1 /* SPDX-License-Identifier: GPL-2.0-only */ 1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* 2 /*
3 * recordmcount.h 3 * recordmcount.h
4 * 4 *
5 * This code was taken out of recordmcount.c w 5 * This code was taken out of recordmcount.c written by
6 * Copyright 2009 John F. Reiser <jreiser@BitW 6 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
7 * 7 *
8 * The original code had the same algorithms f 8 * The original code had the same algorithms for both 32bit
9 * and 64bit ELF files, but the code was dupli 9 * and 64bit ELF files, but the code was duplicated to support
10 * the difference in structures that were used 10 * the difference in structures that were used. This
11 * file creates a macro of everything that is 11 * file creates a macro of everything that is different between
12 * the 64 and 32 bit code, such that by includ 12 * the 64 and 32 bit code, such that by including this header
13 * twice we can create both sets of functions 13 * twice we can create both sets of functions by including this
14 * header once with RECORD_MCOUNT_64 undefined 14 * header once with RECORD_MCOUNT_64 undefined, and again with
15 * it defined. 15 * it defined.
16 * 16 *
17 * This conversion to macros was done by: 17 * This conversion to macros was done by:
18 * Copyright 2010 Steven Rostedt <srostedt@red 18 * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
19 */ 19 */
20 #undef append_func 20 #undef append_func
21 #undef is_fake_mcount 21 #undef is_fake_mcount
22 #undef fn_is_fake_mcount 22 #undef fn_is_fake_mcount
23 #undef MIPS_is_fake_mcount 23 #undef MIPS_is_fake_mcount
24 #undef mcount_adjust 24 #undef mcount_adjust
25 #undef sift_rel_mcount 25 #undef sift_rel_mcount
26 #undef nop_mcount 26 #undef nop_mcount
27 #undef find_secsym_ndx 27 #undef find_secsym_ndx
28 #undef __has_rel_mcount 28 #undef __has_rel_mcount
29 #undef has_rel_mcount 29 #undef has_rel_mcount
30 #undef tot_relsize 30 #undef tot_relsize
31 #undef get_mcountsym 31 #undef get_mcountsym
32 #undef find_symtab <<
33 #undef get_shnum <<
34 #undef set_shnum <<
35 #undef get_shstrndx <<
36 #undef get_symindex <<
37 #undef get_sym_str_and_relp 32 #undef get_sym_str_and_relp
38 #undef do_func 33 #undef do_func
39 #undef Elf_Addr 34 #undef Elf_Addr
40 #undef Elf_Ehdr 35 #undef Elf_Ehdr
41 #undef Elf_Shdr 36 #undef Elf_Shdr
42 #undef Elf_Rel 37 #undef Elf_Rel
43 #undef Elf_Rela 38 #undef Elf_Rela
44 #undef Elf_Sym 39 #undef Elf_Sym
45 #undef ELF_R_SYM 40 #undef ELF_R_SYM
46 #undef Elf_r_sym 41 #undef Elf_r_sym
47 #undef ELF_R_INFO 42 #undef ELF_R_INFO
48 #undef Elf_r_info 43 #undef Elf_r_info
49 #undef ELF_ST_BIND 44 #undef ELF_ST_BIND
50 #undef ELF_ST_TYPE 45 #undef ELF_ST_TYPE
51 #undef fn_ELF_R_SYM 46 #undef fn_ELF_R_SYM
52 #undef fn_ELF_R_INFO 47 #undef fn_ELF_R_INFO
53 #undef uint_t 48 #undef uint_t
54 #undef _w 49 #undef _w
55 #undef _align 50 #undef _align
56 #undef _size 51 #undef _size
57 52
58 #ifdef RECORD_MCOUNT_64 53 #ifdef RECORD_MCOUNT_64
59 # define append_func append64 54 # define append_func append64
60 # define sift_rel_mcount sift64_rel_mco 55 # define sift_rel_mcount sift64_rel_mcount
61 # define nop_mcount nop_mcount_64 56 # define nop_mcount nop_mcount_64
62 # define find_secsym_ndx find64_secsym_ 57 # define find_secsym_ndx find64_secsym_ndx
63 # define __has_rel_mcount __has64_rel_mc 58 # define __has_rel_mcount __has64_rel_mcount
64 # define has_rel_mcount has64_rel_mcou 59 # define has_rel_mcount has64_rel_mcount
65 # define tot_relsize tot64_relsize 60 # define tot_relsize tot64_relsize
66 # define find_symtab find_symtab64 <<
67 # define get_shnum get_shnum64 <<
68 # define set_shnum set_shnum64 <<
69 # define get_shstrndx get_shstrndx64 <<
70 # define get_symindex get_symindex64 <<
71 # define get_sym_str_and_relp get_sym_str_an 61 # define get_sym_str_and_relp get_sym_str_and_relp_64
72 # define do_func do64 62 # define do_func do64
73 # define get_mcountsym get_mcountsym_ 63 # define get_mcountsym get_mcountsym_64
74 # define is_fake_mcount is_fake_mcount 64 # define is_fake_mcount is_fake_mcount64
75 # define fn_is_fake_mcount fn_is_fake_mco 65 # define fn_is_fake_mcount fn_is_fake_mcount64
76 # define MIPS_is_fake_mcount MIPS64_is_fake 66 # define MIPS_is_fake_mcount MIPS64_is_fake_mcount
77 # define mcount_adjust mcount_adjust_ 67 # define mcount_adjust mcount_adjust_64
78 # define Elf_Addr Elf64_Addr 68 # define Elf_Addr Elf64_Addr
79 # define Elf_Ehdr Elf64_Ehdr 69 # define Elf_Ehdr Elf64_Ehdr
80 # define Elf_Shdr Elf64_Shdr 70 # define Elf_Shdr Elf64_Shdr
81 # define Elf_Rel Elf64_Rel 71 # define Elf_Rel Elf64_Rel
82 # define Elf_Rela Elf64_Rela 72 # define Elf_Rela Elf64_Rela
83 # define Elf_Sym Elf64_Sym 73 # define Elf_Sym Elf64_Sym
84 # define ELF_R_SYM ELF64_R_SYM 74 # define ELF_R_SYM ELF64_R_SYM
85 # define Elf_r_sym Elf64_r_sym 75 # define Elf_r_sym Elf64_r_sym
86 # define ELF_R_INFO ELF64_R_INFO 76 # define ELF_R_INFO ELF64_R_INFO
