Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
a53c8fab | 2 | * Copyright IBM Corp. 1999, 2006 |
1da177e4 LT |
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 | ||
1da177e4 LT |
12 | #include <linux/sched.h> |
13 | #include <linux/mm.h> | |
14 | #include <linux/smp.h> | |
1da177e4 LT |
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> | |
753c4dd6 | 25 | #include <linux/tracehook.h> |
26689452 | 26 | #include <linux/syscalls.h> |
7757591a | 27 | #include <linux/compat.h> |
1da177e4 LT |
28 | #include <asm/ucontext.h> |
29 | #include <asm/uaccess.h> | |
30 | #include <asm/lowcore.h> | |
a0616cde | 31 | #include <asm/switch_to.h> |
a806170e | 32 | #include "entry.h" |
1da177e4 | 33 | |
1da177e4 LT |
34 | typedef 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 | ||
43 | typedef 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 | ||
1da177e4 LT |
51 | /* Returns non-zero on fault. */ |
52 | static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs) | |
53 | { | |
6837a8c3 GS |
54 | _sigregs user_sregs; |
55 | ||
1da177e4 LT |
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. */ | |
e258d719 | 60 | user_sregs.regs.psw.mask = PSW_USER_BITS | |
5ebf250d | 61 | (regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI)); |
b05e3703 MS |
62 | user_sregs.regs.psw.addr = regs->psw.addr; |
63 | memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs)); | |
6837a8c3 | 64 | memcpy(&user_sregs.regs.acrs, current->thread.acrs, |
4725c860 | 65 | sizeof(user_sregs.regs.acrs)); |
1da177e4 LT |
66 | /* |
67 | * We have to store the fp registers to current->thread.fp_regs | |
68 | * to merge them with the emulated registers. | |
69 | */ | |
4725c860 MS |
70 | save_fp_ctl(¤t->thread.fp_regs.fpc); |
71 | save_fp_regs(current->thread.fp_regs.fprs); | |
6837a8c3 | 72 | memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs, |
4725c860 | 73 | sizeof(user_sregs.fpregs)); |
f8544ec4 HC |
74 | if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs))) |
75 | return -EFAULT; | |
76 | return 0; | |
1da177e4 LT |
77 | } |
78 | ||
1da177e4 LT |
79 | static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs) |
80 | { | |
6837a8c3 | 81 | _sigregs user_sregs; |
1da177e4 LT |
82 | |
83 | /* Alwys make any pending restarted system call return -EINTR */ | |
84 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
85 | ||
4725c860 | 86 | if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs))) |
f8544ec4 | 87 | return -EFAULT; |
4725c860 | 88 | |
5ebf250d HC |
89 | if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI)) |
90 | return -EINVAL; | |
91 | ||
4725c860 MS |
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 | ||
e258d719 | 96 | /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */ |
aa7e04b3 | 97 | regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) | |
5ebf250d | 98 | (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI)); |
fa968ee2 | 99 | /* Check for invalid user address space control. */ |
e258d719 MS |
100 | if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME) |
101 | regs->psw.mask = PSW_ASC_PRIMARY | | |
fa968ee2 | 102 | (regs->psw.mask & ~PSW_MASK_ASC); |
d4e81b35 MS |
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; | |
b05e3703 | 107 | memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs)); |
6837a8c3 | 108 | memcpy(¤t->thread.acrs, &user_sregs.regs.acrs, |
4725c860 | 109 | sizeof(current->thread.acrs)); |
1da177e4 LT |
110 | restore_access_regs(current->thread.acrs); |
111 | ||
6837a8c3 | 112 | memcpy(¤t->thread.fp_regs, &user_sregs.fpregs, |
4725c860 | 113 | sizeof(current->thread.fp_regs)); |
1da177e4 | 114 | |
4725c860 | 115 | restore_fp_regs(current->thread.fp_regs.fprs); |
b6ef5bb3 | 116 | clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */ |
1da177e4 LT |
117 | return 0; |
118 | } | |
119 | ||
26689452 | 120 | SYSCALL_DEFINE0(sigreturn) |
1da177e4 | 121 | { |
03ff9a23 | 122 | struct pt_regs *regs = task_pt_regs(current); |
1da177e4 LT |
123 | sigframe __user *frame = (sigframe __user *)regs->gprs[15]; |
124 | sigset_t set; | |
125 | ||
1da177e4 LT |
126 | if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE)) |
127 | goto badframe; | |
391c62fe | 128 | set_current_blocked(&set); |
1da177e4 LT |
129 | if (restore_sigregs(regs, &frame->sregs)) |
130 | goto badframe; | |
1da177e4 | 131 | return regs->gprs[2]; |
1da177e4 LT |
132 | badframe: |
133 | force_sig(SIGSEGV, current); | |
134 | return 0; | |
135 | } | |
136 | ||
26689452 | 137 | SYSCALL_DEFINE0(rt_sigreturn) |
1da177e4 | 138 | { |
03ff9a23 | 139 | struct pt_regs *regs = task_pt_regs(current); |
1da177e4 LT |
140 | rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15]; |
141 | sigset_t set; | |
142 | ||
1da177e4 LT |
143 | if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set))) |
144 | goto badframe; | |
391c62fe | 145 | set_current_blocked(&set); |
1da177e4 LT |
146 | if (restore_sigregs(regs, &frame->uc.uc_mcontext)) |
147 | goto badframe; | |
e214125a | 148 | if (restore_altstack(&frame->uc.uc_stack)) |
4e3df37e | 149 | goto badframe; |
1da177e4 | 150 | return regs->gprs[2]; |
1da177e4 LT |
151 | badframe: |
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 | */ | |
164 | static inline void __user * | |
165 | get_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 | ||
de553438 HC |
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 | ||
1da177e4 LT |
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 | ||
1da177e4 LT |
182 | return (void __user *)((sp - frame_size) & -8ul); |
183 | } | |
184 | ||
185 | static 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 | ||
54dfe5dd HC |
195 | static int setup_frame(int sig, struct k_sigaction *ka, |
196 | sigset_t *set, struct pt_regs * regs) | |
1da177e4 LT |
197 | { |
198 | sigframe __user *frame; | |
199 | ||
200 | frame = get_sigframe(ka, regs, sizeof(sigframe)); | |
1da177e4 | 201 | |
de553438 HC |
202 | if (frame == (void __user *) -1UL) |
203 | goto give_sigsegv; | |
204 | ||
1da177e4 LT |
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; | |
fa968ee2 MS |
232 | /* Force default amode and default user address space control. */ |
233 | regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA | | |
e258d719 | 234 | (PSW_USER_BITS & PSW_MASK_ASC) | |
fa968ee2 | 235 | (regs->psw.mask & ~PSW_MASK_ASC); |
1da177e4 LT |
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. */ | |
aa33c8cb MS |
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 | } | |
1da177e4 LT |
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; | |
54dfe5dd | 254 | return 0; |
1da177e4 LT |
255 | |
256 | give_sigsegv: | |
257 | force_sigsegv(sig, current); | |
54dfe5dd | 258 | return -EFAULT; |
1da177e4 LT |
259 | } |
260 | ||
54dfe5dd | 261 | static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
1da177e4 LT |
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)); | |
1da177e4 | 268 | |
de553438 HC |
269 | if (frame == (void __user *) -1UL) |
270 | goto give_sigsegv; | |
271 | ||
1da177e4 LT |
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); | |
c2814476 | 277 | err |= __put_user(NULL, &frame->uc.uc_link); |
e214125a | 278 | err |= __save_altstack(&frame->uc.uc_stack, regs->gprs[15]); |
1da177e4 LT |
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; | |
b44df334 HC |
292 | if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, |
293 | (u16 __user *)(frame->retcode))) | |
294 | goto give_sigsegv; | |
1da177e4 LT |
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; | |
fa968ee2 MS |
