time to explicitly unmap its shared objects. Second, + * even after dlexit() has been called, there are still a couple of + * calls that are made to functions in libc. (This is really a bug + * in crt0.) So libc and the main program, at least, must remain + * mapped in that situation. + * + * Under no reasonable circumstances should this function fail. If + * anything goes wrong, we consider it an internal error, and report + * it with err(). + */ + static void +unmap_object(smp, keep) + struct so_map *smp; + int keep; +{ + struct somap_private *smpp = LM_PRIVATE(smp); + + smpp->spd_refcount--; + if(smpp->spd_refcount == 0) { /* Finished with this object */ + struct so_list *solp; + + if(smpp->spd_flags & RTLD_INIT) { /* Was initialized */ + /* + * Call the object's finalization routine. For + * backward compatibility, we first try to call + * ".fini". If that does not exist, we call + * "__fini". + */ + if(call_map(smp, ".fini") == -1) + call_map(smp, "__fini"); + } + + /* Recursively unreference the object's descendents */ + while((solp = smpp->spd_children) != NULL) { + unmap_object(solp->sol_map, keep); + smpp->spd_children = solp->sol_next; + free(solp); + } + + if(!keep) { /* Unmap the object from memory */ + if(munmap(smp->som_addr, + smpp->a_text + smpp->a_data + smpp->a_bss) < 0) + err(1, "internal error 1: munmap failed"); + + /* Unlink and free the object's link map entry */ + free_link_map(smp); + } + } +} + +static inline int +check_text_reloc(r, smp, addr) +struct relocation_info *r; +struct so_map *smp; +caddr_t addr; +{ + char *sym; + + if (addr >= LM_ETEXT(smp)) + return 0; + + if (RELOC_EXTERN_P(r)) + sym = LM_STRINGS(smp) + + LM_SYMBOL(smp, RELOC_SYMBOL(r))->nz_strx; + else + sym = ""; + + if (!ld_suppress_warnings && ld_warn_non_pure_code) + 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) { + generror ("mprotect failed for \"%s\" : %s", + smp->som_path, strerror (errno)); + return -1; + } + + smp->som_write = 1; + return 0; +} + +static int +reloc_map(smp, bind_now) + struct so_map *smp; + int bind_now; +{ + /* + * Caching structure for reducing the number of calls to + * lookup() during relocation. + * + * While relocating a given shared object, the dynamic linker + * maintains a caching vector that is directly indexed by + * the symbol number in the relocation entry. The first time + * a given symbol is looked up, the caching vector is + * filled in with a pointer to the symbol table entry, and + * a pointer to the so_map of the shared object in which the + * symbol was defined. On subsequent uses of the same symbol, + * that information is retrieved directly from the caching + * vector, without calling lookup() again. + * + * A symbol that is referenced in a relocation entry is + * typically referenced in many relocation entries, so this + * caching reduces the number of calls to lookup() + * dramatically. The overall improvement in the speed of + * dynamic linking is also dramatic -- as much as a factor + * of three for programs that use many shared libaries. + */ + struct cacheent { + struct nzlist *np; /* Pointer to symbol entry */ + struct so_map *src_map; /* Shared object that defined symbol */ + }; + + 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); + long numsyms = LD_STABSZ(dp) / symsize; + size_t cachebytes = numsyms * sizeof(struct cacheent); + struct cacheent *symcache = + (struct cacheent *) alloca(cachebytes); + + if(symcache == NULL) { + generror("Cannot allocate symbol caching vector for %s", + smp->som_path); + return -1; + } + bzero(symcache, cachebytes); + + 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; + + /* + * Objects linked with "-Bsymbolic" can end up having unused + * relocation entries at the end. These can be detected by + * the fact that they have an address of 0. + */ + if(r->r_address == 0) /* Finished relocating this object */ + break; + + addr = smp->som_addr + r->r_address; + if (check_text_reloc(r, smp, addr) < 0) + return -1; + + if (RELOC_EXTERN_P(r)) { + struct so_map *src_map = NULL; + struct nzlist *p, *np; + long relocation; + + if (RELOC_JMPTAB_P(r) && !bind_now) + 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; + + /* + * Look up the symbol, checking the caching + * vector first. + */ + np = symcache[RELOC_SYMBOL(r)].np; + if(np != NULL) /* Symbol already cached */ + src_map = symcache[RELOC_SYMBOL(r)].src_map; + else { /* Symbol not cached yet */ + np = lookup(sym, &src_map, RELOC_JMPTAB_P(r)); + /* + * Record the needed information about + * the symbol in the caching vector, + * so that we won't have to call + * lookup the next time we encounter + * the symbol. + */ + symcache[RELOC_SYMBOL(r)].np = np; + symcache[RELOC_SYMBOL(r)].src_map = src_map; + } + + if (np == NULL) { + generror ("Undefined symbol \"%s\" in %s:%s", + sym, main_progname, smp->som_path); + return -1; + } + + /* + * 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_JMPTAB_P(r)) { + md_bind_jmpslot(relocation, addr); + continue; + } + + relocation += md_get_addend(r, 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) { + generror ("mprotect failed for \"%s\" : %s", + smp->som_path, strerror (errno)); + return -1; + } + smp->som_write = 0; + } + return 0; +} + + static void +reloc_copy(smp) + 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 +init_object(smp) + struct so_map *smp; +{ + struct somap_private *smpp = LM_PRIVATE(smp); + + if(!(smpp->spd_flags & RTLD_INIT)) { /* Not initialized yet */ + smpp->spd_flags |= RTLD_INIT; + + /* Make sure all the children are initialized */ + if(smpp->spd_children != NULL) + init_sods(smpp->spd_children); + + if(call_map(smp, ".init") == -1) + call_map(smp, "__init"); + } +} + + static void +init_sods(solp) + struct so_list *solp; +{ + /* Recursively initialize the rest of the list */ + if(solp->sol_next != NULL) + init_sods(solp->sol_next); + + /* Initialize the first element of the list */ + init_object(solp->sol_map); +} + + +/* + * Call a function in a given shared object. SMP is the shared object, and + * SYM is the name of the function. + * + * Returns 0 on success, or -1 if the symbol was not found. Failure is not + * necessarily an error condition, so no error message is generated. + */ + static int +call_map(smp, sym) + struct so_map *smp; + char *sym; +{ + struct so_map *src_map = smp; + struct nzlist *np; + + np = lookup(sym, &src_map, 1); + if (np) { + (*(void (*)())(src_map->som_addr + np->nz_value))(); + return 0; + } + + return -1; +} + +/* + * 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(key) + char *key; +{ + register char *cp; + register 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(key) + char *key; +{ + register int hashval; + register 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(name, value, type, srcaddr, size, smp) + char *name; + long value; + int type; + caddr_t srcaddr; + long size; + struct so_map *smp; +{ + register int hashval; + register 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) + continue; + + /* 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(name, src_map, strong) + char *name; + struct so_map **src_map; /* IN/OUT */ + int strong; +{ + long common_size = 0; + struct so_map *smp; + struct rt_symbol *rtsp; + + if ((rtsp = lookup_rts(name)) != NULL) + return rtsp->rt_sp; + + /* + * 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; + 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; + } + } + + *src_map = smp; + return 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); + +#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(jsp) + 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: %#x\n", 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 %#x", + 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 