87 # define Elf_r_info Elf64_r_info 77 # define Elf_r_info Elf64_r_info
88 # define ELF_ST_BIND ELF64_ST_BIND 78 # define ELF_ST_BIND ELF64_ST_BIND
89 # define ELF_ST_TYPE ELF64_ST_TYPE 79 # define ELF_ST_TYPE ELF64_ST_TYPE
90 # define fn_ELF_R_SYM fn_ELF64_R_SYM 80 # define fn_ELF_R_SYM fn_ELF64_R_SYM
91 # define fn_ELF_R_INFO fn_ELF64_R_INF 81 # define fn_ELF_R_INFO fn_ELF64_R_INFO
92 # define uint_t uint64_t 82 # define uint_t uint64_t
93 # define _w w8 83 # define _w w8
94 # define _align 7u 84 # define _align 7u
95 # define _size 8 85 # define _size 8
96 #else 86 #else
97 # define append_func append32 87 # define append_func append32
98 # define sift_rel_mcount sift32_rel_mco 88 # define sift_rel_mcount sift32_rel_mcount
99 # define nop_mcount nop_mcount_32 89 # define nop_mcount nop_mcount_32
100 # define find_secsym_ndx find32_secsym_ 90 # define find_secsym_ndx find32_secsym_ndx
101 # define __has_rel_mcount __has32_rel_mc 91 # define __has_rel_mcount __has32_rel_mcount
102 # define has_rel_mcount has32_rel_mcou 92 # define has_rel_mcount has32_rel_mcount
103 # define tot_relsize tot32_relsize 93 # define tot_relsize tot32_relsize
104 # define find_symtab find_symtab32 <<
105 # define get_shnum get_shnum32 <<
106 # define set_shnum set_shnum32 <<
107 # define get_shstrndx get_shstrndx32 <<
108 # define get_symindex get_symindex32 <<
109 # define get_sym_str_and_relp get_sym_str_an 94 # define get_sym_str_and_relp get_sym_str_and_relp_32
110 # define do_func do32 95 # define do_func do32
111 # define get_mcountsym get_mcountsym_ 96 # define get_mcountsym get_mcountsym_32
112 # define is_fake_mcount is_fake_mcount 97 # define is_fake_mcount is_fake_mcount32
113 # define fn_is_fake_mcount fn_is_fake_mco 98 # define fn_is_fake_mcount fn_is_fake_mcount32
114 # define MIPS_is_fake_mcount MIPS32_is_fake 99 # define MIPS_is_fake_mcount MIPS32_is_fake_mcount
115 # define mcount_adjust mcount_adjust_ 100 # define mcount_adjust mcount_adjust_32
116 # define Elf_Addr Elf32_Addr 101 # define Elf_Addr Elf32_Addr
117 # define Elf_Ehdr Elf32_Ehdr 102 # define Elf_Ehdr Elf32_Ehdr
118 # define Elf_Shdr Elf32_Shdr 103 # define Elf_Shdr Elf32_Shdr
119 # define Elf_Rel Elf32_Rel 104 # define Elf_Rel Elf32_Rel
120 # define Elf_Rela Elf32_Rela 105 # define Elf_Rela Elf32_Rela
121 # define Elf_Sym Elf32_Sym 106 # define Elf_Sym Elf32_Sym
122 # define ELF_R_SYM ELF32_R_SYM 107 # define ELF_R_SYM ELF32_R_SYM
123 # define Elf_r_sym Elf32_r_sym 108 # define Elf_r_sym Elf32_r_sym
124 # define ELF_R_INFO ELF32_R_INFO 109 # define ELF_R_INFO ELF32_R_INFO
125 # define Elf_r_info Elf32_r_info 110 # define Elf_r_info Elf32_r_info
126 # define ELF_ST_BIND ELF32_ST_BIND 111 # define ELF_ST_BIND ELF32_ST_BIND
127 # define ELF_ST_TYPE ELF32_ST_TYPE 112 # define ELF_ST_TYPE ELF32_ST_TYPE
128 # define fn_ELF_R_SYM fn_ELF32_R_SYM 113 # define fn_ELF_R_SYM fn_ELF32_R_SYM
129 # define fn_ELF_R_INFO fn_ELF32_R_INF 114 # define fn_ELF_R_INFO fn_ELF32_R_INFO
130 # define uint_t uint32_t 115 # define uint_t uint32_t
131 # define _w w 116 # define _w w
132 # define _align 3u 117 # define _align 3u
133 # define _size 4 118 # define _size 4
134 #endif 119 #endif
135 120
136 /* Functions and pointers that do_file() may o 121 /* Functions and pointers that do_file() may override for specific e_machine. */
137 static int fn_is_fake_mcount(Elf_Rel const *rp 122 static int fn_is_fake_mcount(Elf_Rel const *rp)
138 { 123 {
139 return 0; 124 return 0;
140 } 125 }
141 static int (*is_fake_mcount)(Elf_Rel const *rp 126 static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount;
142 127
143 static uint_t fn_ELF_R_SYM(Elf_Rel const *rp) 128 static uint_t fn_ELF_R_SYM(Elf_Rel const *rp)
144 { 129 {
145 return ELF_R_SYM(_w(rp->r_info)); 130 return ELF_R_SYM(_w(rp->r_info));
146 } 131 }
147 static uint_t (*Elf_r_sym)(Elf_Rel const *rp) 132 static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM;
148 133
149 static void fn_ELF_R_INFO(Elf_Rel *const rp, u 134 static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type)
150 { 135 {
151 rp->r_info = _w(ELF_R_INFO(sym, type)) 136 rp->r_info = _w(ELF_R_INFO(sym, type));
152 } 137 }
153 static void (*Elf_r_info)(Elf_Rel *const rp, u 138 static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO;
154 139
155 static int mcount_adjust = 0; 140 static int mcount_adjust = 0;
156 141
157 /* 142 /*
158 * MIPS mcount long call has 2 _mcount symbols 143 * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st
159 * _mcount symbol is needed for dynamic functi 144 * _mcount symbol is needed for dynamic function tracer, with it, to disable
160 * tracing(ftrace_make_nop), the instruction i 145 * tracing(ftrace_make_nop), the instruction in the position is replaced with
161 * the "b label" instruction, to enable tracin 146 * the "b label" instruction, to enable tracing(ftrace_make_call), replace the
162 * instruction back. So, here, we set the 2nd 147 * instruction back. So, here, we set the 2nd one as fake and filter it.
