1 // SPDX-License-Identifier: GPL-2.0
3 * arch/sh/kernel/signal_64.c
5 * Copyright (C) 2000, 2001 Paolo Alberelli
6 * Copyright (C) 2003 - 2008 Paul Mundt
7 * Copyright (C) 2004 Richard Curnow
9 #include <linux/rwsem.h>
10 #include <linux/sched.h>
12 #include <linux/smp.h>
13 #include <linux/kernel.h>
14 #include <linux/signal.h>
15 #include <linux/errno.h>
16 #include <linux/wait.h>
17 #include <linux/personality.h>
18 #include <linux/ptrace.h>
19 #include <linux/unistd.h>
20 #include <linux/stddef.h>
21 #include <linux/tracehook.h>
22 #include <asm/ucontext.h>
23 #include <linux/uaccess.h>
24 #include <asm/pgtable.h>
25 #include <asm/cacheflush.h>
34 #define REF_REG_RET regs->regs[REG_RET]
35 #define REF_REG_SP regs->regs[REG_SP]
36 #define DEREF_REG_PR regs->regs[REG_PR]
41 handle_signal(struct ksignal
*ksig
, struct pt_regs
*regs
);
44 handle_syscall_restart(struct pt_regs
*regs
, struct sigaction
*sa
)
46 /* If we're not from a syscall, bail out */
47 if (regs
->syscall_nr
< 0)
50 /* check for system call restart.. */
51 switch (regs
->regs
[REG_RET
]) {
52 case -ERESTART_RESTARTBLOCK
:
54 no_system_call_restart
:
55 regs
->regs
[REG_RET
] = -EINTR
;
59 if (!(sa
->sa_flags
& SA_RESTART
))
60 goto no_system_call_restart
;
63 /* Decode syscall # */
64 regs
->regs
[REG_RET
] = regs
->syscall_nr
;
71 * Note that 'init' is a special process: it doesn't get signals it doesn't
72 * want to handle. Thus you cannot kill init even with a SIGKILL even by
75 * Note that we go through the signals twice: once to check the signals that
76 * the kernel can handle, and then we build all the user-level signal handling
77 * stack-frames in one go after that.
79 static void do_signal(struct pt_regs
*regs
)
84 * We want the common case to go fast, which
85 * is why we may in certain cases get here from
86 * kernel mode. Just return without doing anything
92 if (get_signal(&ksig
)) {
93 handle_syscall_restart(regs
, &ksig
.ka
.sa
);
95 /* Whee! Actually deliver the signal. */
96 handle_signal(&ksig
, regs
);
100 /* Did we come from a system call? */
101 if (regs
->syscall_nr
>= 0) {
102 /* Restart the system call - no handlers present */
103 switch (regs
->regs
[REG_RET
]) {
104 case -ERESTARTNOHAND
:
106 case -ERESTARTNOINTR
:
107 /* Decode Syscall # */
108 regs
->regs
[REG_RET
] = regs
->syscall_nr
;
112 case -ERESTART_RESTARTBLOCK
:
113 regs
->regs
[REG_RET
] = __NR_restart_syscall
;
119 /* No signal to deliver -- put the saved sigmask back */
120 restore_saved_sigmask();
124 * Do a signal return; undo the signal stack.
