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1/*
2 * Copyright IBM Corp. 1999, 2006
3 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
4 *
5 * Based on Intel version
6 *
7 * Copyright (C) 1991, 1992 Linus Torvalds
8 *
9 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
10 */
11
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/smp.h>
15#include <linux/kernel.h>
16#include <linux/signal.h>
17#include <linux/errno.h>
18#include <linux/wait.h>
19#include <linux/ptrace.h>
20#include <linux/unistd.h>
21#include <linux/stddef.h>
22#include <linux/tty.h>
23#include <linux/personality.h>
24#include <linux/binfmts.h>
25#include <linux/tracehook.h>
26#include <linux/syscalls.h>
27#include <linux/compat.h>
28#include <asm/ucontext.h>
29#include <asm/uaccess.h>
30#include <asm/lowcore.h>
31#include <asm/switch_to.h>
32#include "entry.h"
33
34typedef struct
35{
36 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
37 struct sigcontext sc;
38 _sigregs sregs;
39 int signo;
40 __u8 retcode[S390_SYSCALL_SIZE];
41} sigframe;
42
43typedef struct
44{
45 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
46 __u8 retcode[S390_SYSCALL_SIZE];
47 struct siginfo info;
48 struct ucontext uc;
49} rt_sigframe;
50
51/* Returns non-zero on fault. */
52static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
53{
54 _sigregs user_sregs;
55
56 save_access_regs(current->thread.acrs);
57
58 /* Copy a 'clean' PSW mask to the user to avoid leaking
59 information about whether PER is currently on. */
60 user_sregs.regs.psw.mask = PSW_USER_BITS |
61 (regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
62 user_sregs.regs.psw.addr = regs->psw.addr;
63 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
64 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
65 sizeof(user_sregs.regs.acrs));
66 /*
67 * We have to store the fp registers to current->thread.fp_regs
68 * to merge them with the emulated registers.
69 */
70 save_fp_ctl(¤t->thread.fp_regs.fpc);
71 save_fp_regs(current->thread.fp_regs.fprs);
72 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
73 sizeof(user_sregs.fpregs));
74 if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs)))
75 return -EFAULT;
76 return 0;
77}
78
79static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
80{
81 _sigregs user_sregs;
82
83 /* Alwys make any pending restarted system call return -EINTR */
84 current_thread_info()->restart_block.fn = do_no_restart_syscall;
85
86 if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs)))
87 return -EFAULT;
88
89 if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI))
90 return -EINVAL;
91
92 /* Loading the floating-point-control word can fail. Do that first. */
93 if (restore_fp_ctl(&user_sregs.fpregs.fpc))
94 return -EINVAL;
95
96 /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
97 regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
98 (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
99 /* Check for invalid user address space control. */
100 if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
101 regs->psw.mask = PSW_ASC_PRIMARY |
102 (regs->psw.mask & ~PSW_MASK_ASC);
103 /* Check for invalid amode */
104 if (regs->psw.mask & PSW_MASK_EA)
105 regs->psw.mask |= PSW_MASK_BA;
106 regs->psw.addr = user_sregs.regs.psw.addr;
107 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
108 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
109 sizeof(current->thread.acrs));
110 restore_access_regs(current->thread.acrs);
111
112 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
113 sizeof(current->thread.fp_regs));
114
115 restore_fp_regs(current->thread.fp_regs.fprs);
116 clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
117 return 0;
118}
119
120SYSCALL_DEFINE0(sigreturn)
121{
122 struct pt_regs *regs = task_pt_regs(current);
123 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
124 sigset_t set;
125
126 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
127 goto badframe;
128 set_current_blocked(&set);
129 if (restore_sigregs(regs, &frame->sregs))
130 goto badframe;
131 return regs->gprs[2];
132badframe:
133 force_sig(SIGSEGV, current);
134 return 0;
135}
136
137SYSCALL_DEFINE0(rt_sigreturn)
138{
139 struct pt_regs *regs = task_pt_regs(current);
140 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
141 sigset_t set;
142
143 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
144 goto badframe;
145 set_current_blocked(&set);
146 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
147 goto badframe;
148 if (restore_altstack(&frame->uc.uc_stack))
149 goto badframe;
150 return regs->gprs[2];
151badframe:
152 force_sig(SIGSEGV, current);
153 return 0;
154}
155
156/*
157 * Set up a signal frame.
