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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/io.h>
26#include <linux/tracehook.h>
27#include <asm/ucontext.h>
28#include <asm/uaccess.h>
29#include <asm/pgtable.h>
30#include <asm/cacheflush.h>
31#include <asm/syscalls.h>
32#include <asm/fpu.h>
33
34struct fdpic_func_descriptor {
35 unsigned long text;
36 unsigned long GOT;
37};
38
39/*
40 * The following define adds a 64 byte gap between the signal
41 * stack frame and previous contents of the stack. This allows
42 * frame unwinding in a function epilogue but only if a frame
43 * pointer is used in the function. This is necessary because
44 * current gcc compilers (<4.3) do not generate unwind info on
45 * SH for function epilogues.
46 */
47#define UNWINDGUARD 64
48
49/*
50 * Do a signal return; undo the signal stack.
51 */
52
53#define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
54#if defined(CONFIG_CPU_SH2)
55#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
56#else
57#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
58#endif
59#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
60
61struct sigframe
62{
63 struct sigcontext sc;
64 unsigned long extramask[_NSIG_WORDS-1];
65 u16 retcode[8];
66};
67
68struct rt_sigframe
69{
70 struct siginfo info;
71 struct ucontext uc;
72 u16 retcode[8];
73};
74
75#ifdef CONFIG_SH_FPU
76static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
77{
78 struct task_struct *tsk = current;
79
80 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
81 return 0;
82
83 set_used_math();
84 return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
85 sizeof(long)*(16*2+2));
86}
87
88static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
89 struct pt_regs *regs)
90{
91 struct task_struct *tsk = current;
92
93 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
94 return 0;
95
96 if (!used_math())
97 return __put_user(0, &sc->sc_ownedfp);
98
99 if (__put_user(1, &sc->sc_ownedfp))
100 return -EFAULT;
101
102 /* This will cause a "finit" to be triggered by the next
103 attempted FPU operation by the 'current' process.
104 */
105 clear_used_math();
106
107 unlazy_fpu(tsk, regs);
108 return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
109 sizeof(long)*(16*2+2));
110}
111#endif /* CONFIG_SH_FPU */
112
113static int
114restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
115{
116 unsigned int err = 0;
117
118#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
119 COPY(regs[1]);
120 COPY(regs[2]); COPY(regs[3]);
121 COPY(regs[4]); COPY(regs[5]);
122 COPY(regs[6]); COPY(regs[7]);
123 COPY(regs[8]); COPY(regs[9]);
124 COPY(regs[10]); COPY(regs[11]);
125 COPY(regs[12]); COPY(regs[13]);
126 COPY(regs[14]); COPY(regs[15]);
127 COPY(gbr); COPY(mach);
128 COPY(macl); COPY(pr);
129 COPY(sr); COPY(pc);
130#undef COPY
131
132#ifdef CONFIG_SH_FPU
133 if (boot_cpu_data.flags & CPU_HAS_FPU) {
134 int owned_fp;
135 struct task_struct *tsk = current;
136
137 regs->sr |= SR_FD; /* Release FPU */
138 clear_fpu(tsk, regs);
139 clear_used_math();
140 err |= __get_user (owned_fp, &sc->sc_ownedfp);
141 if (owned_fp)
142 err |= restore_sigcontext_fpu(sc);
143 }
144#endif
145
146 regs->tra = -1; /* disable syscall checks */
147 err |= __get_user(*r0_p, &sc->sc_regs[0]);
148 return err;
149}
150
151asmlinkage int sys_sigreturn(void)
152{
153 struct pt_regs *regs = current_pt_regs();
154 struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
155 sigset_t set;
156 int r0;
157
158 /* Always make any pending restarted system calls return -EINTR */
159 current->restart_block.fn = do_no_restart_syscall;
160
161 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
162 goto badframe;
163
164 if (__get_user(set.sig[0], &frame->sc.oldmask)
165 || (_NSIG_WORDS > 1
166 && __copy_from_user(&set.sig[1], &frame->extramask,
167 sizeof(frame->extramask))))
168 goto badframe;
169
170 set_current_blocked(&set);
171
172 if (restore_sigcontext(regs, &frame->sc, &r0))
173 goto badframe;
174 return r0;
175
176badframe:
177 force_sig(SIGSEGV, current);
178 return 0;
179}
180
181asmlinkage int sys_rt_sigreturn(void)
182{
183 struct pt_regs *regs = current_pt_regs();
184 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
185 sigset_t set;
186 int r0;
187
188 /* Always make any pending restarted system calls return -EINTR */
189 current->restart_block.fn = do_no_restart_syscall;
190
191 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
192 goto badframe;
193
194 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
195 goto badframe;
196
197 set_current_blocked(&set);
198
199 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
200 goto badframe;
201
202 if (restore_altstack(&frame->uc.uc_stack))
203 goto badframe;
204
205 return r0;
206
207badframe:
208 force_sig(SIGSEGV, current);
209 return 0;
210}
211
212/*
213 * Set up a signal frame.
