[352] | 1 | #define _GNU_SOURCE
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| 2 | #include <stdio.h>
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| 3 | #include <stdlib.h>
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| 4 | #include <stdarg.h>
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| 5 | #include <stddef.h>
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| 6 | #include <string.h>
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| 7 | #include <unistd.h>
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| 8 | #include <stdint.h>
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| 9 | #include <elf.h>
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| 10 | #include <sys/mman.h>
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| 11 | #include <limits.h>
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| 12 | #include <fcntl.h>
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| 13 | #include <sys/stat.h>
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| 14 | #include <errno.h>
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| 15 | #include <link.h>
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| 16 | #include <setjmp.h>
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| 17 | #include <pthread.h>
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| 18 | #include <ctype.h>
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| 19 | #include <dlfcn.h>
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| 20 | #include "pthread_impl.h"
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| 21 | #include "libc.h"
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| 22 | #include "dynlink.h"
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| 23 |
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| 24 | static void error(const char *, ...);
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| 25 |
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| 26 | #define MAXP2(a,b) (-(-(a)&-(b)))
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| 27 | #define ALIGN(x,y) ((x)+(y)-1 & -(y))
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| 28 |
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| 29 | struct debug {
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| 30 | int ver;
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| 31 | void *head;
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| 32 | void (*bp)(void);
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| 33 | int state;
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| 34 | void *base;
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| 35 | };
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| 36 |
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| 37 | struct td_index {
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| 38 | size_t args[2];
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| 39 | struct td_index *next;
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| 40 | };
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| 41 |
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| 42 | struct dso {
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| 43 | #if DL_FDPIC
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| 44 | struct fdpic_loadmap *loadmap;
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| 45 | #else
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| 46 | unsigned char *base;
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| 47 | #endif
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| 48 | char *name;
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| 49 | size_t *dynv;
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| 50 | struct dso *next, *prev;
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| 51 |
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| 52 | Phdr *phdr;
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| 53 | int phnum;
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| 54 | size_t phentsize;
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| 55 | Sym *syms;
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| 56 | Elf_Symndx *hashtab;
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| 57 | uint32_t *ghashtab;
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| 58 | int16_t *versym;
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| 59 | char *strings;
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| 60 | struct dso *syms_next, *lazy_next;
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| 61 | size_t *lazy, lazy_cnt;
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| 62 | unsigned char *map;
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| 63 | size_t map_len;
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| 64 | dev_t dev;
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| 65 | ino_t ino;
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| 66 | char relocated;
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| 67 | char constructed;
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| 68 | char kernel_mapped;
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| 69 | struct dso **deps, *needed_by;
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| 70 | char *rpath_orig, *rpath;
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| 71 | struct tls_module tls;
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| 72 | size_t tls_id;
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| 73 | size_t relro_start, relro_end;
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| 74 | void **new_dtv;
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| 75 | unsigned char *new_tls;
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| 76 | volatile int new_dtv_idx, new_tls_idx;
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| 77 | struct td_index *td_index;
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| 78 | struct dso *fini_next;
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| 79 | char *shortname;
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| 80 | #if DL_FDPIC
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| 81 | unsigned char *base;
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| 82 | #else
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| 83 | struct fdpic_loadmap *loadmap;
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| 84 | #endif
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| 85 | struct funcdesc {
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| 86 | void *addr;
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| 87 | size_t *got;
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| 88 | } *funcdescs;
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| 89 | size_t *got;
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| 90 | char buf[];
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| 91 | };
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| 92 |
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| 93 | struct symdef {
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| 94 | Sym *sym;
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| 95 | struct dso *dso;
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| 96 | };
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| 97 |
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| 98 | int __init_tp(void *);
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| 99 | void __init_libc(char **, char *);
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| 100 | void *__copy_tls(unsigned char *);
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| 101 |
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| 102 | __attribute__((__visibility__("hidden")))
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| 103 | const char *__libc_get_version(void);
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| 104 |
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| 105 | static struct builtin_tls {
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| 106 | char c;
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| 107 | struct pthread pt;
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| 108 | void *space[16];
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| 109 | } builtin_tls[1];
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| 110 | #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
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| 111 |
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| 112 | #define ADDEND_LIMIT 4096
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| 113 | static size_t *saved_addends, *apply_addends_to;
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| 114 |
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| 115 | static struct dso ldso;
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| 116 | static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
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| 117 | static char *env_path, *sys_path;
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| 118 | static unsigned long long gencnt;
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| 119 | static int runtime;
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| 120 | static int ldd_mode;
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| 121 | static int ldso_fail;
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| 122 | static int noload;
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| 123 | static jmp_buf *rtld_fail;
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| 124 | static pthread_rwlock_t lock;
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| 125 | static struct debug debug;
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| 126 | static struct tls_module *tls_tail;
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| 127 | static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
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| 128 | static size_t static_tls_cnt;
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| 129 | static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
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| 130 | static struct fdpic_loadmap *app_loadmap;
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| 131 | static struct fdpic_dummy_loadmap app_dummy_loadmap;
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| 132 | static struct dso *const nodeps_dummy;
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| 133 |
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| 134 | struct debug *_dl_debug_addr = &debug;
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| 135 |
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| 136 | #ifndef __c2__
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| 137 | __attribute__((__visibility__("hidden")))
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| 138 | void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
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| 139 |
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| 140 | __attribute__((__visibility__("hidden")))
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| 141 | extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
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| 142 |
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| 143 | weak_alias(__init_array_start, __init_array_end);
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| 144 | weak_alias(__fini_array_start, __fini_array_end);
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| 145 | #else
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| 146 | void(*const __init_array_start)(void) = 0, (*const __fini_array_start)(void) = 0;
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| 147 | #define __init_array_end __init_array_start
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| 148 | #define __fini_array_end __fini_array_start
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| 149 | #endif
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| 150 |
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| 151 | static int dl_strcmp(const char *l, const char *r)
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| 152 | {
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| 153 | for (; *l==*r && *l; l++, r++);
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| 154 | return *(unsigned char *)l - *(unsigned char *)r;
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| 155 | }
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| 156 | #define strcmp(l,r) dl_strcmp(l,r)
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| 157 |
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| 158 | /* Compute load address for a virtual address in a given dso. */
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| 159 | #if DL_FDPIC
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| 160 | static void *laddr(const struct dso *p, size_t v)
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| 161 | {
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| 162 | size_t j=0;
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| 163 | if (!p->loadmap) return p->base + v;
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| 164 | for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
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| 165 | return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
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| 166 | }
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| 167 | #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
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| 168 | laddr(p, v), (p)->got })
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| 169 | #else
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| 170 | #define laddr(p, v) (void *)((p)->base + (v))
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| 171 | #define fpaddr(p, v) ((void (*)())laddr(p, v))
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| 172 | #endif
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| 173 |
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| 174 | static void decode_vec(size_t *v, size_t *a, size_t cnt)
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| 175 | {
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| 176 | size_t i;
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| 177 | for (i=0; i<cnt; i++) a[i] = 0;
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| 178 | for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
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| 179 | a[0] |= 1UL<<v[0];
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| 180 | a[v[0]] = v[1];
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| 181 | }
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| 182 | }
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| 183 |
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| 184 | static int search_vec(size_t *v, size_t *r, size_t key)
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| 185 | {
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| 186 | for (; v[0]!=key; v+=2)
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| 187 | if (!v[0]) return 0;
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| 188 | *r = v[1];
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| 189 | return 1;
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| 190 | }
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| 191 |
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| 192 | static uint32_t sysv_hash(const char *s0)
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| 193 | {
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| 194 | const unsigned char *s = (void *)s0;
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| 195 | uint_fast32_t h = 0;
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| 196 | while (*s) {
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| 197 | h = 16*h + *s++;
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| 198 | h ^= h>>24 & 0xf0;
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| 199 | }
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| 200 | return h & 0xfffffff;
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| 201 | }
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| 202 |
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| 203 | static uint32_t gnu_hash(const char *s0)
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| 204 | {
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| 205 | const unsigned char *s = (void *)s0;