158 */
159
160
161/*
162 * Determine which stack to use..
163 */
164static inline void __user *
165get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
166{
167 unsigned long sp;
168
169 /* Default to using normal stack */
170 sp = regs->gprs[15];
171
172 /* Overflow on alternate signal stack gives SIGSEGV. */
173 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
174 return (void __user *) -1UL;
175
176 /* This is the X/Open sanctioned signal stack switching. */
177 if (ka->sa.sa_flags & SA_ONSTACK) {
178 if (! sas_ss_flags(sp))
179 sp = current->sas_ss_sp + current->sas_ss_size;
180 }
181
182 return (void __user *)((sp - frame_size) & -8ul);
183}
184
185static inline int map_signal(int sig)
186{
187 if (current_thread_info()->exec_domain
188 && current_thread_info()->exec_domain->signal_invmap
189 && sig < 32)
190 return current_thread_info()->exec_domain->signal_invmap[sig];
191 else
192 return sig;
193}
194
195static int setup_frame(int sig, struct k_sigaction *ka,
196 sigset_t *set, struct pt_regs * regs)
197{
198 sigframe __user *frame;
199
200 frame = get_sigframe(ka, regs, sizeof(sigframe));
201
202 if (frame == (void __user *) -1UL)
203 goto give_sigsegv;
204
205 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
206 goto give_sigsegv;
207
208 if (save_sigregs(regs, &frame->sregs))
209 goto give_sigsegv;
210 if (__put_user(&frame->sregs, &frame->sc.sregs))
211 goto give_sigsegv;
212
213 /* Set up to return from userspace. If provided, use a stub
214 already in userspace. */
215 if (ka->sa.sa_flags & SA_RESTORER) {
216 regs->gprs[14] = (unsigned long)
217 ka->sa.sa_restorer | PSW_ADDR_AMODE;
218 } else {
219 regs->gprs[14] = (unsigned long)
220 frame->retcode | PSW_ADDR_AMODE;
221 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
222 (u16 __user *)(frame->retcode)))
223 goto give_sigsegv;
224 }
225
226 /* Set up backchain. */
227 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
228 goto give_sigsegv;
229
230 /* Set up registers for signal handler */
231 regs->gprs[15] = (unsigned long) frame;
232 /* Force default amode and default user address space control. */
233 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
234 (PSW_USER_BITS & PSW_MASK_ASC) |
235 (regs->psw.mask & ~PSW_MASK_ASC);
236 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
237
238 regs->gprs[2] = map_signal(sig);
239 regs->gprs[3] = (unsigned long) &frame->sc;
240
241 /* We forgot to include these in the sigcontext.