214 */
215
216static int
217setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
218 unsigned long mask)
219{
220 int err = 0;
221
222#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
223 COPY(regs[0]); COPY(regs[1]);
224 COPY(regs[2]); COPY(regs[3]);
225 COPY(regs[4]); COPY(regs[5]);
226 COPY(regs[6]); COPY(regs[7]);
227 COPY(regs[8]); COPY(regs[9]);
228 COPY(regs[10]); COPY(regs[11]);
229 COPY(regs[12]); COPY(regs[13]);
230 COPY(regs[14]); COPY(regs[15]);
231 COPY(gbr); COPY(mach);
232 COPY(macl); COPY(pr);
233 COPY(sr); COPY(pc);
234#undef COPY
235
236#ifdef CONFIG_SH_FPU
237 err |= save_sigcontext_fpu(sc, regs);
238#endif
239
240 /* non-iBCS2 extensions.. */
241 err |= __put_user(mask, &sc->oldmask);
242
243 return err;
244}
245
246/*
247 * Determine which stack to use..
248 */
249static inline void __user *
250get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
251{
252 if (ka->sa.sa_flags & SA_ONSTACK) {
253 if (sas_ss_flags(sp) == 0)
254 sp = current->sas_ss_sp + current->sas_ss_size;
255 }
256
257 return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
258}
259
260/* These symbols are defined with the addresses in the vsyscall page.
261 See vsyscall-trapa.S. */
262extern void __kernel_sigreturn(void);
263extern void __kernel_rt_sigreturn(void);
264
265static int setup_frame(struct ksignal *ksig, sigset_t *set,
266 struct pt_regs *regs)
267{
268 struct sigframe __user *frame;
269 int err = 0, sig = ksig->sig;
270
271 frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
272
273 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
274 return -EFAULT;
275
276 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
277
278 if (_NSIG_WORDS > 1)
279 err |= __copy_to_user(frame->extramask, &set->sig[1],
280 sizeof(frame->extramask));
281
282 /* Set up to return from userspace. If provided, use a stub
283 already in userspace. */
284 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
285 regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
286#ifdef CONFIG_VSYSCALL
287 } else if (likely(current->mm->context.vdso)) {
288 regs->pr = VDSO_SYM(&__kernel_sigreturn);
289#endif
290 } else {
291 /* Generate return code (system call to sigreturn) */
292 err |= __put_user(MOVW(7), &frame->retcode[0]);
293 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
294 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
295 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
296 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
297 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
298 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
299 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
300 regs->pr = (unsigned long) frame->retcode;
301 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
302 }
303
304 if (err)
305 return -EFAULT;
306
307 /* Set up registers for signal handler */
308 regs->regs[15] = (unsigned long) frame;
309 regs->regs[4] = sig; /* Arg for signal handler */
310 regs->regs[5] = 0;
311 regs->regs[6] = (unsigned long) &frame->sc;
312
313 if (current->personality & FDPIC_FUNCPTRS) {
314 struct fdpic_func_descriptor __user *funcptr =
315 (struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
316
317 err |= __get_user(regs->pc, &funcptr->text);
318 err |= __get_user(regs->regs[12], &funcptr->GOT);
319 } else
320 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
321
322 if (err)
323 return -EFAULT;
324
325 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
326 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
327
328 return 0;
329}
330
331static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
332 struct pt_regs *regs)
333{
334 struct rt_sigframe __user *frame;
335 int err = 0, sig = ksig->sig;
336
337 frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
338
339 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
340 return -EFAULT;
341
342 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
343