127 struct sigcontext sc
;
128 unsigned long extramask
[_NSIG_WORDS
-1];
129 long long retcode
[2];
133 struct siginfo __user
*pinfo
;
137 long long retcode
[2];
142 restore_sigcontext_fpu(struct pt_regs
*regs
, struct sigcontext __user
*sc
)
147 err
|= __get_user (fpvalid
, &sc
->sc_fpvalid
);
148 conditional_used_math(fpvalid
);
152 if (current
== last_task_used_math
) {
153 last_task_used_math
= NULL
;
157 err
|= __copy_from_user(¤t
->thread
.xstate
->hardfpu
, &sc
->sc_fpregs
[0],
158 (sizeof(long long) * 32) + (sizeof(int) * 1));
164 setup_sigcontext_fpu(struct pt_regs
*regs
, struct sigcontext __user
*sc
)
169 fpvalid
= !!used_math();
170 err
|= __put_user(fpvalid
, &sc
->sc_fpvalid
);
174 if (current
== last_task_used_math
) {
178 last_task_used_math
= NULL
;
182 err
|= __copy_to_user(&sc
->sc_fpregs
[0], ¤t
->thread
.xstate
->hardfpu
,
183 (sizeof(long long) * 32) + (sizeof(int) * 1));
190 restore_sigcontext_fpu(struct pt_regs
*regs
, struct sigcontext __user
*sc
)
195 setup_sigcontext_fpu(struct pt_regs
*regs
, struct sigcontext __user
*sc
)
202 restore_sigcontext(struct pt_regs
*regs
, struct sigcontext __user
*sc
, long long *r2_p
)
204 unsigned int err
= 0;
205 unsigned long long current_sr
, new_sr
;
206 #define SR_MASK 0xffff8cfd
208 #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
210 COPY(regs
[0]); COPY(regs
[1]); COPY(regs
[2]); COPY(regs
[3]);
211 COPY(regs
[4]); COPY(regs
[5]); COPY(regs
[6]); COPY(regs
[7]);
212 COPY(regs
[8]); COPY(regs
[9]); COPY(regs
[10]); COPY(regs
[11]);
213 COPY(regs
[12]); COPY(regs
[13]); COPY(regs
[14]); COPY(regs
[15]);
214 COPY(regs
[16]); COPY(regs
[17]); COPY(regs
[18]); COPY(regs
[19]);
215 COPY(regs
[20]); COPY(regs
[21]); COPY(regs
[22]); COPY(regs
[23]);
216 COPY(regs
[24]); COPY(regs
[25]); COPY(regs
[26]); COPY(regs
[27]);
217 COPY(regs
[28]); COPY(regs
[29]); COPY(regs
[30]); COPY(regs
[31]);
218 COPY(regs
[32]); COPY(regs
[33]); COPY(regs
[34]); COPY(regs
[35]);
219 COPY(regs
[36]); COPY(regs
[37]); COPY(regs
[38]); COPY(regs
[39]);
220 COPY(regs
[40]); COPY(regs
[41]); COPY(regs
[42]); COPY(regs
[43]);
221 COPY(regs
[44]); COPY(regs
[45]); COPY(regs
[46]); COPY(regs
[47]);
222 COPY(regs
[48]); COPY(regs
[49]); COPY(regs
[50]); COPY(regs
[51]);
223 COPY(regs
[52]); COPY(regs
[53]); COPY(regs
[54]); COPY(regs
[55]);
224 COPY(regs
[56]); COPY(regs
[57]); COPY(regs
[58]); COPY(regs
[59]);
225 COPY(regs
[60]); COPY(regs
[61]); COPY(regs
[62]);
226 COPY(tregs
[0]); COPY(tregs
[1]); COPY(tregs
[2]); COPY(tregs
[3]);
227 COPY(tregs
[4]); COPY(tregs
[5]); COPY(tregs
[6]); COPY(tregs
[7]);
229 /* Prevent the signal handler manipulating SR in a way that can
230 crash the kernel. i.e. only allow S, Q, M, PR, SZ, FR to be
232 current_sr
= regs
->sr
;
233 err
|= __get_user(new_sr
, &sc
->sc_sr
);
235 regs
->sr
|= (new_sr
& ~SR_MASK
);
241 /* Must do this last in case it sets regs->sr.fd (i.e. after rest of sr
242 * has been restored above.) */
243 err
|= restore_sigcontext_fpu(regs
, sc
);
245 regs
->syscall_nr
= -1; /* disable syscall checks */