242 To avoid breaking binary compatibility, they are passed as args. */
243 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
244 sig == SIGTRAP || sig == SIGFPE) {
245 /* set extra registers only for synchronous signals */
246 regs->gprs[4] = regs->int_code & 127;
247 regs->gprs[5] = regs->int_parm_long;
248 regs->gprs[6] = task_thread_info(current)->last_break;
249 }
250
251 /* Place signal number on stack to allow backtrace from handler. */
252 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
253 goto give_sigsegv;
254 return 0;
255
256give_sigsegv:
257 force_sigsegv(sig, current);
258 return -EFAULT;
259}
260
261static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
262 sigset_t *set, struct pt_regs * regs)
263{
264 int err = 0;
265 rt_sigframe __user *frame;
266
267 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
268
269 if (frame == (void __user *) -1UL)
270 goto give_sigsegv;
271
272 if (copy_siginfo_to_user(&frame->info, info))
273 goto give_sigsegv;
274
275 /* Create the ucontext. */
276 err |= __put_user(0, &frame->uc.uc_flags);
277 err |= __put_user(NULL, &frame->uc.uc_link);
278 err |= __save_altstack(&frame->uc.uc_stack, regs->gprs[15]);
279 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
280 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
281 if (err)
282 goto give_sigsegv;
283
284 /* Set up to return from userspace. If provided, use a stub
285 already in userspace. */
286 if (ka->sa.sa_flags & SA_RESTORER) {
287 regs->gprs[14] = (unsigned long)
288 ka->sa.sa_restorer | PSW_ADDR_AMODE;
289 } else {
290 regs->gprs[14] = (unsigned long)
291 frame->retcode | PSW_ADDR_AMODE;
292 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
293 (u16 __user *)(frame->retcode)))
294 goto give_sigsegv;
295 }
296
297 /* Set up backchain. */
298 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
299 goto give_sigsegv;
300
301 /* Set up registers for signal handler */
302 regs->gprs[15] = (unsigned long) frame;
303 /* Force default amode and default user address space control. */
304 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
305 (PSW_USER_BITS & PSW_MASK_ASC) |
306 (regs->psw.mask & ~PSW_MASK_ASC);
307 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
308
309 regs->gprs[2] = map_signal(sig);
310 regs->gprs[3] = (unsigned long) &frame->info;
311 regs->gprs[4] = (unsigned long) &frame->uc;
312 regs->gprs[5] = task_thread_info(current)->last_break;
313 return 0;
314
315give_sigsegv:
316 force_sigsegv(sig, current);
317 return -EFAULT;
318}
319
320static void handle_signal(unsigned long sig, struct k_sigaction *ka,
321 siginfo_t *info, sigset_t *oldset,
322 struct pt_regs *regs)
323{
324 int ret;
325
326 /* Set up the stack frame */
327 if (ka->sa.sa_flags & SA_SIGINFO)
328 ret = setup_rt_frame(sig, ka, info, oldset, regs);
329 else
330 ret = setup_frame(sig, ka, oldset, regs);
331 if (ret)
332 return;
333 signal_delivered(sig, info, ka, regs,
334 test_thread_flag(TIF_SINGLE_STEP));
335}
336
337/*
338 * Note that 'init' is a special process: it doesn't get signals it doesn't
339 * want to handle. Thus you cannot kill init even with a SIGKILL even by
340 * mistake.
341 *
342 * Note that we go through the signals twice: once to check the signals that
343 * the kernel can handle, and then we build all the user-level signal handling
344 * stack-frames in one go after that.
345 */
346void do_signal(struct pt_regs *regs)
347{
348 siginfo_t info;
349 int signr;
350 struct k_sigaction ka;
351 sigset_t *oldset = sigmask_to_save();
352
353 /*
354 * Get signal to deliver. When running under ptrace, at this point
355 * the debugger may change all our registers, including the system
356 * call information.
357 */
358 current_thread_info()->system_call =
359 test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
360 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
361
362 if (signr > 0) {
363 /* Whee! Actually deliver the signal. */
364 if (current_thread_info()->system_call) {
365 regs->int_code = current_thread_info()->system_call;
366 /* Check for system call restarting. */
367 switch (regs->gprs[2]) {
368 case -ERESTART_RESTARTBLOCK:
369 case -ERESTARTNOHAND:
370 regs->gprs[2] = -EINTR;
371 break;
372 case -ERESTARTSYS:
373 if (!(ka.sa.sa_flags & SA_RESTART)) {
374 regs->gprs[2] = -EINTR;
375 break;
376 }
377 /* fallthrough */
378 case -ERESTARTNOINTR:
379 regs->gprs[2] = regs->orig_gpr2;
380 regs->psw.addr =
381 __rewind_psw(regs->psw,
382 regs->int_code >> 16);
383 break;
384 }
385 }
386 /* No longer in a system call */
387 clear_thread_flag(TIF_SYSCALL);
388
389 if (is_compat_task())
390 handle_signal32(signr, &ka, &info, oldset, regs);
391 else
392 handle_signal(signr, &ka, &info, oldset, regs);
393 return;
394 }
395
396 /* No handlers present - check for system call restart */
397 clear_thread_flag(TIF_SYSCALL);
398 if (current_thread_info()->system_call) {
399 regs->int_code = current_thread_info()->system_call;
400 switch (regs->gprs[2]) {
401 case -ERESTART_RESTARTBLOCK:
402 /* Restart with sys_restart_syscall */
403 regs->int_code = __NR_restart_syscall;
404 /* fallthrough */
405 case -ERESTARTNOHAND:
406 case -ERESTARTSYS:
407 case -ERESTARTNOINTR:
408 /* Restart system call with magic TIF bit. */
409 regs->gprs[2] = regs->orig_gpr2;
410 set_thread_flag(TIF_SYSCALL);
411 if (test_thread_flag(TIF_SINGLE_STEP))
412 set_thread_flag(TIF_PER_TRAP);
413 break;
414 }
415 }
416
417 /*
418 * If there's no signal to deliver, we just put the saved sigmask back.