163 * 148 *
164 * c: 3c030000 lui v1,0x0 149 * c: 3c030000 lui v1,0x0 <--> b label
165 * c: R_MIPS_HI16 _mcount 150 * c: R_MIPS_HI16 _mcount
166 * c: R_MIPS_NONE *ABS* 151 * c: R_MIPS_NONE *ABS*
167 * c: R_MIPS_NONE *ABS* 152 * c: R_MIPS_NONE *ABS*
168 * 10: 64630000 daddiu v1,v1,0 153 * 10: 64630000 daddiu v1,v1,0
169 * 10: R_MIPS_LO16 _mcount 154 * 10: R_MIPS_LO16 _mcount
170 * 10: R_MIPS_NONE *ABS* 155 * 10: R_MIPS_NONE *ABS*
171 * 10: R_MIPS_NONE *ABS* 156 * 10: R_MIPS_NONE *ABS*
172 * 14: 03e0082d move at,ra 157 * 14: 03e0082d move at,ra
173 * 18: 0060f809 jalr v1 158 * 18: 0060f809 jalr v1
174 * label: 159 * label:
175 */ 160 */
176 #define MIPS_FAKEMCOUNT_OFFSET 4 161 #define MIPS_FAKEMCOUNT_OFFSET 4
177 162
178 static int MIPS_is_fake_mcount(Elf_Rel const * 163 static int MIPS_is_fake_mcount(Elf_Rel const *rp)
179 { 164 {
180 static Elf_Addr old_r_offset = ~(Elf_A 165 static Elf_Addr old_r_offset = ~(Elf_Addr)0;
181 Elf_Addr current_r_offset = _w(rp->r_o 166 Elf_Addr current_r_offset = _w(rp->r_offset);
182 int is_fake; 167 int is_fake;
183 168
184 is_fake = (old_r_offset != ~(Elf_Addr) 169 is_fake = (old_r_offset != ~(Elf_Addr)0) &&
185 (current_r_offset - old_r_offs 170 (current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET);
186 old_r_offset = current_r_offset; 171 old_r_offset = current_r_offset;
187 172
188 return is_fake; 173 return is_fake;
189 } 174 }
190 175
191 static unsigned int get_symindex(Elf_Sym const <<
192 Elf32_Word co <<
193 { <<
194 unsigned long offset; <<
195 unsigned short shndx = w2(sym->st_shnd <<
196 int index; <<
197 <<
198 if (shndx > SHN_UNDEF && shndx < SHN_L <<
199 return shndx; <<
200 <<
201 if (shndx == SHN_XINDEX) { <<
202 offset = (unsigned long)sym - <<
203 index = offset / sizeof(*sym); <<
204 <<
205 return w(symtab_shndx[index]); <<
206 } <<
207 <<
208 return 0; <<
209 } <<
210 <<
211 static unsigned int get_shnum(Elf_Ehdr const * <<
212 { <<
213 if (shdr0 && !ehdr->e_shnum) <<
214 return w(shdr0->sh_size); <<
215 <<
216 return w2(ehdr->e_shnum); <<
217 } <<
218 <<
219 static void set_shnum(Elf_Ehdr *ehdr, Elf_Shdr <<
220 { <<
221 if (new_shnum >= SHN_LORESERVE) { <<
222 ehdr->e_shnum = 0; <<
223 shdr0->sh_size = w(new_shnum); <<
224 } else <<
225 ehdr->e_shnum = w2(new_shnum); <<
226 } <<
227 <<
228 static int get_shstrndx(Elf_Ehdr const *ehdr, <<
229 { <<
230 if (ehdr->e_shstrndx != SHN_XINDEX) <<
231 return w2(ehdr->e_shstrndx); <<
232 <<
233 return w(shdr0->sh_link); <<
234 } <<
235 <<
236 static void find_symtab(Elf_Ehdr *const ehdr, <<
237 unsigned const nhdr, E <<
238 Elf32_Word **symtab_sh <<
239 { <<
240 Elf_Shdr const *relhdr; <<
241 unsigned k; <<
242 <<
243 *symtab = NULL; <<
244 *symtab_shndx = NULL; <<
245 <<
246 for (relhdr = shdr0, k = nhdr; k; --k, <<
247 if (relhdr->sh_type == SHT_SYM <<
248 *symtab = (void *)ehdr <<
249 else if (relhdr->sh_type == SH <<
250 *symtab_shndx = (void <<
251 <<
252 if (*symtab && *symtab_shndx) <<
253 break; <<
254 } <<
255 } <<
256 <<
257 /* Append the new shstrtab, Elf_Shdr[], __mcou 176 /* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
258 static int append_func(Elf_Ehdr *const ehdr, !! 177 static void append_func(Elf_Ehdr *const ehdr,
259 Elf_Shdr *const shstr, 178 Elf_Shdr *const shstr,
260 uint_t const *const ml 179 uint_t const *const mloc0,
261 uint_t const *const ml 180 uint_t const *const mlocp,
262 Elf_Rel const *const m 181 Elf_Rel const *const mrel0,
263 Elf_Rel const *const m 182 Elf_Rel const *const mrelp,
264 unsigned int const rel 183 unsigned int const rel_entsize,
265 unsigned int const sym 184 unsigned int const symsec_sh_link)
266 { 185 {
267 /* Begin constructing output file */ 186 /* Begin constructing output file */
268 Elf_Shdr mcsec; 187 Elf_Shdr mcsec;
