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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/arch/sh/kernel/signal.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
8 *
9 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
10 *
11 */
12#include <linux/sched.h>
13#include <linux/sched/task_stack.h>
14#include <linux/mm.h>
15#include <linux/smp.h>
16#include <linux/kernel.h>
17#include <linux/signal.h>
18#include <linux/errno.h>
19#include <linux/wait.h>
20#include <linux/ptrace.h>
21#include <linux/unistd.h>
22#include <linux/stddef.h>
23#include <linux/tty.h>
24#include <linux/elf.h>
25#include <linux/personality.h>
26#include <linux/binfmts.h>
27#include <linux/io.h>
28#include <linux/resume_user_mode.h>
29#include <asm/ucontext.h>
30#include <linux/uaccess.h>
31#include <asm/cacheflush.h>
32#include <asm/syscalls.h>
33#include <asm/fpu.h>
34
35struct fdpic_func_descriptor {
36 unsigned long text;
37 unsigned long GOT;
38};
39
40/*
41 * The following define adds a 64 byte gap between the signal
42 * stack frame and previous contents of the stack. This allows
43 * frame unwinding in a function epilogue but only if a frame
44 * pointer is used in the function. This is necessary because
45 * current gcc compilers (<4.3) do not generate unwind info on
46 * SH for function epilogues.
47 */
48#define UNWINDGUARD 64
49
50/*
51 * Do a signal return; undo the signal stack.
52 */
53
54#define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
55#if defined(CONFIG_CPU_SH2)
56#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
57#else
58#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
59#endif
60#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
61
62struct sigframe
63{
64 struct sigcontext sc;
65 unsigned long extramask[_NSIG_WORDS-1];
66 u16 retcode[8];
67};
68
69struct rt_sigframe
70{
71 struct siginfo info;
72 struct ucontext uc;
73 u16 retcode[8];
74};
75
76#ifdef CONFIG_SH_FPU
77static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
78{
79 struct task_struct *tsk = current;
80
81 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
82 return 0;
83
84 set_used_math();
85 return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
86 sizeof(long)*(16*2+2));
87}
88
89static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
90 struct pt_regs *regs)
91{
92 struct task_struct *tsk = current;
93
94 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
95 return 0;
96
97 if (!used_math())
98 return __put_user(0, &sc->sc_ownedfp);
99
100 if (__put_user(1, &sc->sc_ownedfp))
101 return -EFAULT;
102
103 /* This will cause a "finit" to be triggered by the next
104 attempted FPU operation by the 'current' process.
105 */
106 clear_used_math();
107
108 unlazy_fpu(tsk, regs);
109 return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
110 sizeof(long)*(16*2+2));
111}
112#endif /* CONFIG_SH_FPU */
113
114static int
115restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
116{
117 unsigned int err = 0;
118
119#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
120 COPY(regs[1]);
121 COPY(regs[2]); COPY(regs[3]);
122 COPY(regs[4]); COPY(regs[5]);
123 COPY(regs[6]); COPY(regs[7]);
124 COPY(regs[8]); COPY(regs[9]);
125 COPY(regs[10]); COPY(regs[11]);
126 COPY(regs[12]); COPY(regs[13]);