419 */
420 restore_saved_sigmask();
421}
422
423void do_notify_resume(struct pt_regs *regs)
424{
425 clear_thread_flag(TIF_NOTIFY_RESUME);
426 tracehook_notify_resume(regs);
427}
1/*
2 * arch/s390/kernel/signal.c
3 *
4 * Copyright (C) IBM Corp. 1999,2006
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
6 *
7 * Based on Intel version
8 *
9 * Copyright (C) 1991, 1992 Linus Torvalds
10 *
11 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
12 */
13
14#include <linux/sched.h>
15#include <linux/mm.h>
16#include <linux/smp.h>
17#include <linux/kernel.h>
18#include <linux/signal.h>
19#include <linux/errno.h>
20#include <linux/wait.h>
21#include <linux/ptrace.h>
22#include <linux/unistd.h>
23#include <linux/stddef.h>
24#include <linux/tty.h>
25#include <linux/personality.h>
26#include <linux/binfmts.h>
27#include <linux/tracehook.h>
28#include <linux/syscalls.h>
29#include <linux/compat.h>
30#include <asm/ucontext.h>
31#include <asm/uaccess.h>
32#include <asm/lowcore.h>
33#include "entry.h"
34
35#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
36
37
38typedef struct
39{
40 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
41 struct sigcontext sc;
42 _sigregs sregs;
43 int signo;
44 __u8 retcode[S390_SYSCALL_SIZE];
45} sigframe;
46
47typedef struct
48{
49 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
50 __u8 retcode[S390_SYSCALL_SIZE];
51 struct siginfo info;
52 struct ucontext uc;
53} rt_sigframe;
54
55/*
56 * Atomically swap in the new signal mask, and wait for a signal.
57 */
58SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
59{
60 sigset_t blocked;
61
62 current->saved_sigmask = current->blocked;
63 mask &= _BLOCKABLE;
64 siginitset(&blocked, mask);
65 set_current_blocked(&blocked);
66 set_current_state(TASK_INTERRUPTIBLE);
67 schedule();
68 set_restore_sigmask();
69 return -ERESTARTNOHAND;
70}
71
72SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
73 struct old_sigaction __user *, oact)
74{
75 struct k_sigaction new_ka, old_ka;
76 int ret;
77
78 if (act) {
79 old_sigset_t mask;
80 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
81 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
82 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
83 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
84 __get_user(mask, &act->sa_mask))
85 return -EFAULT;
86 siginitset(&new_ka.sa.sa_mask, mask);
87 }
88
89 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
90
91 if (!ret && oact) {
92 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
93 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
94 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
95 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
96 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
97 return -EFAULT;
98 }
99
100 return ret;
101}
102
103SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
104 stack_t __user *, uoss)
105{
106 struct pt_regs *regs = task_pt_regs(current);
107 return do_sigaltstack(uss, uoss, regs->gprs[15]);
108}
109
110/* Returns non-zero on fault. */
111static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
112{
113 _sigregs user_sregs;
114
115 save_access_regs(current->thread.acrs);
116
117 /* Copy a 'clean' PSW mask to the user to avoid leaking
118 information about whether PER is currently on. */
119 user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
120 user_sregs.regs.psw.addr = regs->psw.addr;
121 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
122 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
123 sizeof(sregs->regs.acrs));
124 /*
125 * We have to store the fp registers to current->thread.fp_regs
126 * to merge them with the emulated registers.
