Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * a.out loader for x86-64 | |
4 | * | |
5 | * Copyright (C) 1991, 1992, 1996 Linus Torvalds | |
6 | * Hacked together by Andi Kleen | |
7 | */ | |
8 | ||
9 | #include <linux/module.h> | |
10 | ||
11 | #include <linux/time.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/mm.h> | |
14 | #include <linux/mman.h> | |
15 | #include <linux/a.out.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/signal.h> | |
18 | #include <linux/string.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/file.h> | |
21 | #include <linux/stat.h> | |
22 | #include <linux/fcntl.h> | |
23 | #include <linux/ptrace.h> | |
24 | #include <linux/user.h> | |
1da177e4 LT |
25 | #include <linux/binfmts.h> |
26 | #include <linux/personality.h> | |
27 | #include <linux/init.h> | |
e5fc3161 | 28 | #include <linux/jiffies.h> |
7d2f551f | 29 | #include <linux/perf_event.h> |
68db0cf1 | 30 | #include <linux/sched/task_stack.h> |
1da177e4 | 31 | |
7c0f6ba6 | 32 | #include <linux/uaccess.h> |
1da177e4 LT |
33 | #include <asm/pgalloc.h> |
34 | #include <asm/cacheflush.h> | |
35 | #include <asm/user32.h> | |
36 | #include <asm/ia32.h> | |
37 | ||
38 | #undef WARN_OLD | |
1da177e4 | 39 | |
71613c3b | 40 | static int load_aout_binary(struct linux_binprm *); |
8edf8bee | 41 | static int load_aout_library(struct file *); |
1da177e4 | 42 | |
1da177e4 LT |
43 | static struct linux_binfmt aout_format = { |
44 | .module = THIS_MODULE, | |
45 | .load_binary = load_aout_binary, | |
46 | .load_shlib = load_aout_library, | |
1da177e4 LT |
47 | }; |
48 | ||
5d22fc25 | 49 | static int set_brk(unsigned long start, unsigned long end) |
1da177e4 LT |
50 | { |
51 | start = PAGE_ALIGN(start); | |
52 | end = PAGE_ALIGN(end); | |
53 | if (end <= start) | |
5d22fc25 | 54 | return 0; |
864778b1 | 55 | return vm_brk(start, end - start); |
1da177e4 LT |
56 | } |
57 | ||
1da177e4 LT |
58 | |
59 | /* | |
60 | * create_aout_tables() parses the env- and arg-strings in new user | |
61 | * memory and creates the pointer tables from them, and puts their | |
62 | * addresses on the "stack", returning the new stack pointer value. | |
63 | */ | |
64 | static u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm) | |
65 | { | |
8edf8bee TG |
66 | u32 __user *argv, *envp, *sp; |
67 | int argc = bprm->argc, envc = bprm->envc; | |
1da177e4 LT |
68 | |
69 | sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p); | |
70 | sp -= envc+1; | |
71 | envp = sp; | |
72 | sp -= argc+1; | |
73 | argv = sp; | |
8edf8bee TG |
74 | put_user((unsigned long) envp, --sp); |
75 | put_user((unsigned long) argv, --sp); | |
76 | put_user(argc, --sp); | |
1da177e4 | 77 | current->mm->arg_start = (unsigned long) p; |
8edf8bee | 78 | while (argc-- > 0) { |
1da177e4 | 79 | char c; |
8edf8bee TG |
80 | |
81 | put_user((u32)(unsigned long)p, argv++); | |
1da177e4 | 82 | do { |
8edf8bee | 83 | get_user(c, p++); |
1da177e4 LT |
84 | } while (c); |
85 | } | |
74019699 | 86 | put_user(0, argv); |
1da177e4 | 87 | current->mm->arg_end = current->mm->env_start = (unsigned long) p; |