269 char const *mc_name = (sizeof(Elf_Rela 188 char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)
270 ? ".rela__mcount_loc" 189 ? ".rela__mcount_loc"
271 : ".rel__mcount_loc"; 190 : ".rel__mcount_loc";
>> 191 unsigned const old_shnum = w2(ehdr->e_shnum);
272 uint_t const old_shoff = _w(ehdr->e_sh 192 uint_t const old_shoff = _w(ehdr->e_shoff);
273 uint_t const old_shstr_sh_size = _w( 193 uint_t const old_shstr_sh_size = _w(shstr->sh_size);
274 uint_t const old_shstr_sh_offset = _w( 194 uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);
275 Elf_Shdr *const shdr0 = (Elf_Shdr *)(o <<
276 unsigned int const old_shnum = get_shn <<
277 unsigned int const new_shnum = 2 + old <<
278 uint_t t = 1 + strlen(mc_name) + _w(sh 195 uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);
279 uint_t new_e_shoff; 196 uint_t new_e_shoff;
280 197
281 shstr->sh_size = _w(t); 198 shstr->sh_size = _w(t);
282 shstr->sh_offset = _w(sb.st_size); 199 shstr->sh_offset = _w(sb.st_size);
283 t += sb.st_size; 200 t += sb.st_size;
284 t += (_align & -t); /* word-byte alig 201 t += (_align & -t); /* word-byte align */
285 new_e_shoff = t; 202 new_e_shoff = t;
286 203
287 set_shnum(ehdr, shdr0, new_shnum); <<
288 <<
289 /* body for new shstrtab */ 204 /* body for new shstrtab */
290 if (ulseek(sb.st_size, SEEK_SET) < 0) !! 205 ulseek(fd_map, sb.st_size, SEEK_SET);
291 return -1; !! 206 uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
292 if (uwrite(old_shstr_sh_offset + (void !! 207 uwrite(fd_map, mc_name, 1 + strlen(mc_name));
293 return -1; <<
294 if (uwrite(mc_name, 1 + strlen(mc_name <<
295 return -1; <<
296 208
297 /* old(modified) Elf_Shdr table, word- 209 /* old(modified) Elf_Shdr table, word-byte aligned */
298 if (ulseek(t, SEEK_SET) < 0) !! 210 ulseek(fd_map, t, SEEK_SET);
299 return -1; <<
300 t += sizeof(Elf_Shdr) * old_shnum; 211 t += sizeof(Elf_Shdr) * old_shnum;
301 if (uwrite(old_shoff + (void *)ehdr, !! 212 uwrite(fd_map, old_shoff + (void *)ehdr,
302 sizeof(Elf_Shdr) * old_shnum) < !! 213 sizeof(Elf_Shdr) * old_shnum);
303 return -1; <<
304 214
305 /* new sections __mcount_loc and .rel_ 215 /* new sections __mcount_loc and .rel__mcount_loc */
306 t += 2*sizeof(mcsec); 216 t += 2*sizeof(mcsec);
307 mcsec.sh_name = w((sizeof(Elf_Rela) == 217 mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")
308 + old_shstr_sh_size); 218 + old_shstr_sh_size);
309 mcsec.sh_type = w(SHT_PROGBITS); 219 mcsec.sh_type = w(SHT_PROGBITS);
310 mcsec.sh_flags = _w(SHF_ALLOC); 220 mcsec.sh_flags = _w(SHF_ALLOC);
311 mcsec.sh_addr = 0; 221 mcsec.sh_addr = 0;
312 mcsec.sh_offset = _w(t); 222 mcsec.sh_offset = _w(t);
313 mcsec.sh_size = _w((void *)mlocp - (vo 223 mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);
314 mcsec.sh_link = 0; 224 mcsec.sh_link = 0;
315 mcsec.sh_info = 0; 225 mcsec.sh_info = 0;
316 mcsec.sh_addralign = _w(_size); 226 mcsec.sh_addralign = _w(_size);
317 mcsec.sh_entsize = _w(_size); 227 mcsec.sh_entsize = _w(_size);
318 if (uwrite(&mcsec, sizeof(mcsec)) < 0) !! 228 uwrite(fd_map, &mcsec, sizeof(mcsec));
319 return -1; <<
320 229
321 mcsec.sh_name = w(old_shstr_sh_size); 230 mcsec.sh_name = w(old_shstr_sh_size);
322 mcsec.sh_type = (sizeof(Elf_Rela) == r 231 mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
323 ? w(SHT_RELA) 232 ? w(SHT_RELA)
324 : w(SHT_REL); 233 : w(SHT_REL);
325 mcsec.sh_flags = 0; 234 mcsec.sh_flags = 0;
326 mcsec.sh_addr = 0; 235 mcsec.sh_addr = 0;
327 mcsec.sh_offset = _w((void *)mlocp - ( 236 mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);
328 mcsec.sh_size = _w((void *)mrelp - ( 237 mcsec.sh_size = _w((void *)mrelp - (void *)mrel0);
329 mcsec.sh_link = w(symsec_sh_link); 238 mcsec.sh_link = w(symsec_sh_link);