127 */
128 save_fp_regs(¤t->thread.fp_regs);
129 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
130 sizeof(s390_fp_regs));
131 return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
132}
133
134/* Returns positive number on error */
135static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
136{
137 int err;
138 _sigregs user_sregs;
139
140 /* Alwys make any pending restarted system call return -EINTR */
141 current_thread_info()->restart_block.fn = do_no_restart_syscall;
142
143 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
144 if (err)
145 return err;
146 regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
147 user_sregs.regs.psw.mask);
148 regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
149 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
150 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
151 sizeof(sregs->regs.acrs));
152 restore_access_regs(current->thread.acrs);
153
154 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
155 sizeof(s390_fp_regs));
156 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
157
158 restore_fp_regs(¤t->thread.fp_regs);
159 regs->svcnr = 0; /* disable syscall checks */
160 return 0;
161}
162
163SYSCALL_DEFINE0(sigreturn)
164{
165 struct pt_regs *regs = task_pt_regs(current);
166 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
167 sigset_t set;
168
169 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
170 goto badframe;
171 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
172 goto badframe;
173 sigdelsetmask(&set, ~_BLOCKABLE);
174 set_current_blocked(&set);
175 if (restore_sigregs(regs, &frame->sregs))
176 goto badframe;
177 return regs->gprs[2];
178badframe:
179 force_sig(SIGSEGV, current);
180 return 0;
181}
182
183SYSCALL_DEFINE0(rt_sigreturn)
184{
185 struct pt_regs *regs = task_pt_regs(current);
186 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
187 sigset_t set;
188
189 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
190 goto badframe;
191 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
192 goto badframe;
193 sigdelsetmask(&set, ~_BLOCKABLE);
194 set_current_blocked(&set);
195 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
196 goto badframe;
197 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
198 regs->gprs[15]) == -EFAULT)
199 goto badframe;
200 return regs->gprs[2];
201badframe:
202 force_sig(SIGSEGV, current);
203 return 0;
204}
205
206/*
207 * Set up a signal frame.
208 */
209
210
211/*
212 * Determine which stack to use..
213 */
214static inline void __user *
215get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
216{
217 unsigned long sp;
218
219 /* Default to using normal stack */
220 sp = regs->gprs[15];
221
222 /* Overflow on alternate signal stack gives SIGSEGV. */
223 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
224 return (void __user *) -1UL;
225
226 /* This is the X/Open sanctioned signal stack switching. */
227 if (ka->sa.sa_flags & SA_ONSTACK) {
228 if (! sas_ss_flags(sp))
229 sp = current->sas_ss_sp + current->sas_ss_size;
230 }
231
232 /* This is the legacy signal stack switching. */
233 else if (!user_mode(regs) &&
234 !(ka->sa.sa_flags & SA_RESTORER) &&
235 ka->sa.sa_restorer) {
236 sp = (unsigned long) ka->sa.sa_restorer;
237 }
238
239 return (void __user *)((sp - frame_size) & -8ul);
240}
241
242static inline int map_signal(int sig)
243{
244 if (current_thread_info()->exec_domain
245 && current_thread_info()->exec_domain->signal_invmap
246 && sig < 32)
247 return current_thread_info()->exec_domain->signal_invmap[sig];
248 else
249 return sig;
250}
251
252static int setup_frame(int sig, struct k_sigaction *ka,
253 sigset_t *set, struct pt_regs * regs)
254{
255 sigframe __user *frame;
256
257 frame = get_sigframe(ka, regs, sizeof(sigframe));
258 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
259 goto give_sigsegv;
260
261 if (frame == (void __user *) -1UL)
262 goto give_sigsegv;
263
264 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
265 goto give_sigsegv;
266
267 if (save_sigregs(regs, &frame->sregs))
268 goto give_sigsegv;
269 if (__put_user(&frame->sregs, &frame->sc.sregs))
270 goto give_sigsegv;
271
272 /* Set up to return from userspace. If provided, use a stub
273 already in userspace. */
274 if (ka->sa.sa_flags & SA_RESTORER) {
275 regs->gprs[14] = (unsigned long)
276 ka->sa.sa_restorer | PSW_ADDR_AMODE;
277 } else {
278 regs->gprs[14] = (unsigned long)
279 frame->retcode | PSW_ADDR_AMODE;
280 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
281 (u16 __user *)(frame->retcode)))
282 goto give_sigsegv;
283 }
284
285 /* Set up backchain. */
286 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
287 goto give_sigsegv;
288
289 /* Set up registers for signal handler */
290 regs->gprs[15] = (unsigned long) frame;
291 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
292
293 regs->gprs[2] = map_signal(sig);
294 regs->gprs[3] = (unsigned long) &frame->sc;
295
296 /* We forgot to include these in the sigcontext.