8edf8bee | 88 | while (envc-- > 0) { |
1da177e4 | 89 | char c; |
8edf8bee TG |
90 | |
91 | put_user((u32)(unsigned long)p, envp++); | |
1da177e4 | 92 | do { |
8edf8bee | 93 | get_user(c, p++); |
1da177e4 LT |
94 | } while (c); |
95 | } | |
74019699 | 96 | put_user(0, envp); |
1da177e4 LT |
97 | current->mm->env_end = (unsigned long) p; |
98 | return sp; | |
99 | } | |
100 | ||
101 | /* | |
102 | * These are the functions used to load a.out style executables and shared | |
103 | * libraries. There is no binary dependent code anywhere else. | |
104 | */ | |
71613c3b | 105 | static int load_aout_binary(struct linux_binprm *bprm) |
1da177e4 | 106 | { |
8edf8bee | 107 | unsigned long error, fd_offset, rlim; |
71613c3b | 108 | struct pt_regs *regs = current_pt_regs(); |
1da177e4 | 109 | struct exec ex; |
1da177e4 LT |
110 | int retval; |
111 | ||
112 | ex = *((struct exec *) bprm->buf); /* exec-header */ | |
113 | if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && | |
114 | N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) || | |
115 | N_TRSIZE(ex) || N_DRSIZE(ex) || | |
496ad9aa | 116 | i_size_read(file_inode(bprm->file)) < |
8edf8bee | 117 | ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { |
1da177e4 LT |
118 | return -ENOEXEC; |
119 | } | |
120 | ||
121 | fd_offset = N_TXTOFF(ex); | |
122 | ||
123 | /* Check initial limits. This avoids letting people circumvent | |
124 | * size limits imposed on them by creating programs with large | |
125 | * arrays in the data or bss. | |
126 | */ | |
2854e72b | 127 | rlim = rlimit(RLIMIT_DATA); |
1da177e4 LT |
128 | if (rlim >= RLIM_INFINITY) |
129 | rlim = ~0; | |
130 | if (ex.a_data + ex.a_bss > rlim) | |
131 | return -ENOMEM; | |
132 | ||
133 | /* Flush all traces of the currently running executable */ | |
134 | retval = flush_old_exec(bprm); | |
135 | if (retval) | |
136 | return retval; | |
137 | ||
1da177e4 LT |
138 | /* OK, This is the point of no return */ |
139 | set_personality(PER_LINUX); | |
ce7e5d2d | 140 | set_personality_ia32(false); |
1da177e4 | 141 | |
221af7f8 LT |
142 | setup_new_exec(bprm); |
143 | ||
144 | regs->cs = __USER32_CS; | |
145 | regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 = | |
146 | regs->r13 = regs->r14 = regs->r15 = 0; | |
147 | ||
1da177e4 LT |
148 | current->mm->end_code = ex.a_text + |
149 | (current->mm->start_code = N_TXTADDR(ex)); | |
150 | current->mm->end_data = ex.a_data + | |
151 | (current->mm->start_data = N_DATADDR(ex)); | |
152 | current->mm->brk = ex.a_bss + | |
153 | (current->mm->start_brk = N_BSSADDR(ex)); | |
1da177e4 | 154 | |
6414fa6a | 155 | retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT); |
19d860a1 | 156 | if (retval < 0) |
6414fa6a | 157 | return retval; |
6414fa6a | 158 | |
a6f76f23 | 159 | install_exec_creds(bprm); |
1da177e4 LT |
160 | |
161 | if (N_MAGIC(ex) == OMAGIC) { | |
162 | unsigned long text_addr, map_size; | |
1da177e4 LT |
163 | |
164 | text_addr = N_TXTADDR(ex); | |
1da177e4 LT |
165 | map_size = ex.a_text+ex.a_data; |
166 | ||
e4eb1ff6 | 167 | error = vm_brk(text_addr & PAGE_MASK, map_size); |
1da177e4 | 168 | |
