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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - arch/openrisc/kernel/signal.c
4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
8 * Modifications for the OpenRISC architecture:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
18 #include <linux/sched.h>
20 #include <linux/smp.h>
21 #include <linux/kernel.h>
22 #include <linux/signal.h>
23 #include <linux/errno.h>
24 #include <linux/wait.h>
25 #include <linux/ptrace.h>
26 #include <linux/unistd.h>
27 #include <linux/stddef.h>
28 #include <linux/tracehook.h>
30 #include <asm/processor.h>
31 #include <asm/ucontext.h>
32 #include <asm/uaccess.h>
36 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
39 _sys_sigaltstack(const stack_t
*uss
, stack_t
*uoss
, struct pt_regs
*regs
)
41 return do_sigaltstack(uss
, uoss
, regs
->sp
);
45 struct siginfo
*pinfo
;
49 unsigned char retcode
[16]; /* trampoline code */
52 static int restore_sigcontext(struct pt_regs
*regs
, struct sigcontext
*sc
)
56 /* Alwys make any pending restarted system call return -EINTR */
57 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
60 * Restore the regs from &sc->regs.
61 * (sc is already checked for VERIFY_READ since the sigframe was
62 * checked in sys_sigreturn previously)
64 if (__copy_from_user(regs
, sc
->regs
.gpr
, 32 * sizeof(unsigned long)))
66 if (__copy_from_user(®s
->pc
, &sc
->regs
.pc
, sizeof(unsigned long)))
68 if (__copy_from_user(®s
->sr
, &sc
->regs
.sr
, sizeof(unsigned long)))
71 /* make sure the SM-bit is cleared so user-mode cannot fool us */
72 regs
->sr
&= ~SPR_SR_SM
;
74 /* TODO: the other ports use regs->orig_XX to disable syscall checks
75 * after this completes, but we don't use that mechanism. maybe we can
85 asmlinkage
long _sys_rt_sigreturn(struct pt_regs
*regs
)
87 struct rt_sigframe
*frame
= (struct rt_sigframe __user
*)regs
->sp
;
92 * Since we stacked the signal on a dword boundary,
93 * then frame should be dword aligned here. If it's
94 * not, then the user is trying to mess with us.
96 if (((long)frame
) & 3)
99 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
101 if (__copy_from_user(&set
, &frame
->uc
.uc_sigmask
, sizeof(set
)))
104 sigdelsetmask(&set
, ~_BLOCKABLE
);
105 set_current_blocked(&set
);
107 if (restore_sigcontext(regs
, &frame
->uc
.uc_mcontext
))
110 if (__copy_from_user(&st
, &frame
->uc
.uc_stack
, sizeof(st
)))
112 /* It is more difficult to avoid calling this function than to
113 call it and ignore errors. */
114 do_sigaltstack(&st
, NULL
, regs
->sp
);
116 return regs
->gpr
[11];
119 force_sig(SIGSEGV
, current
);
124 * Set up a signal frame.
127 static int setup_sigcontext(struct sigcontext
*sc
, struct pt_regs
*regs
,
134 err
|= __copy_to_user(sc
->regs
.gpr
, regs
, 32 * sizeof(unsigned long));
135 err
|= __copy_to_user(&sc
->regs
.pc
, ®s
->pc
, sizeof(unsigned long));
136 err
|= __copy_to_user(&sc
->regs
.sr
, ®s
->sr
, sizeof(unsigned long));
138 /* then some other stuff */
140 err
|= __put_user(mask
, &sc
->oldmask
);
145 static inline unsigned long align_sigframe(unsigned long sp
)
151 * Work out where the signal frame should go. It's either on the user stack
152 * or the alternate stack.
155 static inline void __user
*get_sigframe(struct k_sigaction
*ka
,
156 struct pt_regs
*regs
, size_t frame_size
)
158 unsigned long sp
= regs
->sp
;
159 int onsigstack
= on_sig_stack(sp
);
162 sp
-= STACK_FRAME_OVERHEAD
;
164 /* This is the X/Open sanctioned signal stack switching. */
165 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) && !onsigstack
) {
166 if (current
->sas_ss_size
)
167 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
170 sp
= align_sigframe(sp
- frame_size
);
173 * If we are on the alternate signal stack and would overflow it, don't.
174 * Return an always-bogus address instead so we will die with SIGSEGV.
176 if (onsigstack
&& !likely(on_sig_stack(sp
)))
177 return (void __user
*)-1L;
179 return (void __user
*)sp
;
182 /* grab and setup a signal frame.
184 * basically we stack a lot of state info, and arrange for the
185 * user-mode program to return to the kernel using either a
186 * trampoline which performs the syscall sigreturn, or a provided
187 * user-mode trampoline.