127 COPY(regs[14]); COPY(regs[15]);
128 COPY(gbr); COPY(mach);
129 COPY(macl); COPY(pr);
130 COPY(sr); COPY(pc);
131#undef COPY
132
133#ifdef CONFIG_SH_FPU
134 if (boot_cpu_data.flags & CPU_HAS_FPU) {
135 int owned_fp;
136 struct task_struct *tsk = current;
137
138 regs->sr |= SR_FD; /* Release FPU */
139 clear_fpu(tsk, regs);
140 clear_used_math();
141 err |= __get_user (owned_fp, &sc->sc_ownedfp);
142 if (owned_fp)
143 err |= restore_sigcontext_fpu(sc);
144 }
145#endif
146
147 regs->tra = -1; /* disable syscall checks */
148 err |= __get_user(*r0_p, &sc->sc_regs[0]);
149 return err;
150}
151
152asmlinkage int sys_sigreturn(void)
153{
154 struct pt_regs *regs = current_pt_regs();
155 struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
156 sigset_t set;
157 int r0;
158
159 /* Always make any pending restarted system calls return -EINTR */
160 current->restart_block.fn = do_no_restart_syscall;
161
162 if (!access_ok(frame, sizeof(*frame)))
163 goto badframe;
164
165 if (__get_user(set.sig[0], &frame->sc.oldmask)
166 || (_NSIG_WORDS > 1
167 && __copy_from_user(&set.sig[1], &frame->extramask,
168 sizeof(frame->extramask))))
169 goto badframe;
170
171 set_current_blocked(&set);
172
173 if (restore_sigcontext(regs, &frame->sc, &r0))
174 goto badframe;
175 return r0;
176
177badframe:
178 force_sig(SIGSEGV);
179 return 0;
180}
181
182asmlinkage int sys_rt_sigreturn(void)
183{
184 struct pt_regs *regs = current_pt_regs();
185 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
186 sigset_t set;
187 int r0;
188
189 /* Always make any pending restarted system calls return -EINTR */
190 current->restart_block.fn = do_no_restart_syscall;
191
192 if (!access_ok(frame, sizeof(*frame)))
193 goto badframe;
194
195 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
196 goto badframe;
197
198 set_current_blocked(&set);
199
200 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
201 goto badframe;
202
203 if (restore_altstack(&frame->uc.uc_stack))
204 goto badframe;
205
206 return r0;
207
208badframe:
209 force_sig(SIGSEGV);
210 return 0;
211}
212
213/*
214 * Set up a signal frame.
215 */
216
217static int
218setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
219 unsigned long mask)
220{
221 int err = 0;
222
223#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
224 COPY(regs[0]); COPY(regs[1]);
225 COPY(regs[2]); COPY(regs[3]);
226 COPY(regs[4]); COPY(regs[5]);
227 COPY(regs[6]); COPY(regs[7]);
228 COPY(regs[8]); COPY(regs[9]);
229 COPY(regs[10]); COPY(regs[11]);
230 COPY(regs[12]); COPY(regs[13]);
231 COPY(regs[14]); COPY(regs[15]);
232 COPY(gbr); COPY(mach);
233 COPY(macl); COPY(pr);
234 COPY(sr); COPY(pc);
235#undef COPY
236
237#ifdef CONFIG_SH_FPU
238 err |= save_sigcontext_fpu(sc, regs);
239#endif
240
241 /* non-iBCS2 extensions.. */
242 err |= __put_user(mask, &sc->oldmask);
243
244 return err;
245}
246
247/*
248 * Determine which stack to use..
249 */
250static inline void __user *
251get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
252{
253 if (ka->sa.sa_flags & SA_ONSTACK) {
254 if (sas_ss_flags(sp) == 0)
255 sp = current->sas_ss_sp + current->sas_ss_size;
256 }
257
258 return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
259}
260
261/* These symbols are defined with the addresses in the vsyscall page.
