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1/*
2 * linux/arch/m32r/kernel/signal.c
3 *
4 * Copyright (c) 2003 Hitoshi Yamamoto
5 *
6 * Taken from i386 version.
7 * Copyright (C) 1991, 1992 Linus Torvalds
8 *
9 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
10 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
11 */
12
13#include <linux/sched.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/unistd.h>
21#include <linux/stddef.h>
22#include <linux/personality.h>
23#include <linux/freezer.h>
24#include <linux/tracehook.h>
25#include <asm/cacheflush.h>
26#include <asm/ucontext.h>
27#include <asm/uaccess.h>
28
29#define DEBUG_SIG 0
30
31asmlinkage int
32sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
33 unsigned long r2, unsigned long r3, unsigned long r4,
34 unsigned long r5, unsigned long r6, struct pt_regs *regs)
35{
36 return do_sigaltstack(uss, uoss, regs->spu);
37}
38
39
40/*
41 * Do a signal return; undo the signal stack.
42 */
43
44struct rt_sigframe
45{
46 int sig;
47 struct siginfo __user *pinfo;
48 void __user *puc;
49 struct siginfo info;
50 struct ucontext uc;
51// struct _fpstate fpstate;
52};
53
54static int
55restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
56 int *r0_p)
57{
58 unsigned int err = 0;
59
60 /* Always make any pending restarted system calls return -EINTR */
61 current_thread_info()->restart_block.fn = do_no_restart_syscall;
62
63#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
64 COPY(r4);
65 COPY(r5);
66 COPY(r6);
67 COPY(pt_regs);
68 /* COPY(r0); Skip r0 */
69 COPY(r1);
70 COPY(r2);
71 COPY(r3);
72 COPY(r7);
73 COPY(r8);
74 COPY(r9);
75 COPY(r10);
76 COPY(r11);
77 COPY(r12);
78 COPY(acc0h);
79 COPY(acc0l);
80 COPY(acc1h); /* ISA_DSP_LEVEL2 only */
81 COPY(acc1l); /* ISA_DSP_LEVEL2 only */
82 COPY(psw);
83 COPY(bpc);
84 COPY(bbpsw);
85 COPY(bbpc);
86 COPY(spu);
87 COPY(fp);
88 COPY(lr);
89 COPY(spi);
90#undef COPY
91
92 regs->syscall_nr = -1; /* disable syscall checks */
93 err |= __get_user(*r0_p, &sc->sc_r0);
94
95 return err;
96}
97
98asmlinkage int
99sys_rt_sigreturn(unsigned long r0, unsigned long r1,
100 unsigned long r2, unsigned long r3, unsigned long r4,
101 unsigned long r5, unsigned long r6, struct pt_regs *regs)
102{
103 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
104 sigset_t set;
105 int result;
106
107 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
108 goto badframe;
109 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
110 goto badframe;
111
112 set_current_blocked(&set);
113
114 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
115 goto badframe;
116
117 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
118 goto badframe;
119
120 return result;
121
122badframe:
123 force_sig(SIGSEGV, current);
124 return 0;
125}
126
127/*
128 * Set up a signal frame.
129 */
130
131static int
132setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
133 unsigned long mask)
134{
135 int err = 0;
136
137#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
138 COPY(r4);
139 COPY(r5);
140 COPY(r6);
141 COPY(pt_regs);
142 COPY(r0);
143 COPY(r1);
144 COPY(r2);
145 COPY(r3);
146 COPY(r7);
147 COPY(r8);
148 COPY(r9);
149 COPY(r10);
150 COPY(r11);
151 COPY(r12);
152 COPY(acc0h);
153 COPY(acc0l);
154 COPY(acc1h); /* ISA_DSP_LEVEL2 only */
155 COPY(acc1l); /* ISA_DSP_LEVEL2 only */
156 COPY(psw);
157 COPY(bpc);
158 COPY(bbpsw);
159 COPY(bbpc);
160 COPY(spu);
161 COPY(fp);
162 COPY(lr);
163 COPY(spi);
164#undef COPY
165
166 err |= __put_user(mask, &sc->oldmask);
167
168 return err;
169}
170
171/*
172 * Determine which stack to use..