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| 206 | uint_fast32_t h = 5381;
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| 207 | for (; *s; s++)
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| 208 | h += h*32 + *s;
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| 209 | return h;
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| 210 | }
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| 211 |
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| 212 | static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
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| 213 | {
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| 214 | size_t i;
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| 215 | Sym *syms = dso->syms;
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| 216 | Elf_Symndx *hashtab = dso->hashtab;
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| 217 | char *strings = dso->strings;
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| 218 | for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
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| 219 | if ((!dso->versym || dso->versym[i] >= 0)
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| 220 | && (!strcmp(s, strings+syms[i].st_name)))
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| 221 | return syms+i;
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| 222 | }
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| 223 | return 0;
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| 224 | }
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| 225 |
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| 226 | static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
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| 227 | {
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| 228 | uint32_t nbuckets = hashtab[0];
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| 229 | uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
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| 230 | uint32_t i = buckets[h1 % nbuckets];
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| 231 |
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| 232 | if (!i) return 0;
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| 233 |
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| 234 | uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
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| 235 |
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| 236 | for (h1 |= 1; ; i++) {
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| 237 | uint32_t h2 = *hashval++;
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| 238 | if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
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| 239 | && !strcmp(s, dso->strings + dso->syms[i].st_name))
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| 240 | return dso->syms+i;
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| 241 | if (h2 & 1) break;
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| 242 | }
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| 243 |
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| 244 | return 0;
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| 245 | }
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| 246 |
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| 247 | static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
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| 248 | {
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| 249 | const size_t *bloomwords = (const void *)(hashtab+4);
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| 250 | size_t f = bloomwords[fofs & (hashtab[2]-1)];
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| 251 | if (!(f & fmask)) return 0;
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| 252 |
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| 253 | f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
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| 254 | if (!(f & 1)) return 0;
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| 255 |
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| 256 | return gnu_lookup(h1, hashtab, dso, s);
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| 257 | }
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| 258 |
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| 259 | #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
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| 260 | #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
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| 261 |
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| 262 | #ifndef ARCH_SYM_REJECT_UND
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| 263 | #define ARCH_SYM_REJECT_UND(s) 0
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| 264 | #endif
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| 265 |
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| 266 | static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
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| 267 | {
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| 268 | uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
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| 269 | size_t ghm = 1ul << gh % (8*sizeof(size_t));
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| 270 | struct symdef def = {0};
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| 271 | for (; dso; dso=dso->syms_next) {
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| 272 | Sym *sym;
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| 273 | if ((ght = dso->ghashtab)) {
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| 274 | sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
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| 275 | } else {
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| 276 | if (!h) h = sysv_hash(s);
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| 277 | sym = sysv_lookup(s, h, dso);
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| 278 | }
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| 279 | if (!sym) continue;
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| 280 | if (!sym->st_shndx)
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| 281 | if (need_def || (sym->st_info&0xf) == STT_TLS
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| 282 | || ARCH_SYM_REJECT_UND(sym))
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| 283 | continue;
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| 284 | if (!sym->st_value)
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| 285 | if ((sym->st_info&0xf) != STT_TLS)
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| 286 | continue;
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| 287 | if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
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| 288 | if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
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| 289 | def.sym = sym;
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| 290 | def.dso = dso;
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| 291 | break;
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| 292 | }
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| 293 | return def;
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| 294 | }
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| 295 |
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| 296 | __attribute__((__visibility__("hidden")))
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| 297 | ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
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| 298 |
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| 299 | static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
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| 300 | {
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| 301 | unsigned char *base = dso->base;
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| 302 | Sym *syms = dso->syms;
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| 303 | char *strings = dso->strings;
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| 304 | Sym *sym;
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| 305 | const char *name;
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| 306 | void *ctx;
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| 307 | int type;
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| 308 | int sym_index;
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| 309 | struct symdef def;
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| 310 | size_t *reloc_addr;
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| 311 | size_t sym_val;
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| 312 | size_t tls_val;
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| 313 | size_t addend;
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| 314 | int skip_relative = 0, reuse_addends = 0, save_slot = 0;
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| 315 |
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| 316 | if (dso == &ldso) {
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| 317 | /* Only ldso's REL table needs addend saving/reuse. */
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| 318 | if (rel == apply_addends_to)
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| 319 | reuse_addends = 1;
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| 320 | skip_relative = 1;
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| 321 | }
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| 322 |
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| 323 | for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
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| 324 | if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
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| 325 | type = R_TYPE(rel[1]);
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| 326 | if (type == REL_NONE) continue;
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| 327 | reloc_addr = laddr(dso, rel[0]);
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| 328 |
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| 329 | if (stride > 2) {
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| 330 | addend = rel[2];
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| 331 | } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
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| 332 | addend = 0;
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| 333 | } else if (reuse_addends) {
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| 334 | /* Save original addend in stage 2 where the dso
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| 335 | * chain consists of just ldso; otherwise read back
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| 336 | * saved addend since the inline one was clobbered. */
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| 337 | if (head==&ldso)
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| 338 | saved_addends[save_slot] = *reloc_addr;
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| 339 | addend = saved_addends[save_slot++];
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| 340 | } else {
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| 341 | addend = *reloc_addr;
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| 342 | }
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| 343 |
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| 344 | sym_index = R_SYM(rel[1]);
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| 345 | if (sym_index) {
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| 346 | sym = syms + sym_index;
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| 347 | name = strings + sym->st_name;
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| 348 | ctx = type==REL_COPY ? head->syms_next : head;
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| 349 | def = (sym->st_info&0xf) == STT_SECTION
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| 350 | ? (struct symdef){ .dso = dso, .sym = sym }
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| 351 | : find_sym(ctx, name, type==REL_PLT);
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| 352 | if (!def.sym && (sym->st_shndx != SHN_UNDEF
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| 353 | || sym->st_info>>4 != STB_WEAK)) {
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| 354 | if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
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| 355 | dso->lazy[3*dso->lazy_cnt+0] = rel[0];
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| 356 | dso->lazy[3*dso->lazy_cnt+1] = rel[1];
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| 357 | dso->lazy[3*dso->lazy_cnt+2] = addend;
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| 358 | dso->lazy_cnt++;
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| 359 | continue;
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| 360 | }
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| 361 | error("Error relocating %s: %s: symbol not found",
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| 362 | dso->name, name);
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| 363 | if (runtime) longjmp(*rtld_fail, 1);
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| 364 | continue;
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| 365 | }
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| 366 | } else {
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| 367 | sym = 0;
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| 368 | def.sym = 0;
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| 369 | def.dso = dso;
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| 370 | }
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| 371 |
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| 372 | sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
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| 373 | tls_val = def.sym ? def.sym->st_value : 0;
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| 374 |
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| 375 | switch(type) {
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| 376 | case REL_NONE:
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| 377 | break;
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| 378 | case REL_OFFSET:
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| 379 | addend -= (size_t)reloc_addr;
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| 380 | case REL_SYMBOLIC:
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| 381 | case REL_GOT:
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| 382 | case REL_PLT:
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| 383 | *reloc_addr = sym_val + addend;
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| 384 | break;
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| 385 | case REL_RELATIVE:
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| 386 | *reloc_addr = (size_t)base + addend;
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| 387 | break;
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| 388 | case REL_SYM_OR_REL:
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| 389 | if (sym) *reloc_addr = sym_val + addend;
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| 390 | else *reloc_addr = (size_t)base + addend;
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| 391 | break;
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| 392 | case REL_COPY:
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| 393 | memcpy(reloc_addr, (void *)sym_val, sym->st_size);
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| 394 | break;
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| 395 | case REL_OFFSET32:
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| 396 | *(uint32_t *)reloc_addr = sym_val + addend
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| 397 | - (size_t)reloc_addr;
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| 398 | break;
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| 399 | case REL_FUNCDESC:
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| 400 | *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
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| 401 | + (def.sym - def.dso->syms)) : 0;
