1 /*
2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 */
14
15 #include <linux/sched.h>
16 #include <linux/mm.h>
17 #include <linux/smp.h>
18 #include <linux/kernel.h>
19 #include <linux/signal.h>
20 #include <linux/errno.h>
21 #include <linux/wait.h>
22 #include <linux/unistd.h>
23 #include <linux/stddef.h>
24 #include <linux/personality.h>
25 #include <linux/suspend.h>
26 #include <linux/ptrace.h>
27 #include <linux/elf.h>
28 #include <linux/compat.h>
29 #include <linux/syscalls.h>
30 #include <linux/uaccess.h>
31 #include <asm/processor.h>
32 #include <asm/ucontext.h>
33 #include <asm/sigframe.h>
34 #include <asm/syscalls.h>
35 #include <arch/interrupts.h>
36
37 struct compat_sigaction {
38 compat_uptr_t sa_handler;
39 compat_ulong_t sa_flags;
40 compat_uptr_t sa_restorer;
41 sigset_t sa_mask __packed;
42 };
43
44 struct compat_sigaltstack {
45 compat_uptr_t ss_sp;
46 int ss_flags;
47 compat_size_t ss_size;
48 };
49
50 struct compat_ucontext {
51 compat_ulong_t uc_flags;
52 compat_uptr_t uc_link;
53 struct compat_sigaltstack uc_stack;
54 struct sigcontext uc_mcontext;
55 sigset_t uc_sigmask; /* mask last for extensibility */
56 };
57
58 #define COMPAT_SI_PAD_SIZE ((SI_MAX_SIZE - 3 * sizeof(int)) / sizeof(int))
59
60 struct compat_siginfo {
61 int si_signo;
62 int si_errno;
63 int si_code;
64
65 union {
66 int _pad[COMPAT_SI_PAD_SIZE];
67
68 /* kill() */
69 struct {
70 unsigned int _pid; /* sender's pid */
71 unsigned int _uid; /* sender's uid */
72 } _kill;
73
74 /* POSIX.1b timers */
75 struct {
76 compat_timer_t _tid; /* timer id */
77 int _overrun; /* overrun count */
78 compat_sigval_t _sigval; /* same as below */
79 int _sys_private; /* not to be passed to user */
80 int _overrun_incr; /* amount to add to overrun */
81 } _timer;
82
83 /* POSIX.1b signals */
84 struct {
85 unsigned int _pid; /* sender's pid */
86 unsigned int _uid; /* sender's uid */
87 compat_sigval_t _sigval;
88 } _rt;
89
90 /* SIGCHLD */
91 struct {
92 unsigned int _pid; /* which child */
93 unsigned int _uid; /* sender's uid */
94 int _status; /* exit code */
95 compat_clock_t _utime;
96 compat_clock_t _stime;
97 } _sigchld;
98
99 /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
100 struct {
101 unsigned int _addr; /* faulting insn/memory ref. */
102 #ifdef __ARCH_SI_TRAPNO
103 int _trapno; /* TRAP # which caused the signal */
104 #endif
105 } _sigfault;
106
107 /* SIGPOLL */
108 struct {
109 int _band; /* POLL_IN, POLL_OUT, POLL_MSG */
110 int _fd;
111 } _sigpoll;
112 } _sifields;
113 };
114
115 struct compat_rt_sigframe {
116 unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */
117 struct compat_siginfo info;
118 struct compat_ucontext uc;
119 };
120
121 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
122
compat_sys_rt_sigaction(int sig,struct compat_sigaction __user * act,struct compat_sigaction __user * oact,size_t sigsetsize)123 long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act,
124 struct compat_sigaction __user *oact,
125 size_t sigsetsize)
126 {
127 struct k_sigaction new_sa, old_sa;
128 int ret = -EINVAL;
129
130 /* XXX: Don't preclude handling different sized sigset_t's. */
131 if (sigsetsize != sizeof(sigset_t))
132 goto out;
133
134 if (act) {
135 compat_uptr_t handler, restorer;
136
137 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
138 __get_user(handler, &act->sa_handler) ||
139 __get_user(new_sa.sa.sa_flags, &act->sa_flags) ||
140 __get_user(restorer, &act->sa_restorer) ||
141 __copy_from_user(&new_sa.sa.sa_mask, &act->sa_mask,
142 sizeof(sigset_t)))
143 return -EFAULT;
144 new_sa.sa.sa_handler = compat_ptr(handler);
145 new_sa.sa.sa_restorer = compat_ptr(restorer);
146 }
147
148 ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL);
149
150 if (!ret && oact) {
151 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
152 __put_user(ptr_to_compat(old_sa.sa.sa_handler),
153 &oact->sa_handler) ||
154 __put_user(ptr_to_compat(old_sa.sa.sa_restorer),
155 &oact->sa_restorer) ||
156 __put_user(old_sa.sa.sa_flags, &oact->sa_flags) ||
157 __copy_to_user(&oact->sa_mask, &old_sa.sa.sa_mask,
158 sizeof(sigset_t)))
159 return -EFAULT;
160 }
161 out:
162 return ret;
163 }
164
compat_sys_rt_sigqueueinfo(int pid,int sig,struct compat_siginfo __user * uinfo)165 long compat_sys_rt_sigqueueinfo(int pid, int sig,
166 struct compat_siginfo __user *uinfo)
167 {
168 siginfo_t info;
169 int ret;
170 mm_segment_t old_fs = get_fs();
171
172 if (copy_siginfo_from_user32(&info, uinfo))
173 return -EFAULT;
174 set_fs(KERNEL_DS);
175 ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __force __user *)&info);
176 set_fs(old_fs);
177 return ret;
178 }
179
copy_siginfo_to_user32(struct compat_siginfo __user * to,siginfo_t * from)180 int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from)
181 {
182 int err;
183
184 if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo)))
185 return -EFAULT;
186
187 /* If you change siginfo_t structure, please make sure that
188 this code is fixed accordingly.