262 See vsyscall-trapa.S. */
263extern void __kernel_sigreturn(void);
264extern void __kernel_rt_sigreturn(void);
265
266static int setup_frame(struct ksignal *ksig, sigset_t *set,
267 struct pt_regs *regs)
268{
269 struct sigframe __user *frame;
270 int err = 0, sig = ksig->sig;
271
272 frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
273
274 if (!access_ok(frame, sizeof(*frame)))
275 return -EFAULT;
276
277 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
278
279 if (_NSIG_WORDS > 1)
280 err |= __copy_to_user(frame->extramask, &set->sig[1],
281 sizeof(frame->extramask));
282
283 /* Set up to return from userspace. If provided, use a stub
284 already in userspace. */
285 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
286 regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
287#ifdef CONFIG_VSYSCALL
288 } else if (likely(current->mm->context.vdso)) {
289 regs->pr = VDSO_SYM(&__kernel_sigreturn);
290#endif
291 } else {
292 /* Generate return code (system call to sigreturn) */
293 err |= __put_user(MOVW(7), &frame->retcode[0]);
294 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
295 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
296 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
297 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
298 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
299 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
300 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
301 regs->pr = (unsigned long) frame->retcode;
302 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
303 }
304
305 if (err)
306 return -EFAULT;
307
308 /* Set up registers for signal handler */
309 regs->regs[15] = (unsigned long) frame;
310 regs->regs[4] = sig; /* Arg for signal handler */
311 regs->regs[5] = 0;
312 regs->regs[6] = (unsigned long) &frame->sc;
313
314 if (current->personality & FDPIC_FUNCPTRS) {
315 struct fdpic_func_descriptor __user *funcptr =
316 (struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
317
318 err |= __get_user(regs->pc, &funcptr->text);
319 err |= __get_user(regs->regs[12], &funcptr->GOT);
320 } else
321 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
322
323 if (err)
324 return -EFAULT;
325
326 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
327 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
328
329 return 0;
330}
331
332static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
333 struct pt_regs *regs)
334{
335 struct rt_sigframe __user *frame;
336 int err = 0, sig = ksig->sig;
337
338 frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
339
340 if (!access_ok(frame, sizeof(*frame)))
341 return -EFAULT;
342
343 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
344
345 /* Create the ucontext. */
346 err |= __put_user(0, &frame->uc.uc_flags);
347 err |= __put_user(NULL, &frame->uc.uc_link);
348 err |= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
349 err |= setup_sigcontext(&frame->uc.uc_mcontext,
350 regs, set->sig[0]);
351 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
352
353 /* Set up to return from userspace. If provided, use a stub
354 already in userspace. */
355 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
356 regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
357#ifdef CONFIG_VSYSCALL
358 } else if (likely(current->mm->context.vdso)) {
359 regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
360#endif
361 } else {
362 /* Generate return code (system call to rt_sigreturn) */
363 err |= __put_user(MOVW(7), &frame->retcode[0]);
364 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
365 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
366 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
367 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
368 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
369 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
370 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
371 regs->pr = (unsigned long) frame->retcode;
372 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
373 }
374
375 if (err)
376 return -EFAULT;
377
378 /* Set up registers for signal handler */
379 regs->regs[15] = (unsigned long) frame;
380 regs->regs[4] = sig; /* Arg for signal handler */
381 regs->regs[5] = (unsigned long) &frame->info;
382 regs->regs[6] = (unsigned long) &frame->uc;
383
384 if (current->personality & FDPIC_FUNCPTRS) {
385 struct fdpic_func_descriptor __user *funcptr =
386 (struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
387
388 err |= __get_user(regs->pc, &funcptr->text);
389 err |= __get_user(regs->regs[12], &funcptr->GOT);
390 } else
391 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
392
393 if (err)
394 return -EFAULT;
395
396 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
397 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
398
399 return 0;
400}
401
402static inline void
403handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
404 struct sigaction *sa)
405{
406 /* If we're not from a syscall, bail out */
407 if (regs->tra < 0)
408 return;
409
410 /* check for system call restart.. */
411 switch (regs->regs[0]) {
412 case -ERESTART_RESTARTBLOCK:
413 case -ERESTARTNOHAND:
414 no_system_call_restart:
415 regs->regs[0] = -EINTR;
416 break;
417
418 case -ERESTARTSYS:
419 if (!(sa->sa_flags & SA_RESTART))
420 goto no_system_call_restart;
421 fallthrough;
422 case -ERESTARTNOINTR:
423 regs->regs[0] = save_r0;
424 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
425 break;
426 }
427}
428
429/*
430 * OK, we're invoking a handler
431 */
432static void
433handle_signal(struct ksignal *ksig, struct pt_regs *regs, unsigned int save_r0)
434{
435 sigset_t *oldset = sigmask_to_save();
436 int ret;
437
438 /* Set up the stack frame */
439 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
440 ret = setup_rt_frame(ksig, oldset, regs);
441 else
442 ret = setup_frame(ksig, oldset, regs);
443
444 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
445}
446
447/*
448 * Note that 'init' is a special process: it doesn't get signals it doesn't
449 * want to handle. Thus you cannot kill init even with a SIGKILL even by
450 * mistake.