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| 402 | break;
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| 403 | case REL_FUNCDESC_VAL:
|
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| 404 | if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
|
---|
| 405 | else *reloc_addr = sym_val;
|
---|
| 406 | reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
|
---|
| 407 | break;
|
---|
| 408 | case REL_DTPMOD:
|
---|
| 409 | *reloc_addr = def.dso->tls_id;
|
---|
| 410 | break;
|
---|
| 411 | case REL_DTPOFF:
|
---|
| 412 | *reloc_addr = tls_val + addend - DTP_OFFSET;
|
---|
| 413 | break;
|
---|
| 414 | #ifdef TLS_ABOVE_TP
|
---|
| 415 | case REL_TPOFF:
|
---|
| 416 | *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
|
---|
| 417 | break;
|
---|
| 418 | #else
|
---|
| 419 | case REL_TPOFF:
|
---|
| 420 | *reloc_addr = tls_val - def.dso->tls.offset + addend;
|
---|
| 421 | break;
|
---|
| 422 | case REL_TPOFF_NEG:
|
---|
| 423 | *reloc_addr = def.dso->tls.offset - tls_val + addend;
|
---|
| 424 | break;
|
---|
| 425 | #endif
|
---|
| 426 | case REL_TLSDESC:
|
---|
| 427 | if (stride<3) addend = reloc_addr[1];
|
---|
| 428 | if (runtime && def.dso->tls_id >= static_tls_cnt) {
|
---|
| 429 | struct td_index *new = malloc(sizeof *new);
|
---|
| 430 | if (!new) {
|
---|
| 431 | error(
|
---|
| 432 | "Error relocating %s: cannot allocate TLSDESC for %s",
|
---|
| 433 | dso->name, sym ? name : "(local)" );
|
---|
| 434 | longjmp(*rtld_fail, 1);
|
---|
| 435 | }
|
---|
| 436 | new->next = dso->td_index;
|
---|
| 437 | dso->td_index = new;
|
---|
| 438 | new->args[0] = def.dso->tls_id;
|
---|
| 439 | new->args[1] = tls_val + addend;
|
---|
| 440 | reloc_addr[0] = (size_t)__tlsdesc_dynamic;
|
---|
| 441 | reloc_addr[1] = (size_t)new;
|
---|
| 442 | } else {
|
---|
| 443 | reloc_addr[0] = (size_t)__tlsdesc_static;
|
---|
| 444 | #ifdef TLS_ABOVE_TP
|
---|
| 445 | reloc_addr[1] = tls_val + def.dso->tls.offset
|
---|
| 446 | + TPOFF_K + addend;
|
---|
| 447 | #else
|
---|
| 448 | reloc_addr[1] = tls_val - def.dso->tls.offset
|
---|
| 449 | + addend;
|
---|
| 450 | #endif
|
---|
| 451 | }
|
---|
| 452 | break;
|
---|
| 453 | default:
|
---|
| 454 | error("Error relocating %s: unsupported relocation type %d",
|
---|
| 455 | dso->name, type);
|
---|
| 456 | if (runtime) longjmp(*rtld_fail, 1);
|
---|
| 457 | continue;
|
---|
| 458 | }
|
---|
| 459 | }
|
---|
| 460 | }
|
---|
| 461 |
|
---|
| 462 | static void redo_lazy_relocs()
|
---|
| 463 | {
|
---|
| 464 | struct dso *p = lazy_head, *next;
|
---|
| 465 | lazy_head = 0;
|
---|
| 466 | for (; p; p=next) {
|
---|
| 467 | next = p->lazy_next;
|
---|
| 468 | size_t size = p->lazy_cnt*3*sizeof(size_t);
|
---|
| 469 | p->lazy_cnt = 0;
|
---|
| 470 | do_relocs(p, p->lazy, size, 3);
|
---|
| 471 | if (p->lazy_cnt) {
|
---|
| 472 | p->lazy_next = lazy_head;
|
---|
| 473 | lazy_head = p;
|
---|
| 474 | } else {
|
---|
| 475 | free(p->lazy);
|
---|
| 476 | p->lazy = 0;
|
---|
| 477 | p->lazy_next = 0;
|
---|
| 478 | }
|
---|
| 479 | }
|
---|
| 480 | }
|
---|
| 481 |
|
---|
| 482 | /* A huge hack: to make up for the wastefulness of shared libraries
|
---|
| 483 | * needing at least a page of dirty memory even if they have no global
|
---|
| 484 | * data, we reclaim the gaps at the beginning and end of writable maps
|
---|
| 485 | * and "donate" them to the heap by setting up minimal malloc
|
---|
| 486 | * structures and then freeing them. */
|
---|
| 487 |
|
---|
| 488 | static void reclaim(struct dso *dso, size_t start, size_t end)
|
---|
| 489 | {
|
---|
| 490 | size_t *a, *z;
|
---|
| 491 | if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
|
---|
| 492 | if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
|
---|
| 493 | start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
|
---|
| 494 | end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
|
---|
| 495 | if (start>end || end-start < 4*sizeof(size_t)) return;
|
---|
| 496 | a = laddr(dso, start);
|
---|
| 497 | z = laddr(dso, end);
|
---|
| 498 | a[-2] = 1;
|
---|
| 499 | a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
|
---|
| 500 | z[1] = 1;
|
---|
| 501 | free(a);
|
---|
| 502 | }
|
---|
| 503 |
|
---|
| 504 | static void reclaim_gaps(struct dso *dso)
|
---|
| 505 | {
|
---|
| 506 | Phdr *ph = dso->phdr;
|
---|
| 507 | size_t phcnt = dso->phnum;
|
---|
| 508 |
|
---|
| 509 | if (DL_FDPIC) return; // FIXME
|
---|
| 510 | for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
|
---|
| 511 | if (ph->p_type!=PT_LOAD) continue;
|
---|
| 512 | if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
|
---|
| 513 | reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
|
---|
| 514 | reclaim(dso, ph->p_vaddr+ph->p_memsz,
|
---|
| 515 | ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
|
---|
| 516 | }
|
---|
| 517 | }
|
---|
| 518 |
|
---|
| 519 | static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
|
---|
| 520 | {
|
---|
| 521 | static int no_map_fixed;
|
---|
| 522 | char *q;
|
---|
| 523 | if (!no_map_fixed) {
|
---|
| 524 | q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
|
---|
| 525 | if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
|
---|
| 526 | return q;
|
---|
| 527 | no_map_fixed = 1;
|
---|
| 528 | }
|
---|
| 529 | /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
|
---|
| 530 | if (flags & MAP_ANONYMOUS) {
|
---|
| 531 | memset(p, 0, n);
|
---|
| 532 | return p;
|
---|
| 533 | }
|
---|
| 534 | ssize_t r;
|
---|
| 535 | if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
|
---|
| 536 | for (q=p; n; q+=r, off+=r, n-=r) {
|
---|
| 537 | r = read(fd, q, n);
|
---|
| 538 | if (r < 0 && errno != EINTR) return MAP_FAILED;
|
---|
| 539 | if (!r) {
|
---|
| 540 | memset(q, 0, n);
|
---|
| 541 | break;
|
---|
| 542 | }
|
---|
| 543 | }
|
---|
| 544 | return p;
|
---|
| 545 | }
|
---|
| 546 |
|
---|
| 547 | static void unmap_library(struct dso *dso)
|
---|
| 548 | {
|
---|
| 549 | if (dso->loadmap) {
|
---|
| 550 | size_t i;
|
---|
| 551 | for (i=0; i<dso->loadmap->nsegs; i++) {
|
---|
| 552 | if (!dso->loadmap->segs[i].p_memsz)
|
---|
| 553 | continue;
|
---|
| 554 | munmap((void *)dso->loadmap->segs[i].addr,
|
---|
| 555 | dso->loadmap->segs[i].p_memsz);
|
---|
| 556 | }
|
---|
| 557 | free(dso->loadmap);
|
---|
| 558 | } else if (dso->map && dso->map_len) {
|
---|
| 559 | munmap(dso->map, dso->map_len);
|
---|
| 560 | }
|
---|
| 561 | }
|
---|
| 562 |
|
---|
| 563 | static void *map_library(int fd, struct dso *dso)
|
---|
| 564 | {
|
---|
| 565 | Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
|
---|
| 566 | void *allocated_buf=0;
|
---|
| 567 | size_t phsize;
|
---|
| 568 | size_t addr_min=SIZE_MAX, addr_max=0, map_len;
|
---|
| 569 | size_t this_min, this_max;
|
---|
| 570 | size_t nsegs = 0;
|
---|
| 571 | off_t off_start;
|
---|
| 572 | Ehdr *eh;
|
---|
| 573 | Phdr *ph, *ph0;
|
---|
| 574 | unsigned prot;
|
---|
| 575 | unsigned char *map=MAP_FAILED, *base;
|
---|
| 576 | size_t dyn=0;
|
---|
| 577 | size_t tls_image=0;
|
---|
| 578 | size_t i;
|
---|
| 579 |
|
---|
| 580 | ssize_t l = read(fd, buf, sizeof buf);
|
---|
| 581 | eh = buf;
|
---|
| 582 | if (l<0) return 0;
|
---|
| 583 | if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
|
---|
| 584 | goto noexec;
|
---|
| 585 | phsize = eh->e_phentsize * eh->e_phnum;
|
---|
| 586 | if (phsize > sizeof buf - sizeof *eh) {
|
---|
| 587 | allocated_buf = malloc(phsize);
|
---|
| 588 | if (!allocated_buf) return 0;
|
---|
| 589 | l = pread(fd, allocated_buf, phsize, eh->e_phoff);
|
---|
| 590 | if (l < 0) goto error;
|
---|
| 591 | if (l != phsize) goto noexec;
|
---|
| 592 | ph = ph0 = allocated_buf;
|
---|
| 593 | } else if (eh->e_phoff + phsize > l) {
|
---|
| 594 | l = pread(fd, buf+1, phsize, eh->e_phoff);
|
---|
| 595 | if (l < 0) goto error;
|
---|
| 596 | if (l != phsize) goto noexec;
|
---|
| 597 | ph = ph0 = (void *)(buf + 1);
|
---|
| 598 | } else {
|
---|
| 599 | ph = ph0 = (void *)((char *)buf + eh->e_phoff);
|
---|
| 600 | }
|
---|
| 601 | for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
|
---|
| 602 | if (ph->p_type == PT_DYNAMIC) {
|
---|
| 603 | dyn = ph->p_vaddr;
|
---|
| 604 | } else if (ph->p_type == PT_TLS) {
|
---|
| 605 | tls_image = ph->p_vaddr;
|
---|
| 606 | dso->tls.align = ph->p_align;
|
---|
| 607 | dso->tls.len = ph->p_filesz;
|
---|
| 608 | dso->tls.size = ph->p_memsz;
|
---|
| 609 | } else if (ph->p_type == PT_GNU_RELRO) {
|
---|
| 610 | dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
|
---|
| 611 | dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
|
---|
| 612 | }
|
---|
| 613 | if (ph->p_type != PT_LOAD) continue;
|
---|
| 614 | nsegs++;
|
---|
| 615 | if (ph->p_vaddr < addr_min) {
|
---|
| 616 | addr_min = ph->p_vaddr;
|
---|
| 617 | off_start = ph->p_offset;
|
---|
| 618 | prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
|
---|
| 619 | ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
|
---|
| 620 | ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
|
---|
| 621 | }
|
---|
| 622 | if (ph->p_vaddr+ph->p_memsz > addr_max) {
|
---|
| 623 | addr_max = ph->p_vaddr+ph->p_memsz;
|
---|
| 624 | }
|
---|
| 625 | }
|
---|
| 626 | if (!dyn) goto noexec;
|
---|
| 627 | if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
|
---|
| 628 | dso->loadmap = calloc(1, sizeof *dso->loadmap
|
---|
| 629 | + nsegs * sizeof *dso->loadmap->segs);
|
---|
| 630 | if (!dso->loadmap) goto error;
|
---|
| 631 | dso->loadmap->nsegs = nsegs;
|
---|
| 632 | for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
|
---|
| 633 | if (ph->p_type != PT_LOAD) continue;
|
---|
| 634 | prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
|
---|
| 635 | ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
|
---|
| 636 | ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
|
---|
| 637 | map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
|
---|
| 638 | prot, MAP_PRIVATE,
|
---|
| 639 | fd, ph->p_offset & -PAGE_SIZE);
|
---|
| 640 | if (map == MAP_FAILED) {
|
---|
| 641 | unmap_library(dso);
|
---|
| 642 | goto error;
|
---|
| 643 | }
|
---|
| 644 | dso->loadmap->segs[i].addr = (size_t)map +
|
---|
| 645 | (ph->p_vaddr & PAGE_SIZE-1);
|
---|
| 646 | dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
|
---|
| 647 | dso->loadmap->segs[i].p_memsz = ph->p_memsz;
|
---|
| 648 | i++;
|
---|
| 649 | if (prot & PROT_WRITE) {
|
---|
| 650 | size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
|
---|
| 651 | + ph->p_filesz;
|
---|
| 652 | size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
| 653 | size_t pgend = brk + ph->p_memsz - ph->p_filesz
|
---|
| 654 | + PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
| 655 | if (pgend > pgbrk && mmap_fixed(map+pgbrk,
|
---|
| 656 | pgend-pgbrk, prot,
|
---|
| 657 | MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
|
---|
| 658 | -1, off_start) == MAP_FAILED)
|
---|
| 659 | goto error;
|
---|
| 660 | memset(map + brk, 0, pgbrk-brk);
|
---|
| 661 | }
|
---|
| 662 | }
|
---|
| 663 | map = (void *)dso->loadmap->segs[0].addr;
|
---|
| 664 | map_len = 0;
|
---|
| 665 | goto done_mapping;
|
---|
| 666 | }
|
---|
| 667 | addr_max += PAGE_SIZE-1;
|
---|
| 668 | addr_max &= -PAGE_SIZE;
|
---|
| 669 | addr_min &= -PAGE_SIZE;
|
---|
| 670 | off_start &= -PAGE_SIZE;
|
---|
| 671 | map_len = addr_max - addr_min + off_start;
|
---|
| 672 | /* The first time, we map too much, possibly even more than
|
---|
| 673 | * the length of the file. This is okay because we will not
|
---|
| 674 | * use the invalid part; we just need to reserve the right
|
---|
| 675 | * amount of virtual address space to map over later. */
|
---|
| 676 | map = DL_NOMMU_SUPPORT
|
---|
| 677 | ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
|
---|
| 678 | MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
|
---|
| 679 | : mmap((void *)addr_min, map_len, prot,
|
---|
| 680 | MAP_PRIVATE, fd, off_start);
|
---|
| 681 | if (map==MAP_FAILED) goto error;
|
---|
| 682 | dso->map = map;
|
---|
| 683 | dso->map_len = map_len;
|
---|
| 684 | /* If the loaded file is not relocatable and the requested address is
|
---|
| 685 | * not available, then the load operation must fail. */
|
---|
| 686 | if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
|
---|
| 687 | errno = EBUSY;
|
---|
| 688 | goto error;
|
---|
| 689 | }
|
---|
| 690 | base = map - addr_min;
|
---|
| 691 | dso->phdr = 0;
|
---|
| 692 | dso->phnum = 0;
|
---|
| 693 | for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
|
---|
| 694 | if (ph->p_type != PT_LOAD) continue;
|
---|
| 695 | /* Check if the programs headers are in this load segment, and
|
---|
| 696 | * if so, record the address for use by dl_iterate_phdr. */
|
---|
| 697 | if (!dso->phdr && eh->e_phoff >= ph->p_offset
|
---|
| 698 | && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
|
---|
| 699 | dso->phdr = (void *)(base + ph->p_vaddr
|
---|
| 700 | + (eh->e_phoff-ph->p_offset));
|
---|
| 701 | dso->phnum = eh->e_phnum;
|
---|
| 702 | dso->phentsize = eh->e_phentsize;
|
---|
| 703 | }
|
---|
| 704 | /* Reuse the existing mapping for the lowest-address LOAD */
|
---|
| 705 | if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
|
---|
| 706 | continue;
|
---|
| 707 | this_min = ph->p_vaddr & -PAGE_SIZE;
|
---|
| 708 | this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
| 709 | off_start = ph->p_offset & -PAGE_SIZE;
|
---|
| 710 | prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
|
---|
| 711 | ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
|
---|
| 712 | ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
|
---|
| 713 | if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
|
---|
| 714 | goto error;
|
---|
| 715 | if (ph->p_memsz > ph->p_filesz) {
|
---|
| 716 | size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
|
---|
| 717 | size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
| 718 | memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
|
---|
| 719 | if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
|
---|
| 720 | goto error;
|
---|
| 721 | }
|
---|
| 722 | }
|
---|
| 723 | for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
|
---|
| 724 | if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
|
---|
| 725 | if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
|
---|
| 726 | && errno != ENOSYS)
|
---|
| 727 | goto error;
|
---|
| 728 | break;
|
---|
| 729 | }
|
---|
| 730 | done_mapping:
|
---|
| 731 | dso->base = base;
|
---|
| 732 | dso->dynv = laddr(dso, dyn);
|
---|
| 733 | if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
|
---|
| 734 | if (!runtime) reclaim_gaps(dso);
|
---|
| 735 | free(allocated_buf);
|
---|
| 736 | return map;
|
---|
| 737 | noexec:
|
---|
| 738 | errno = ENOEXEC;
|
---|
| 739 | error:
|
---|
| 740 | if (map!=MAP_FAILED) unmap_library(dso);
|
---|
| 741 | free(allocated_buf);
|
---|
| 742 | return 0;
|
---|
| 743 | }
|
---|
| 744 |
|
---|
| 745 | static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
|
---|
| 746 | {
|
---|
| 747 | size_t l;
|
---|
| 748 | int fd;
|
---|
| 749 | for (;;) {
|
---|
| 750 | s += strspn(s, ":\n");
|
---|
| 751 | l = strcspn(s, ":\n");
|
---|
| 752 | if (l-1 >= INT_MAX) return -1;
|
---|
| 753 | if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
|
---|
| 754 | if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
|
---|
| 755 | switch (errno) {
|
---|
| 756 | case ENOENT:
|
---|
| 757 | case ENOTDIR:
|
---|
| 758 | case EACCES:
|
---|
| 759 | case ENAMETOOLONG:
|
---|
| 760 | break;
|
---|
| 761 | default:
|
---|
| 762 | /* Any negative value but -1 will inhibit
|
---|
| 763 | * futher path search. */
|
---|
| 764 | return -2;
|
---|
| 765 | }
|
---|
| 766 | }
|
---|
| 767 | s += l;
|
---|
| 768 | }
|
---|
| 769 | }
|
---|
| 770 |
|
---|
| 771 | static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
|
---|
| 772 | {
|
---|
| 773 | size_t n, l;
|
---|
| 774 | const char *s, *t, *origin;
|
---|
| 775 | char *d;
|
---|
| 776 | if (p->rpath || !p->rpath_orig) return 0;
|
---|
| 777 | if (!strchr(p->rpath_orig, '$')) {
|
---|
| 778 | p->rpath = p->rpath_orig;
|
---|
| 779 | return 0;
|
---|
| 780 | }
|
---|
| 781 | n = 0;
|
---|
| 782 | s = p->rpath_orig;
|
---|
| 783 | while ((t=strchr(s, '$'))) {
|
---|
| 784 | if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
|
---|
| 785 | return 0;
|
---|
| 786 | s = t+1;
|
---|
| 787 | n++;
|
---|
| 788 | }
|
---|
| 789 | if (n > SSIZE_MAX/PATH_MAX) return 0;
|
---|
| 790 |
|
---|
| 791 | if (p->kernel_mapped) {
|
---|
| 792 | /* $ORIGIN searches cannot be performed for the main program
|
---|
| 793 | * when it is suid/sgid/AT_SECURE. This is because the
|
---|
| 794 | * pathname is under the control of the caller of execve.
