Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
a53c8fab | 3 | * Copyright IBM Corp. 1999, 2006 |
1da177e4 LT |
4 | * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) |
5 | * | |
6 | * Based on Intel version | |
7 | * | |
8 | * Copyright (C) 1991, 1992 Linus Torvalds | |
9 | * | |
10 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
11 | */ | |
12 | ||
1da177e4 | 13 | #include <linux/sched.h> |
68db0cf1 | 14 | #include <linux/sched/task_stack.h> |
1da177e4 LT |
15 | #include <linux/mm.h> |
16 | #include <linux/smp.h> | |
1da177e4 LT |
17 | #include <linux/kernel.h> |
18 | #include <linux/signal.h> | |
c1971eae | 19 | #include <linux/entry-common.h> |
1da177e4 LT |
20 | #include <linux/errno.h> |
21 | #include <linux/wait.h> | |
22 | #include <linux/ptrace.h> | |
23 | #include <linux/unistd.h> | |
24 | #include <linux/stddef.h> | |
25 | #include <linux/tty.h> | |
26 | #include <linux/personality.h> | |
27 | #include <linux/binfmts.h> | |
26689452 | 28 | #include <linux/syscalls.h> |
7757591a | 29 | #include <linux/compat.h> |
1da177e4 | 30 | #include <asm/ucontext.h> |
7c0f6ba6 | 31 | #include <linux/uaccess.h> |
1da177e4 | 32 | #include <asm/lowcore.h> |
a0616cde | 33 | #include <asm/switch_to.h> |
df29a744 | 34 | #include <asm/vdso.h> |
a806170e | 35 | #include "entry.h" |
1da177e4 | 36 | |
80703617 MS |
37 | /* |
38 | * Layout of an old-style signal-frame: | |
39 | * ----------------------------------------- | |
40 | * | save area (_SIGNAL_FRAMESIZE) | | |
41 | * ----------------------------------------- | |
42 | * | struct sigcontext | | |
43 | * | oldmask | | |
44 | * | _sigregs * | | |
45 | * ----------------------------------------- | |
46 | * | _sigregs with | | |
47 | * | _s390_regs_common | | |
48 | * | _s390_fp_regs | | |
49 | * ----------------------------------------- | |
50 | * | int signo | | |
51 | * ----------------------------------------- | |
52 | * | _sigregs_ext with | | |
53 | * | gprs_high 64 byte (opt) | | |
54 | * | vxrs_low 128 byte (opt) | | |
55 | * | vxrs_high 256 byte (opt) | | |
56 | * | reserved 128 byte (opt) | | |
57 | * ----------------------------------------- | |
58 | * | __u16 svc_insn | | |
59 | * ----------------------------------------- | |
60 | * The svc_insn entry with the sigreturn system call opcode does not | |
61 | * have a fixed position and moves if gprs_high or vxrs exist. | |
62 | * Future extensions will be added to _sigregs_ext. | |
63 | */ | |
64 | struct sigframe | |
1da177e4 LT |
65 | { |
66 | __u8 callee_used_stack[__SIGNAL_FRAMESIZE]; | |
67 | struct sigcontext sc; | |
68 | _sigregs sregs; | |
69 | int signo; | |
80703617 MS |
70 | _sigregs_ext sregs_ext; |
71 | __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */ | |
72 | }; | |
1da177e4 | 73 | |
80703617 MS |
74 | /* |
75 | * Layout of an rt signal-frame: | |
76 | * ----------------------------------------- | |
77 | * | save area (_SIGNAL_FRAMESIZE) | | |
78 | * ----------------------------------------- | |
79 | * | svc __NR_rt_sigreturn 2 byte | | |
80 | * ----------------------------------------- | |
81 | * | struct siginfo | | |
82 | * ----------------------------------------- | |
83 | * | struct ucontext_extended with | | |
84 | * | unsigned long uc_flags | | |
85 | * | struct ucontext *uc_link | | |
86 | * | stack_t uc_stack | | |
87 | * | _sigregs uc_mcontext with | | |
88 | * | _s390_regs_common | | |
89 | * | _s390_fp_regs | | |
90 | * | sigset_t uc_sigmask | | |
91 | * | _sigregs_ext uc_mcontext_ext | | |
92 | * | gprs_high 64 byte (opt) | | |
93 | * | vxrs_low 128 byte (opt) | | |
94 | * | vxrs_high 256 byte (opt)| | |
95 | * | reserved 128 byte (opt) | | |
96 | * ----------------------------------------- | |
97 | * Future extensions will be added to _sigregs_ext. | |
98 | */ | |
99 | struct rt_sigframe | |
1da177e4 LT |
100 | { |
101 | __u8 callee_used_stack[__SIGNAL_FRAMESIZE]; | |
80703617 | 102 | __u16 svc_insn; |
1da177e4 | 103 | struct siginfo info; |
80703617 MS |
104 | struct ucontext_extended uc; |
105 | }; | |
106 | ||
107 | /* Store registers needed to create the signal frame */ | |
108 | static void store_sigregs(void) | |
109 | { | |
110 | save_access_regs(current->thread.acrs); | |
d0164ee2 | 111 | save_fpu_regs(); |
80703617 MS |
112 | } |
113 | ||
114 | /* Load registers after signal return */ | |
115 | static void load_sigregs(void) | |
116 | { | |
117 | restore_access_regs(current->thread.acrs); | |
80703617 | 118 | } |
1da177e4 | 119 | |