173 */
174static inline void __user *
175get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
176{
177 /* This is the X/Open sanctioned signal stack switching. */
178 if (ka->sa.sa_flags & SA_ONSTACK) {
179 if (sas_ss_flags(sp) == 0)
180 sp = current->sas_ss_sp + current->sas_ss_size;
181 }
182
183 return (void __user *)((sp - frame_size) & -8ul);
184}
185
186static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
187 sigset_t *set, struct pt_regs *regs)
188{
189 struct rt_sigframe __user *frame;
190 int err = 0;
191 int signal;
192
193 frame = get_sigframe(ka, regs->spu, sizeof(*frame));
194
195 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
196 goto give_sigsegv;
197
198 signal = current_thread_info()->exec_domain
199 && current_thread_info()->exec_domain->signal_invmap
200 && sig < 32
201 ? current_thread_info()->exec_domain->signal_invmap[sig]
202 : sig;
203
204 err |= __put_user(signal, &frame->sig);
205 if (err)
206 goto give_sigsegv;
207
208 err |= __put_user(&frame->info, &frame->pinfo);
209 err |= __put_user(&frame->uc, &frame->puc);
210 err |= copy_siginfo_to_user(&frame->info, info);
211 if (err)
212 goto give_sigsegv;
213
214 /* Create the ucontext. */
215 err |= __put_user(0, &frame->uc.uc_flags);
216 err |= __put_user(0, &frame->uc.uc_link);
217 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
218 err |= __put_user(sas_ss_flags(regs->spu),
219 &frame->uc.uc_stack.ss_flags);
220 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
221 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
222 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
223 if (err)
224 goto give_sigsegv;
225
226 /* Set up to return from userspace. */
227 regs->lr = (unsigned long)ka->sa.sa_restorer;
228
229 /* Set up registers for signal handler */
230 regs->spu = (unsigned long)frame;
231 regs->r0 = signal; /* Arg for signal handler */
232 regs->r1 = (unsigned long)&frame->info;
233 regs->r2 = (unsigned long)&frame->uc;
234 regs->bpc = (unsigned long)ka->sa.sa_handler;
235
236 set_fs(USER_DS);
237
238#if DEBUG_SIG
239 printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
240 current->comm, current->pid, frame, regs->pc);
241#endif
242
243 return 0;
244
245give_sigsegv:
246 force_sigsegv(sig, current);
247 return -EFAULT;
248}
249
250static int prev_insn(struct pt_regs *regs)
251{
252 u16 inst;
253 if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
254 return -EFAULT;
255 if ((inst & 0xfff0) == 0x10f0) /* trap ? */
256 regs->bpc -= 2;
257 else
258 regs->bpc -= 4;
259 regs->syscall_nr = -1;
260 return 0;
261}
262
263/*
264 * OK, we're invoking a handler
265 */
266
267static void
268handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
269 struct pt_regs *regs)
270{
271 /* Are we from a system call? */
272 if (regs->syscall_nr >= 0) {
273 /* If so, check system call restarting.. */
274 switch (regs->r0) {
275 case -ERESTART_RESTARTBLOCK:
276 case -ERESTARTNOHAND:
277 regs->r0 = -EINTR;
278 break;
279
280 case -ERESTARTSYS:
281 if (!(ka->sa.sa_flags & SA_RESTART)) {
282 regs->r0 = -EINTR;
283 break;
284 }
285 /* fallthrough */
286 case -ERESTARTNOINTR:
287 regs->r0 = regs->orig_r0;
288 if (prev_insn(regs) < 0)
289 return;
290 }
291 }
292
293 /* Set up the stack frame */
294 if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs))
295 return;
296
297 signal_delivered(sig, info, ka, regs, 0);
298}
299
300/*
301 * Note that 'init' is a special process: it doesn't get signals it doesn't
302 * want to handle. Thus you cannot kill init even with a SIGKILL even by
303 * mistake.
304 */
305static void do_signal(struct pt_regs *regs)
306{
307 siginfo_t info;
308 int signr;
309 struct k_sigaction ka;
310
311 /*
312 * We want the common case to go fast, which
313 * is why we may in certain cases get here from
314 * kernel mode. Just return without doing anything
315 * if so.
316 */
317 if (!user_mode(regs))
318 return;
319
320 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
321 if (signr > 0) {
322 /* Re-enable any watchpoints before delivering the
323 * signal to user space. The processor register will
324 * have been cleared if the watchpoint triggered
325 * inside the kernel.
326 */
327
328 /* Whee! Actually deliver the signal. */
329 handle_signal(signr, &ka, &info, regs);
330
331 return;
332 }
333
334 /* Did we come from a system call? */
335 if (regs->syscall_nr >= 0) {
336 /* Restart the system call - no handlers present */
337 if (regs->r0 == -ERESTARTNOHAND ||
338 regs->r0 == -ERESTARTSYS ||
339 regs->r0 == -ERESTARTNOINTR) {
340 regs->r0 = regs->orig_r0;
341 prev_insn(regs);
342 } else if (regs->r0 == -ERESTART_RESTARTBLOCK){
343 regs->r0 = regs->orig_r0;
344 regs->r7 = __NR_restart_syscall;
345 prev_insn(regs);
346 }
347 }
348 restore_saved_sigmask();
349}
350
351/*
352 * notification of userspace execution resumption
353 * - triggered by current->work.notify_resume
354 */
355void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
356{
357 /* Pending single-step? */
358 if (thread_info_flags & _TIF_SINGLESTEP)
359 clear_thread_flag(TIF_SINGLESTEP);
360
361 /* deal with pending signal delivery */
362 if (thread_info_flags & _TIF_SIGPENDING)
363 do_signal(regs);
364
365 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
366 clear_thread_flag(TIF_NOTIFY_RESUME);
367 tracehook_notify_resume(regs);
368 }
369
370 clear_thread_flag(TIF_IRET);
371}