|
---|
| 795 | * For libraries, however, $ORIGIN can be processed safely
|
---|
| 796 | * since the library's pathname came from a trusted source
|
---|
| 797 | * (either system paths or a call to dlopen). */
|
---|
| 798 | if (libc.secure)
|
---|
| 799 | return 0;
|
---|
| 800 | l = readlink("/proc/self/exe", buf, buf_size);
|
---|
| 801 | if (l == -1) switch (errno) {
|
---|
| 802 | case ENOENT:
|
---|
| 803 | case ENOTDIR:
|
---|
| 804 | case EACCES:
|
---|
| 805 | break;
|
---|
| 806 | default:
|
---|
| 807 | return -1;
|
---|
| 808 | }
|
---|
| 809 | if (l >= buf_size)
|
---|
| 810 | return 0;
|
---|
| 811 | buf[l] = 0;
|
---|
| 812 | origin = buf;
|
---|
| 813 | } else {
|
---|
| 814 | origin = p->name;
|
---|
| 815 | }
|
---|
| 816 | t = strrchr(origin, '/');
|
---|
| 817 | l = t ? t-origin : 0;
|
---|
| 818 | p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
|
---|
| 819 | if (!p->rpath) return -1;
|
---|
| 820 |
|
---|
| 821 | d = p->rpath;
|
---|
| 822 | s = p->rpath_orig;
|
---|
| 823 | while ((t=strchr(s, '$'))) {
|
---|
| 824 | memcpy(d, s, t-s);
|
---|
| 825 | d += t-s;
|
---|
| 826 | memcpy(d, origin, l);
|
---|
| 827 | d += l;
|
---|
| 828 | /* It was determined previously that the '$' is followed
|
---|
| 829 | * either by "ORIGIN" or "{ORIGIN}". */
|
---|
| 830 | s = t + 7 + 2*(t[1]=='{');
|
---|
| 831 | }
|
---|
| 832 | strcpy(d, s);
|
---|
| 833 | return 0;
|
---|
| 834 | }
|
---|
| 835 |
|
---|
| 836 | static void decode_dyn(struct dso *p)
|
---|
| 837 | {
|
---|
| 838 | size_t dyn[DYN_CNT];
|
---|
| 839 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
| 840 | p->syms = laddr(p, dyn[DT_SYMTAB]);
|
---|
| 841 | p->strings = laddr(p, dyn[DT_STRTAB]);
|
---|
| 842 | if (dyn[0]&(1<<DT_HASH))
|
---|
| 843 | p->hashtab = laddr(p, dyn[DT_HASH]);
|
---|
| 844 | if (dyn[0]&(1<<DT_RPATH))
|
---|
| 845 | p->rpath_orig = p->strings + dyn[DT_RPATH];
|
---|
| 846 | if (dyn[0]&(1<<DT_RUNPATH))
|
---|
| 847 | p->rpath_orig = p->strings + dyn[DT_RUNPATH];
|
---|
| 848 | if (dyn[0]&(1<<DT_PLTGOT))
|
---|
| 849 | p->got = laddr(p, dyn[DT_PLTGOT]);
|
---|
| 850 | if (search_vec(p->dynv, dyn, DT_GNU_HASH))
|
---|
| 851 | p->ghashtab = laddr(p, *dyn);
|
---|
| 852 | if (search_vec(p->dynv, dyn, DT_VERSYM))
|
---|
| 853 | p->versym = laddr(p, *dyn);
|
---|
| 854 | }
|
---|
| 855 |
|
---|
| 856 | static size_t count_syms(struct dso *p)
|
---|
| 857 | {
|
---|
| 858 | if (p->hashtab) return p->hashtab[1];
|
---|
| 859 |
|
---|
| 860 | size_t nsym, i;
|
---|
| 861 | uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
|
---|
| 862 | uint32_t *hashval;
|
---|
| 863 | for (i = nsym = 0; i < p->ghashtab[0]; i++) {
|
---|
| 864 | if (buckets[i] > nsym)
|
---|
| 865 | nsym = buckets[i];
|
---|
| 866 | }
|
---|
| 867 | if (nsym) {
|
---|
| 868 | hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
|
---|
| 869 | do nsym++;
|
---|
| 870 | while (!(*hashval++ & 1));
|
---|
| 871 | }
|
---|
| 872 | return nsym;
|
---|
| 873 | }
|
---|
| 874 |
|
---|
| 875 | static void *dl_mmap(size_t n)
|
---|
| 876 | {
|
---|
| 877 | void *p;
|
---|
| 878 | int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
|
---|
| 879 | #ifdef SYS_mmap2
|
---|
| 880 | p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
|
---|
| 881 | #else
|
---|
| 882 | p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
|
---|
| 883 | #endif
|
---|
| 884 | return p == MAP_FAILED ? 0 : p;
|
---|
| 885 | }
|
---|
| 886 |
|
---|
| 887 | static void makefuncdescs(struct dso *p)
|
---|
| 888 | {
|
---|
| 889 | static int self_done;
|
---|
| 890 | size_t nsym = count_syms(p);
|
---|
| 891 | size_t i, size = nsym * sizeof(*p->funcdescs);
|
---|
| 892 |
|
---|
| 893 | if (!self_done) {
|
---|
| 894 | p->funcdescs = dl_mmap(size);
|
---|
| 895 | self_done = 1;
|
---|
| 896 | } else {
|
---|
| 897 | p->funcdescs = malloc(size);
|
---|
| 898 | }
|
---|
| 899 | if (!p->funcdescs) {
|
---|
| 900 | if (!runtime) a_crash();
|
---|
| 901 | error("Error allocating function descriptors for %s", p->name);
|
---|
| 902 | longjmp(*rtld_fail, 1);
|
---|
| 903 | }
|
---|
| 904 | for (i=0; i<nsym; i++) {
|
---|
| 905 | if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
|
---|
| 906 | p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
|
---|
| 907 | p->funcdescs[i].got = p->got;
|
---|
| 908 | } else {
|
---|
| 909 | p->funcdescs[i].addr = 0;
|
---|
| 910 | p->funcdescs[i].got = 0;
|
---|
| 911 | }
|
---|
| 912 | }
|
---|
| 913 | }
|
---|
| 914 |
|
---|
| 915 | static struct dso *load_library(const char *name, struct dso *needed_by)
|
---|
| 916 | {
|
---|
| 917 | char buf[2*NAME_MAX+2];
|
---|
| 918 | const char *pathname;
|
---|
| 919 | unsigned char *map;
|
---|
| 920 | struct dso *p, temp_dso = {0};
|
---|
| 921 | int fd;
|
---|
| 922 | struct stat st;
|
---|
| 923 | size_t alloc_size;
|
---|
| 924 | int n_th = 0;
|
---|
| 925 | int is_self = 0;
|
---|
| 926 |
|
---|
| 927 | if (!*name) {
|
---|
| 928 | errno = EINVAL;
|
---|
| 929 | return 0;
|
---|
| 930 | }
|
---|
| 931 |
|
---|
| 932 | /* Catch and block attempts to reload the implementation itself */
|
---|
| 933 | if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
|
---|
| 934 | static const char reserved[] =
|
---|
| 935 | "c.pthread.rt.m.dl.util.xnet.";
|
---|
| 936 | const char *rp, *next;
|
---|
| 937 | for (rp=reserved; *rp; rp=next) {
|
---|
| 938 | next = strchr(rp, '.') + 1;
|
---|
| 939 | if (strncmp(name+3, rp, next-rp) == 0)
|
---|
| 940 | break;
|
---|
| 941 | }
|
---|
| 942 | if (*rp) {
|
---|
| 943 | if (ldd_mode) {
|
---|
| 944 | /* Track which names have been resolved
|
---|
| 945 | * and only report each one once. */
|
---|
| 946 | static unsigned reported;
|
---|
| 947 | unsigned mask = 1U<<(rp-reserved);
|
---|
| 948 | if (!(reported & mask)) {
|
---|
| 949 | reported |= mask;
|
---|
| 950 | dprintf(1, "\t%s => %s (%p)\n",
|
---|
| 951 | name, ldso.name,
|
---|
| 952 | ldso.base);
|
---|
| 953 | }
|
---|
| 954 | }
|
---|
| 955 | is_self = 1;
|
---|
| 956 | }
|
---|
| 957 | }
|
---|
| 958 | if (!strcmp(name, ldso.name)) is_self = 1;
|
---|
| 959 | if (is_self) {
|
---|
| 960 | if (!ldso.prev) {
|
---|
| 961 | tail->next = &ldso;
|
---|
| 962 | ldso.prev = tail;
|
---|
| 963 | tail = &ldso;
|
---|
| 964 | }
|
---|
| 965 | return &ldso;
|
---|
| 966 | }
|
---|
| 967 | if (strchr(name, '/')) {
|
---|
| 968 | pathname = name;
|
---|
| 969 | fd = open(name, O_RDONLY|O_CLOEXEC);
|
---|
| 970 | } else {
|
---|
| 971 | /* Search for the name to see if it's already loaded */
|
---|
| 972 | for (p=head->next; p; p=p->next) {
|
---|
| 973 | if (p->shortname && !strcmp(p->shortname, name)) {
|
---|
| 974 | return p;
|
---|
| 975 | }
|
---|
| 976 | }
|
---|
| 977 | if (strlen(name) > NAME_MAX) return 0;
|
---|
| 978 | fd = -1;
|
---|
| 979 | if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
|
---|
| 980 | for (p=needed_by; fd == -1 && p; p=p->needed_by) {
|
---|
| 981 | if (fixup_rpath(p, buf, sizeof buf) < 0)
|
---|
| 982 | fd = -2; /* Inhibit further search. */
|
---|
| 983 | if (p->rpath)
|
---|
| 984 | fd = path_open(name, p->rpath, buf, sizeof buf);
|
---|
| 985 | }
|
---|
| 986 | if (fd == -1) {
|
---|
| 987 | if (!sys_path) {
|
---|
| 988 | char *prefix = 0;
|
---|
| 989 | size_t prefix_len;
|
---|
| 990 | if (ldso.name[0]=='/') {
|
---|
| 991 | char *s, *t, *z;
|
---|
| 992 | for (s=t=z=ldso.name; *s; s++)
|
---|
| 993 | if (*s=='/') z=t, t=s;
|
---|
| 994 | prefix_len = z-ldso.name;
|
---|
| 995 | if (prefix_len < PATH_MAX)
|
---|
| 996 | prefix = ldso.name;
|
---|
| 997 | }
|
---|
| 998 | if (!prefix) {
|
---|
| 999 | prefix = "";
|
---|
| 1000 | prefix_len = 0;
|
---|
| 1001 | }
|
---|
| 1002 | char etc_ldso_path[prefix_len + 1
|
---|
| 1003 | + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
|
---|
| 1004 | snprintf(etc_ldso_path, sizeof etc_ldso_path,
|
---|
| 1005 | "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
|
---|
| 1006 | (int)prefix_len, prefix);
|
---|
| 1007 | FILE *f = fopen(etc_ldso_path, "rbe");
|
---|
| 1008 | if (f) {
|
---|
| 1009 | if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
|
---|
| 1010 | free(sys_path);
|
---|
| 1011 | sys_path = "";
|
---|
| 1012 | }
|
---|
| 1013 | fclose(f);
|
---|
| 1014 | } else if (errno != ENOENT) {
|
---|
| 1015 | sys_path = "";
|
---|
| 1016 | }
|
---|
| 1017 | }
|
---|
| 1018 | if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
|
---|
| 1019 | fd = path_open(name, sys_path, buf, sizeof buf);
|
---|
| 1020 | }
|
---|
| 1021 | pathname = buf;
|
---|
| 1022 | }
|
---|
| 1023 | if (fd < 0) return 0;
|
---|
| 1024 | if (fstat(fd, &st) < 0) {
|
---|
| 1025 | close(fd);
|
---|
| 1026 | return 0;
|
---|
| 1027 | }
|
---|
| 1028 | for (p=head->next; p; p=p->next) {
|
---|
| 1029 | if (p->dev == st.st_dev && p->ino == st.st_ino) {
|
---|
| 1030 | /* If this library was previously loaded with a
|
---|
| 1031 | * pathname but a search found the same inode,
|
---|
| 1032 | * setup its shortname so it can be found by name. */
|
---|
| 1033 | if (!p->shortname && pathname != name)
|
---|
| 1034 | p->shortname = strrchr(p->name, '/')+1;
|
---|
| 1035 | close(fd);
|
---|
| 1036 | return p;
|
---|
| 1037 | }
|
---|
| 1038 | }
|
---|
| 1039 | map = noload ? 0 : map_library(fd, &temp_dso);
|
---|
| 1040 | close(fd);
|
---|
| 1041 | if (!map) return 0;
|
---|
| 1042 |
|
---|
| 1043 | /* Avoid the danger of getting two versions of libc mapped into the
|
---|
| 1044 | * same process when an absolute pathname was used. The symbols
|
---|
| 1045 | * checked are chosen to catch both musl and glibc, and to avoid
|
---|
| 1046 | * false positives from interposition-hack libraries. */
|
---|
| 1047 | decode_dyn(&temp_dso);
|
---|
| 1048 | if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
|
---|
| 1049 | find_sym(&temp_dso, "stdin", 1).sym) {
|
---|
| 1050 | unmap_library(&temp_dso);
|
---|
| 1051 | return load_library("libc.so", needed_by);
|
---|
| 1052 | }
|
---|
| 1053 |
|
---|
| 1054 | /* Allocate storage for the new DSO. When there is TLS, this
|
---|
| 1055 | * storage must include a reservation for all pre-existing
|
---|
| 1056 | * threads to obtain copies of both the new TLS, and an
|
---|
| 1057 | * extended DTV capable of storing an additional slot for
|
---|
| 1058 | * the newly-loaded DSO. */
|
---|
| 1059 | alloc_size = sizeof *p + strlen(pathname) + 1;
|
---|
| 1060 | if (runtime && temp_dso.tls.image) {
|
---|
| 1061 | size_t per_th = temp_dso.tls.size + temp_dso.tls.align