246 err
|= __get_user(*r2_p
, &sc
->sc_regs
[REG_RET
]);
250 asmlinkage
int sys_sigreturn(unsigned long r2
, unsigned long r3
,
251 unsigned long r4
, unsigned long r5
,
252 unsigned long r6
, unsigned long r7
,
253 struct pt_regs
* regs
)
255 struct sigframe __user
*frame
= (struct sigframe __user
*) (long) REF_REG_SP
;
259 /* Always make any pending restarted system calls return -EINTR */
260 current
->restart_block
.fn
= do_no_restart_syscall
;
262 if (!access_ok(frame
, sizeof(*frame
)))
265 if (__get_user(set
.sig
[0], &frame
->sc
.oldmask
)
267 && __copy_from_user(&set
.sig
[1], &frame
->extramask
,
268 sizeof(frame
->extramask
))))
271 set_current_blocked(&set
);
273 if (restore_sigcontext(regs
, &frame
->sc
, &ret
))
284 asmlinkage
int sys_rt_sigreturn(unsigned long r2
, unsigned long r3
,
285 unsigned long r4
, unsigned long r5
,
286 unsigned long r6
, unsigned long r7
,
287 struct pt_regs
* regs
)
289 struct rt_sigframe __user
*frame
= (struct rt_sigframe __user
*) (long) REF_REG_SP
;
293 /* Always make any pending restarted system calls return -EINTR */
294 current
->restart_block
.fn
= do_no_restart_syscall
;
296 if (!access_ok(frame
, sizeof(*frame
)))
299 if (__copy_from_user(&set
, &frame
->uc
.uc_sigmask
, sizeof(set
)))
302 set_current_blocked(&set
);
304 if (restore_sigcontext(regs
, &frame
->uc
.uc_mcontext
, &ret
))
308 if (restore_altstack(&frame
->uc
.uc_stack
))
319 * Set up a signal frame.
322 setup_sigcontext(struct sigcontext __user
*sc
, struct pt_regs
*regs
,
327 /* Do this first, otherwise is this sets sr->fd, that value isn't preserved. */
328 err
|= setup_sigcontext_fpu(regs
, sc
);
330 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
332 COPY(regs
[0]); COPY(regs
[1]); COPY(regs
[2]); COPY(regs
[3]);
333 COPY(regs
[4]); COPY(regs
[5]); COPY(regs
[6]); COPY(regs
[7]);
334 COPY(regs
[8]); COPY(regs
[9]); COPY(regs
[10]); COPY(regs
[11]);
335 COPY(regs
[12]); COPY(regs
[13]); COPY(regs
[14]); COPY(regs
[15]);
336 COPY(regs
[16]); COPY(regs
[17]); COPY(regs
[18]); COPY(regs
[19]);
337 COPY(regs
[20]); COPY(regs
[21]); COPY(regs
[22]); COPY(regs
[23]);
338 COPY(regs
[24]); COPY(regs
[25]); COPY(regs
[26]); COPY(regs
[27]);
339 COPY(regs
[28]); COPY(regs
[29]); COPY(regs
[30]); COPY(regs
[31]);
340 COPY(regs
[32]); COPY(regs
[33]); COPY(regs
[34]); COPY(regs
[35]);
341 COPY(regs
[36]); COPY(regs
[37]); COPY(regs
[38]); COPY(regs
[39]);
342 COPY(regs
[40]); COPY(regs
[41]); COPY(regs
[42]); COPY(regs
[43]);
343 COPY(regs
[44]); COPY(regs
[45]); COPY(regs
[46]); COPY(regs
[47]);
344 COPY(regs
[48]); COPY(regs
[49]); COPY(regs
[50]); COPY(regs
[51]);
345 COPY(regs
[52]); COPY(regs
[53]); COPY(regs
[54]); COPY(regs
[55]);
346 COPY(regs
[56]); COPY(regs
[57]); COPY(regs
[58]); COPY(regs
[59]);
347 COPY(regs
[60]); COPY(regs
[61]); COPY(regs
[62]);
348 COPY(tregs
[0]); COPY(tregs
[1]); COPY(tregs
[2]); COPY(tregs
[3]);
349 COPY(tregs
[4]); COPY(tregs
[5]); COPY(tregs
[6]); COPY(tregs
[7]);
354 err
|= __put_user(mask
, &sc
->oldmask
);
360 * Determine which stack to use..