303 | /* Force default amode and default user address space control. */ |
304 | regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA | | |
e258d719 | 305 | (PSW_USER_BITS & PSW_MASK_ASC) | |
fa968ee2 | 306 | (regs->psw.mask & ~PSW_MASK_ASC); |
1da177e4 LT |
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; | |
86f2552b | 312 | regs->gprs[5] = task_thread_info(current)->last_break; |
54dfe5dd | 313 | return 0; |
1da177e4 LT |
314 | |
315 | give_sigsegv: | |
316 | force_sigsegv(sig, current); | |
54dfe5dd | 317 | return -EFAULT; |
1da177e4 LT |
318 | } |
319 | ||
a610d6e6 | 320 | static void handle_signal(unsigned long sig, struct k_sigaction *ka, |
391c62fe HC |
321 | siginfo_t *info, sigset_t *oldset, |
322 | struct pt_regs *regs) | |
1da177e4 | 323 | { |
54dfe5dd HC |
324 | int ret; |
325 | ||
1da177e4 LT |
326 | /* Set up the stack frame */ |
327 | if (ka->sa.sa_flags & SA_SIGINFO) | |
54dfe5dd | 328 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
1da177e4 | 329 | else |
54dfe5dd | 330 | ret = setup_frame(sig, ka, oldset, regs); |
391c62fe | 331 | if (ret) |
a610d6e6 | 332 | return; |
efee984c | 333 | signal_delivered(sig, info, ka, regs, |
a610d6e6 | 334 | test_thread_flag(TIF_SINGLE_STEP)); |
1da177e4 LT |
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 | */ | |
54dfe5dd | 346 | void do_signal(struct pt_regs *regs) |
1da177e4 | 347 | { |
1da177e4 LT |
348 | siginfo_t info; |
349 | int signr; | |
350 | struct k_sigaction ka; | |
b7f9a11a | 351 | sigset_t *oldset = sigmask_to_save(); |
1da177e4 | 352 | |
20b40a79 MS |
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 | */ | |
b6ef5bb3 | 358 | current_thread_info()->system_call = |
aa33c8cb | 359 | test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0; |
1da177e4 | 360 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
1da177e4 LT |
361 | |
362 | if (signr > 0) { | |
363 | /* Whee! Actually deliver the signal. */ | |
b6ef5bb3 | 364 | if (current_thread_info()->system_call) { |
aa33c8cb | 365 | regs->int_code = current_thread_info()->system_call; |
20b40a79 MS |
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; | |
ccf45caf MS |
380 | regs->psw.addr = |
381 | __rewind_psw(regs->psw, | |
aa33c8cb | 382 | regs->int_code >> 16); |
20b40a79 MS |
383 | break; |
384 | } | |
20b40a79 | 385 | } |
d9ae6772 MS |
386 | /* No longer in a system call */ |
387 | clear_thread_flag(TIF_SYSCALL); | |
20b40a79 | 388 | |
a610d6e6 AV |
389 | if (is_compat_task()) |
390 | handle_signal32(signr, &ka, &info, oldset, regs); | |
391 | else | |
392 | handle_signal(signr, &ka, &info, oldset, regs); | |
54dfe5dd HC |
393 | return; |
394 | } | |
395 | ||
20b40a79 | 396 | /* No handlers present - check for system call restart */ |
d9ae6772 | 397 | clear_thread_flag(TIF_SYSCALL); |
b6ef5bb3 | 398 | if (current_thread_info()->system_call) { |
aa33c8cb | 399 | regs->int_code = current_thread_info()->system_call; |
20b40a79 MS |
400 | switch (regs->gprs[2]) { |
401 | case -ERESTART_RESTARTBLOCK: | |
402 | /* Restart with sys_restart_syscall */ | |
aa33c8cb | 403 | regs->int_code = __NR_restart_syscall; |
20b40a79 MS |
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; | |
b6ef5bb3 | 410 | set_thread_flag(TIF_SYSCALL); |
39efd4ec MS |
411 | if (test_thread_flag(TIF_SINGLE_STEP)) |
412 | set_thread_flag(TIF_PER_TRAP); | |
b6ef5bb3 | 413 | break; |
20b40a79 MS |
414 | } |
415 | } | |
416 | ||
54dfe5dd HC |
417 | /* |
418 | * If there's no signal to deliver, we just put the saved sigmask back. | |
419 | */ | |
51a7b448 | 420 | restore_saved_sigmask(); |
1da177e4 | 421 | } |
753c4dd6 MS |
422 | |
423 | void do_notify_resume(struct pt_regs *regs) | |
424 | { | |
425 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
426 | tracehook_notify_resume(regs); | |
427 | } |