297 To avoid breaking binary compatibility, they are passed as args. */
298 regs->gprs[4] = current->thread.trap_no;
299 regs->gprs[5] = current->thread.prot_addr;
300 regs->gprs[6] = task_thread_info(current)->last_break;
301
302 /* Place signal number on stack to allow backtrace from handler. */
303 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
304 goto give_sigsegv;
305 return 0;
306
307give_sigsegv:
308 force_sigsegv(sig, current);
309 return -EFAULT;
310}
311
312static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
313 sigset_t *set, struct pt_regs * regs)
314{
315 int err = 0;
316 rt_sigframe __user *frame;
317
318 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
319 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
320 goto give_sigsegv;
321
322 if (frame == (void __user *) -1UL)
323 goto give_sigsegv;
324
325 if (copy_siginfo_to_user(&frame->info, info))
326 goto give_sigsegv;
327
328 /* Create the ucontext. */
329 err |= __put_user(0, &frame->uc.uc_flags);
330 err |= __put_user(NULL, &frame->uc.uc_link);
331 err |= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
332 err |= __put_user(sas_ss_flags(regs->gprs[15]),
333 &frame->uc.uc_stack.ss_flags);
334 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
335 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
336 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
337 if (err)
338 goto give_sigsegv;
339
340 /* Set up to return from userspace. If provided, use a stub
341 already in userspace. */
342 if (ka->sa.sa_flags & SA_RESTORER) {
343 regs->gprs[14] = (unsigned long)
344 ka->sa.sa_restorer | PSW_ADDR_AMODE;
345 } else {
346 regs->gprs[14] = (unsigned long)
347 frame->retcode | PSW_ADDR_AMODE;
348 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
349 (u16 __user *)(frame->retcode)))
350 goto give_sigsegv;
351 }
352
353 /* Set up backchain. */
354 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
355 goto give_sigsegv;
356
357 /* Set up registers for signal handler */
358 regs->gprs[15] = (unsigned long) frame;
359 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
360
361 regs->gprs[2] = map_signal(sig);
362 regs->gprs[3] = (unsigned long) &frame->info;
363 regs->gprs[4] = (unsigned long) &frame->uc;
364 regs->gprs[5] = task_thread_info(current)->last_break;
365 return 0;
366
367give_sigsegv:
368 force_sigsegv(sig, current);
369 return -EFAULT;
370}
371
372static int handle_signal(unsigned long sig, struct k_sigaction *ka,
373 siginfo_t *info, sigset_t *oldset,
374 struct pt_regs *regs)
375{
376 sigset_t blocked;
377 int ret;
378
379 /* Set up the stack frame */
380 if (ka->sa.sa_flags & SA_SIGINFO)
381 ret = setup_rt_frame(sig, ka, info, oldset, regs);
382 else
383 ret = setup_frame(sig, ka, oldset, regs);
384 if (ret)
385 return ret;
386 sigorsets(&blocked, ¤t->blocked, &ka->sa.sa_mask);
387 if (!(ka->sa.sa_flags & SA_NODEFER))
388 sigaddset(&blocked, sig);
389 set_current_blocked(&blocked);
390 return 0;
391}
392
393/*
394 * Note that 'init' is a special process: it doesn't get signals it doesn't
395 * want to handle. Thus you cannot kill init even with a SIGKILL even by
396 * mistake.