struct hints_header *hheader; /* NULL means not mapped */ +static struct hints_bucket *hbuckets; +static char *hstrtab; + +/* + * Map the hints file into memory, if it is not already mapped. Returns + * 0 on success, or -1 on failure. + */ + static int +maphints __P((void)) +{ + static int hints_bad; /* TRUE if hints are unusable */ + static int paths_added; + int hfd; + struct hints_header hdr; + caddr_t addr; + + if (hheader != NULL) /* Already mapped */ + return 0; + + if (hints_bad) /* Known to be corrupt or unavailable */ + return -1; + + if ((hfd = open(_PATH_LD_HINTS, O_RDONLY, 0)) == -1) { + hints_bad = 1; + return -1; + } + + /* Read the header and check it */ + + if (read(hfd, &hdr, sizeof hdr) != sizeof hdr || + HH_BADMAG(hdr) || + (hdr.hh_version != LD_HINTS_VERSION_1 && + hdr.hh_version != LD_HINTS_VERSION_2)) { + close(hfd); + hints_bad = 1; + return -1; + } + + /* Map the hints into memory */ + + addr = mmap(0, hdr.hh_ehints, PROT_READ, MAP_SHARED, hfd, 0); + if (addr == (caddr_t)-1) { + close(hfd); + hints_bad = 1; + return -1; + } + + close(hfd); + + hheader = (struct hints_header *)addr; + hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab); + hstrtab = (char *)(addr + hheader->hh_strtab); + /* pluck out the system ldconfig path */ + if (hheader->hh_version >= LD_HINTS_VERSION_2 && !paths_added) { + add_search_path(hstrtab + hheader->hh_dirlist); + paths_added = 1; + } + + return 0; +} + +/* + * Unmap the hints file, if it is currently mapped. + */ + static void +unmaphints() +{ + if (hheader != NULL) { + munmap((caddr_t)hheader, hheader->hh_ehints); + hheader = NULL; + } +} + + int +hinthash(cp, vmajor) + char *cp; + int vmajor; +{ + int k = 0; + + while (*cp) + k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff; + + k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff; + + return k; +} + +#undef major +#undef minor + +/* + * Search for a library in the hints generated by ldconfig. On success, + * returns the full pathname of the matching library. This string is + * always dynamically allocated on the heap. + * + * Returns the minor number of the matching library via the pointer + * argument MINORP. + * + * Returns NULL if the library cannot be found. + */ + static char * +findhint(name, major, minorp) + char *name; + int major; + int *minorp; +{ + struct hints_bucket *bp = + hbuckets + (hinthash(name, major) % hheader->hh_nbucket); + + while (1) { + /* Sanity check */ + if (bp->hi_namex >= hheader->hh_strtab_sz) { + warnx("Bad name index: %#x\n", bp->hi_namex); + break; + } + if (bp->hi_pathx >= hheader->hh_strtab_sz) { + warnx("Bad path index: %#x\n", bp->hi_pathx); + break; + } + + /* + * We accept the current hints entry if its name matches + * and its major number matches. We don't have to search + * for the best minor number, because that was already + * done by "ldconfig" when it built the hints file. + */ + if (strcmp(name, hstrtab + bp->hi_namex) == 0 && + bp->hi_major == major) { + struct stat s; + + if (stat(hstrtab + bp->hi_pathx, &s) == -1) + return NULL; /* Doesn't actually exist */ + *minorp = bp->hi_ndewey >= 2 ? bp->hi_minor : -1; + return strdup(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; +} + +/* + * Search for the given shared library. On success, returns a string + * containing the full pathname for the library. This string is always + * dynamically allocated on the heap. + * + * Returns NULL if the library cannot be found. + */ + static char * +rtfindlib(name, major, minor) + char *name; + int major, minor; +{ + char *ld_path = ld_library_path; + char *path = NULL; + int realminor = -1; + + if (ld_path != NULL) { /* First, search the directories in ld_path */ + /* + * There is no point in trying to use the hints file for this. + */ + char *dir; + + while (path == NULL && (dir = strsep(&ld_path, ":")) != NULL) { + path = search_lib_dir(dir, name, &major, &realminor, 0); + if (ld_path != NULL) + *(ld_path - 1) = ':'; + } + } + + if (path == NULL && maphints() == 0) /* Search the hints file */ + path = findhint(name, major, &realminor); + + if (path == NULL) /* Search the standard directories */ + path = findshlib(name, &major, &realminor, 0); + + if (path != NULL && realminor < minor && !ld_suppress_warnings) { + warnx("warning: %s: minor version %d" + " older than expected %d, using it anyway", + path, realminor, minor); + } + + return path; +} + +/* + * Search for the given shared library file. This is similar to rtfindlib, + * except that the argument is the actual name of the desired library file. + * Thus there is no need to worry about version numbers. The return value + * is a string containing the full pathname for the library. This string + * is always dynamically allocated on the heap. + * + * Returns NULL if the library cannot be found. + */ + static char * +rtfindfile(name) + char *name; +{ + char *ld_path = ld_library_path; + char *path = NULL; + + if (ld_path != NULL) { /* First, search the directories in ld_path */ + char *dir; + + while (path == NULL && (dir = strsep(&ld_path, ":")) != NULL) { + struct stat sb; + + path = concat(dir, "/", name); + if (lstat(path, &sb) == -1) { /* Does not exist */ + free(path); + path = NULL; + } + if (ld_path != NULL) + *(ld_path - 1) = ':'; + } + } + + /* + * We don't search the hints file. It is organized around major + * and minor version numbers, so it is not suitable for finding + * a specific file name. + */ + + if (path == NULL) /* Search the standard directories */ + path = find_lib_file(name); + + return path; +} + +/* + * Buffer for error messages and a pointer that is set to point to the buffer + * when a error occurs. It acts as a last error flag, being set to NULL + * after an error is returned. + */ +#define DLERROR_BUF_SIZE 512 +static char dlerror_buf [DLERROR_BUF_SIZE]; +static char *dlerror_msg = NULL; + + + static void * +__dlopen(path, mode) + char *path; + int mode; +{ + struct so_map *old_tail = link_map_tail; + struct so_map *smp; + int bind_now = mode == RTLD_NOW; + + /* + * path == NULL is handled by map_object() + */ + + anon_open(); + + /* Map the object, and the objects on which it depends */ + smp = map_object(path, (struct sod *) NULL, (struct so_map *) NULL); + if(smp == NULL) /* Failed */ + return NULL; + LM_PRIVATE(smp)->spd_flags |= RTLD_DL; + + /* Relocate and initialize all newly-mapped objects */ + if(link_map_tail != old_tail) { /* We have mapped some new objects */ + if(reloc_and_init(smp, bind_now) == -1) /* Failed */ + return NULL; + } + + unmaphints(); + anon_close(); + + return smp; +} + + static int +__dlclose(fd) + void *fd; +{ + struct so_map *smp = (struct so_map *)fd; + struct so_map *scanp; + +#ifdef DEBUG + xprintf("dlclose(%s): refcount = %d\n", smp->som_path, + LM_PRIVATE(smp)->spd_refcount); +#endif + /* Check the argument for validity */ + for(scanp = link_map_head; scanp != NULL; scanp = scanp->som_next) + if(scanp == smp) /* We found the map in the list */ + break; + if(scanp == NULL || !(LM_PRIVATE(smp)->spd_flags & RTLD_DL)) { + generror("Invalid argument to dlclose"); + return -1; + } + + unmap_object(smp, 0); + + return 0; +} + +/* + * This form of dlsym is obsolete. Current versions of crt0 don't call + * it. It can still be called by old executables that were linked with + * old versions of crt0. + */ + static void * +__dlsym(fd, sym) + void *fd; + char *sym; +{ + if (fd == RTLD_NEXT) { + generror("RTLD_NEXT not supported by this version of" + " /usr/lib/crt0.o"); + return NULL; + } + return __dlsym3(fd, sym, NULL); +} + + static void * +__dlsym3(fd, sym, retaddr) + void *fd; + char *sym; + void *retaddr; +{ + struct so_map *smp; + struct so_map *src_map; + struct nzlist *np; + long addr; + + if (fd == RTLD_NEXT) { + /* Find the shared object that contains the caller. */ + for (smp = link_map_head; smp != NULL; smp = smp->som_next) { + void *textbase = smp->som_addr + LM_TXTADDR(smp); + void *textlimit = LM_ETEXT(smp); + + if (textbase <= retaddr && retaddr < textlimit) + break; + } + if (smp == NULL) { + generror("Cannot determine caller's shared object"); + return NULL; + } + smp = smp->som_next; + if (smp != NULL && LM_PRIVATE(smp)->spd_flags & RTLD_RTLD) + smp = smp->som_next; + if (smp == NULL) { + generror("No next shared object for RTLD_NEXT"); + return NULL; + } + do { + src_map = smp; + np = lookup(sym, &src_map, 1); + } while (np == NULL && (smp = smp->som_next) != NULL); + } else { + smp = (struct so_map *)fd; + src_map = NULL; + + /* + * Restrict search to passed map if dlopen()ed. + */ + if (smp != NULL && LM_PRIVATE(smp)->spd_flags & RTLD_DL) + src_map = smp; + + np = lookup(sym, &src_map, 1); + } + + if (np == NULL) { + generror("Undefined symbol"); + return NULL; + } + + addr = np->nz_value; + if (src_map) + addr += (long)src_map->som_addr; + + return (void *)addr; +} + + static char * +__dlerror __P((void)) +{ + char *err; + + err = dlerror_msg; + dlerror_msg = NULL; /* Next call will return NULL */ + + return err; +} + + static void +__dlexit __P((void)) +{ +#ifdef DEBUG +xprintf("__dlexit called\n"); +#endif + + unmap_object(link_map_head, 1); +} + +/* + * Print the current error message and exit with failure status. + */ +static void +die __P((void)) +{ + char *msg; + + fprintf(stderr, "ld.so failed"); + if ((msg = __dlerror()) != NULL) + fprintf(stderr, ": %s", msg); + putc('\n', stderr); + _exit(1); +} + + +/* + * Generate an error message that can be later be retrieved via dlerror. + */ +static void +#if __STDC__ +generror(char *fmt, ...) +#else +generror(fmt, va_alist) +char *fmt; +#endif +{ + va_list ap; +#if __STDC__ + va_start(ap, fmt); +#else + va_start(ap); +#endif + vsnprintf (dlerror_buf, DLERROR_BUF_SIZE, fmt, ap); + dlerror_msg = dlerror_buf; + + va_end(ap); +} + +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 + + vsnprintf(buf, sizeof(buf), fmt, ap); + (void)write(1, buf, strlen(buf)); + va_end(ap); +} + +/* + * rt_readenv() etc. + * + * Do a sweep over the environment once only, pick up what + * looks interesting. + * + * This is pretty obscure, but is relatively simple. Simply + * look at each environment variable, if it starts with "LD_" then + * look closer at it. If it's in our table, set the variable + * listed. effectively, this is like: + * ld_preload = careful ? NULL : getenv("LD_PRELOAD"); + * except that the environment is scanned once only to pick up all + * known variables, rather than scanned multiple times for each + * variable. + * + * If an environment variable of interest is set to the empty string, we + * treat it as if it were unset. + */ + +#define L(n, u, v) { n, sizeof(n) - 1, u, v }, +struct env_scan_tab { + char *name; + int len; + int unsafe; + char **value; +} scan_tab[] = { + L("LD_LIBRARY_PATH=", 1, &ld_library_path) + L("LD_PRELOAD=", 1, &ld_preload) + L("LD_IGNORE_MISSING_OBJECTS=", 1, &ld_ignore_missing_objects) + L("LD_TRACE_LOADED_OBJECTS=", 0, &ld_tracing) + L("LD_BIND_NOW=", 0, &ld_bind_now) + L("LD_SUPPRESS_WARNINGS=", 0, &ld_suppress_warnings) + L("LD_WARN_NON_PURE_CODE=", 0, &ld_warn_non_pure_code) + { NULL, 0, NULL } +}; +#undef L + +static void +rt_readenv() +{ + char **p = environ; + char *v; + struct env_scan_tab *t; + + /* for each string in the environment... */ + while ((v = *p++)) { + + /* check for LD_xxx */ + if (v[0] != 'L' || v[1] != 'D' || v[2] != '_') + continue; + + for (t = scan_tab; t->name; t++) { + if (careful && t->unsafe) + continue; /* skip for set[ug]id */ + if (strncmp(t->name, v, t->len) == 0) { + if (*(v + t->len) != '\0') /* Not empty */ + *t->value = v + t->len; + break; + } + } + } +} |