344 /* Create the ucontext. */
345 err |= __put_user(0, &frame->uc.uc_flags);
346 err |= __put_user(NULL, &frame->uc.uc_link);
347 err |= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
348 err |= setup_sigcontext(&frame->uc.uc_mcontext,
349 regs, set->sig[0]);
350 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
351
352 /* Set up to return from userspace. If provided, use a stub
353 already in userspace. */
354 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
355 regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
356#ifdef CONFIG_VSYSCALL
357 } else if (likely(current->mm->context.vdso)) {
358 regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
359#endif
360 } else {
361 /* Generate return code (system call to rt_sigreturn) */
362 err |= __put_user(MOVW(7), &frame->retcode[0]);
363 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
364 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
365 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
366 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
367 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
368 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
369 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
370 regs->pr = (unsigned long) frame->retcode;
371 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
372 }
373
374 if (err)
375 return -EFAULT;
376
377 /* Set up registers for signal handler */
378 regs->regs[15] = (unsigned long) frame;
379 regs->regs[4] = sig; /* Arg for signal handler */
380 regs->regs[5] = (unsigned long) &frame->info;
381 regs->regs[6] = (unsigned long) &frame->uc;
382
383 if (current->personality & FDPIC_FUNCPTRS) {
384 struct fdpic_func_descriptor __user *funcptr =
385 (struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
386
387 err |= __get_user(regs->pc, &funcptr->text);
388 err |= __get_user(regs->regs[12], &funcptr->GOT);
389 } else
390 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
391
392 if (err)
393 return -EFAULT;
394
395 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
396 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
397
398 return 0;
399}
400
401static inline void
402handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
403 struct sigaction *sa)
404{
405 /* If we're not from a syscall, bail out */
406 if (regs->tra < 0)
407 return;
408
409 /* check for system call restart.. */
410 switch (regs->regs[0]) {
411 case -ERESTART_RESTARTBLOCK:
412 case -ERESTARTNOHAND:
413 no_system_call_restart:
414 regs->regs[0] = -EINTR;
415 break;
416
417 case -ERESTARTSYS:
418 if (!(sa->sa_flags & SA_RESTART))
419 goto no_system_call_restart;
420 /* fallthrough */
421 case -ERESTARTNOINTR:
422 regs->regs[0] = save_r0;
423 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
424 break;
425 }
426}
427
428/*
429 * OK, we're invoking a handler
430 */
431static void
432handle_signal(struct ksignal *ksig, struct pt_regs *regs, unsigned int save_r0)
433{
434 sigset_t *oldset = sigmask_to_save();
435 int ret;
436
437 /* Set up the stack frame */
438 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
439 ret = setup_rt_frame(ksig, oldset, regs);
440 else
441 ret = setup_frame(ksig, oldset, regs);
442
443 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
444}
445
446/*
447 * Note that 'init' is a special process: it doesn't get signals it doesn't
448 * want to handle. Thus you cannot kill init even with a SIGKILL even by
449 * mistake.
450 *
451 * Note that we go through the signals twice: once to check the signals that
452 * the kernel can handle, and then we build all the user-level signal handling
453 * stack-frames in one go after that.
454 */
455static void do_signal(struct pt_regs *regs, unsigned int save_r0)
456{
457 struct ksignal ksig;
458
459 /*
460 * We want the common case to go fast, which
461 * is why we may in certain cases get here from
462 * kernel mode. Just return without doing anything
463 * if so.
