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1 #include <elf.h> | 1 #include <elf.h> |
2 #include <limits.h> | 2 #include <limits.h> |
3 #include <stdint.h> | 3 #include <stdint.h> |
4 #include <string.h> | 4 #include <string.h> |
5 #include "libc.h" | 5 #include "libc.h" |
6 #include "syscall.h" | 6 #include "syscall.h" |
7 | 7 |
8 #ifdef VDSO_USEFUL | 8 #ifdef VDSO_USEFUL |
9 | 9 |
10 #if ULONG_MAX == 0xffffffff | 10 #if ULONG_MAX == 0xffffffff |
11 typedef Elf32_Ehdr Ehdr; | 11 typedef Elf32_Ehdr Ehdr; |
12 typedef Elf32_Phdr Phdr; | 12 typedef Elf32_Phdr Phdr; |
13 typedef Elf32_Sym Sym; | 13 typedef Elf32_Sym Sym; |
14 typedef Elf32_Verdef Verdef; | 14 typedef Elf32_Verdef Verdef; |
15 typedef Elf32_Verdaux Verdaux; | 15 typedef Elf32_Verdaux Verdaux; |
16 #else | 16 #else |
17 typedef Elf64_Ehdr Ehdr; | 17 typedef Elf64_Ehdr Ehdr; |
18 typedef Elf64_Phdr Phdr; | 18 typedef Elf64_Phdr Phdr; |
19 typedef Elf64_Sym Sym; | 19 typedef Elf64_Sym Sym; |
20 typedef Elf64_Verdef Verdef; | 20 typedef Elf64_Verdef Verdef; |
21 typedef Elf64_Verdaux Verdaux; | 21 typedef Elf64_Verdaux Verdaux; |
22 #endif | 22 #endif |
23 | 23 |
24 static int checkver(Verdef *def, int vsym, const char *vername, char *strings) | 24 static int checkver(Verdef* def, int vsym, const char* vername, char* strings) { |
25 { | 25 vsym &= 0x7fff; |
26 » vsym &= 0x7fff; | 26 for (;;) { |
27 » for (;;) { | 27 if (!(def->vd_flags & VER_FLG_BASE) && (def->vd_ndx & 0x7fff) == vsym) |
28 » » if (!(def->vd_flags & VER_FLG_BASE) | 28 break; |
29 » » && (def->vd_ndx & 0x7fff) == vsym) | 29 if (def->vd_next == 0) |
30 » » » break; | 30 return 0; |
31 » » if (def->vd_next == 0) | 31 def = (Verdef*)((char*)def + def->vd_next); |
32 » » » return 0; | 32 } |
33 » » def = (Verdef *)((char *)def + def->vd_next); | 33 Verdaux* aux = (Verdaux*)((char*)def + def->vd_aux); |
34 » } | 34 return !strcmp(vername, strings + aux->vda_name); |
35 » Verdaux *aux = (Verdaux *)((char *)def + def->vd_aux); | |
36 » return !strcmp(vername, strings + aux->vda_name); | |
37 } | 35 } |
38 | 36 |
39 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON) | 37 #define OK_TYPES \ |
40 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE) | 38 (1 << STT_NOTYPE | 1 << STT_OBJECT | 1 << STT_FUNC | 1 << STT_COMMON) |
| 39 #define OK_BINDS (1 << STB_GLOBAL | 1 << STB_WEAK | 1 << STB_GNU_UNIQUE) |
41 | 40 |
42 void *__vdsosym(const char *vername, const char *name) | 41 void* __vdsosym(const char* vername, const char* name) { |
43 { | 42 size_t i; |
44 » size_t i; | 43 for (i = 0; libc.auxv[i] != AT_SYSINFO_EHDR; i += 2) |
45 » for (i=0; libc.auxv[i] != AT_SYSINFO_EHDR; i+=2) | 44 if (!libc.auxv[i]) |
46 » » if (!libc.auxv[i]) return 0; | 45 return 0; |
47 » Ehdr *eh = (void *)libc.auxv[i+1]; | 46 Ehdr* eh = (void*)libc.auxv[i + 1]; |
48 » Phdr *ph = (void *)((char *)eh + eh->e_phoff); | 47 Phdr* ph = (void*)((char*)eh + eh->e_phoff); |