451 *
452 * Note that we go through the signals twice: once to check the signals that
453 * the kernel can handle, and then we build all the user-level signal handling
454 * stack-frames in one go after that.
455 */
456static void do_signal(struct pt_regs *regs, unsigned int save_r0)
457{
458 struct ksignal ksig;
459
460 /*
461 * We want the common case to go fast, which
462 * is why we may in certain cases get here from
463 * kernel mode. Just return without doing anything
464 * if so.
465 */
466 if (!user_mode(regs))
467 return;
468
469 if (get_signal(&ksig)) {
470 handle_syscall_restart(save_r0, regs, &ksig.ka.sa);
471
472 /* Whee! Actually deliver the signal. */
473 handle_signal(&ksig, regs, save_r0);
474 return;
475 }
476
477 /* Did we come from a system call? */
478 if (regs->tra >= 0) {
479 /* Restart the system call - no handlers present */
480 if (regs->regs[0] == -ERESTARTNOHAND ||
481 regs->regs[0] == -ERESTARTSYS ||
482 regs->regs[0] == -ERESTARTNOINTR) {
483 regs->regs[0] = save_r0;
484 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
485 } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
486 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
487 regs->regs[3] = __NR_restart_syscall;
488 }
489 }
490
491 /*
492 * If there's no signal to deliver, we just put the saved sigmask
493 * back.
494 */
495 restore_saved_sigmask();
496}
497
498asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
499 unsigned long thread_info_flags)
500{
501 /* deal with pending signal delivery */
502 if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
503 do_signal(regs, save_r0);
504
505 if (thread_info_flags & _TIF_NOTIFY_RESUME)
506 resume_user_mode_work(regs);
507}
1/*
2 * linux/arch/sh/kernel/signal.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
7 *
8 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
9 *
10 */
11#include <linux/sched.h>
12#include <linux/mm.h>
13#include <linux/smp.h>
14#include <linux/kernel.h>
15#include <linux/signal.h>
16#include <linux/errno.h>
17#include <linux/wait.h>
18#include <linux/ptrace.h>
19#include <linux/unistd.h>
20#include <linux/stddef.h>
21#include <linux/tty.h>
22#include <linux/elf.h>
23#include <linux/personality.h>
24#include <linux/binfmts.h>
25#include <linux/freezer.h>
26#include <linux/io.h>
27#include <linux/tracehook.h>
28#include <asm/system.h>
29#include <asm/ucontext.h>
30#include <asm/uaccess.h>
31#include <asm/pgtable.h>
32#include <asm/cacheflush.h>
33#include <asm/syscalls.h>
34#include <asm/fpu.h>
35
36#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
37
38struct fdpic_func_descriptor {
39 unsigned long text;
40 unsigned long GOT;
41};
42
43/*
44 * The following define adds a 64 byte gap between the signal
45 * stack frame and previous contents of the stack. This allows
46 * frame unwinding in a function epilogue but only if a frame
47 * pointer is used in the function. This is necessary because
48 * current gcc compilers (<4.3) do not generate unwind info on
49 * SH for function epilogues.
50 */
51#define UNWINDGUARD 64
52
53/*
54 * Atomically swap in the new signal mask, and wait for a signal.
55 */
56asmlinkage int
57sys_sigsuspend(old_sigset_t mask,
58 unsigned long r5, unsigned long r6, unsigned long r7,
59 struct pt_regs __regs)
60{
61 mask &= _BLOCKABLE;
62 spin_lock_irq(¤t->sighand->siglock);
63 current->saved_sigmask = current->blocked;
64 siginitset(¤t->blocked, mask);
65 recalc_sigpending();
66 spin_unlock_irq(¤t->sighand->siglock);
67
68 current->state = TASK_INTERRUPTIBLE;
69 schedule();
70 set_restore_sigmask();
71
72 return -ERESTARTNOHAND;
73}
74
75asmlinkage int
76sys_sigaction(int sig, const struct old_sigaction __user *act,
77 struct old_sigaction __user *oact)
78{
79 struct k_sigaction new_ka, old_ka;
80 int ret;
81
82 if (act) {
83 old_sigset_t mask;
84 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
85 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
86 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
87 return -EFAULT;
88 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
89 __get_user(mask, &act->sa_mask);
90 siginitset(&new_ka.sa.sa_mask, mask);
91 }
92
93 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
94
95 if (!ret && oact) {
96 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
97 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
98 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
99 return -EFAULT;
100 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
101 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
102 }
103
104 return ret;
105}
106
107asmlinkage int
108sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
109 unsigned long r6, unsigned long r7,
110 struct pt_regs __regs)
111{
112 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
113
114 return do_sigaltstack(uss, uoss, regs->regs[15]);
115}
116
117
118/*
119 * Do a signal return; undo the signal stack.