464 */
465 if (!user_mode(regs))
466 return;
467
468 if (get_signal(&ksig)) {
469 handle_syscall_restart(save_r0, regs, &ksig.ka.sa);
470
471 /* Whee! Actually deliver the signal. */
472 handle_signal(&ksig, regs, save_r0);
473 return;
474 }
475
476 /* Did we come from a system call? */
477 if (regs->tra >= 0) {
478 /* Restart the system call - no handlers present */
479 if (regs->regs[0] == -ERESTARTNOHAND ||
480 regs->regs[0] == -ERESTARTSYS ||
481 regs->regs[0] == -ERESTARTNOINTR) {
482 regs->regs[0] = save_r0;
483 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
484 } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
485 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
486 regs->regs[3] = __NR_restart_syscall;
487 }
488 }
489
490 /*
491 * If there's no signal to deliver, we just put the saved sigmask
492 * back.
493 */
494 restore_saved_sigmask();
495}
496
497asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
498 unsigned long thread_info_flags)
499{
500 /* deal with pending signal delivery */
501 if (thread_info_flags & _TIF_SIGPENDING)
502 do_signal(regs, save_r0);
503
504 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
505 clear_thread_flag(TIF_NOTIFY_RESUME);
506 tracehook_notify_resume(regs);
507 }
508}
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/io.h>
26#include <linux/tracehook.h>
27#include <asm/ucontext.h>
28#include <asm/uaccess.h>
29#include <asm/pgtable.h>
30#include <asm/cacheflush.h>
31#include <asm/syscalls.h>
32#include <asm/fpu.h>
33
34struct fdpic_func_descriptor {
35 unsigned long text;
36 unsigned long GOT;
37};
38
39/*
40 * The following define adds a 64 byte gap between the signal
41 * stack frame and previous contents of the stack. This allows
42 * frame unwinding in a function epilogue but only if a frame
43 * pointer is used in the function. This is necessary because
44 * current gcc compilers (<4.3) do not generate unwind info on
45 * SH for function epilogues.
46 */
47#define UNWINDGUARD 64
48
49/*
50 * Do a signal return; undo the signal stack.
51 */
52
53#define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
54#if defined(CONFIG_CPU_SH2)
55#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
56#else
57#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
58#endif
59#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
60
61struct sigframe
62{
63 struct sigcontext sc;
64 unsigned long extramask[_NSIG_WORDS-1];
65 u16 retcode[8];
66};
67
68struct rt_sigframe
69{
70 struct siginfo info;
71 struct ucontext uc;
72 u16 retcode[8];
73};
74
75#ifdef CONFIG_SH_FPU
76static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
77{
78 struct task_struct *tsk = current;
79
80 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
81 return 0;
82
83 set_used_math();
84 return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
85 sizeof(long)*(16*2+2));
86}
87
88static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
89 struct pt_regs *regs)
90{
91 struct task_struct *tsk = current;
92
93 if (!(boot_cpu_data.flags & CPU_HAS_FPU))
94 return 0;
95
96 if (!used_math())
97 return __put_user(0, &sc->sc_ownedfp);
98
99 if (__put_user(1, &sc->sc_ownedfp))
100 return -EFAULT;
101
102 /* This will cause a "finit" to be triggered by the next
103 attempted FPU operation by the 'current' process.