362 static inline void __user
*
363 get_sigframe(struct k_sigaction
*ka
, unsigned long sp
, size_t frame_size
)
365 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) != 0 && ! sas_ss_flags(sp
))
366 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
368 return (void __user
*)((sp
- frame_size
) & -8ul);
371 void sa_default_restorer(void); /* See comments below */
372 void sa_default_rt_restorer(void); /* See comments below */
374 static int setup_frame(struct ksignal
*ksig
, sigset_t
*set
, struct pt_regs
*regs
)
376 struct sigframe __user
*frame
;
377 int err
= 0, sig
= ksig
->sig
;
380 frame
= get_sigframe(&ksig
->ka
, regs
->regs
[REG_SP
], sizeof(*frame
));
382 if (!access_ok(frame
, sizeof(*frame
)))
385 err
|= setup_sigcontext(&frame
->sc
, regs
, set
->sig
[0]);
387 /* Give up earlier as i386, in case */
391 if (_NSIG_WORDS
> 1) {
392 err
|= __copy_to_user(frame
->extramask
, &set
->sig
[1],
393 sizeof(frame
->extramask
)); }
395 /* Give up earlier as i386, in case */
399 /* Set up to return from userspace. If provided, use a stub
400 already in userspace. */
401 if (ksig
->ka
.sa
.sa_flags
& SA_RESTORER
) {
403 * On SH5 all edited pointers are subject to NEFF
405 DEREF_REG_PR
= neff_sign_extend((unsigned long)
406 ksig
->ka
->sa
.sa_restorer
| 0x1);
409 * Different approach on SH5.
410 * . Endianness independent asm code gets placed in entry.S .
411 * This is limited to four ASM instructions corresponding
412 * to two long longs in size.
413 * . err checking is done on the else branch only
414 * . flush_icache_range() is called upon __put_user() only
415 * . all edited pointers are subject to NEFF
416 * . being code, linker turns ShMedia bit on, always
417 * dereference index -1.
419 DEREF_REG_PR
= neff_sign_extend((unsigned long)
420 frame
->retcode
| 0x01);
422 if (__copy_to_user(frame
->retcode
,
423 (void *)((unsigned long)sa_default_restorer
& (~1)), 16) != 0)
426 /* Cohere the trampoline with the I-cache. */
427 flush_cache_sigtramp(DEREF_REG_PR
-1);
431 * Set up registers for signal handler.
432 * All edited pointers are subject to NEFF.
434 regs
->regs
[REG_SP
] = neff_sign_extend((unsigned long)frame
);
435 regs
->regs
[REG_ARG1
] = sig
; /* Arg for signal handler */
438 The glibc profiling support for SH-5 needs to be passed a sigcontext
439 so it can retrieve the PC. At some point during 2003 the glibc
440 support was changed to receive the sigcontext through the 2nd
441 argument, but there are still versions of libc.so in use that use
442 the 3rd argument. Until libc.so is stabilised, pass the sigcontext
443 through both 2nd and 3rd arguments.
