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>
37 _sys_sigaltstack(const stack_t
*uss
, stack_t
*uoss
, struct pt_regs
*regs
)
39 return do_sigaltstack(uss
, uoss
, regs
->sp
);
43 struct siginfo
*pinfo
;
47 unsigned char retcode
[16]; /* trampoline code */
50 static int restore_sigcontext(struct pt_regs
*regs
, struct sigcontext
*sc
)
54 /* Alwys make any pending restarted system call return -EINTR */
55 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
58 * Restore the regs from &sc->regs.
59 * (sc is already checked for VERIFY_READ since the sigframe was
60 * checked in sys_sigreturn previously)
62 if (__copy_from_user(regs
, sc
->regs
.gpr
, 32 * sizeof(unsigned long)))
64 if (__copy_from_user(®s
->pc
, &sc
->regs
.pc
, sizeof(unsigned long)))
66 if (__copy_from_user(®s
->sr
, &sc
->regs
.sr
, sizeof(unsigned long)))
69 /* make sure the SM-bit is cleared so user-mode cannot fool us */
70 regs
->sr
&= ~SPR_SR_SM
;
72 /* TODO: the other ports use regs->orig_XX to disable syscall checks
73 * after this completes, but we don't use that mechanism. maybe we can
83 asmlinkage
long _sys_rt_sigreturn(struct pt_regs
*regs
)
85 struct rt_sigframe
*frame
= (struct rt_sigframe __user
*)regs
->sp
;
90 * Since we stacked the signal on a dword boundary,
91 * then frame should be dword aligned here. If it's
92 * not, then the user is trying to mess with us.
94 if (((long)frame
) & 3)
97 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
99 if (__copy_from_user(&set
, &frame
->uc
.uc_sigmask
, sizeof(set
)))
102 set_current_blocked(&set
);
104 if (restore_sigcontext(regs
, &frame
->uc
.uc_mcontext
))
107 if (__copy_from_user(&st
, &frame
->uc
.uc_stack
, sizeof(st
)))
109 /* It is more difficult to avoid calling this function than to
110 call it and ignore errors. */
111 do_sigaltstack(&st
, NULL
, regs
->sp
);
113 return regs
->gpr
[11];
116 force_sig(SIGSEGV
, current
);
121 * Set up a signal frame.
124 static int setup_sigcontext(struct sigcontext
*sc
, struct pt_regs
*regs
,
131 err
|= __copy_to_user(sc
->regs
.gpr
, regs
, 32 * sizeof(unsigned long));
132 err
|= __copy_to_user(&sc
->regs
.pc
, ®s
->pc
, sizeof(unsigned long));
133 err
|= __copy_to_user(&sc
->regs
.sr
, ®s
->sr
, sizeof(unsigned long));
135 /* then some other stuff */
137 err
|= __put_user(mask
, &sc
->oldmask
);
142 static inline unsigned long align_sigframe(unsigned long sp
)
148 * Work out where the signal frame should go. It's either on the user stack
149 * or the alternate stack.
152 static inline void __user
*get_sigframe(struct k_sigaction
*ka
,
153 struct pt_regs
*regs
, size_t frame_size
)
155 unsigned long sp
= regs
->sp
;
156 int onsigstack
= on_sig_stack(sp
);
159 sp
-= STACK_FRAME_OVERHEAD
;
161 /* This is the X/Open sanctioned signal stack switching. */
162 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) && !onsigstack
) {
163 if (current
->sas_ss_size
)
164 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
167 sp
= align_sigframe(sp
- frame_size
);
170 * If we are on the alternate signal stack and would overflow it, don't.
171 * Return an always-bogus address instead so we will die with SIGSEGV.
173 if (onsigstack
&& !likely(on_sig_stack(sp
)))
174 return (void __user
*)-1L;
176 return (void __user
*)sp
;
179 /* grab and setup a signal frame.
181 * basically we stack a lot of state info, and arrange for the
182 * user-mode program to return to the kernel using either a
183 * trampoline which performs the syscall sigreturn, or a provided
184 * user-mode trampoline.