120 */
121
122#define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
123#if defined(CONFIG_CPU_SH2)
124#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
125#else
126#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
127#endif
128#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
129
130struct sigframe
131{
132 struct sigcontext sc;
133 unsigned long extramask[_NSIG_WORDS-1];
134 u16 retcode[8];
135};
136
137struct rt_sigframe
138{
139 struct siginfo info;
140 struct ucontext uc;
141 u16 retcode[8];
142};
143
144#ifdef CONFIG_SH_FPU
145static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
146{
147 struct task_struct *tsk = current;
148
149 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
150 return 0;
151
152 set_used_math();
153 return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
154 sizeof(long)*(16*2+2));
155}
156
157static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
158 struct pt_regs *regs)
159{
160 struct task_struct *tsk = current;
161
162 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
163 return 0;
164
165 if (!used_math()) {
166 __put_user(0, &sc->sc_ownedfp);
167 return 0;
168 }
169
170 __put_user(1, &sc->sc_ownedfp);
171
172 /* This will cause a "finit" to be triggered by the next
173 attempted FPU operation by the 'current' process.
174 */
175 clear_used_math();
176
177 unlazy_fpu(tsk, regs);
178 return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
179 sizeof(long)*(16*2+2));
180}
181#endif /* CONFIG_SH_FPU */
182
183static int
184restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
185{
186 unsigned int err = 0;
187
188#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
189 COPY(regs[1]);
190 COPY(regs[2]); COPY(regs[3]);
191 COPY(regs[4]); COPY(regs[5]);
192 COPY(regs[6]); COPY(regs[7]);
193 COPY(regs[8]); COPY(regs[9]);
194 COPY(regs[10]); COPY(regs[11]);
195 COPY(regs[12]); COPY(regs[13]);
196 COPY(regs[14]); COPY(regs[15]);
197 COPY(gbr); COPY(mach);
198 COPY(macl); COPY(pr);
199 COPY(sr); COPY(pc);
200#undef COPY
201
202#ifdef CONFIG_SH_FPU
203 if (boot_cpu_data.flags & CPU_HAS_FPU) {
204 int owned_fp;
205 struct task_struct *tsk = current;
206
207 regs->sr |= SR_FD; /* Release FPU */
208 clear_fpu(tsk, regs);
209 clear_used_math();
210 __get_user (owned_fp, &sc->sc_ownedfp);
211 if (owned_fp)
212 err |= restore_sigcontext_fpu(sc);
213 }
214#endif
215
216 regs->tra = -1; /* disable syscall checks */
217 err |= __get_user(*r0_p, &sc->sc_regs[0]);
218 return err;
219}
220
221asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
222 unsigned long r6, unsigned long r7,
223 struct pt_regs __regs)
224{
225 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
226 struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
227 sigset_t set;
228 int r0;
229
230 /* Always make any pending restarted system calls return -EINTR */
231 current_thread_info()->restart_block.fn = do_no_restart_syscall;
232
233 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
234 goto badframe;
235
236 if (__get_user(set.sig[0], &frame->sc.oldmask)
237 || (_NSIG_WORDS > 1
238 && __copy_from_user(&set.sig[1], &frame->extramask,
239 sizeof(frame->extramask))))
240 goto badframe;
241
242 sigdelsetmask(&set, ~_BLOCKABLE);
243
244 spin_lock_irq(¤t->sighand->siglock);
245 current->blocked = set;
246 recalc_sigpending();
247 spin_unlock_irq(¤t->sighand->siglock);
248
249 if (restore_sigcontext(regs, &frame->sc, &r0))
250 goto badframe;
251 return r0;
252
253badframe:
254 force_sig(SIGSEGV, current);
255 return 0;
256}
257
258asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
259 unsigned long r6, unsigned long r7,
260 struct pt_regs __regs)
261{
262 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
263 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
264 sigset_t set;
265 int r0;
266
267 /* Always make any pending restarted system calls return -EINTR */