189 It should never copy any pad contained in the structure
190 to avoid security leaks, but must copy the generic
191 3 ints plus the relevant union member. */
192 err = __put_user(from->si_signo, &to->si_signo);
193 err |= __put_user(from->si_errno, &to->si_errno);
194 err |= __put_user((short)from->si_code, &to->si_code);
195
196 if (from->si_code < 0) {
197 err |= __put_user(from->si_pid, &to->si_pid);
198 err |= __put_user(from->si_uid, &to->si_uid);
199 err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
200 } else {
201 /*
202 * First 32bits of unions are always present:
203 * si_pid === si_band === si_tid === si_addr(LS half)
204 */
205 err |= __put_user(from->_sifields._pad[0],
206 &to->_sifields._pad[0]);
207 switch (from->si_code >> 16) {
208 case __SI_FAULT >> 16:
209 break;
210 case __SI_CHLD >> 16:
211 err |= __put_user(from->si_utime, &to->si_utime);
212 err |= __put_user(from->si_stime, &to->si_stime);
213 err |= __put_user(from->si_status, &to->si_status);
214 /* FALL THROUGH */
215 default:
216 case __SI_KILL >> 16:
217 err |= __put_user(from->si_uid, &to->si_uid);
218 break;
219 case __SI_POLL >> 16:
220 err |= __put_user(from->si_fd, &to->si_fd);
221 break;
222 case __SI_TIMER >> 16:
223 err |= __put_user(from->si_overrun, &to->si_overrun);
224 err |= __put_user(ptr_to_compat(from->si_ptr),
225 &to->si_ptr);
226 break;
227 /* This is not generated by the kernel as of now. */
228 case __SI_RT >> 16:
229 case __SI_MESGQ >> 16:
230 err |= __put_user(from->si_uid, &to->si_uid);
231 err |= __put_user(from->si_int, &to->si_int);
232 break;
233 }
234 }
235 return err;
236 }
237
copy_siginfo_from_user32(siginfo_t * to,struct compat_siginfo __user * from)238 int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
239 {
240 int err;
241 u32 ptr32;
242
243 if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo)))
244 return -EFAULT;
245
246 err = __get_user(to->si_signo, &from->si_signo);
247 err |= __get_user(to->si_errno, &from->si_errno);
248 err |= __get_user(to->si_code, &from->si_code);
249
250 err |= __get_user(to->si_pid, &from->si_pid);
251 err |= __get_user(to->si_uid, &from->si_uid);
252 err |= __get_user(ptr32, &from->si_ptr);
253 to->si_ptr = compat_ptr(ptr32);
254
255 return err;
256 }
257
compat_sys_sigaltstack(const struct compat_sigaltstack __user * uss_ptr,struct compat_sigaltstack __user * uoss_ptr,struct pt_regs * regs)258 long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
259 struct compat_sigaltstack __user *uoss_ptr,
260 struct pt_regs *regs)
261 {
262 stack_t uss, uoss;
263 int ret;
264 mm_segment_t seg;
265
266 if (uss_ptr) {
267 u32 ptr;
268
269 memset(&uss, 0, sizeof(stack_t));
270 if (!access_ok(VERIFY_READ, uss_ptr, sizeof(*uss_ptr)) ||
271 __get_user(ptr, &uss_ptr->ss_sp) ||
272 __get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
273 __get_user(uss.ss_size, &uss_ptr->ss_size))
274 return -EFAULT;
275 uss.ss_sp = compat_ptr(ptr);
276 }
277 seg = get_fs();
278 set_fs(KERNEL_DS);
279 ret = do_sigaltstack(uss_ptr ? (stack_t __user __force *)&uss : NULL,
280 (stack_t __user __force *)&uoss,
281 (unsigned long)compat_ptr(regs->sp));
282 set_fs(seg);
283 if (ret >= 0 && uoss_ptr) {
284 if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(*uoss_ptr)) ||
285 __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
286 __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
287 __put_user(uoss.ss_size, &uoss_ptr->ss_size))
288 ret = -EFAULT;
289 }
290 return ret;
291 }
292
293 /* The assembly shim for this function arranges to ignore the return value. */
compat_sys_rt_sigreturn(struct pt_regs * regs)294 long compat_sys_rt_sigreturn(struct pt_regs *regs)
295 {
296 struct compat_rt_sigframe __user *frame =
297 (struct compat_rt_sigframe __user *) compat_ptr(regs->sp);
298 sigset_t set;
299
300 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
301 goto badframe;
302 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
303 goto badframe;
304
305 sigdelsetmask(&set, ~_BLOCKABLE);
306 set_current_blocked(&set);
307
308 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
309 goto badframe;
310
311 if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0)
312 goto badframe;
313
314 return 0;
315
316 badframe:
317 signal_fault("bad sigreturn frame", regs, frame, 0);
318 return 0;
319 }
320
321 /*
322 * Determine which stack to use..