330 mcsec.sh_info = w(old_shnum); 239 mcsec.sh_info = w(old_shnum);
331 mcsec.sh_addralign = _w(_size); 240 mcsec.sh_addralign = _w(_size);
332 mcsec.sh_entsize = _w(rel_entsize); 241 mcsec.sh_entsize = _w(rel_entsize);
>> 242 uwrite(fd_map, &mcsec, sizeof(mcsec));
333 243
334 if (uwrite(&mcsec, sizeof(mcsec)) < 0) !! 244 uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
335 return -1; !! 245 uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
336 <<
337 if (uwrite(mloc0, (void *)mlocp - (voi <<
338 return -1; <<
339 if (uwrite(mrel0, (void *)mrelp - (voi <<
340 return -1; <<
341 246
342 ehdr->e_shoff = _w(new_e_shoff); 247 ehdr->e_shoff = _w(new_e_shoff);
343 if (ulseek(0, SEEK_SET) < 0) !! 248 ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */
344 return -1; !! 249 ulseek(fd_map, 0, SEEK_SET);
345 if (uwrite(ehdr, sizeof(*ehdr)) < 0) !! 250 uwrite(fd_map, ehdr, sizeof(*ehdr));
346 return -1; <<
347 return 0; <<
348 } 251 }
349 252
350 static unsigned get_mcountsym(Elf_Sym const *c 253 static unsigned get_mcountsym(Elf_Sym const *const sym0,
351 Elf_Rel const *r 254 Elf_Rel const *relp,
352 char const *cons 255 char const *const str0)
353 { 256 {
354 unsigned mcountsym = 0; 257 unsigned mcountsym = 0;
355 258
356 Elf_Sym const *const symp = 259 Elf_Sym const *const symp =
357 &sym0[Elf_r_sym(relp)]; 260 &sym0[Elf_r_sym(relp)];
358 char const *symname = &str0[w(symp->st 261 char const *symname = &str0[w(symp->st_name)];
359 char const *mcount = gpfx == '_' ? "_m 262 char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
360 char const *fentry = "__fentry__"; 263 char const *fentry = "__fentry__";
361 264
362 if (symname[0] == '.') 265 if (symname[0] == '.')
363 ++symname; /* ppc64 hack */ 266 ++symname; /* ppc64 hack */
364 if (strcmp(mcount, symname) == 0 || 267 if (strcmp(mcount, symname) == 0 ||
365 (altmcount && strcmp(altmcount, sy 268 (altmcount && strcmp(altmcount, symname) == 0) ||
366 (strcmp(fentry, symname) == 0)) 269 (strcmp(fentry, symname) == 0))
367 mcountsym = Elf_r_sym(relp); 270 mcountsym = Elf_r_sym(relp);
368 271
369 return mcountsym; 272 return mcountsym;
370 } 273 }
371 274
372 static void get_sym_str_and_relp(Elf_Shdr cons 275 static void get_sym_str_and_relp(Elf_Shdr const *const relhdr,
373 Elf_Ehdr cons 276 Elf_Ehdr const *const ehdr,
374 Elf_Sym const 277 Elf_Sym const **sym0,
375 char const ** 278 char const **str0,
376 Elf_Rel const 279 Elf_Rel const **relp)
377 { 280 {
378 Elf_Shdr *const shdr0 = (Elf_Shdr *)(_ 281 Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
379 + (void *)ehdr); 282 + (void *)ehdr);
380 unsigned const symsec_sh_link = w(relh 283 unsigned const symsec_sh_link = w(relhdr->sh_link);
381 Elf_Shdr const *const symsec = &shdr0[ 284 Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
382 Elf_Shdr const *const strsec = &shdr0[ 285 Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
383 Elf_Rel const *const rel0 = (Elf_Rel c 286 Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
384 + (void *)ehdr); 287 + (void *)ehdr);
385 288
386 *sym0 = (Elf_Sym const *)(_w(symsec->s 289 *sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
387 + (void *)eh 290 + (void *)ehdr);
388 291
389 *str0 = (char const *)(_w(strsec->sh_o 292 *str0 = (char const *)(_w(strsec->sh_offset)
390 + (void *)ehdr) 293 + (void *)ehdr);
391 294
392 *relp = rel0; 295 *relp = rel0;
393 } 296 }
394 297
395 /* 298 /*
396 * Look at the relocations in order to find th 299 * Look at the relocations in order to find the calls to mcount.
397 * Accumulate the section offsets that are fou 300 * Accumulate the section offsets that are found, and their relocation info,
398 * onto the end of the existing arrays. 301 * onto the end of the existing arrays.