397 *
398 * Note that we go through the signals twice: once to check the signals that
399 * the kernel can handle, and then we build all the user-level signal handling
400 * stack-frames in one go after that.
401 */
402void do_signal(struct pt_regs *regs)
403{
404 unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
405 siginfo_t info;
406 int signr;
407 struct k_sigaction ka;
408 sigset_t *oldset;
409
410 /*
411 * We want the common case to go fast, which
412 * is why we may in certain cases get here from
413 * kernel mode. Just return without doing anything
414 * if so.
415 */
416 if (!user_mode(regs))
417 return;
418
419 if (test_thread_flag(TIF_RESTORE_SIGMASK))
420 oldset = ¤t->saved_sigmask;
421 else
422 oldset = ¤t->blocked;
423
424 /* Are we from a system call? */
425 if (regs->svcnr) {
426 continue_addr = regs->psw.addr;
427 restart_addr = continue_addr - regs->ilc;
428 retval = regs->gprs[2];
429
430 /* Prepare for system call restart. We do this here so that a
431 debugger will see the already changed PSW. */
432 switch (retval) {
433 case -ERESTARTNOHAND:
434 case -ERESTARTSYS:
435 case -ERESTARTNOINTR:
436 regs->gprs[2] = regs->orig_gpr2;
437 regs->psw.addr = restart_addr;
438 break;
439 case -ERESTART_RESTARTBLOCK:
440 regs->gprs[2] = -EINTR;
441 }
442 regs->svcnr = 0; /* Don't deal with this again. */
443 }
444
445 /* Get signal to deliver. When running under ptrace, at this point
446 the debugger may change all our registers ... */
447 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
448
449 /* Depending on the signal settings we may need to revert the
450 decision to restart the system call. */
451 if (signr > 0 && regs->psw.addr == restart_addr) {
452 if (retval == -ERESTARTNOHAND
453 || (retval == -ERESTARTSYS
454 && !(current->sighand->action[signr-1].sa.sa_flags
455 & SA_RESTART))) {
456 regs->gprs[2] = -EINTR;
457 regs->psw.addr = continue_addr;
458 }
459 }
460
461 if (signr > 0) {
462 /* Whee! Actually deliver the signal. */
463 int ret;
464#ifdef CONFIG_COMPAT
465 if (is_compat_task()) {
466 ret = handle_signal32(signr, &ka, &info, oldset, regs);
467 }
468 else
469#endif
470 ret = handle_signal(signr, &ka, &info, oldset, regs);
471 if (!ret) {
472 /*
473 * A signal was successfully delivered; the saved
474 * sigmask will have been stored in the signal frame,
475 * and will be restored by sigreturn, so we can simply
476 * clear the TIF_RESTORE_SIGMASK flag.
477 */
478 if (test_thread_flag(TIF_RESTORE_SIGMASK))
479 clear_thread_flag(TIF_RESTORE_SIGMASK);
480
481 /*
482 * Let tracing know that we've done the handler setup.
483 */
484 tracehook_signal_handler(signr, &info, &ka, regs,
485 test_thread_flag(TIF_SINGLE_STEP));
486 }
487 return;
488 }
489
490 /*
491 * If there's no signal to deliver, we just put the saved sigmask back.
492 */
493 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
494 clear_thread_flag(TIF_RESTORE_SIGMASK);
495 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
496 }
497
498 /* Restart a different system call. */
499 if (retval == -ERESTART_RESTARTBLOCK
500 && regs->psw.addr == continue_addr) {
501 regs->gprs[2] = __NR_restart_syscall;
502 set_thread_flag(TIF_RESTART_SVC);
503 }
504}
505
506void do_notify_resume(struct pt_regs *regs)
507{
508 clear_thread_flag(TIF_NOTIFY_RESUME);
509 tracehook_notify_resume(regs);
510 if (current->replacement_session_keyring)
511 key_replace_session_keyring();
512}