104 */
105 clear_used_math();
106
107 unlazy_fpu(tsk, regs);
108 return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
109 sizeof(long)*(16*2+2));
110}
111#endif /* CONFIG_SH_FPU */
112
113static int
114restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
115{
116 unsigned int err = 0;
117
118#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
119 COPY(regs[1]);
120 COPY(regs[2]); COPY(regs[3]);
121 COPY(regs[4]); COPY(regs[5]);
122 COPY(regs[6]); COPY(regs[7]);
123 COPY(regs[8]); COPY(regs[9]);
124 COPY(regs[10]); COPY(regs[11]);
125 COPY(regs[12]); COPY(regs[13]);
126 COPY(regs[14]); COPY(regs[15]);
127 COPY(gbr); COPY(mach);
128 COPY(macl); COPY(pr);
129 COPY(sr); COPY(pc);
130#undef COPY
131
132#ifdef CONFIG_SH_FPU
133 if (boot_cpu_data.flags & CPU_HAS_FPU) {
134 int owned_fp;
135 struct task_struct *tsk = current;
136
137 regs->sr |= SR_FD; /* Release FPU */
138 clear_fpu(tsk, regs);
139 clear_used_math();
140 err |= __get_user (owned_fp, &sc->sc_ownedfp);
141 if (owned_fp)
142 err |= restore_sigcontext_fpu(sc);
143 }
144#endif
145
146 regs->tra = -1; /* disable syscall checks */
147 err |= __get_user(*r0_p, &sc->sc_regs[0]);
148 return err;
149}
150
151asmlinkage int sys_sigreturn(void)
152{
153 struct pt_regs *regs = current_pt_regs();
154 struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
155 sigset_t set;
156 int r0;
157
158 /* Always make any pending restarted system calls return -EINTR */
159 current_thread_info()->restart_block.fn = do_no_restart_syscall;
160
161 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
162 goto badframe;
163
164 if (__get_user(set.sig[0], &frame->sc.oldmask)
165 || (_NSIG_WORDS > 1
166 && __copy_from_user(&set.sig[1], &frame->extramask,
167 sizeof(frame->extramask))))
168 goto badframe;
169
170 set_current_blocked(&set);
171
172 if (restore_sigcontext(regs, &frame->sc, &r0))
173 goto badframe;
174 return r0;
175
176badframe:
177 force_sig(SIGSEGV, current);
178 return 0;
179}
180
181asmlinkage int sys_rt_sigreturn(void)
182{
183 struct pt_regs *regs = current_pt_regs();
184 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
185 sigset_t set;
186 int r0;
187
188 /* Always make any pending restarted system calls return -EINTR */
189 current_thread_info()->restart_block.fn = do_no_restart_syscall;
190
191 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
192 goto badframe;
193
194 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
195 goto badframe;
196
197 set_current_blocked(&set);
198
199 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
200 goto badframe;
201
202 if (restore_altstack(&frame->uc.uc_stack))
203 goto badframe;
204
205 return r0;
206
207badframe:
208 force_sig(SIGSEGV, current);
209 return 0;
210}
211
212/*
213 * Set up a signal frame.
214 */
215
216static int
217setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
218 unsigned long mask)
219{
220 int err = 0;
221
222#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
223 COPY(regs[0]); COPY(regs[1]);
224 COPY(regs[2]); COPY(regs[3]);
225 COPY(regs[4]); COPY(regs[5]);
226 COPY(regs[6]); COPY(regs[7]);
227 COPY(regs[8]); COPY(regs[9]);
228 COPY(regs[10]); COPY(regs[11]);
229 COPY(regs[12]); COPY(regs[13]);
230 COPY(regs[14]); COPY(regs[15]);
231 COPY(gbr); COPY(mach);
232 COPY(macl); COPY(pr);
233 COPY(sr); COPY(pc);
234#undef COPY
235
236#ifdef CONFIG_SH_FPU
237 err |= save_sigcontext_fpu(sc, regs);
238#endif
239
240 /* non-iBCS2 extensions.. */
241 err |= __put_user(mask, &sc->oldmask);
242
243 return err;
244}
245
246/*
247 * Determine which stack to use..
248 */
249static inline void __user *
250get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
251{
252 if (ka->sa.sa_flags & SA_ONSTACK) {
253 if (sas_ss_flags(sp) == 0)
254 sp = current->sas_ss_sp + current->sas_ss_size;
255 }
256
257 return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
258}
259
260/* These symbols are defined with the addresses in the vsyscall page.