399 */ 302 */
400 static uint_t *sift_rel_mcount(uint_t *mlocp, 303 static uint_t *sift_rel_mcount(uint_t *mlocp,
401 unsigned const 304 unsigned const offbase,
402 Elf_Rel **const 305 Elf_Rel **const mrelpp,
403 Elf_Shdr const 306 Elf_Shdr const *const relhdr,
404 Elf_Ehdr const 307 Elf_Ehdr const *const ehdr,
405 unsigned const 308 unsigned const recsym,
406 uint_t const re 309 uint_t const recval,
407 unsigned const 310 unsigned const reltype)
408 { 311 {
409 uint_t *const mloc0 = mlocp; 312 uint_t *const mloc0 = mlocp;
410 Elf_Rel *mrelp = *mrelpp; 313 Elf_Rel *mrelp = *mrelpp;
411 Elf_Sym const *sym0; 314 Elf_Sym const *sym0;
412 char const *str0; 315 char const *str0;
413 Elf_Rel const *relp; 316 Elf_Rel const *relp;
414 unsigned rel_entsize = _w(relhdr->sh_e 317 unsigned rel_entsize = _w(relhdr->sh_entsize);
415 unsigned const nrel = _w(relhdr->sh_si 318 unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
416 unsigned mcountsym = 0; 319 unsigned mcountsym = 0;
417 unsigned t; 320 unsigned t;
418 321
419 get_sym_str_and_relp(relhdr, ehdr, &sy 322 get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
420 323
421 for (t = nrel; t; --t) { 324 for (t = nrel; t; --t) {
422 if (!mcountsym) 325 if (!mcountsym)
423 mcountsym = get_mcount 326 mcountsym = get_mcountsym(sym0, relp, str0);
424 327
425 if (mcountsym && mcountsym == 328 if (mcountsym && mcountsym == Elf_r_sym(relp) &&
426 !is_fake_mcoun 329 !is_fake_mcount(relp)) {
427 uint_t const addend = 330 uint_t const addend =
428 _w(_w(relp->r_ 331 _w(_w(relp->r_offset) - recval + mcount_adjust);
429 mrelp->r_offset = _w(o 332 mrelp->r_offset = _w(offbase
430 + ((void *)mlo 333 + ((void *)mlocp - (void *)mloc0));
431 Elf_r_info(mrelp, recs 334 Elf_r_info(mrelp, recsym, reltype);
432 if (rel_entsize == siz 335 if (rel_entsize == sizeof(Elf_Rela)) {
433 ((Elf_Rela *)m 336 ((Elf_Rela *)mrelp)->r_addend = addend;
434 *mlocp++ = 0; 337 *mlocp++ = 0;
435 } else 338 } else
436 *mlocp++ = add 339 *mlocp++ = addend;
437 340
438 mrelp = (Elf_Rel *)(re 341 mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);
439 } 342 }
440 relp = (Elf_Rel const *)(rel_e 343 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
441 } 344 }
442 *mrelpp = mrelp; 345 *mrelpp = mrelp;
443 return mlocp; 346 return mlocp;
444 } 347 }
445 348
446 /* 349 /*
447 * Read the relocation table again, but this t 350 * Read the relocation table again, but this time its called on sections
448 * that are not going to be traced. The mcount 351 * that are not going to be traced. The mcount calls here will be converted
449 * into nops. 352 * into nops.
450 */ 353 */
451 static int nop_mcount(Elf_Shdr const *const re !! 354 static void nop_mcount(Elf_Shdr const *const relhdr,
452 Elf_Ehdr const *const eh !! 355 Elf_Ehdr const *const ehdr,
453 const char *const txtnam !! 356 const char *const txtname)
454 { 357 {
455 Elf_Shdr *const shdr0 = (Elf_Shdr *)(_ 358 Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
456 + (void *)ehdr); 359 + (void *)ehdr);
457 Elf_Sym const *sym0; 360 Elf_Sym const *sym0;
458 char const *str0; 361 char const *str0;
459 Elf_Rel const *relp; 362 Elf_Rel const *relp;
460 Elf_Shdr const *const shdr = &shdr0[w( 363 Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];
461 unsigned rel_entsize = _w(relhdr->sh_e 364 unsigned rel_entsize = _w(relhdr->sh_entsize);
462 unsigned const nrel = _w(relhdr->sh_si 365 unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
463 unsigned mcountsym = 0; 366 unsigned mcountsym = 0;
464 unsigned t; 367 unsigned t;
465 int once = 0; 368 int once = 0;
466 369
467 get_sym_str_and_relp(relhdr, ehdr, &sy 370 get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
468 371
469 for (t = nrel; t; --t) { 372 for (t = nrel; t; --t) {
470 int ret = -1; 373 int ret = -1;
471 374
472 if (!mcountsym) 375 if (!mcountsym)
473 mcountsym = get_mcount 376 mcountsym = get_mcountsym(sym0, relp, str0);
474 377
475 if (mcountsym == Elf_r_sym(rel 378 if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
476 if (make_nop) 379 if (make_nop)
477 ret = make_nop 380 ret = make_nop((void *)ehdr, _w(shdr->sh_offset) + _w(relp->r_offset));
478 if (warn_on_notrace_se 381 if (warn_on_notrace_sect && !once) {
479 printf("Sectio 382 printf("Section %s has mcount callers being ignored\n",
480 txtname 383 txtname);
481 once = 1; 384 once = 1;
482 /* just warn? 385 /* just warn? */
483 if (!make_nop) 386 if (!make_nop)
484 return !! 387 return;
485 } 388 }
486 } 389 }
487 390
488 /* 391 /*
489 * If we successfully removed 392 * If we successfully removed the mcount, mark the relocation
490 * as a nop (don't do anything 393 * as a nop (don't do anything with it).