446 regs
->regs
[REG_ARG2
] = (unsigned long long)(unsigned long)(signed long)&frame
->sc
;
447 regs
->regs
[REG_ARG3
] = (unsigned long long)(unsigned long)(signed long)&frame
->sc
;
449 regs
->pc
= neff_sign_extend((unsigned long)ksig
->ka
.sa
.sa_handler
);
452 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
453 sig
, current
->comm
, current
->pid
, frame
,
454 regs
->pc
>> 32, regs
->pc
& 0xffffffff,
455 DEREF_REG_PR
>> 32, DEREF_REG_PR
& 0xffffffff);
460 static int setup_rt_frame(struct ksignal
*kig
, sigset_t
*set
,
461 struct pt_regs
*regs
)
463 struct rt_sigframe __user
*frame
;
464 int err
= 0, sig
= ksig
->sig
;
466 frame
= get_sigframe(&ksig
->ka
, regs
->regs
[REG_SP
], sizeof(*frame
));
468 if (!access_ok(frame
, sizeof(*frame
)))
471 err
|= __put_user(&frame
->info
, &frame
->pinfo
);
472 err
|= __put_user(&frame
->uc
, &frame
->puc
);
473 err
|= copy_siginfo_to_user(&frame
->info
, &ksig
->info
);
475 /* Give up earlier as i386, in case */
479 /* Create the ucontext. */
480 err
|= __put_user(0, &frame
->uc
.uc_flags
);
481 err
|= __put_user(0, &frame
->uc
.uc_link
);
482 err
|= __save_altstack(&frame
->uc
.uc_stack
, regs
->regs
[REG_SP
]);
483 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
,
485 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
487 /* Give up earlier as i386, in case */
491 /* Set up to return from userspace. If provided, use a stub
492 already in userspace. */
493 if (ksig
->ka
.sa
.sa_flags
& SA_RESTORER
) {
495 * On SH5 all edited pointers are subject to NEFF
497 DEREF_REG_PR
= neff_sign_extend((unsigned long)
498 ksig
->ka
.sa
.sa_restorer
| 0x1);
501 * Different approach on SH5.
502 * . Endianness independent asm code gets placed in entry.S .
503 * This is limited to four ASM instructions corresponding
504 * to two long longs in size.
505 * . err checking is done on the else branch only
506 * . flush_icache_range() is called upon __put_user() only
507 * . all edited pointers are subject to NEFF
508 * . being code, linker turns ShMedia bit on, always
509 * dereference index -1.
511 DEREF_REG_PR
= neff_sign_extend((unsigned long)
512 frame
->retcode
| 0x01);
514 if (__copy_to_user(frame
->retcode
,
515 (void *)((unsigned long)sa_default_rt_restorer
& (~1)), 16) != 0)
518 /* Cohere the trampoline with the I-cache. */
519 flush_icache_range(DEREF_REG_PR
-1, DEREF_REG_PR
-1+15);
523 * Set up registers for signal handler.
524 * All edited pointers are subject to NEFF.
526 regs
->regs
[REG_SP
] = neff_sign_extend((unsigned long)frame
);
527 regs
->regs
[REG_ARG1
] = sig
; /* Arg for signal handler */
528 regs
->regs
[REG_ARG2
] = (unsigned long long)(unsigned long)(signed long)&frame
->info
;
529 regs
->regs
[REG_ARG3
] = (unsigned long long)(unsigned long)(signed long)&frame
->uc
.uc_mcontext
;
530 regs
->pc
= neff_sign_extend((unsigned long)ksig
->ka
.sa
.sa_handler
);
532 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
533 sig
, current
->comm
, current
->pid
, frame
,
534 regs
->pc
>> 32, regs
->pc
& 0xffffffff,
535 DEREF_REG_PR
>> 32, DEREF_REG_PR
& 0xffffffff);
541 * OK, we're invoking a handler
544 handle_signal(struct ksignal
*ksig
, struct pt_regs
*regs
)
546 sigset_t
*oldset
= sigmask_to_save();
549 /* Set up the stack frame */
550 if (ksig
->ka
.sa
.sa_flags
& SA_SIGINFO
)
551 ret
= setup_rt_frame(ksig
, oldset
, regs
);
553 ret
= setup_frame(ksig
, oldset
, regs
);
555 signal_setup_done(ret
, ksig
, test_thread_flag(TIF_SINGLESTEP
));
558 asmlinkage
void do_notify_resume(struct pt_regs
*regs
, unsigned long thread_info_flags
)
560 if (thread_info_flags
& _TIF_SIGPENDING
)
563 if (thread_info_flags
& _TIF_NOTIFY_RESUME
) {
564 clear_thread_flag(TIF_NOTIFY_RESUME
);
565 tracehook_notify_resume(regs
);