|
---|
| 1062 | + sizeof(void *) * (tls_cnt+3);
|
---|
| 1063 | n_th = libc.threads_minus_1 + 1;
|
---|
| 1064 | if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
|
---|
| 1065 | else alloc_size += n_th * per_th;
|
---|
| 1066 | }
|
---|
| 1067 | p = calloc(1, alloc_size);
|
---|
| 1068 | if (!p) {
|
---|
| 1069 | unmap_library(&temp_dso);
|
---|
| 1070 | return 0;
|
---|
| 1071 | }
|
---|
| 1072 | memcpy(p, &temp_dso, sizeof temp_dso);
|
---|
| 1073 | p->dev = st.st_dev;
|
---|
| 1074 | p->ino = st.st_ino;
|
---|
| 1075 | p->needed_by = needed_by;
|
---|
| 1076 | p->name = p->buf;
|
---|
| 1077 | strcpy(p->name, pathname);
|
---|
| 1078 | /* Add a shortname only if name arg was not an explicit pathname. */
|
---|
| 1079 | if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
|
---|
| 1080 | if (p->tls.image) {
|
---|
| 1081 | p->tls_id = ++tls_cnt;
|
---|
| 1082 | tls_align = MAXP2(tls_align, p->tls.align);
|
---|
| 1083 | #ifdef TLS_ABOVE_TP
|
---|
| 1084 | p->tls.offset = tls_offset + ( (tls_align-1) &
|
---|
| 1085 | -(tls_offset + (uintptr_t)p->tls.image) );
|
---|
| 1086 | tls_offset += p->tls.size;
|
---|
| 1087 | #else
|
---|
| 1088 | tls_offset += p->tls.size + p->tls.align - 1;
|
---|
| 1089 | tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
|
---|
| 1090 | & (p->tls.align-1);
|
---|
| 1091 | p->tls.offset = tls_offset;
|
---|
| 1092 | #endif
|
---|
| 1093 | p->new_dtv = (void *)(-sizeof(size_t) &
|
---|
| 1094 | (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
|
---|
| 1095 | p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
|
---|
| 1096 | if (tls_tail) tls_tail->next = &p->tls;
|
---|
| 1097 | else libc.tls_head = &p->tls;
|
---|
| 1098 | tls_tail = &p->tls;
|
---|
| 1099 | }
|
---|
| 1100 |
|
---|
| 1101 | tail->next = p;
|
---|
| 1102 | p->prev = tail;
|
---|
| 1103 | tail = p;
|
---|
| 1104 |
|
---|
| 1105 | if (DL_FDPIC) makefuncdescs(p);
|
---|
| 1106 |
|
---|
| 1107 | if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
|
---|
| 1108 |
|
---|
| 1109 | return p;
|
---|
| 1110 | }
|
---|
| 1111 |
|
---|
| 1112 | static void load_deps(struct dso *p)
|
---|
| 1113 | {
|
---|
| 1114 | size_t i, ndeps=0;
|
---|
| 1115 | struct dso ***deps = &p->deps, **tmp, *dep;
|
---|
| 1116 | for (; p; p=p->next) {
|
---|
| 1117 | for (i=0; p->dynv[i]; i+=2) {
|
---|
| 1118 | if (p->dynv[i] != DT_NEEDED) continue;
|
---|
| 1119 | dep = load_library(p->strings + p->dynv[i+1], p);
|
---|
| 1120 | if (!dep) {
|
---|
| 1121 | error("Error loading shared library %s: %m (needed by %s)",
|
---|
| 1122 | p->strings + p->dynv[i+1], p->name);
|
---|
| 1123 | if (runtime) longjmp(*rtld_fail, 1);
|
---|
| 1124 | continue;
|
---|
| 1125 | }
|
---|
| 1126 | if (runtime) {
|
---|
| 1127 | tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
|
---|
| 1128 | if (!tmp) longjmp(*rtld_fail, 1);
|
---|
| 1129 | tmp[ndeps++] = dep;
|
---|
| 1130 | tmp[ndeps] = 0;
|
---|
| 1131 | *deps = tmp;
|
---|
| 1132 | }
|
---|
| 1133 | }
|
---|
| 1134 | }
|
---|
| 1135 | if (!*deps) *deps = (struct dso **)&nodeps_dummy;
|
---|
| 1136 | }
|
---|
| 1137 |
|
---|
| 1138 | static void load_preload(char *s)
|
---|
| 1139 | {
|
---|
| 1140 | int tmp;
|
---|
| 1141 | char *z;
|
---|
| 1142 | for (z=s; *z; s=z) {
|
---|
| 1143 | for ( ; *s && (isspace(*s) || *s==':'); s++);
|
---|
| 1144 | for (z=s; *z && !isspace(*z) && *z!=':'; z++);
|
---|
| 1145 | tmp = *z;
|
---|
| 1146 | *z = 0;
|
---|
| 1147 | load_library(s, 0);
|
---|
| 1148 | *z = tmp;
|
---|
| 1149 | }
|
---|
| 1150 | }
|
---|
| 1151 |
|
---|
| 1152 | static void add_syms(struct dso *p)
|
---|
| 1153 | {
|
---|
| 1154 | if (!p->syms_next && syms_tail != p) {
|
---|
| 1155 | syms_tail->syms_next = p;
|
---|
| 1156 | syms_tail = p;
|
---|
| 1157 | }
|
---|
| 1158 | }
|
---|
| 1159 |
|
---|
| 1160 | static void revert_syms(struct dso *old_tail)
|
---|
| 1161 | {
|
---|
| 1162 | struct dso *p, *next;
|
---|
| 1163 | /* Chop off the tail of the list of dsos that participate in
|
---|
| 1164 | * the global symbol table, reverting them to RTLD_LOCAL. */
|
---|
| 1165 | for (p=old_tail; p; p=next) {
|
---|
| 1166 | next = p->syms_next;
|
---|
| 1167 | p->syms_next = 0;
|
---|
| 1168 | }
|
---|
| 1169 | syms_tail = old_tail;
|
---|
| 1170 | }
|
---|
| 1171 |
|
---|
| 1172 | static void do_mips_relocs(struct dso *p, size_t *got)
|
---|
| 1173 | {
|
---|
| 1174 | size_t i, j, rel[2];
|
---|
| 1175 | unsigned char *base = p->base;
|
---|
| 1176 | i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
|
---|
| 1177 | if (p==&ldso) {
|
---|
| 1178 | got += i;
|
---|
| 1179 | } else {
|
---|
| 1180 | while (i--) *got++ += (size_t)base;
|
---|
| 1181 | }
|
---|
| 1182 | j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
|
---|
| 1183 | i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
|
---|
| 1184 | Sym *sym = p->syms + j;
|
---|
| 1185 | rel[0] = (unsigned char *)got - base;
|
---|
| 1186 | for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
|
---|
| 1187 | rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
|
---|
| 1188 | do_relocs(p, rel, sizeof rel, 2);
|
---|
| 1189 | }
|
---|
| 1190 | }
|
---|
| 1191 |
|
---|
| 1192 | static void reloc_all(struct dso *p)
|
---|
| 1193 | {
|
---|
| 1194 | size_t dyn[DYN_CNT];
|
---|
| 1195 | for (; p; p=p->next) {
|
---|
| 1196 | if (p->relocated) continue;
|
---|
| 1197 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
| 1198 | if (NEED_MIPS_GOT_RELOCS)
|
---|
| 1199 | do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
|
---|
| 1200 | do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
|
---|
| 1201 | 2+(dyn[DT_PLTREL]==DT_RELA));
|
---|
| 1202 | do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
|
---|
| 1203 | do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
|
---|
| 1204 |
|
---|
| 1205 | if (head != &ldso && p->relro_start != p->relro_end &&
|
---|
| 1206 | mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
|
---|
| 1207 | && errno != ENOSYS) {
|
---|
| 1208 | error("Error relocating %s: RELRO protection failed: %m",
|
---|
| 1209 | p->name);
|
---|
| 1210 | if (runtime) longjmp(*rtld_fail, 1);
|
---|
| 1211 | }
|
---|
| 1212 |
|
---|
| 1213 | p->relocated = 1;
|
---|
| 1214 | }
|
---|
| 1215 | }
|
---|
| 1216 |
|
---|
| 1217 | static void kernel_mapped_dso(struct dso *p)
|
---|
| 1218 | {
|
---|
| 1219 | size_t min_addr = -1, max_addr = 0, cnt;
|
---|
| 1220 | Phdr *ph = p->phdr;
|
---|
| 1221 | for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
|
---|
| 1222 | if (ph->p_type == PT_DYNAMIC) {
|
---|
| 1223 | p->dynv = laddr(p, ph->p_vaddr);
|
---|
| 1224 | } else if (ph->p_type == PT_GNU_RELRO) {
|
---|
| 1225 | p->relro_start = ph->p_vaddr & -PAGE_SIZE;
|
---|
| 1226 | p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
|
---|
| 1227 | }
|
---|
| 1228 | if (ph->p_type != PT_LOAD) continue;
|
---|
| 1229 | if (ph->p_vaddr < min_addr)
|
---|
| 1230 | min_addr = ph->p_vaddr;
|
---|
| 1231 | if (ph->p_vaddr+ph->p_memsz > max_addr)
|
---|
| 1232 | max_addr = ph->p_vaddr+ph->p_memsz;
|
---|
| 1233 | }
|
---|
| 1234 | min_addr &= -PAGE_SIZE;
|
---|
| 1235 | max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
|
---|
| 1236 | p->map = p->base + min_addr;
|
---|
| 1237 | p->map_len = max_addr - min_addr;
|
---|
| 1238 | p->kernel_mapped = 1;
|
---|
| 1239 | }
|
---|
| 1240 |
|
---|
| 1241 | void __libc_exit_fini()
|
---|
| 1242 | {
|
---|
| 1243 | struct dso *p;
|
---|
| 1244 | size_t dyn[DYN_CNT];
|
---|
| 1245 | for (p=fini_head; p; p=p->fini_next) {
|
---|
| 1246 | if (!p->constructed) continue;
|
---|
| 1247 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
| 1248 | if (dyn[0] & (1<<DT_FINI_ARRAY)) {
|
---|
| 1249 | size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
|
---|
| 1250 | size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
|
---|
| 1251 | while (n--) ((void (*)(void))*--fn)();
|
---|
| 1252 | }
|
---|
| 1253 | #ifndef NO_LEGACY_INITFINI
|
---|
| 1254 | if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
|
---|
| 1255 | fpaddr(p, dyn[DT_FINI])();
|
---|
| 1256 | #endif
|
---|
| 1257 | }
|
---|
| 1258 | }
|
---|
| 1259 |
|
---|
| 1260 | static void do_init_fini(struct dso *p)
|
---|
| 1261 | {
|
---|
| 1262 | size_t dyn[DYN_CNT];
|
---|
| 1263 | int need_locking = libc.threads_minus_1;
|
---|
| 1264 | /* Allow recursive calls that arise when a library calls
|
---|
| 1265 | * dlopen from one of its constructors, but block any
|
---|
| 1266 | * other threads until all ctors have finished. */
|
---|
| 1267 | if (need_locking) pthread_mutex_lock(&init_fini_lock);
|
---|
| 1268 | for (; p; p=p->prev) {
|
---|
| 1269 | if (p->constructed) continue;
|
---|
| 1270 | p->constructed = 1;
|
---|
| 1271 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
| 1272 | if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
|
---|
| 1273 | p->fini_next = fini_head;
|
---|
| 1274 | fini_head = p;
|
---|
| 1275 | }
|
---|
| 1276 | #ifndef NO_LEGACY_INITFINI
|
---|
| 1277 | if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
|
---|
| 1278 | fpaddr(p, dyn[DT_INIT])();
|
---|
| 1279 | #endif
|
---|
| 1280 | if (dyn[0] & (1<<DT_INIT_ARRAY)) {
|
---|
| 1281 | size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
|
---|
| 1282 | size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
|
---|
| 1283 | while (n--) ((void (*)(void))*fn++)();
|
---|
| 1284 | }
|
---|
| 1285 | if (!need_locking && libc.threads_minus_1) {
|
---|
| 1286 | need_locking = 1;
|
---|
| 1287 | pthread_mutex_lock(&init_fini_lock);
|
---|
| 1288 | }
|
---|
| 1289 | }
|
---|
| 1290 | if (need_locking) pthread_mutex_unlock(&init_fini_lock);
|
---|
| 1291 | }
|
---|
| 1292 |
|
---|
| 1293 | #ifndef __c2__
|
---|
| 1294 | void __libc_start_init(void)
|
---|
| 1295 | {
|
---|
| 1296 | do_init_fini(tail);
|
---|
| 1297 | }
|
---|
| 1298 | #endif
|
---|
| 1299 |
|
---|
| 1300 | static void dl_debug_state(void)
|
---|
| 1301 | {
|
---|
| 1302 | }
|
---|
| 1303 |
|
---|
| 1304 | #ifndef __c2__
|
---|
| 1305 | weak_alias(dl_debug_state, _dl_debug_state);
|
---|
| 1306 |
|
---|
| 1307 | void __init_tls(size_t *auxv)
|
---|
| 1308 | {
|
---|
| 1309 | }
|
---|
| 1310 | #else
|
---|
| 1311 | __attribute__((weak))
|
---|
| 1312 | void _dl_debug_state(void)
|
---|
| 1313 | {
|
---|
| 1314 | dl_debug_state();
|
---|
| 1315 | }
|
---|
| 1316 | #endif
|
---|
| 1317 |
|
---|
| 1318 | __attribute__((__visibility__("hidden")))
