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