186 static int setup_rt_frame(int sig
, struct k_sigaction
*ka
, siginfo_t
*info
,
187 sigset_t
*set
, struct pt_regs
*regs
)
189 struct rt_sigframe
*frame
;
190 unsigned long return_ip
;
193 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
195 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(*frame
)))
198 err
|= __put_user(&frame
->info
, &frame
->pinfo
);
199 err
|= __put_user(&frame
->uc
, &frame
->puc
);
201 if (ka
->sa
.sa_flags
& SA_SIGINFO
)
202 err
|= copy_siginfo_to_user(&frame
->info
, info
);
206 /* Clear all the bits of the ucontext we don't use. */
207 err
|= __clear_user(&frame
->uc
, offsetof(struct ucontext
, uc_mcontext
));
208 err
|= __put_user(0, &frame
->uc
.uc_flags
);
209 err
|= __put_user(NULL
, &frame
->uc
.uc_link
);
210 err
|= __put_user((void *)current
->sas_ss_sp
,
211 &frame
->uc
.uc_stack
.ss_sp
);
212 err
|= __put_user(sas_ss_flags(regs
->sp
), &frame
->uc
.uc_stack
.ss_flags
);
213 err
|= __put_user(current
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
214 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
, regs
, set
->sig
[0]);
216 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
221 /* trampoline - the desired return ip is the retcode itself */
222 return_ip
= (unsigned long)&frame
->retcode
;
223 /* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
224 err
|= __put_user(0xa960, (short *)(frame
->retcode
+ 0));
225 err
|= __put_user(__NR_rt_sigreturn
, (short *)(frame
->retcode
+ 2));
226 err
|= __put_user(0x20000001, (unsigned long *)(frame
->retcode
+ 4));
227 err
|= __put_user(0x15000000, (unsigned long *)(frame
->retcode
+ 8));
232 /* TODO what is the current->exec_domain stuff and invmap ? */
234 /* Set up registers for signal handler */
235 regs
->pc
= (unsigned long)ka
->sa
.sa_handler
; /* what we enter NOW */
236 regs
->gpr
[9] = (unsigned long)return_ip
; /* what we enter LATER */
237 regs
->gpr
[3] = (unsigned long)sig
; /* arg 1: signo */
238 regs
->gpr
[4] = (unsigned long)&frame
->info
; /* arg 2: (siginfo_t*) */
239 regs
->gpr
[5] = (unsigned long)&frame
->uc
; /* arg 3: ucontext */
241 /* actually move the usp to reflect the stacked frame */
242 regs
->sp
= (unsigned long)frame
;
247 force_sigsegv(sig
, current
);
252 handle_signal(unsigned long sig
,
253 siginfo_t
*info
, struct k_sigaction
*ka
,
254 struct pt_regs
*regs
)
258 ret
= setup_rt_frame(sig
, ka
, info
, sigmask_to_save(), regs
);
262 signal_delivered(sig
, info
, ka
, regs
,
263 test_thread_flag(TIF_SINGLESTEP
));
267 * Note that 'init' is a special process: it doesn't get signals it doesn't
268 * want to handle. Thus you cannot kill init even with a SIGKILL even by
271 * Also note that the regs structure given here as an argument, is the latest
272 * pushed pt_regs. It may or may not be the same as the first pushed registers
273 * when the initial usermode->kernelmode transition took place. Therefore
274 * we can use user_mode(regs) to see if we came directly from kernel or user
278 void do_signal(struct pt_regs
*regs
)
282 struct k_sigaction ka
;
285 * We want the common case to go fast, which
286 * is why we may in certain cases get here from
287 * kernel mode. Just return without doing anything
290 if (!user_mode(regs
))
293 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
295 /* If we are coming out of a syscall then we need
296 * to check if the syscall was interrupted and wants to be
297 * restarted after handling the signal. If so, the original
298 * syscall number is put back into r11 and the PC rewound to
299 * point at the l.sys instruction that resulted in the
300 * original syscall. Syscall results other than the four
301 * below mean that the syscall executed to completion and no
302 * restart is necessary.
304 if (regs
->orig_gpr11
) {
307 switch (regs
->gpr
[11]) {
308 case -ERESTART_RESTARTBLOCK
:
309 case -ERESTARTNOHAND
:
310 /* Restart if there is no signal handler */
311 restart
= (signr
<= 0);
314 /* Restart if there no signal handler or
315 * SA_RESTART flag is set */
316 restart
= (signr
<= 0 || (ka
.sa
.sa_flags
& SA_RESTART
));
318 case -ERESTARTNOINTR
:
325 if (regs
->gpr
[11] == -ERESTART_RESTARTBLOCK
)
326 regs
->gpr
[11] = __NR_restart_syscall
;
328 regs
->gpr
[11] = regs
->orig_gpr11
;
331 regs
->gpr
[11] = -EINTR
;
336 /* no signal to deliver so we just put the saved sigmask
338 restore_saved_sigmask();
339 } else { /* signr > 0 */
340 /* Whee! Actually deliver the signal. */
341 handle_signal(signr
, &info
, &ka
, regs
);
347 asmlinkage
void do_notify_resume(struct pt_regs
*regs
)
349 if (current_thread_info()->flags
& _TIF_SIGPENDING
)
352 if (current_thread_info()->flags
& _TIF_NOTIFY_RESUME
) {
353 clear_thread_flag(TIF_NOTIFY_RESUME
);
354 tracehook_notify_resume(regs
);
This page took 0.040069 seconds and 6 git commands to generate.