|
---|
| 1319 | void *__tls_get_new(tls_mod_off_t *v)
|
---|
| 1320 | {
|
---|
| 1321 | pthread_t self = __pthread_self();
|
---|
| 1322 |
|
---|
| 1323 | /* Block signals to make accessing new TLS async-signal-safe */
|
---|
| 1324 | sigset_t set;
|
---|
| 1325 | __block_all_sigs(&set);
|
---|
| 1326 | if (v[0]<=(size_t)self->dtv[0]) {
|
---|
| 1327 | __restore_sigs(&set);
|
---|
| 1328 | return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
|
---|
| 1329 | }
|
---|
| 1330 |
|
---|
| 1331 | /* This is safe without any locks held because, if the caller
|
---|
| 1332 | * is able to request the Nth entry of the DTV, the DSO list
|
---|
| 1333 | * must be valid at least that far out and it was synchronized
|
---|
| 1334 | * at program startup or by an already-completed call to dlopen. */
|
---|
| 1335 | struct dso *p;
|
---|
| 1336 | for (p=head; p->tls_id != v[0]; p=p->next);
|
---|
| 1337 |
|
---|
| 1338 | /* Get new DTV space from new DSO if needed */
|
---|
| 1339 | if (v[0] > (size_t)self->dtv[0]) {
|
---|
| 1340 | void **newdtv = p->new_dtv +
|
---|
| 1341 | (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
|
---|
| 1342 | memcpy(newdtv, self->dtv,
|
---|
| 1343 | ((size_t)self->dtv[0]+1) * sizeof(void *));
|
---|
| 1344 | newdtv[0] = (void *)v[0];
|
---|
| 1345 | self->dtv = self->dtv_copy = newdtv;
|
---|
| 1346 | }
|
---|
| 1347 |
|
---|
| 1348 | /* Get new TLS memory from all new DSOs up to the requested one */
|
---|
| 1349 | unsigned char *mem;
|
---|
| 1350 | for (p=head; ; p=p->next) {
|
---|
| 1351 | if (!p->tls_id || self->dtv[p->tls_id]) continue;
|
---|
| 1352 | mem = p->new_tls + (p->tls.size + p->tls.align)
|
---|
| 1353 | * a_fetch_add(&p->new_tls_idx,1);
|
---|
| 1354 | mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
|
---|
| 1355 | & (p->tls.align-1);
|
---|
| 1356 | self->dtv[p->tls_id] = mem;
|
---|
| 1357 | memcpy(mem, p->tls.image, p->tls.len);
|
---|
| 1358 | if (p->tls_id == v[0]) break;
|
---|
| 1359 | }
|
---|
| 1360 | __restore_sigs(&set);
|
---|
| 1361 | return mem + v[1] + DTP_OFFSET;
|
---|
| 1362 | }
|
---|
| 1363 |
|
---|
| 1364 | static void update_tls_size()
|
---|
| 1365 | {
|
---|
| 1366 | libc.tls_cnt = tls_cnt;
|
---|
| 1367 | libc.tls_align = tls_align;
|
---|
| 1368 | libc.tls_size = ALIGN(
|
---|
| 1369 | (1+tls_cnt) * sizeof(void *) +
|
---|
| 1370 | tls_offset +
|
---|
| 1371 | sizeof(struct pthread) +
|
---|
| 1372 | tls_align * 2,
|
---|
| 1373 | tls_align);
|
---|
| 1374 | }
|
---|
| 1375 |
|
---|
| 1376 | /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
|
---|
| 1377 | * following stage 2 and stage 3 functions via primitive symbolic lookup
|
---|
| 1378 | * since it does not have access to their addresses to begin with. */
|
---|
| 1379 |
|
---|
| 1380 | /* Stage 2 of the dynamic linker is called after relative relocations
|
---|
| 1381 | * have been processed. It can make function calls to static functions
|
---|
| 1382 | * and access string literals and static data, but cannot use extern
|
---|
| 1383 | * symbols. Its job is to perform symbolic relocations on the dynamic
|
---|
| 1384 | * linker itself, but some of the relocations performed may need to be
|
---|
| 1385 | * replaced later due to copy relocations in the main program. */
|
---|
| 1386 |
|
---|
| 1387 | __attribute__((__visibility__("hidden")))
|
---|
| 1388 | void __dls2(unsigned char *base, size_t *sp)
|
---|
| 1389 | {
|
---|
| 1390 | if (DL_FDPIC) {
|
---|
| 1391 | void *p1 = (void *)sp[-2];
|
---|
| 1392 | void *p2 = (void *)sp[-1];
|
---|
| 1393 | if (!p1) {
|
---|
| 1394 | size_t *auxv, aux[AUX_CNT];
|
---|
| 1395 | for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
|
---|
| 1396 | decode_vec(auxv, aux, AUX_CNT);
|
---|
| 1397 | if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
|
---|
| 1398 | else ldso.base = (void *)(aux[AT_PHDR] & -4096);
|
---|
| 1399 | }
|
---|
| 1400 | app_loadmap = p2 ? p1 : 0;
|
---|
| 1401 | ldso.loadmap = p2 ? p2 : p1;
|
---|
| 1402 | ldso.base = laddr(&ldso, 0);
|
---|
| 1403 | } else {
|
---|
| 1404 | ldso.base = base;
|
---|
| 1405 | }
|
---|
| 1406 | Ehdr *ehdr = (void *)ldso.base;
|
---|
| 1407 | ldso.name = ldso.shortname = "libc.so";
|
---|
| 1408 | ldso.phnum = ehdr->e_phnum;
|
---|
| 1409 | ldso.phdr = laddr(&ldso, ehdr->e_phoff);
|
---|
| 1410 | ldso.phentsize = ehdr->e_phentsize;
|
---|
| 1411 | kernel_mapped_dso(&ldso);
|
---|
| 1412 | decode_dyn(&ldso);
|
---|
| 1413 |
|
---|
| 1414 | if (DL_FDPIC) makefuncdescs(&ldso);
|
---|
| 1415 |
|
---|
| 1416 | /* Prepare storage for to save clobbered REL addends so they
|
---|
| 1417 | * can be reused in stage 3. There should be very few. If
|
---|
| 1418 | * something goes wrong and there are a huge number, abort
|
---|
| 1419 | * instead of risking stack overflow. */
|
---|
| 1420 | size_t dyn[DYN_CNT];
|
---|
| 1421 | decode_vec(ldso.dynv, dyn, DYN_CNT);
|
---|
| 1422 | size_t *rel = laddr(&ldso, dyn[DT_REL]);
|
---|
| 1423 | size_t rel_size = dyn[DT_RELSZ];
|
---|
| 1424 | size_t symbolic_rel_cnt = 0;
|
---|
| 1425 | apply_addends_to = rel;
|
---|
| 1426 | for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
|
---|
| 1427 | if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
|
---|
| 1428 | if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
|
---|
| 1429 | size_t addends[symbolic_rel_cnt+1];
|
---|
| 1430 | saved_addends = addends;
|
---|
| 1431 |
|
---|
| 1432 | head = &ldso;
|
---|
| 1433 | reloc_all(&ldso);
|
---|
| 1434 |
|
---|
| 1435 | ldso.relocated = 0;
|
---|
| 1436 |
|
---|
| 1437 | /* Call dynamic linker stage-3, __dls3, looking it up
|
---|
| 1438 | * symbolically as a barrier against moving the address
|
---|
| 1439 | * load across the above relocation processing. */
|
---|
| 1440 | struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
|
---|
| 1441 | if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
|
---|
| 1442 | else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
|
---|
| 1443 | }
|
---|
| 1444 |
|
---|
| 1445 | /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
|
---|
| 1446 | * fully functional. Its job is to load (if not already loaded) and
|
---|
| 1447 | * process dependencies and relocations for the main application and
|
---|
| 1448 | * transfer control to its entry point. */
|
---|
| 1449 |
|
---|
| 1450 | _Noreturn void __dls3(size_t *sp)
|
---|
| 1451 | {
|
---|
| 1452 | static struct dso app, vdso;
|
---|
| 1453 | size_t aux[AUX_CNT], *auxv;
|
---|
| 1454 | size_t i;
|
---|
| 1455 | char *env_preload=0;
|
---|
| 1456 | char *replace_argv0=0;
|
---|
| 1457 | size_t vdso_base;
|
---|
| 1458 | int argc = *sp;
|
---|
| 1459 | char **argv = (void *)(sp+1);
|
---|
| 1460 | char **argv_orig = argv;
|
---|
| 1461 | char **envp = argv+argc+1;
|
---|
| 1462 |
|
---|
| 1463 | /* Find aux vector just past environ[] and use it to initialize
|
---|
| 1464 | * global data that may be needed before we can make syscalls. */
|
---|
| 1465 | __environ = envp;
|
---|
| 1466 | for (i=argc+1; argv[i]; i++);
|
---|
| 1467 | libc.auxv = auxv = (void *)(argv+i+1);
|
---|
| 1468 | decode_vec(auxv, aux, AUX_CNT);
|
---|
| 1469 | __hwcap = aux[AT_HWCAP];
|
---|
| 1470 | libc.page_size = aux[AT_PAGESZ];
|
---|
| 1471 | libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
|
---|
| 1472 | || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
|
---|
| 1473 |
|
---|
| 1474 | /* Setup early thread pointer in builtin_tls for ldso/libc itself to
|
---|
| 1475 | * use during dynamic linking. If possible it will also serve as the
|
---|
| 1476 | * thread pointer at runtime. */
|
---|
| 1477 | libc.tls_size = sizeof builtin_tls;
|
---|
| 1478 | libc.tls_align = tls_align;
|
---|
| 1479 | if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
|
---|
| 1480 | a_crash();
|
---|
| 1481 | }
|
---|
| 1482 |
|
---|
| 1483 | /* Only trust user/env if kernel says we're not suid/sgid */
|
---|
| 1484 | if (!libc.secure) {
|
---|
| 1485 | env_path = getenv("LD_LIBRARY_PATH");
|
---|
| 1486 | env_preload = getenv("LD_PRELOAD");
|
---|
| 1487 | }
|
---|
| 1488 |
|
---|
| 1489 | /* If the main program was already loaded by the kernel,
|
---|
| 1490 | * AT_PHDR will point to some location other than the dynamic
|
---|
| 1491 | * linker's program headers. */
|
---|
| 1492 | if (aux[AT_PHDR] != (size_t)ldso.phdr) {
|
---|
| 1493 | size_t interp_off = 0;
|
---|
| 1494 | size_t tls_image = 0;
|
---|
| 1495 | /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
|
---|
| 1496 | Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
|
---|
| 1497 | app.phnum = aux[AT_PHNUM];
|
---|
| 1498 | app.phentsize = aux[AT_PHENT];
|
---|
| 1499 | for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
|
---|
| 1500 | if (phdr->p_type == PT_PHDR)
|
---|
| 1501 | app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
|
---|
| 1502 | else if (phdr->p_type == PT_INTERP)
|
---|
| 1503 | interp_off = (size_t)phdr->p_vaddr;
|
---|
| 1504 | else if (phdr->p_type == PT_TLS) {
|
---|
| 1505 | tls_image = phdr->p_vaddr;
|
---|
| 1506 | app.tls.len = phdr->p_filesz;
|
---|
| 1507 | app.tls.size = phdr->p_memsz;
|
---|
| 1508 | app.tls.align = phdr->p_align;
|
---|
| 1509 | }
|
---|
| 1510 | }
|
---|
| 1511 | if (DL_FDPIC) app.loadmap = app_loadmap;
|
---|
| 1512 | if (app.tls.size) app.tls.image = laddr(&app, tls_image);
|
---|
| 1513 | if (interp_off) ldso.name = laddr(&app, interp_off);
|
---|
| 1514 | if ((aux[0] & (1UL<<AT_EXECFN))
|
---|
| 1515 | && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
|
---|
| 1516 | app.name = (char *)aux[AT_EXECFN];
|
---|
| 1517 | else
|
---|
| 1518 | app.name = argv[0];
|
---|
| 1519 | kernel_mapped_dso(&app);
|
---|
| 1520 | } else {
|
---|
| 1521 | int fd;
|
---|
| 1522 | char *ldname = argv[0];
|
---|
| 1523 | size_t l = strlen(ldname);
|
---|
| 1524 | if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
|
---|
| 1525 | argv++;
|
---|
| 1526 | while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
|
---|
| 1527 | char *opt = argv[0]+2;
|
---|
| 1528 | *argv++ = (void *)-1;
|
---|
| 1529 | if (!*opt) {
|
---|
| 1530 | break;
|
---|
| 1531 | } else if (!memcmp(opt, "list", 5)) {
|
---|
| 1532 | ldd_mode = 1;
|
---|
| 1533 | } else if (!memcmp(opt, "library-path", 12)) {
|
---|
| 1534 | if (opt[12]=='=') env_path = opt+13;
|
---|
| 1535 | else if (opt[12]) *argv = 0;
|
---|
| 1536 | else if (*argv) env_path = *argv++;
|
---|
| 1537 | } else if (!memcmp(opt, "preload", 7)) {
|