268 current_thread_info()->restart_block.fn = do_no_restart_syscall;
269
270 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
271 goto badframe;
272
273 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
274 goto badframe;
275
276 sigdelsetmask(&set, ~_BLOCKABLE);
277 spin_lock_irq(¤t->sighand->siglock);
278 current->blocked = set;
279 recalc_sigpending();
280 spin_unlock_irq(¤t->sighand->siglock);
281
282 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
283 goto badframe;
284
285 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
286 regs->regs[15]) == -EFAULT)
287 goto badframe;
288
289 return r0;
290
291badframe:
292 force_sig(SIGSEGV, current);
293 return 0;
294}
295
296/*
297 * Set up a signal frame.
298 */
299
300static int
301setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
302 unsigned long mask)
303{
304 int err = 0;
305
306#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
307 COPY(regs[0]); COPY(regs[1]);
308 COPY(regs[2]); COPY(regs[3]);
309 COPY(regs[4]); COPY(regs[5]);
310 COPY(regs[6]); COPY(regs[7]);
311 COPY(regs[8]); COPY(regs[9]);
312 COPY(regs[10]); COPY(regs[11]);
313 COPY(regs[12]); COPY(regs[13]);
314 COPY(regs[14]); COPY(regs[15]);
315 COPY(gbr); COPY(mach);
316 COPY(macl); COPY(pr);
317 COPY(sr); COPY(pc);
318#undef COPY
319
320#ifdef CONFIG_SH_FPU
321 err |= save_sigcontext_fpu(sc, regs);
322#endif
323
324 /* non-iBCS2 extensions.. */
325 err |= __put_user(mask, &sc->oldmask);
326
327 return err;
328}
329
330/*
331 * Determine which stack to use..
332 */
333static inline void __user *
334get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
335{
336 if (ka->sa.sa_flags & SA_ONSTACK) {
337 if (sas_ss_flags(sp) == 0)
338 sp = current->sas_ss_sp + current->sas_ss_size;
339 }
340
341 return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
342}
343
344/* These symbols are defined with the addresses in the vsyscall page.
345 See vsyscall-trapa.S. */
346extern void __kernel_sigreturn(void);
347extern void __kernel_rt_sigreturn(void);
348
349static int setup_frame(int sig, struct k_sigaction *ka,
350 sigset_t *set, struct pt_regs *regs)
351{
352 struct sigframe __user *frame;
353 int err = 0;
354 int signal;
355
356 frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
357
358 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
359 goto give_sigsegv;
360
361 signal = current_thread_info()->exec_domain
362 && current_thread_info()->exec_domain->signal_invmap
363 && sig < 32
364 ? current_thread_info()->exec_domain->signal_invmap[sig]
365 : sig;
366
367 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
368
369 if (_NSIG_WORDS > 1)
370 err |= __copy_to_user(frame->extramask, &set->sig[1],
371 sizeof(frame->extramask));
372
373 /* Set up to return from userspace. If provided, use a stub
374 already in userspace. */
375 if (ka->sa.sa_flags & SA_RESTORER) {
376 regs->pr = (unsigned long) ka->sa.sa_restorer;
377#ifdef CONFIG_VSYSCALL
378 } else if (likely(current->mm->context.vdso)) {
379 regs->pr = VDSO_SYM(&__kernel_sigreturn);
380#endif
381 } else {
382 /* Generate return code (system call to sigreturn) */
383 err |= __put_user(MOVW(7), &frame->retcode[0]);
384 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
385 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
386 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
387 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
388 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
389 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
390 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
391 regs->pr = (unsigned long) frame->retcode;
392 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
393 }
394
395 if (err)
396 goto give_sigsegv;
397
398 /* Set up registers for signal handler */
399 regs->regs[15] = (unsigned long) frame;
400 regs->regs[4] = signal; /* Arg for signal handler */
401 regs->regs[5] = 0;