323 */
compat_get_sigframe(struct k_sigaction * ka,struct pt_regs * regs,size_t frame_size)324 static inline void __user *compat_get_sigframe(struct k_sigaction *ka,
325 struct pt_regs *regs,
326 size_t frame_size)
327 {
328 unsigned long sp;
329
330 /* Default to using normal stack */
331 sp = (unsigned long)compat_ptr(regs->sp);
332
333 /*
334 * If we are on the alternate signal stack and would overflow
335 * it, don't. Return an always-bogus address instead so we
336 * will die with SIGSEGV.
337 */
338 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
339 return (void __user __force *)-1UL;
340
341 /* This is the X/Open sanctioned signal stack switching. */
342 if (ka->sa.sa_flags & SA_ONSTACK) {
343 if (sas_ss_flags(sp) == 0)
344 sp = current->sas_ss_sp + current->sas_ss_size;
345 }
346
347 sp -= frame_size;
348 /*
349 * Align the stack pointer according to the TILE ABI,
350 * i.e. so that on function entry (sp & 15) == 0.
351 */
352 sp &= -16UL;
353 return (void __user *) sp;
354 }
355
compat_setup_rt_frame(int sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * set,struct pt_regs * regs)356 int compat_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
357 sigset_t *set, struct pt_regs *regs)
358 {
359 unsigned long restorer;
360 struct compat_rt_sigframe __user *frame;
361 int err = 0;
362 int usig;
363
364 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
365
366 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
367 goto give_sigsegv;
368
369 usig = current_thread_info()->exec_domain
370 && current_thread_info()->exec_domain->signal_invmap
371 && sig < 32
372 ? current_thread_info()->exec_domain->signal_invmap[sig]
373 : sig;
374
375 /* Always write at least the signal number for the stack backtracer. */
376 if (ka->sa.sa_flags & SA_SIGINFO) {
377 /* At sigreturn time, restore the callee-save registers too. */
378 err |= copy_siginfo_to_user32(&frame->info, info);
379 regs->flags |= PT_FLAGS_RESTORE_REGS;
380 } else {
381 err |= __put_user(info->si_signo, &frame->info.si_signo);
382 }
383
384 /* Create the ucontext. */
385 err |= __clear_user(&frame->save_area, sizeof(frame->save_area));
386 err |= __put_user(0, &frame->uc.uc_flags);
387 err |= __put_user(0, &frame->uc.uc_link);
388 err |= __put_user(ptr_to_compat((void *)(current->sas_ss_sp)),
389 &frame->uc.uc_stack.ss_sp);
390 err |= __put_user(sas_ss_flags(regs->sp),
391 &frame->uc.uc_stack.ss_flags);
392 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
393 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs);
394 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
395 if (err)
396 goto give_sigsegv;
397
398 restorer = VDSO_BASE;
399 if (ka->sa.sa_flags & SA_RESTORER)
400 restorer = ptr_to_compat_reg(ka->sa.sa_restorer);
401
402 /*
403 * Set up registers for signal handler.
404 * Registers that we don't modify keep the value they had from
405 * user-space at the time we took the signal.
406 */
407 regs->pc = ptr_to_compat_reg(ka->sa.sa_handler);
408 regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
409 regs->sp = ptr_to_compat_reg(frame);
410 regs->lr = restorer;
411 regs->regs[0] = (unsigned long) usig;
412
413 if (ka->sa.sa_flags & SA_SIGINFO) {
414 /* Need extra arguments, so mark to restore caller-saves. */
415 regs->regs[1] = ptr_to_compat_reg(&frame->info);
416 regs->regs[2] = ptr_to_compat_reg(&frame->uc);
417 regs->flags |= PT_FLAGS_CALLER_SAVES;
418 }
419
420 /*
421 * Notify any tracer that was single-stepping it.
422 * The tracer may want to single-step inside the
423 * handler too.
424 */
425 if (test_thread_flag(TIF_SINGLESTEP))
426 ptrace_notify(SIGTRAP);
427
428 return 0;
429
430 give_sigsegv:
431 signal_fault("bad setup frame", regs, frame, sig);
432 return -EFAULT;
433 }
434