---|
| 1538 | if (opt[7]=='=') env_preload = opt+8;
|
---|
| 1539 | else if (opt[7]) *argv = 0;
|
---|
| 1540 | else if (*argv) env_preload = *argv++;
|
---|
| 1541 | } else if (!memcmp(opt, "argv0", 5)) {
|
---|
| 1542 | if (opt[5]=='=') replace_argv0 = opt+6;
|
---|
| 1543 | else if (opt[5]) *argv = 0;
|
---|
| 1544 | else if (*argv) replace_argv0 = *argv++;
|
---|
| 1545 | } else {
|
---|
| 1546 | argv[0] = 0;
|
---|
| 1547 | }
|
---|
| 1548 | }
|
---|
| 1549 | argv[-1] = (void *)(argc - (argv-argv_orig));
|
---|
| 1550 | if (!argv[0]) {
|
---|
| 1551 | dprintf(2, "musl libc (" LDSO_ARCH ")\n"
|
---|
| 1552 | "Version %s\n"
|
---|
| 1553 | "Dynamic Program Loader\n"
|
---|
| 1554 | "Usage: %s [options] [--] pathname%s\n",
|
---|
| 1555 | __libc_get_version(), ldname,
|
---|
| 1556 | ldd_mode ? "" : " [args]");
|
---|
| 1557 | _exit(1);
|
---|
| 1558 | }
|
---|
| 1559 | fd = open(argv[0], O_RDONLY);
|
---|
| 1560 | if (fd < 0) {
|
---|
| 1561 | dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
|
---|
| 1562 | _exit(1);
|
---|
| 1563 | }
|
---|
| 1564 | runtime = 1;
|
---|
| 1565 | Ehdr *ehdr = (void *)map_library(fd, &app);
|
---|
| 1566 | if (!ehdr) {
|
---|
| 1567 | dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
|
---|
| 1568 | _exit(1);
|
---|
| 1569 | }
|
---|
| 1570 | runtime = 0;
|
---|
| 1571 | close(fd);
|
---|
| 1572 | ldso.name = ldname;
|
---|
| 1573 | app.name = argv[0];
|
---|
| 1574 | aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
|
---|
| 1575 | /* Find the name that would have been used for the dynamic
|
---|
| 1576 | * linker had ldd not taken its place. */
|
---|
| 1577 | if (ldd_mode) {
|
---|
| 1578 | for (i=0; i<app.phnum; i++) {
|
---|
| 1579 | if (app.phdr[i].p_type == PT_INTERP)
|
---|
| 1580 | ldso.name = laddr(&app, app.phdr[i].p_vaddr);
|
---|
| 1581 | }
|
---|
| 1582 | dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
|
---|
| 1583 | }
|
---|
| 1584 | }
|
---|
| 1585 | if (app.tls.size) {
|
---|
| 1586 | libc.tls_head = tls_tail = &app.tls;
|
---|
| 1587 | app.tls_id = tls_cnt = 1;
|
---|
| 1588 | #ifdef TLS_ABOVE_TP
|
---|
| 1589 | app.tls.offset = 0;
|
---|
| 1590 | tls_offset = app.tls.size
|
---|
| 1591 | + ( -((uintptr_t)app.tls.image + app.tls.size)
|
---|
| 1592 | & (app.tls.align-1) );
|
---|
| 1593 | #else
|
---|
| 1594 | tls_offset = app.tls.offset = app.tls.size
|
---|
| 1595 | + ( -((uintptr_t)app.tls.image + app.tls.size)
|
---|
| 1596 | & (app.tls.align-1) );
|
---|
| 1597 | #endif
|
---|
| 1598 | tls_align = MAXP2(tls_align, app.tls.align);
|
---|
| 1599 | }
|
---|
| 1600 | decode_dyn(&app);
|
---|
| 1601 | if (DL_FDPIC) {
|
---|
| 1602 | makefuncdescs(&app);
|
---|
| 1603 | if (!app.loadmap) {
|
---|
| 1604 | app.loadmap = (void *)&app_dummy_loadmap;
|
---|
| 1605 | app.loadmap->nsegs = 1;
|
---|
| 1606 | app.loadmap->segs[0].addr = (size_t)app.map;
|
---|
| 1607 | app.loadmap->segs[0].p_vaddr = (size_t)app.map
|
---|
| 1608 | - (size_t)app.base;
|
---|
| 1609 | app.loadmap->segs[0].p_memsz = app.map_len;
|
---|
| 1610 | }
|
---|
| 1611 | argv[-3] = (void *)app.loadmap;
|
---|
| 1612 | }
|
---|
| 1613 |
|
---|
| 1614 | /* Initial dso chain consists only of the app. */
|
---|
| 1615 | head = tail = syms_tail = &app;
|
---|
| 1616 |
|
---|
| 1617 | /* Donate unused parts of app and library mapping to malloc */
|
---|
| 1618 | reclaim_gaps(&app);
|
---|
| 1619 | reclaim_gaps(&ldso);
|
---|
| 1620 |
|
---|
| 1621 | /* Load preload/needed libraries, add symbols to global namespace. */
|
---|
| 1622 | if (env_preload) load_preload(env_preload);
|
---|
| 1623 | load_deps(&app);
|
---|
| 1624 | for (struct dso *p=head; p; p=p->next)
|
---|
| 1625 | add_syms(p);
|
---|
| 1626 |
|
---|
| 1627 | /* Attach to vdso, if provided by the kernel, last so that it does
|
---|
| 1628 | * not become part of the global namespace. */
|
---|
| 1629 | if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
|
---|
| 1630 | Ehdr *ehdr = (void *)vdso_base;
|
---|
| 1631 | Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
|
---|
| 1632 | vdso.phnum = ehdr->e_phnum;
|
---|
| 1633 | vdso.phentsize = ehdr->e_phentsize;
|
---|
| 1634 | for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
|
---|
| 1635 | if (phdr->p_type == PT_DYNAMIC)
|
---|
| 1636 | vdso.dynv = (void *)(vdso_base + phdr->p_offset);
|
---|
| 1637 | if (phdr->p_type == PT_LOAD)
|
---|
| 1638 | vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
|
---|
| 1639 | }
|
---|
| 1640 | vdso.name = "";
|
---|
| 1641 | vdso.shortname = "linux-gate.so.1";
|
---|
| 1642 | vdso.relocated = 1;
|
---|
| 1643 | decode_dyn(&vdso);
|
---|
| 1644 | vdso.prev = tail;
|
---|
| 1645 | tail->next = &vdso;
|
---|
| 1646 | tail = &vdso;
|
---|
| 1647 | }
|
---|
| 1648 |
|
---|
| 1649 | for (i=0; app.dynv[i]; i+=2) {
|
---|
| 1650 | if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
|
---|
| 1651 | app.dynv[i+1] = (size_t)&debug;
|
---|
| 1652 | if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
|
---|
| 1653 | size_t *ptr = (size_t *) app.dynv[i+1];
|
---|
| 1654 | *ptr = (size_t)&debug;
|
---|
| 1655 | }
|
---|
| 1656 | }
|
---|
| 1657 |
|
---|
| 1658 | /* The main program must be relocated LAST since it may contin
|
---|
| 1659 | * copy relocations which depend on libraries' relocations. */
|
---|
| 1660 | reloc_all(app.next);
|
---|
| 1661 | reloc_all(&app);
|
---|
| 1662 |
|
---|
| 1663 | update_tls_size();
|
---|
| 1664 | if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
|
---|
| 1665 | void *initial_tls = calloc(libc.tls_size, 1);
|
---|
| 1666 | if (!initial_tls) {
|
---|
| 1667 | dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
|
---|
| 1668 | argv[0], libc.tls_size);
|
---|
| 1669 | _exit(127);
|
---|
| 1670 | }
|
---|
| 1671 | if (__init_tp(__copy_tls(initial_tls)) < 0) {
|
---|
| 1672 | a_crash();
|
---|
| 1673 | }
|
---|
| 1674 | } else {
|
---|
| 1675 | size_t tmp_tls_size = libc.tls_size;
|
---|
| 1676 | pthread_t self = __pthread_self();
|
---|
| 1677 | /* Temporarily set the tls size to the full size of
|
---|
| 1678 | * builtin_tls so that __copy_tls will use the same layout
|
---|
| 1679 | * as it did for before. Then check, just to be safe. */
|
---|
| 1680 | libc.tls_size = sizeof builtin_tls;
|
---|
| 1681 | if (__copy_tls((void*)builtin_tls) != self) a_crash();
|
---|
| 1682 | libc.tls_size = tmp_tls_size;
|
---|
| 1683 | }
|
---|
| 1684 | static_tls_cnt = tls_cnt;
|
---|
| 1685 |
|
---|
| 1686 | if (ldso_fail) _exit(127);
|
---|
| 1687 | if (ldd_mode) _exit(0);
|
---|
| 1688 |
|
---|
| 1689 | /* Switch to runtime mode: any further failures in the dynamic
|
---|
| 1690 | * linker are a reportable failure rather than a fatal startup
|
---|
| 1691 | * error. */
|
---|
| 1692 | runtime = 1;
|
---|
| 1693 |
|
---|
| 1694 | debug.ver = 1;
|
---|
| 1695 | debug.bp = dl_debug_state;
|
---|
| 1696 | debug.head = head;
|
---|
| 1697 | debug.base = ldso.base;
|
---|
| 1698 | debug.state = 0;
|
---|
| 1699 | _dl_debug_state();
|
---|
| 1700 |
|
---|
| 1701 | if (replace_argv0) argv[0] = replace_argv0;
|
---|
| 1702 |
|
---|
| 1703 | errno = 0;
|
---|
| 1704 |
|
---|
| 1705 | CRTJMP((void *)aux[AT_ENTRY], argv-1);
|
---|
| 1706 | for(;;);
|
---|
| 1707 | }
|
---|
| 1708 |
|
---|
| 1709 | static void prepare_lazy(struct dso *p)
|
---|
| 1710 | {
|
---|
| 1711 | size_t dyn[DYN_CNT], n, flags1=0;
|
---|
| 1712 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
| 1713 | search_vec(p->dynv, &flags1, DT_FLAGS_1);
|
---|
| 1714 | if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
|
---|
| 1715 | return;
|
---|
| 1716 | n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
|
---|
| 1717 | if (NEED_MIPS_GOT_RELOCS) {
|
---|
| 1718 | size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
|
---|
| 1719 | size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
|
---|
| 1720 | n += i-j;
|
---|
| 1721 | }
|
---|
| 1722 | p->lazy = calloc(n, 3*sizeof(size_t));
|
---|
| 1723 | if (!p->lazy) {
|
---|
| 1724 | error("Error preparing lazy relocation for %s: %m", p->name);
|
---|
| 1725 | longjmp(*rtld_fail, 1);
|
---|
| 1726 | }
|
---|
| 1727 | p->lazy_next = lazy_head;
|
---|
| 1728 | lazy_head = p;
|
---|
| 1729 | }
|
---|
| 1730 |
|
---|
| 1731 | void *dlopen(const char *file, int mode)
|
---|
| 1732 | {
|
---|
| 1733 | struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
|
---|
| 1734 | struct tls_module *orig_tls_tail;
|
---|
| 1735 | size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
|
---|
| 1736 | size_t i;
|
---|
| 1737 | int cs;
|
---|
| 1738 | jmp_buf jb;
|
---|
| 1739 |
|
---|
| 1740 | if (!file) return head;
|
---|
| 1741 |
|
---|
| 1742 | pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
|
---|
| 1743 | pthread_rwlock_wrlock(&lock);
|
---|
| 1744 | __inhibit_ptc();
|
---|
| 1745 |
|
---|
| 1746 | p = 0;
|
---|
| 1747 | orig_tls_tail = tls_tail;
|
---|
| 1748 | orig_tls_cnt = tls_cnt;
|
---|
| 1749 | orig_tls_offset = tls_offset;
|
---|
| 1750 | orig_tls_align = tls_align;
|
---|
| 1751 | orig_lazy_head = lazy_head;
|
---|
| 1752 | orig_syms_tail = syms_tail;
|
---|
| 1753 | orig_tail = tail;
|
---|
| 1754 | noload = mode & RTLD_NOLOAD;
|
---|
| 1755 |
|
---|
| 1756 | rtld_fail = &jb;
|
---|
| 1757 | if (setjmp(*rtld_fail)) {
|
---|
| 1758 | /* Clean up anything new that was (partially) loaded */
|
---|
| 1759 | revert_syms(orig_syms_tail);
|
---|
| 1760 | for (p=orig_tail->next; p; p=next) {
|
---|
| 1761 | next = p->next;
|
---|
| 1762 | while (p->td_index) {
|
---|
| 1763 | void *tmp = p->td_index->next;
|
---|
| 1764 | free(p->td_index);
|
---|
| 1765 | p->td_index = tmp;
|
---|
| 1766 | }
|
---|
| 1767 | free(p->funcdescs);
|
---|
| 1768 | if (p->rpath != p->rpath_orig)
|
---|
| 1769 | free(p->rpath);
|
---|
| 1770 | if (p->deps != &nodeps_dummy)
|
---|
| 1771 | free(p->deps);
|
---|
| 1772 | unmap_library(p);
|
---|
| 1773 | free(p);
|
---|
| 1774 | }
|
---|
| 1775 | if (!orig_tls_tail) libc.tls_head = 0;
|
---|
| 1776 | tls_tail = orig_tls_tail;
|
---|
| 1777 | if (tls_tail) tls_tail->next = 0;
|
---|
| 1778 | tls_cnt = orig_tls_cnt;
|
---|
| 1779 | tls_offset = orig_tls_offset;
|
---|
| 1780 | tls_align = orig_tls_align;
|
---|
| 1781 | lazy_head = orig_lazy_head;
|
---|
| 1782 | tail = orig_tail;
|
---|
| 1783 | tail->next = 0;
|
---|
| 1784 | p = 0;
|
---|
| 1785 | goto end;
|
---|
| 1786 | } else p = load_library(file, head);
|
---|
| 1787 |
|
---|
| 1788 | if (!p) {
|
---|
| 1789 | error(noload ?