491 */ 394 */
492 if (!ret) { 395 if (!ret) {
493 Elf_Rel rel; 396 Elf_Rel rel;
494 rel = *(Elf_Rel *)relp 397 rel = *(Elf_Rel *)relp;
495 Elf_r_info(&rel, Elf_r 398 Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop);
496 if (ulseek((void *)rel !! 399 ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);
497 return -1; !! 400 uwrite(fd_map, &rel, sizeof(rel));
498 if (uwrite(&rel, sizeo <<
499 return -1; <<
500 } 401 }
501 relp = (Elf_Rel const *)(rel_e 402 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
502 } 403 }
503 return 0; <<
504 } 404 }
505 405
>> 406
506 /* 407 /*
507 * Find a symbol in the given section, to be u 408 * Find a symbol in the given section, to be used as the base for relocating
508 * the table of offsets of calls to mcount. A 409 * the table of offsets of calls to mcount. A local or global symbol suffices,
509 * but avoid a Weak symbol because it may be o 410 * but avoid a Weak symbol because it may be overridden; the change in value
510 * would invalidate the relocations of the off 411 * would invalidate the relocations of the offsets of the calls to mcount.
511 * Often the found symbol will be the unnamed 412 * Often the found symbol will be the unnamed local symbol generated by
512 * GNU 'as' for the start of each section. Fo 413 * GNU 'as' for the start of each section. For example:
513 * Num: Value Size Type Bind Vis 414 * Num: Value Size Type Bind Vis Ndx Name
514 * 2: 00000000 0 SECTION LOCAL DEFAU 415 * 2: 00000000 0 SECTION LOCAL DEFAULT 1
515 */ 416 */
516 static int find_secsym_ndx(unsigned const txtn !! 417 static unsigned find_secsym_ndx(unsigned const txtndx,
517 char const *co 418 char const *const txtname,
518 uint_t *const 419 uint_t *const recvalp,
519 unsigned int * <<
520 Elf_Shdr const 420 Elf_Shdr const *const symhdr,
521 Elf32_Word con <<
522 Elf32_Word con <<
523 Elf_Ehdr const 421 Elf_Ehdr const *const ehdr)
524 { 422 {
525 Elf_Sym const *const sym0 = (Elf_Sym c 423 Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
526 + (void *)ehdr); 424 + (void *)ehdr);
527 unsigned const nsym = _w(symhdr->sh_si 425 unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
528 Elf_Sym const *symp; 426 Elf_Sym const *symp;
529 unsigned t; 427 unsigned t;
530 428
531 for (symp = sym0, t = nsym; t; --t, ++ 429 for (symp = sym0, t = nsym; t; --t, ++symp) {
532 unsigned int const st_bind = E 430 unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
533 431
534 if (txtndx == get_symindex(sym !! 432 if (txtndx == w2(symp->st_shndx)
535 /* avoid STB_WEAK */ 433 /* avoid STB_WEAK */
536 && (STB_LOCAL == st_bind | 434 && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
537 /* function symbols on 435 /* function symbols on ARM have quirks, avoid them */
538 if (w2(ehdr->e_machine 436 if (w2(ehdr->e_machine) == EM_ARM
539 && ELF_ST_TYPE(sym 437 && ELF_ST_TYPE(symp->st_info) == STT_FUNC)
540 continue; 438 continue;
541 439
542 *recvalp = _w(symp->st 440 *recvalp = _w(symp->st_value);
543 *sym_index = symp - sy !! 441 return symp - sym0;
544 return 0; <<
545 } 442 }
546 } 443 }
547 fprintf(stderr, "Cannot find symbol fo 444 fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
548 txtndx, txtname); 445 txtndx, txtname);
549 return -1; !! 446 fail_file();
550 } 447 }
551 448
>> 449
552 /* Evade ISO C restriction: no declaration aft 450 /* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
553 static char const * __has_rel_mcount(Elf_Shdr !! 451 static char const *
554 Elf_Shdr !! 452 __has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
555 char cons !! 453 Elf_Shdr const *const shdr0,
556 char cons !! 454 char const *const shstrtab,
>> 455 char const *const fname)
557 { 456 {
558 /* .sh_info depends on .sh_type == SHT 457 /* .sh_info depends on .sh_type == SHT_REL[,A] */
559 Elf_Shdr const *const txthdr = &shdr0[ 458 Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
560 char const *const txtname = &shstrtab[ 459 char const *const txtname = &shstrtab[w(txthdr->sh_name)];
561 460
562 if (strcmp("__mcount_loc", txtname) == 461 if (strcmp("__mcount_loc", txtname) == 0) {
563 fprintf(stderr, "warning: __mc 462 fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
564 fname); 463 fname);
565 return already_has_rel_mcount; !! 464 succeed_file();
566 } 465 }
567 if (w(txthdr->sh_type) != SHT_PROGBITS 466 if (w(txthdr->sh_type) != SHT_PROGBITS ||
568 !(_w(txthdr->sh_flags) & SHF_EXECI 467 !(_w(txthdr->sh_flags) & SHF_EXECINSTR))
569 return NULL; 468 return NULL;
570 return txtname; 469 return txtname;
571 } 470 }
572 471
573 static char const *has_rel_mcount(Elf_Shdr con 472 static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
574 Elf_Shdr con 473 Elf_Shdr const *const shdr0,
575 char const * 474 char const *const shstrtab,
576 char const * 475 char const *const fname)
577 { 476 {
578 if (w(relhdr->sh_type) != SHT_REL && w 477 if (w(relhdr->sh_type) != SHT_REL && w(relhdr->sh_type) != SHT_RELA)
579 return NULL; 478 return NULL;