261 See vsyscall-trapa.S. */
262extern void __kernel_sigreturn(void);
263extern void __kernel_rt_sigreturn(void);
264
265static int setup_frame(int sig, struct k_sigaction *ka,
266 sigset_t *set, struct pt_regs *regs)
267{
268 struct sigframe __user *frame;
269 int err = 0;
270 int signal;
271
272 frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
273
274 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
275 goto give_sigsegv;
276
277 signal = current_thread_info()->exec_domain
278 && current_thread_info()->exec_domain->signal_invmap
279 && sig < 32
280 ? current_thread_info()->exec_domain->signal_invmap[sig]
281 : sig;
282
283 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
284
285 if (_NSIG_WORDS > 1)
286 err |= __copy_to_user(frame->extramask, &set->sig[1],
287 sizeof(frame->extramask));
288
289 /* Set up to return from userspace. If provided, use a stub
290 already in userspace. */
291 if (ka->sa.sa_flags & SA_RESTORER) {
292 regs->pr = (unsigned long) ka->sa.sa_restorer;
293#ifdef CONFIG_VSYSCALL
294 } else if (likely(current->mm->context.vdso)) {
295 regs->pr = VDSO_SYM(&__kernel_sigreturn);
296#endif
297 } else {
298 /* Generate return code (system call to sigreturn) */
299 err |= __put_user(MOVW(7), &frame->retcode[0]);
300 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
301 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
302 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
303 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
304 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
305 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
306 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
307 regs->pr = (unsigned long) frame->retcode;
308 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
309 }
310
311 if (err)
312 goto give_sigsegv;
313
314 /* Set up registers for signal handler */
315 regs->regs[15] = (unsigned long) frame;
316 regs->regs[4] = signal; /* Arg for signal handler */
317 regs->regs[5] = 0;
318 regs->regs[6] = (unsigned long) &frame->sc;
319
320 if (current->personality & FDPIC_FUNCPTRS) {
321 struct fdpic_func_descriptor __user *funcptr =
322 (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
323
324 err |= __get_user(regs->pc, &funcptr->text);
325 err |= __get_user(regs->regs[12], &funcptr->GOT);
326 } else
327 regs->pc = (unsigned long)ka->sa.sa_handler;
328
329 if (err)
330 goto give_sigsegv;
331
332 set_fs(USER_DS);
333
334 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
335 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
336
337 return 0;
338
339give_sigsegv:
340 force_sigsegv(sig, current);
341 return -EFAULT;
342}
343
344static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
345 sigset_t *set, struct pt_regs *regs)
346{
347 struct rt_sigframe __user *frame;
348 int err = 0;
349 int signal;
350
351 frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
352
353 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
354 goto give_sigsegv;
355
356 signal = current_thread_info()->exec_domain
357 && current_thread_info()->exec_domain->signal_invmap
358 && sig < 32
359 ? current_thread_info()->exec_domain->signal_invmap[sig]
360 : sig;
361
362 err |= copy_siginfo_to_user(&frame->info, info);
363
364 /* Create the ucontext. */
365 err |= __put_user(0, &frame->uc.uc_flags);
366 err |= __put_user(NULL, &frame->uc.uc_link);
367 err |= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
368 err |= setup_sigcontext(&frame->uc.uc_mcontext,
369 regs, set->sig[0]);
370 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
371
372 /* Set up to return from userspace. If provided, use a stub
373 already in userspace. */
374 if (ka->sa.sa_flags & SA_RESTORER) {
375 regs->pr = (unsigned long) ka->sa.sa_restorer;
376#ifdef CONFIG_VSYSCALL
377 } else if (likely(current->mm->context.vdso)) {
378 regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
379#endif
380 } else {
381 /* Generate return code (system call to rt_sigreturn) */
382 err |= __put_user(MOVW(7), &frame->retcode[0]);
383 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
384 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
385 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
386 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
387 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