|
---|
| 1790 | "Library %s is not already loaded" :
|
---|
| 1791 | "Error loading shared library %s: %m",
|
---|
| 1792 | file);
|
---|
| 1793 | goto end;
|
---|
| 1794 | }
|
---|
| 1795 |
|
---|
| 1796 | /* First load handling */
|
---|
| 1797 | int first_load = !p->deps;
|
---|
| 1798 | if (first_load) {
|
---|
| 1799 | load_deps(p);
|
---|
| 1800 | if (!p->relocated && (mode & RTLD_LAZY)) {
|
---|
| 1801 | prepare_lazy(p);
|
---|
| 1802 | for (i=0; p->deps[i]; i++)
|
---|
| 1803 | if (!p->deps[i]->relocated)
|
---|
| 1804 | prepare_lazy(p->deps[i]);
|
---|
| 1805 | }
|
---|
| 1806 | }
|
---|
| 1807 | if (first_load || (mode & RTLD_GLOBAL)) {
|
---|
| 1808 | /* Make new symbols global, at least temporarily, so we can do
|
---|
| 1809 | * relocations. If not RTLD_GLOBAL, this is reverted below. */
|
---|
| 1810 | add_syms(p);
|
---|
| 1811 | for (i=0; p->deps[i]; i++)
|
---|
| 1812 | add_syms(p->deps[i]);
|
---|
| 1813 | }
|
---|
| 1814 | if (first_load) {
|
---|
| 1815 | reloc_all(p);
|
---|
| 1816 | }
|
---|
| 1817 |
|
---|
| 1818 | /* If RTLD_GLOBAL was not specified, undo any new additions
|
---|
| 1819 | * to the global symbol table. This is a nop if the library was
|
---|
| 1820 | * previously loaded and already global. */
|
---|
| 1821 | if (!(mode & RTLD_GLOBAL))
|
---|
| 1822 | revert_syms(orig_syms_tail);
|
---|
| 1823 |
|
---|
| 1824 | /* Processing of deferred lazy relocations must not happen until
|
---|
| 1825 | * the new libraries are committed; otherwise we could end up with
|
---|
| 1826 | * relocations resolved to symbol definitions that get removed. */
|
---|
| 1827 | redo_lazy_relocs();
|
---|
| 1828 |
|
---|
| 1829 | update_tls_size();
|
---|
| 1830 | _dl_debug_state();
|
---|
| 1831 | orig_tail = tail;
|
---|
| 1832 | end:
|
---|
| 1833 | __release_ptc();
|
---|
| 1834 | if (p) gencnt++;
|
---|
| 1835 | pthread_rwlock_unlock(&lock);
|
---|
| 1836 | if (p) do_init_fini(orig_tail);
|
---|
| 1837 | pthread_setcancelstate(cs, 0);
|
---|
| 1838 | return p;
|
---|
| 1839 | }
|
---|
| 1840 |
|
---|
| 1841 | __attribute__((__visibility__("hidden")))
|
---|
| 1842 | int __dl_invalid_handle(void *h)
|
---|
| 1843 | {
|
---|
| 1844 | struct dso *p;
|
---|
| 1845 | for (p=head; p; p=p->next) if (h==p) return 0;
|
---|
| 1846 | error("Invalid library handle %p", (void *)h);
|
---|
| 1847 | return 1;
|
---|
| 1848 | }
|
---|
| 1849 |
|
---|
| 1850 | static void *addr2dso(size_t a)
|
---|
| 1851 | {
|
---|
| 1852 | struct dso *p;
|
---|
| 1853 | size_t i;
|
---|
| 1854 | if (DL_FDPIC) for (p=head; p; p=p->next) {
|
---|
| 1855 | i = count_syms(p);
|
---|
| 1856 | if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
|
---|
| 1857 | return p;
|
---|
| 1858 | }
|
---|
| 1859 | for (p=head; p; p=p->next) {
|
---|
| 1860 | if (DL_FDPIC && p->loadmap) {
|
---|
| 1861 | for (i=0; i<p->loadmap->nsegs; i++) {
|
---|
| 1862 | if (a-p->loadmap->segs[i].p_vaddr
|
---|
| 1863 | < p->loadmap->segs[i].p_memsz)
|
---|
| 1864 | return p;
|
---|
| 1865 | }
|
---|
| 1866 | } else {
|
---|
| 1867 | if (a-(size_t)p->map < p->map_len)
|
---|
| 1868 | return p;
|
---|
| 1869 | }
|
---|
| 1870 | }
|
---|
| 1871 | return 0;
|
---|
| 1872 | }
|
---|
| 1873 |
|
---|
| 1874 | void *__tls_get_addr(tls_mod_off_t *);
|
---|
| 1875 |
|
---|
| 1876 | static void *do_dlsym(struct dso *p, const char *s, void *ra)
|
---|
| 1877 | {
|
---|
| 1878 | size_t i;
|
---|
| 1879 | uint32_t h = 0, gh = 0, *ght;
|
---|
| 1880 | Sym *sym;
|
---|
| 1881 | if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
|
---|
| 1882 | if (p == RTLD_DEFAULT) {
|
---|
| 1883 | p = head;
|
---|
| 1884 | } else if (p == RTLD_NEXT) {
|
---|
| 1885 | p = addr2dso((size_t)ra);
|
---|
| 1886 | if (!p) p=head;
|
---|
| 1887 | p = p->next;
|
---|
| 1888 | }
|
---|
| 1889 | struct symdef def = find_sym(p, s, 0);
|
---|
| 1890 | if (!def.sym) goto failed;
|
---|
| 1891 | if ((def.sym->st_info&0xf) == STT_TLS)
|
---|
| 1892 | return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
|
---|
| 1893 | if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
|
---|
| 1894 | return def.dso->funcdescs + (def.sym - def.dso->syms);
|
---|
| 1895 | return laddr(def.dso, def.sym->st_value);
|
---|
| 1896 | }
|
---|
| 1897 | if (__dl_invalid_handle(p))
|
---|
| 1898 | return 0;
|
---|
| 1899 | if ((ght = p->ghashtab)) {
|
---|
| 1900 | gh = gnu_hash(s);
|
---|
| 1901 | sym = gnu_lookup(gh, ght, p, s);
|
---|
| 1902 | } else {
|
---|
| 1903 | h = sysv_hash(s);
|
---|
| 1904 | sym = sysv_lookup(s, h, p);
|
---|
| 1905 | }
|
---|
| 1906 | if (sym && (sym->st_info&0xf) == STT_TLS)
|
---|
| 1907 | return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
|
---|
| 1908 | if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
|
---|
| 1909 | return p->funcdescs + (sym - p->syms);
|
---|
| 1910 | if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
|
---|
| 1911 | return laddr(p, sym->st_value);
|
---|
| 1912 | for (i=0; p->deps[i]; i++) {
|
---|
| 1913 | if ((ght = p->deps[i]->ghashtab)) {
|
---|
| 1914 | if (!gh) gh = gnu_hash(s);
|
---|
| 1915 | sym = gnu_lookup(gh, ght, p->deps[i], s);
|
---|
| 1916 | } else {
|
---|
| 1917 | if (!h) h = sysv_hash(s);
|
---|
| 1918 | sym = sysv_lookup(s, h, p->deps[i]);
|
---|
| 1919 | }
|
---|
| 1920 | if (sym && (sym->st_info&0xf) == STT_TLS)
|
---|
| 1921 | return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
|
---|
| 1922 | if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
|
---|
| 1923 | return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
|
---|
| 1924 | if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
|
---|
| 1925 | return laddr(p->deps[i], sym->st_value);
|
---|
| 1926 | }
|
---|
| 1927 | failed:
|
---|
| 1928 | error("Symbol not found: %s", s);
|
---|
| 1929 | return 0;
|
---|
| 1930 | }
|
---|
| 1931 |
|
---|
| 1932 | int dladdr(const void *addr, Dl_info *info)
|
---|
| 1933 | {
|
---|
| 1934 | struct dso *p;
|
---|
| 1935 | Sym *sym, *bestsym;
|
---|
| 1936 | uint32_t nsym;
|
---|
| 1937 | char *strings;
|
---|
| 1938 | void *best = 0;
|
---|
| 1939 |
|
---|
| 1940 | pthread_rwlock_rdlock(&lock);
|
---|
| 1941 | p = addr2dso((size_t)addr);
|
---|
| 1942 | pthread_rwlock_unlock(&lock);
|
---|
| 1943 |
|
---|
| 1944 | if (!p) return 0;
|
---|
| 1945 |
|
---|
| 1946 | sym = p->syms;
|
---|
| 1947 | strings = p->strings;
|
---|
| 1948 | nsym = count_syms(p);
|
---|
| 1949 |
|
---|
| 1950 | if (DL_FDPIC) {
|
---|
| 1951 | size_t idx = ((size_t)addr-(size_t)p->funcdescs)
|
---|
| 1952 | / sizeof(*p->funcdescs);
|
---|
| 1953 | if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
|
---|
| 1954 | best = p->funcdescs + idx;
|
---|
| 1955 | bestsym = sym + idx;
|
---|
| 1956 | }
|
---|
| 1957 | }
|
---|
| 1958 |
|
---|
| 1959 | if (!best) for (; nsym; nsym--, sym++) {
|
---|
| 1960 | if (sym->st_value
|
---|
| 1961 | && (1<<(sym->st_info&0xf) & OK_TYPES)
|
---|
| 1962 | && (1<<(sym->st_info>>4) & OK_BINDS)) {
|
---|
| 1963 | void *symaddr = laddr(p, sym->st_value);
|
---|
| 1964 | if (symaddr > addr || symaddr < best)
|
---|
| 1965 | continue;
|
---|
| 1966 | best = symaddr;
|
---|
| 1967 | bestsym = sym;
|
---|
| 1968 | if (addr == symaddr)
|
---|
| 1969 | break;
|
---|
| 1970 | }
|
---|
| 1971 | }
|
---|
| 1972 |
|
---|
| 1973 | if (!best) return 0;
|
---|
| 1974 |
|
---|
| 1975 | if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
|
---|
| 1976 | best = p->funcdescs + (bestsym - p->syms);
|
---|
| 1977 |
|
---|
| 1978 | info->dli_fname = p->name;
|
---|
| 1979 | info->dli_fbase = p->base;
|
---|
| 1980 | info->dli_sname = strings + bestsym->st_name;
|
---|
| 1981 | info->dli_saddr = best;
|
---|
| 1982 |
|
---|
| 1983 | return 1;
|
---|
| 1984 | }
|
---|
| 1985 |
|
---|
| 1986 | __attribute__((__visibility__("hidden")))
|
---|
| 1987 | void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
|
---|
| 1988 | {
|
---|
| 1989 | void *res;
|
---|
| 1990 | pthread_rwlock_rdlock(&lock);
|
---|
| 1991 | res = do_dlsym(p, s, ra);
|
---|
| 1992 | pthread_rwlock_unlock(&lock);
|
---|
| 1993 | return res;
|
---|
| 1994 | }
|
---|
| 1995 |
|
---|
| 1996 | int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
|
---|
| 1997 | {
|
---|
| 1998 | struct dso *current;
|
---|
| 1999 | struct dl_phdr_info info;
|
---|
| 2000 | int ret = 0;
|
---|
| 2001 | for(current = head; current;) {
|
---|
| 2002 | info.dlpi_addr = (uintptr_t)current->base;
|
---|
| 2003 | info.dlpi_name = current->name;
|
---|
| 2004 | info.dlpi_phdr = current->phdr;
|
---|
| 2005 | info.dlpi_phnum = current->phnum;
|
---|
| 2006 | info.dlpi_adds = gencnt;
|
---|
| 2007 | info.dlpi_subs = 0;
|
---|
| 2008 | info.dlpi_tls_modid = current->tls_id;
|
---|
| 2009 | info.dlpi_tls_data = current->tls.image;
|
---|
| 2010 |
|
---|
| 2011 | ret = (callback)(&info, sizeof (info), data);
|
---|
| 2012 |
|
---|
| 2013 | if (ret != 0) break;
|
---|
| 2014 |
|
---|
| 2015 | pthread_rwlock_rdlock(&lock);
|
---|
| 2016 | current = current->next;
|
---|
| 2017 | pthread_rwlock_unlock(&lock);
|
---|
| 2018 | }
|
---|
| 2019 | return ret;
|
---|
| 2020 | }
|
---|
| 2021 |
|
---|
| 2022 | __attribute__((__visibility__("hidden")))
|
---|
| 2023 | void __dl_vseterr(const char *, va_list);
|
---|
| 2024 |
|
---|
| 2025 | static void error(const char *fmt, ...)
|
---|
| 2026 | {
|
---|
| 2027 | va_list ap;
|
---|
| 2028 | va_start(ap, fmt);
|
---|
| 2029 | if (!runtime) {
|
---|
| 2030 | vdprintf(2, fmt, ap);
|
---|
| 2031 | dprintf(2, "\n");
|
---|
| 2032 | ldso_fail = 1;
|
---|
| 2033 | va_end(ap);
|
---|
| 2034 | return;
|
---|
| 2035 | }
|
---|
| 2036 | __dl_vseterr(fmt, ap);
|
---|
| 2037 | va_end(ap);
|
---|
| 2038 | }
|
---|