402 regs->regs[6] = (unsigned long) &frame->sc;
403
404 if (current->personality & FDPIC_FUNCPTRS) {
405 struct fdpic_func_descriptor __user *funcptr =
406 (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
407
408 __get_user(regs->pc, &funcptr->text);
409 __get_user(regs->regs[12], &funcptr->GOT);
410 } else
411 regs->pc = (unsigned long)ka->sa.sa_handler;
412
413 set_fs(USER_DS);
414
415 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
416 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
417
418 return 0;
419
420give_sigsegv:
421 force_sigsegv(sig, current);
422 return -EFAULT;
423}
424
425static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
426 sigset_t *set, struct pt_regs *regs)
427{
428 struct rt_sigframe __user *frame;
429 int err = 0;
430 int signal;
431
432 frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
433
434 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
435 goto give_sigsegv;
436
437 signal = current_thread_info()->exec_domain
438 && current_thread_info()->exec_domain->signal_invmap
439 && sig < 32
440 ? current_thread_info()->exec_domain->signal_invmap[sig]
441 : sig;
442
443 err |= copy_siginfo_to_user(&frame->info, info);
444
445 /* Create the ucontext. */
446 err |= __put_user(0, &frame->uc.uc_flags);
447 err |= __put_user(NULL, &frame->uc.uc_link);
448 err |= __put_user((void *)current->sas_ss_sp,
449 &frame->uc.uc_stack.ss_sp);
450 err |= __put_user(sas_ss_flags(regs->regs[15]),
451 &frame->uc.uc_stack.ss_flags);
452 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
453 err |= setup_sigcontext(&frame->uc.uc_mcontext,
454 regs, set->sig[0]);
455 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
456
457 /* Set up to return from userspace. If provided, use a stub
458 already in userspace. */
459 if (ka->sa.sa_flags & SA_RESTORER) {
460 regs->pr = (unsigned long) ka->sa.sa_restorer;
461#ifdef CONFIG_VSYSCALL
462 } else if (likely(current->mm->context.vdso)) {
463 regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
464#endif
465 } else {
466 /* Generate return code (system call to rt_sigreturn) */
467 err |= __put_user(MOVW(7), &frame->retcode[0]);
468 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
469 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
470 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
471 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
472 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
473 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
474 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
475 regs->pr = (unsigned long) frame->retcode;
476 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
477 }
478
479 if (err)
480 goto give_sigsegv;
481
482 /* Set up registers for signal handler */
483 regs->regs[15] = (unsigned long) frame;
484 regs->regs[4] = signal; /* Arg for signal handler */
485 regs->regs[5] = (unsigned long) &frame->info;
486 regs->regs[6] = (unsigned long) &frame->uc;
487
488 if (current->personality & FDPIC_FUNCPTRS) {
489 struct fdpic_func_descriptor __user *funcptr =
490 (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
491
492 __get_user(regs->pc, &funcptr->text);
493 __get_user(regs->regs[12], &funcptr->GOT);
494 } else
495 regs->pc = (unsigned long)ka->sa.sa_handler;
496
497 set_fs(USER_DS);
498
499 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
500 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
501
502 return 0;
503
504give_sigsegv:
505 force_sigsegv(sig, current);
506 return -EFAULT;
507}
508
509static inline void
510handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
511 struct sigaction *sa)
512{
513 /* If we're not from a syscall, bail out */
514 if (regs->tra < 0)
515 return;
516
517 /* check for system call restart.. */
518 switch (regs->regs[0]) {
519 case -ERESTART_RESTARTBLOCK:
520 case -ERESTARTNOHAND:
521 no_system_call_restart:
522 regs->regs[0] = -EINTR;
523 break;