49 » size_t *dynv=0, base=-1; | 48 size_t *dynv = 0, base = -1; |
50 » for (i=0; i<eh->e_phnum; i++, ph=(void *)((char *)ph+eh->e_phentsize)) { | 49 for (i = 0; i < eh->e_phnum; i++, ph = (void*)((char*)ph + eh->e_phentsize)) { |
51 » » if (ph->p_type == PT_LOAD) | 50 if (ph->p_type == PT_LOAD) |
52 » » » base = (size_t)eh + ph->p_offset - ph->p_vaddr; | 51 base = (size_t)eh + ph->p_offset - ph->p_vaddr; |
53 » » else if (ph->p_type == PT_DYNAMIC) | 52 else if (ph->p_type == PT_DYNAMIC) |
54 » » » dynv = (void *)((char *)eh + ph->p_offset); | 53 dynv = (void*)((char*)eh + ph->p_offset); |
55 » } | 54 } |
56 » if (!dynv || base==(size_t)-1) return 0; | 55 if (!dynv || base == (size_t)-1) |
| 56 return 0; |
57 | 57 |
58 » char *strings = 0; | 58 char* strings = 0; |
59 » Sym *syms = 0; | 59 Sym* syms = 0; |
60 » uint32_t *hashtab = 0; | 60 uint32_t* hashtab = 0; |
61 » uint16_t *versym = 0; | 61 uint16_t* versym = 0; |
62 » Verdef *verdef = 0; | 62 Verdef* verdef = 0; |
63 » | |
64 » for (i=0; dynv[i]; i+=2) { | |
65 » » void *p = (void *)(base + dynv[i+1]); | |
66 » » switch(dynv[i]) { | |
67 » » case DT_STRTAB: strings = p; break; | |
68 » » case DT_SYMTAB: syms = p; break; | |
69 » » case DT_HASH: hashtab = p; break; | |
70 » » case DT_VERSYM: versym = p; break; | |
71 » » case DT_VERDEF: verdef = p; break; | |
72 » » } | |
73 » }» | |
74 | 63 |
75 » if (!strings || !syms || !hashtab) return 0; | 64 for (i = 0; dynv[i]; i += 2) { |
76 » if (!verdef) versym = 0; | 65 void* p = (void*)(base + dynv[i + 1]); |
| 66 switch (dynv[i]) { |
| 67 case DT_STRTAB: |
| 68 strings = p; |
| 69 break; |
| 70 case DT_SYMTAB: |
| 71 syms = p; |
| 72 break; |
| 73 case DT_HASH: |
| 74 hashtab = p; |
| 75 break; |
| 76 case DT_VERSYM: |
| 77 versym = p; |
| 78 break; |
| 79 case DT_VERDEF: |
| 80 verdef = p; |
| 81 break; |
| 82 } |
| 83 } |
77 | 84 |
78 » for (i=0; i<hashtab[1]; i++) { | 85 if (!strings || !syms || !hashtab) |
79 » » if (!(1<<(syms[i].st_info&0xf) & OK_TYPES)) continue; | 86 return 0; |
80 » » if (!(1<<(syms[i].st_info>>4) & OK_BINDS)) continue; | 87 if (!verdef) |
81 » » if (!syms[i].st_shndx) continue; | 88 versym = 0; |
82 » » if (strcmp(name, strings+syms[i].st_name)) continue; | |
83 » » if (versym && !checkver(verdef, versym[i], vername, strings)) | |
84 » » » continue; | |
85 » » return (void *)(base + syms[i].st_value); | |
86 » } | |
87 | 89 |
88 » return 0; | 90 for (i = 0; i < hashtab[1]; i++) { |
| 91 if (!(1 << (syms[i].st_info & 0xf) & OK_TYPES)) |
| 92 continue; |
| 93 if (!(1 << (syms[i].st_info >> 4) & OK_BINDS)) |
| 94 continue; |
| 95 if (!syms[i].st_shndx) |
| 96 continue; |
| 97 if (strcmp(name, strings + syms[i].st_name)) |
| 98 continue; |
| 99 if (versym && !checkver(verdef, versym[i], vername, strings)) |
| 100 continue; |
| 101 return (void*)(base + syms[i].st_value); |
| 102 } |
| 103 |
| 104 return 0; |
89 } | 105 } |
90 | 106 |
91 #endif | 107 #endif |
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