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18#include <linux/sched.h>
19#include <linux/mm.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>
29
30#include <asm/processor.h>
31#include <asm/syscall.h>
32#include <asm/ucontext.h>
33#include <asm/uaccess.h>
34
35#define DEBUG_SIG 0
36
37struct rt_sigframe {
38 struct siginfo info;
39 struct ucontext uc;
40 unsigned char retcode[16];
41};
42
43static int restore_sigcontext(struct pt_regs *regs,
44 struct sigcontext __user *sc)
45{
46 int err = 0;
47
48
49 current->restart_block.fn = do_no_restart_syscall;
50
51
52
53
54
55
56 err |= __copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long));
57 err |= __copy_from_user(®s->pc, &sc->regs.pc, sizeof(unsigned long));
58 err |= __copy_from_user(®s->sr, &sc->regs.sr, sizeof(unsigned long));
59
60
61 regs->sr &= ~SPR_SR_SM;
62
63 regs->orig_gpr11 = -1;
64
65
66
67
68
69
70 return err;
71}
72
73asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
74{
75 struct rt_sigframe *frame = (struct rt_sigframe __user *)regs->sp;
76 sigset_t set;
77
78
79
80
81
82
83 if (((long)frame) & 3)
84 goto badframe;
85
86 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
87 goto badframe;
88 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
89 goto badframe;
90
91 set_current_blocked(&set);
92
93 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
94 goto badframe;
95
96 if (restore_altstack(&frame->uc.uc_stack))
97 goto badframe;
98
99 return regs->gpr[11];
100
101badframe:
102 force_sig(SIGSEGV, current);
103 return 0;
104}
105
106
107
108
109
110static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
111{
112 int err = 0;
113
114
115
116
117
118 err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long));
119 err |= __copy_to_user(&sc->regs.pc, ®s->pc, sizeof(unsigned long));
120 err |= __copy_to_user(&sc->regs.sr, ®s->sr, sizeof(unsigned long));
121
122 return err;
123}
124
125static inline unsigned long align_sigframe(unsigned long sp)
126{
127 return sp & ~3UL;
128}
129
130
131
132
133
134
135static inline void __user *get_sigframe(struct ksignal *ksig,
136 struct pt_regs *regs, size_t frame_size)
137{
138 unsigned long sp = regs->sp;
139
140
141 sp -= STACK_FRAME_OVERHEAD;
142 sp = sigsp(sp, ksig);
143 sp = align_sigframe(sp - frame_size);
144
145 return (void __user *)sp;
146}
147
148
149
150
151
152
153
154
155static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
156 struct pt_regs *regs)
157{
158 struct rt_sigframe *frame;
159 unsigned long return_ip;
160 int err = 0;
161
162 frame = get_sigframe(ksig, regs, sizeof(*frame));
163
164 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
165 return -EFAULT;
166
167
168 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
169 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
170
171
172 err |= __put_user(0, &frame->uc.uc_flags);
173 err |= __put_user(NULL, &frame->uc.uc_link);
174 err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
175 err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
176
177 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
178
179 if (err)
180 return -EFAULT;
181
182
183 return_ip = (unsigned long)&frame->retcode;
184
185
186
187
188 err |= __put_user(0xa960, (short *)(frame->retcode + 0));
189 err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode + 2));
190 err |= __put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
191 err |= __put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
192
193 if (err)
194 return -EFAULT;
195
196
197 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
198 regs->gpr[9] = (unsigned long)return_ip;
199 regs->gpr[3] = (unsigned long)ksig->sig;
200 regs->gpr[4] = (unsigned long)&frame->info;
201 regs->gpr[5] = (unsigned long)&frame->uc;
202
203
204 regs->sp = (unsigned long)frame;
205
206 return 0;
207}
208
209static inline void
210handle_signal(struct ksignal *ksig, struct pt_regs *regs)
211{
212 int ret;
213
214 ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
215
216 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
217}
218
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229
230
231int do_signal(struct pt_regs *regs, int syscall)
232{
233 struct ksignal ksig;
234 unsigned long continue_addr = 0;
235 unsigned long restart_addr = 0;
236 unsigned long retval = 0;
237 int restart = 0;
238
239 if (syscall) {
240 continue_addr = regs->pc;
241 restart_addr = continue_addr - 4;
242 retval = regs->gpr[11];
243
244
245
246
247
248 switch (retval) {
249 case -ERESTART_RESTARTBLOCK:
250 restart = -2;
251
252 case -ERESTARTNOHAND:
253 case -ERESTARTSYS:
254 case -ERESTARTNOINTR:
255 restart++;
256 regs->gpr[11] = regs->orig_gpr11;
257 regs->pc = restart_addr;
258 break;
259 }
260 }
261
262
263
264
265
266
267
268 if (get_signal(&ksig)) {
269 if (unlikely(restart) && regs->pc == restart_addr) {
270 if (retval == -ERESTARTNOHAND ||
271 retval == -ERESTART_RESTARTBLOCK
272 || (retval == -ERESTARTSYS
273 && !(ksig.ka.sa.sa_flags & SA_RESTART))) {
274
275 regs->gpr[11] = -EINTR;
276 regs->pc = continue_addr;
277 }
278 }
279 handle_signal(&ksig, regs);
280 } else {
281
282 restore_saved_sigmask();
283
284
285
286
287 if (unlikely(restart) && regs->pc == restart_addr) {
288 regs->pc = continue_addr;
289 return restart;
290 }
291 }
292
293 return 0;
294}
295
296asmlinkage int
297do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
298{
299 do {
300 if (likely(thread_flags & _TIF_NEED_RESCHED)) {
301 schedule();
302 } else {
303 if (unlikely(!user_mode(regs)))
304 return 0;
305 local_irq_enable();
306 if (thread_flags & _TIF_SIGPENDING) {
307 int restart = do_signal(regs, syscall);
308 if (unlikely(restart)) {
309
310
311
312
313
314 return restart;
315 }
316 syscall = 0;
317 } else {
318 clear_thread_flag(TIF_NOTIFY_RESUME);
319 tracehook_notify_resume(regs);
320 }
321 }
322 local_irq_disable();
323 thread_flags = current_thread_info()->flags;
324 } while (thread_flags & _TIF_WORK_MASK);
325 return 0;
326}
327