524
525 case -ERESTARTSYS:
526 if (!(sa->sa_flags & SA_RESTART))
527 goto no_system_call_restart;
528 /* fallthrough */
529 case -ERESTARTNOINTR:
530 regs->regs[0] = save_r0;
531 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
532 break;
533 }
534}
535
536/*
537 * OK, we're invoking a handler
538 */
539static int
540handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
541 sigset_t *oldset, struct pt_regs *regs, unsigned int save_r0)
542{
543 int ret;
544
545 /* Set up the stack frame */
546 if (ka->sa.sa_flags & SA_SIGINFO)
547 ret = setup_rt_frame(sig, ka, info, oldset, regs);
548 else
549 ret = setup_frame(sig, ka, oldset, regs);
550
551 if (ka->sa.sa_flags & SA_ONESHOT)
552 ka->sa.sa_handler = SIG_DFL;
553
554 if (ret == 0) {
555 spin_lock_irq(¤t->sighand->siglock);
556 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
557 if (!(ka->sa.sa_flags & SA_NODEFER))
558 sigaddset(¤t->blocked,sig);
559 recalc_sigpending();
560 spin_unlock_irq(¤t->sighand->siglock);
561 }
562
563 return ret;
564}
565
566/*
567 * Note that 'init' is a special process: it doesn't get signals it doesn't
568 * want to handle. Thus you cannot kill init even with a SIGKILL even by
569 * mistake.
570 *
571 * Note that we go through the signals twice: once to check the signals that
572 * the kernel can handle, and then we build all the user-level signal handling
573 * stack-frames in one go after that.
574 */
575static void do_signal(struct pt_regs *regs, unsigned int save_r0)
576{
577 siginfo_t info;
578 int signr;
579 struct k_sigaction ka;
580 sigset_t *oldset;
581
582 /*
583 * We want the common case to go fast, which
584 * is why we may in certain cases get here from
585 * kernel mode. Just return without doing anything
586 * if so.
587 */
588 if (!user_mode(regs))
589 return;
590
591 if (try_to_freeze())
592 goto no_signal;
593
594 if (current_thread_info()->status & TS_RESTORE_SIGMASK)
595 oldset = ¤t->saved_sigmask;
596 else
597 oldset = ¤t->blocked;
598
599 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
600 if (signr > 0) {
601 handle_syscall_restart(save_r0, regs, &ka.sa);
602
603 /* Whee! Actually deliver the signal. */
604 if (handle_signal(signr, &ka, &info, oldset,
605 regs, save_r0) == 0) {
606 /*
607 * A signal was successfully delivered; the saved
608 * sigmask will have been stored in the signal frame,
609 * and will be restored by sigreturn, so we can simply
610 * clear the TS_RESTORE_SIGMASK flag
611 */
612 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
613
614 tracehook_signal_handler(signr, &info, &ka, regs,
615 test_thread_flag(TIF_SINGLESTEP));
616 }
617
618 return;
619 }
620
621no_signal:
622 /* Did we come from a system call? */
623 if (regs->tra >= 0) {
624 /* Restart the system call - no handlers present */
625 if (regs->regs[0] == -ERESTARTNOHAND ||
626 regs->regs[0] == -ERESTARTSYS ||
627 regs->regs[0] == -ERESTARTNOINTR) {
628 regs->regs[0] = save_r0;
629 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
630 } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
631 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
632 regs->regs[3] = __NR_restart_syscall;
633 }
634 }
635
636 /*
637 * If there's no signal to deliver, we just put the saved sigmask
638 * back.
639 */
640 if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
641 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
642 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
643 }
644}
645
646asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
647 unsigned long thread_info_flags)
648{
649 /* deal with pending signal delivery */
650 if (thread_info_flags & _TIF_SIGPENDING)
651 do_signal(regs, save_r0);
652
653 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
654 clear_thread_flag(TIF_NOTIFY_RESUME);
655 tracehook_notify_resume(regs);
656 if (current->replacement_session_keyring)
657 key_replace_session_keyring();
658 }
659}