580 return __has_rel_mcount(relhdr, shdr0, 479 return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
581 } 480 }
582 481
583 482
584 static unsigned tot_relsize(Elf_Shdr const *co 483 static unsigned tot_relsize(Elf_Shdr const *const shdr0,
585 unsigned nhdr, 484 unsigned nhdr,
586 const char *const 485 const char *const shstrtab,
587 const char *const 486 const char *const fname)
588 { 487 {
589 unsigned totrelsz = 0; 488 unsigned totrelsz = 0;
590 Elf_Shdr const *shdrp = shdr0; 489 Elf_Shdr const *shdrp = shdr0;
591 char const *txtname; 490 char const *txtname;
592 491
593 for (; nhdr; --nhdr, ++shdrp) { 492 for (; nhdr; --nhdr, ++shdrp) {
594 txtname = has_rel_mcount(shdrp 493 txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname);
595 if (txtname == already_has_rel <<
596 totrelsz = 0; <<
597 break; <<
598 } <<
599 if (txtname && is_mcounted_sec 494 if (txtname && is_mcounted_section_name(txtname))
600 totrelsz += _w(shdrp-> 495 totrelsz += _w(shdrp->sh_size);
601 } 496 }
602 return totrelsz; 497 return totrelsz;
603 } 498 }
604 499
>> 500
605 /* Overall supervision for Elf32 ET_REL file. 501 /* Overall supervision for Elf32 ET_REL file. */
606 static int do_func(Elf_Ehdr *const ehdr, char !! 502 static void
607 unsigned const reltype) !! 503 do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
608 { 504 {
609 Elf_Shdr *const shdr0 = (Elf_Shdr *)(_ 505 Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
610 + (void *)ehdr); 506 + (void *)ehdr);
611 unsigned const nhdr = get_shnum(ehdr, !! 507 unsigned const nhdr = w2(ehdr->e_shnum);
612 Elf_Shdr *const shstr = &shdr0[get_shs !! 508 Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
613 char const *const shstrtab = (char con 509 char const *const shstrtab = (char const *)(_w(shstr->sh_offset)
614 + (void *)ehdr); 510 + (void *)ehdr);
615 511
616 Elf_Shdr const *relhdr; 512 Elf_Shdr const *relhdr;
617 unsigned k; 513 unsigned k;
618 514
619 Elf32_Word *symtab; <<
620 Elf32_Word *symtab_shndx; <<
621 <<
622 /* Upper bound on space: assume all re 515 /* Upper bound on space: assume all relevant relocs are for mcount. */
623 unsigned totrelsz; !! 516 unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
>> 517 Elf_Rel *const mrel0 = umalloc(totrelsz);
>> 518 Elf_Rel * mrelp = mrel0;
624 519
625 Elf_Rel * mrel0; !! 520 /* 2*sizeof(address) <= sizeof(Elf_Rel) */
626 Elf_Rel * mrelp; !! 521 uint_t *const mloc0 = umalloc(totrelsz>>1);
627 !! 522 uint_t * mlocp = mloc0;
628 uint_t * mloc0; <<
629 uint_t * mlocp; <<
630 523
631 unsigned rel_entsize = 0; 524 unsigned rel_entsize = 0;
632 unsigned symsec_sh_link = 0; 525 unsigned symsec_sh_link = 0;
633 526
634 int result = 0; <<
635 <<
636 totrelsz = tot_relsize(shdr0, nhdr, sh <<
637 if (totrelsz == 0) <<
638 return 0; <<
639 mrel0 = umalloc(totrelsz); <<
640 mrelp = mrel0; <<
641 if (!mrel0) <<
642 return -1; <<
643 <<
644 /* 2*sizeof(address) <= sizeof(Elf_Rel <<
645 mloc0 = umalloc(totrelsz>>1); <<
646 mlocp = mloc0; <<
647 if (!mloc0) { <<
648 free(mrel0); <<
649 return -1; <<
650 } <<
651 <<
652 find_symtab(ehdr, shdr0, nhdr, &symtab <<
653 <<
654 for (relhdr = shdr0, k = nhdr; k; --k, 527 for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
655 char const *const txtname = ha 528 char const *const txtname = has_rel_mcount(relhdr, shdr0,
656 shstrtab, fname); 529 shstrtab, fname);
657 if (txtname == already_has_rel <<
658 result = 0; <<
659 file_updated = 0; <<
660 goto out; /* Nothing t <<
661 } <<
662 if (txtname && is_mcounted_sec 530 if (txtname && is_mcounted_section_name(txtname)) {
663 unsigned int recsym; <<
664 uint_t recval = 0; 531 uint_t recval = 0;
665 !! 532 unsigned const recsym = find_secsym_ndx(
666 symsec_sh_link = w(rel !! 533 w(relhdr->sh_info), txtname, &recval,
667 result = find_secsym_n !! 534 &shdr0[symsec_sh_link = w(relhdr->sh_link)],
668 !! 535 ehdr);
669 <<
670 <<
671 <<
672 if (result) <<
673 goto out; <<
674 536
675 rel_entsize = _w(relhd 537 rel_entsize = _w(relhdr->sh_entsize);
676 mlocp = sift_rel_mcoun 538 mlocp = sift_rel_mcount(mlocp,
677 (void *)mlocp 539 (void *)mlocp - (void *)mloc0, &mrelp,
678 relhdr, ehdr, 540 relhdr, ehdr, recsym, recval, reltype);
679 } else if (txtname && (warn_on 541 } else if (txtname && (warn_on_notrace_sect || make_nop)) {
680 /* 542 /*
681 * This section is ign 543 * This section is ignored by ftrace, but still
682 * has mcount calls. C 544 * has mcount calls. Convert them to nops now.
683 */ 545 */
684 if (nop_mcount(relhdr, !! 546 nop_mcount(relhdr, ehdr, txtname);
685 result = -1; <<
686 goto out; <<
687 } <<
688 } 547 }
689 } 548 }
690 if (!result && mloc0 != mlocp) !! 549 if (mloc0 != mlocp) {
691 result = append_func(ehdr, shs !! 550 append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
692 rel_entsi !! 551 rel_entsize, symsec_sh_link);
693 out: !! 552 }
694 free(mrel0); 553 free(mrel0);
695 free(mloc0); 554 free(mloc0);
696 return result; <<
697 } 555 }
698 556
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