5d22fc25 | 169 | if (error) |
1da177e4 | 170 | return error; |
1da177e4 | 171 | |
3dc20cb2 AV |
172 | error = read_code(bprm->file, text_addr, 32, |
173 | ex.a_text + ex.a_data); | |
19d860a1 | 174 | if ((signed long)error < 0) |
1da177e4 | 175 | return error; |
1da177e4 LT |
176 | } else { |
177 | #ifdef WARN_OLD | |
178 | static unsigned long error_time, error_time2; | |
179 | if ((ex.a_text & 0xfff || ex.a_data & 0xfff) && | |
e5fc3161 JL |
180 | (N_MAGIC(ex) != NMAGIC) && |
181 | time_after(jiffies, error_time2 + 5*HZ)) { | |
1da177e4 LT |
182 | printk(KERN_NOTICE "executable not page aligned\n"); |
183 | error_time2 = jiffies; | |
184 | } | |
185 | ||
186 | if ((fd_offset & ~PAGE_MASK) != 0 && | |
e5fc3161 | 187 | time_after(jiffies, error_time + 5*HZ)) { |
8edf8bee TG |
188 | printk(KERN_WARNING |
189 | "fd_offset is not page aligned. Please convert " | |
a455589f AV |
190 | "program: %pD\n", |
191 | bprm->file); | |
1da177e4 LT |
192 | error_time = jiffies; |
193 | } | |
194 | #endif | |
195 | ||
8edf8bee | 196 | if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) { |
864778b1 | 197 | error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data); |
5d22fc25 | 198 | if (error) |
864778b1 MH |
199 | return error; |
200 | ||
3dc20cb2 AV |
201 | read_code(bprm->file, N_TXTADDR(ex), fd_offset, |
202 | ex.a_text+ex.a_data); | |
1da177e4 LT |
203 | goto beyond_if; |
204 | } | |
205 | ||
6be5ceb0 | 206 | error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text, |
8edf8bee TG |
207 | PROT_READ | PROT_EXEC, |
208 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | | |
209 | MAP_EXECUTABLE | MAP_32BIT, | |
210 | fd_offset); | |
1da177e4 | 211 | |
19d860a1 | 212 | if (error != N_TXTADDR(ex)) |
1da177e4 | 213 | return error; |
1da177e4 | 214 | |
6be5ceb0 | 215 | error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data, |
1da177e4 | 216 | PROT_READ | PROT_WRITE | PROT_EXEC, |
8edf8bee TG |
217 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | |
218 | MAP_EXECUTABLE | MAP_32BIT, | |
1da177e4 | 219 | fd_offset + ex.a_text); |
19d860a1 | 220 | if (error != N_DATADDR(ex)) |
1da177e4 | 221 | return error; |
1da177e4 | 222 | } |
864778b1 | 223 | |
1da177e4 | 224 | beyond_if: |
864778b1 | 225 | error = set_brk(current->mm->start_brk, current->mm->brk); |
5d22fc25 | 226 | if (error) |
864778b1 | 227 | return error; |
1da177e4 | 228 | |
864778b1 | 229 | set_binfmt(&aout_format); |
1da177e4 | 230 | |
1da177e4 LT |
231 | current->mm->start_stack = |
232 | (unsigned long)create_aout_tables((char __user *)bprm->p, bprm); | |
233 | /* start thread */ | |
b6edbb1e JF |
234 | loadsegment(fs, 0); |
235 | loadsegment(ds, __USER32_DS); | |
236 | loadsegment(es, __USER32_DS); | |
8edf8bee | 237 | load_gs_index(0); |
65ea5b03 PA |
238 | (regs)->ip = ex.a_entry; |
239 | (regs)->sp = current->mm->start_stack; | |
240 | (regs)->flags = 0x200; | |
1da177e4 LT |
241 | (regs)->cs = __USER32_CS; |
242 | (regs)->ss = __USER32_DS; | |
f891dd18 AK |
243 | regs->r8 = regs->r9 = regs->r10 = regs->r11 = |
244 | regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0; | |