189 static int setup_rt_frame(int sig
, struct k_sigaction
*ka
, siginfo_t
*info
,
190 sigset_t
*set
, struct pt_regs
*regs
)
192 struct rt_sigframe
*frame
;
193 unsigned long return_ip
;
196 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
198 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(*frame
)))
201 err
|= __put_user(&frame
->info
, &frame
->pinfo
);
202 err
|= __put_user(&frame
->uc
, &frame
->puc
);
204 if (ka
->sa
.sa_flags
& SA_SIGINFO
)
205 err
|= copy_siginfo_to_user(&frame
->info
, info
);
209 /* Clear all the bits of the ucontext we don't use. */
210 err
|= __clear_user(&frame
->uc
, offsetof(struct ucontext
, uc_mcontext
));
211 err
|= __put_user(0, &frame
->uc
.uc_flags
);
212 err
|= __put_user(NULL
, &frame
->uc
.uc_link
);
213 err
|= __put_user((void *)current
->sas_ss_sp
,
214 &frame
->uc
.uc_stack
.ss_sp
);
215 err
|= __put_user(sas_ss_flags(regs
->sp
), &frame
->uc
.uc_stack
.ss_flags
);
216 err
|= __put_user(current
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
217 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
, regs
, set
->sig
[0]);
219 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
224 /* trampoline - the desired return ip is the retcode itself */
225 return_ip
= (unsigned long)&frame
->retcode
;
226 /* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
227 err
|= __put_user(0xa960, (short *)(frame
->retcode
+ 0));
228 err
|= __put_user(__NR_rt_sigreturn
, (short *)(frame
->retcode
+ 2));
229 err
|= __put_user(0x20000001, (unsigned long *)(frame
->retcode
+ 4));
230 err
|= __put_user(0x15000000, (unsigned long *)(frame
->retcode
+ 8));
235 /* TODO what is the current->exec_domain stuff and invmap ? */
237 /* Set up registers for signal handler */
238 regs
->pc
= (unsigned long)ka
->sa
.sa_handler
; /* what we enter NOW */
239 regs
->gpr
[9] = (unsigned long)return_ip
; /* what we enter LATER */
240 regs
->gpr
[3] = (unsigned long)sig
; /* arg 1: signo */
241 regs
->gpr
[4] = (unsigned long)&frame
->info
; /* arg 2: (siginfo_t*) */
242 regs
->gpr
[5] = (unsigned long)&frame
->uc
; /* arg 3: ucontext */
244 /* actually move the usp to reflect the stacked frame */
245 regs
->sp
= (unsigned long)frame
;
250 force_sigsegv(sig
, current
);
255 handle_signal(unsigned long sig
,
256 siginfo_t
*info
, struct k_sigaction
*ka
,
257 sigset_t
*oldset
, struct pt_regs
*regs
)
261 ret
= setup_rt_frame(sig
, ka
, info
, oldset
, regs
);
265 block_sigmask(ka
, sig
);
271 * Note that 'init' is a special process: it doesn't get signals it doesn't
272 * want to handle. Thus you cannot kill init even with a SIGKILL even by
275 * Also note that the regs structure given here as an argument, is the latest
276 * pushed pt_regs. It may or may not be the same as the first pushed registers
277 * when the initial usermode->kernelmode transition took place. Therefore
278 * we can use user_mode(regs) to see if we came directly from kernel or user
282 void do_signal(struct pt_regs
*regs
)
286 struct k_sigaction ka
;
289 * We want the common case to go fast, which
290 * is why we may in certain cases get here from
291 * kernel mode. Just return without doing anything
294 if (!user_mode(regs
))
297 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
299 /* If we are coming out of a syscall then we need
300 * to check if the syscall was interrupted and wants to be
301 * restarted after handling the signal. If so, the original
302 * syscall number is put back into r11 and the PC rewound to
303 * point at the l.sys instruction that resulted in the
304 * original syscall. Syscall results other than the four
305 * below mean that the syscall executed to completion and no
306 * restart is necessary.
308 if (regs
->orig_gpr11
) {
311 switch (regs
->gpr
[11]) {
312 case -ERESTART_RESTARTBLOCK
:
313 case -ERESTARTNOHAND
:
314 /* Restart if there is no signal handler */
315 restart
= (signr
<= 0);
318 /* Restart if there no signal handler or
319 * SA_RESTART flag is set */
320 restart
= (signr
<= 0 || (ka
.sa
.sa_flags
& SA_RESTART
));
322 case -ERESTARTNOINTR
:
329 if (regs
->gpr
[11] == -ERESTART_RESTARTBLOCK
)
330 regs
->gpr
[11] = __NR_restart_syscall
;
332 regs
->gpr
[11] = regs
->orig_gpr11
;
335 regs
->gpr
[11] = -EINTR
;
340 /* no signal to deliver so we just put the saved sigmask
342 restore_saved_sigmask();
343 } else { /* signr > 0 */
346 if (current_thread_info()->flags
& _TIF_RESTORE_SIGMASK
)
347 oldset
= ¤t
->saved_sigmask
;
349 oldset
= ¤t
->blocked
;
351 /* Whee! Actually deliver the signal. */
352 if (!handle_signal(signr
, &info
, &ka
, oldset
, regs
)) {
353 /* a signal was successfully delivered; the saved
354 * sigmask will have been stored in the signal frame,
355 * and will be restored by sigreturn, so we can simply
356 * clear the TIF_RESTORE_SIGMASK flag */
357 clear_thread_flag(TIF_RESTORE_SIGMASK
);
360 tracehook_signal_handler(signr
, &info
, &ka
, regs
,
361 test_thread_flag(TIF_SINGLESTEP
));
367 asmlinkage
void do_notify_resume(struct pt_regs
*regs
)
369 if (current_thread_info()->flags
& _TIF_SIGPENDING
)
372 if (current_thread_info()->flags
& _TIF_NOTIFY_RESUME
) {
373 clear_thread_flag(TIF_NOTIFY_RESUME
);
374 tracehook_notify_resume(regs
);