388 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
389 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
390 regs->pr = (unsigned long) frame->retcode;
391 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
392 }
393
394 if (err)
395 goto give_sigsegv;
396
397 /* Set up registers for signal handler */
398 regs->regs[15] = (unsigned long) frame;
399 regs->regs[4] = signal; /* Arg for signal handler */
400 regs->regs[5] = (unsigned long) &frame->info;
401 regs->regs[6] = (unsigned long) &frame->uc;
402
403 if (current->personality & FDPIC_FUNCPTRS) {
404 struct fdpic_func_descriptor __user *funcptr =
405 (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
406
407 err |= __get_user(regs->pc, &funcptr->text);
408 err |= __get_user(regs->regs[12], &funcptr->GOT);
409 } else
410 regs->pc = (unsigned long)ka->sa.sa_handler;
411
412 if (err)
413 goto give_sigsegv;
414
415 set_fs(USER_DS);
416
417 pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
418 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
419
420 return 0;
421
422give_sigsegv:
423 force_sigsegv(sig, current);
424 return -EFAULT;
425}
426
427static inline void
428handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
429 struct sigaction *sa)
430{
431 /* If we're not from a syscall, bail out */
432 if (regs->tra < 0)
433 return;
434
435 /* check for system call restart.. */
436 switch (regs->regs[0]) {
437 case -ERESTART_RESTARTBLOCK:
438 case -ERESTARTNOHAND:
439 no_system_call_restart:
440 regs->regs[0] = -EINTR;
441 break;
442
443 case -ERESTARTSYS:
444 if (!(sa->sa_flags & SA_RESTART))
445 goto no_system_call_restart;
446 /* fallthrough */
447 case -ERESTARTNOINTR:
448 regs->regs[0] = save_r0;
449 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
450 break;
451 }
452}
453
454/*
455 * OK, we're invoking a handler
456 */
457static void
458handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
459 struct pt_regs *regs, unsigned int save_r0)
460{
461 sigset_t *oldset = sigmask_to_save();
462 int ret;
463
464 /* Set up the stack frame */
465 if (ka->sa.sa_flags & SA_SIGINFO)
466 ret = setup_rt_frame(sig, ka, info, oldset, regs);
467 else
468 ret = setup_frame(sig, ka, oldset, regs);
469
470 if (ret)
471 return;
472 signal_delivered(sig, info, ka, regs,
473 test_thread_flag(TIF_SINGLESTEP));
474}
475
476/*
477 * Note that 'init' is a special process: it doesn't get signals it doesn't
478 * want to handle. Thus you cannot kill init even with a SIGKILL even by
479 * mistake.
480 *
481 * Note that we go through the signals twice: once to check the signals that
482 * the kernel can handle, and then we build all the user-level signal handling
483 * stack-frames in one go after that.
484 */
485static void do_signal(struct pt_regs *regs, unsigned int save_r0)
486{
487 siginfo_t info;
488 int signr;
489 struct k_sigaction ka;
490
491 /*
492 * We want the common case to go fast, which
493 * is why we may in certain cases get here from
494 * kernel mode. Just return without doing anything
495 * if so.
496 */
497 if (!user_mode(regs))
498 return;
499
500 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
501 if (signr > 0) {
502 handle_syscall_restart(save_r0, regs, &ka.sa);
503
504 /* Whee! Actually deliver the signal. */
505 handle_signal(signr, &ka, &info, regs, save_r0);
506 return;
507 }
508
509 /* Did we come from a system call? */
510 if (regs->tra >= 0) {
511 /* Restart the system call - no handlers present */
512 if (regs->regs[0] == -ERESTARTNOHAND ||
513 regs->regs[0] == -ERESTARTSYS ||
514 regs->regs[0] == -ERESTARTNOINTR) {
515 regs->regs[0] = save_r0;
516 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
517 } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
518 regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
519 regs->regs[3] = __NR_restart_syscall;
520 }
521 }
522
523 /*
524 * If there's no signal to deliver, we just put the saved sigmask
525 * back.
526 */
527 restore_saved_sigmask();
528}
529
530asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
531 unsigned long thread_info_flags)
532{
533 /* deal with pending signal delivery */
534 if (thread_info_flags & _TIF_SIGPENDING)
535 do_signal(regs, save_r0);
536
537 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
538 clear_thread_flag(TIF_NOTIFY_RESUME);
539 tracehook_notify_resume(regs);
540 }
541}