1da177e4 | 245 | set_fs(USER_DS); |
1da177e4 LT |
246 | return 0; |
247 | } | |
248 | ||
249 | static int load_aout_library(struct file *file) | |
250 | { | |
8edf8bee | 251 | unsigned long bss, start_addr, len, error; |
1da177e4 LT |
252 | int retval; |
253 | struct exec ex; | |
bdd1d2d3 | 254 | loff_t pos = 0; |
1da177e4 LT |
255 | |
256 | retval = -ENOEXEC; | |
bdd1d2d3 | 257 | error = kernel_read(file, &ex, sizeof(ex), &pos); |
1da177e4 LT |
258 | if (error != sizeof(ex)) |
259 | goto out; | |
260 | ||
261 | /* We come in here for the regular a.out style of shared libraries */ | |
262 | if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) || | |
263 | N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) || | |
496ad9aa | 264 | i_size_read(file_inode(file)) < |
8edf8bee | 265 | ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { |
1da177e4 LT |
266 | goto out; |
267 | } | |
268 | ||
269 | if (N_FLAGS(ex)) | |
270 | goto out; | |
271 | ||
272 | /* For QMAGIC, the starting address is 0x20 into the page. We mask | |
273 | this off to get the starting address for the page */ | |
274 | ||
275 | start_addr = ex.a_entry & 0xfffff000; | |
276 | ||
277 | if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) { | |
1da177e4 LT |
278 | #ifdef WARN_OLD |
279 | static unsigned long error_time; | |
e5fc3161 | 280 | if (time_after(jiffies, error_time + 5*HZ)) { |
8edf8bee TG |
281 | printk(KERN_WARNING |
282 | "N_TXTOFF is not page aligned. Please convert " | |
a455589f AV |
283 | "library: %pD\n", |
284 | file); | |
1da177e4 LT |
285 | error_time = jiffies; |
286 | } | |
287 | #endif | |
864778b1 | 288 | retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); |
5d22fc25 | 289 | if (retval) |
864778b1 | 290 | goto out; |
8edf8bee | 291 | |
3dc20cb2 AV |
292 | read_code(file, start_addr, N_TXTOFF(ex), |
293 | ex.a_text + ex.a_data); | |
1da177e4 LT |
294 | retval = 0; |
295 | goto out; | |
296 | } | |
297 | /* Now use mmap to map the library into memory. */ | |
6be5ceb0 | 298 | error = vm_mmap(file, start_addr, ex.a_text + ex.a_data, |
1da177e4 LT |
299 | PROT_READ | PROT_WRITE | PROT_EXEC, |
300 | MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT, | |
301 | N_TXTOFF(ex)); | |
1da177e4 LT |
302 | retval = error; |
303 | if (error != start_addr) | |
304 | goto out; | |
305 | ||
306 | len = PAGE_ALIGN(ex.a_text + ex.a_data); | |
307 | bss = ex.a_text + ex.a_data + ex.a_bss; | |
308 | if (bss > len) { | |
5d22fc25 LT |
309 | retval = vm_brk(start_addr + len, bss - len); |
310 | if (retval) | |
1da177e4 LT |
311 | goto out; |
312 | } | |
313 | retval = 0; | |
314 | out: | |
315 | return retval; | |
316 | } | |
317 | ||
318 | static int __init init_aout_binfmt(void) | |
319 | { | |
8fc3dc5a AV |
320 | register_binfmt(&aout_format); |
321 | return 0; | |
1da177e4 LT |
322 | } |
323 | ||
324 | static void __exit exit_aout_binfmt(void) | |
325 | { | |
326 | unregister_binfmt(&aout_format); | |
327 | } | |
328 | ||
329 | module_init(init_aout_binfmt); | |
330 | module_exit(exit_aout_binfmt); | |
331 | MODULE_LICENSE("GPL"); |