1da177e4 LT |
120 | /* Returns non-zero on fault. */ |
121 | static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs) | |
122 | { | |
6837a8c3 GS |
123 | _sigregs user_sregs; |
124 | ||
1da177e4 LT |
125 | /* Copy a 'clean' PSW mask to the user to avoid leaking |
126 | information about whether PER is currently on. */ | |
e258d719 | 127 | user_sregs.regs.psw.mask = PSW_USER_BITS | |
5ebf250d | 128 | (regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI)); |
b05e3703 MS |
129 | user_sregs.regs.psw.addr = regs->psw.addr; |
130 | memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs)); | |
6837a8c3 | 131 | memcpy(&user_sregs.regs.acrs, current->thread.acrs, |
4725c860 | 132 | sizeof(user_sregs.regs.acrs)); |
904818e2 | 133 | fpregs_store(&user_sregs.fpregs, ¤t->thread.fpu); |
f8544ec4 HC |
134 | if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs))) |
135 | return -EFAULT; | |
136 | return 0; | |
1da177e4 LT |
137 | } |
138 | ||
1da177e4 LT |
139 | static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs) |
140 | { | |
6837a8c3 | 141 | _sigregs user_sregs; |
1da177e4 | 142 | |
0ecf337f | 143 | /* Always make any pending restarted system call return -EINTR */ |
f56141e3 | 144 | current->restart_block.fn = do_no_restart_syscall; |
1da177e4 | 145 | |
4725c860 | 146 | if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs))) |
f8544ec4 | 147 | return -EFAULT; |
4725c860 | 148 | |
5ebf250d HC |
149 | if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI)) |
150 | return -EINVAL; | |
151 | ||
4084eb77 HB |
152 | /* Test the floating-point-control word. */ |
153 | if (test_fp_ctl(user_sregs.fpregs.fpc)) | |
4725c860 MS |
154 | return -EINVAL; |
155 | ||
e258d719 | 156 | /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */ |
aa7e04b3 | 157 | regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) | |
5ebf250d | 158 | (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI)); |
fa968ee2 | 159 | /* Check for invalid user address space control. */ |
e258d719 MS |
160 | if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME) |
161 | regs->psw.mask = PSW_ASC_PRIMARY | | |
fa968ee2 | 162 | (regs->psw.mask & ~PSW_MASK_ASC); |
d4e81b35 MS |
163 | /* Check for invalid amode */ |
164 | if (regs->psw.mask & PSW_MASK_EA) | |
165 | regs->psw.mask |= PSW_MASK_BA; | |
166 | regs->psw.addr = user_sregs.regs.psw.addr; | |
b05e3703 | 167 | memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs)); |
6837a8c3 | 168 | memcpy(¤t->thread.acrs, &user_sregs.regs.acrs, |
4725c860 | 169 | sizeof(current->thread.acrs)); |
1da177e4 | 170 | |
904818e2 | 171 | fpregs_load(&user_sregs.fpregs, ¤t->thread.fpu); |
1da177e4 | 172 | |
d3a73acb | 173 | clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */ |
1da177e4 LT |
174 | return 0; |
175 | } | |
176 | ||
80703617 MS |
177 | /* Returns non-zero on fault. */ |
178 | static int save_sigregs_ext(struct pt_regs *regs, | |
179 | _sigregs_ext __user *sregs_ext) | |
180 | { | |
80703617 MS |
181 | __u64 vxrs[__NUM_VXRS_LOW]; |
182 | int i; | |
183 | ||
184 | /* Save vector registers to signal stack */ | |
b5510d9b | 185 | if (MACHINE_HAS_VX) { |
80703617 | 186 | for (i = 0; i < __NUM_VXRS_LOW; i++) |
a02d584e | 187 | vxrs[i] = current->thread.fpu.vxrs[i].low; |
80703617 MS |
188 | if (__copy_to_user(&sregs_ext->vxrs_low, vxrs, |
189 | sizeof(sregs_ext->vxrs_low)) || | |
190 | __copy_to_user(&sregs_ext->vxrs_high, | |
904818e2 | 191 | current->thread.fpu.vxrs + __NUM_VXRS_LOW, |
80703617 MS |
192 | sizeof(sregs_ext->vxrs_high))) |
193 | return -EFAULT; | |
194 | } | |
80703617 MS |
195 | return 0; |
196 | } | |
197 | ||
198 | static int restore_sigregs_ext(struct pt_regs *regs, | |
199 | _sigregs_ext __user *sregs_ext) | |
200 | { | |
80703617 MS |
201 | __u64 vxrs[__NUM_VXRS_LOW]; |
202 | int i; | |
203 | ||
204 | /* Restore vector registers from signal stack */ | |
b5510d9b | 205 | if (MACHINE_HAS_VX) { |
80703617 MS |
206 | if (__copy_from_user(vxrs, &sregs_ext->vxrs_low, |
207 | sizeof(sregs_ext->vxrs_low)) || | |
904818e2 | 208 | __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW, |
80703617 MS |
209 | &sregs_ext->vxrs_high, |
210 | sizeof(sregs_ext->vxrs_high))) | |
211 | return -EFAULT; | |
212 | for (i = 0; i < __NUM_VXRS_LOW; i++) | |
a02d584e | 213 | current->thread.fpu.vxrs[i].low = vxrs[i]; |
80703617 | 214 | } |
80703617 MS |
215 | return 0; |
216 | } | |
217 | ||
26689452 | 218 | SYSCALL_DEFINE0(sigreturn) |
1da177e4 | 219 | { |
03ff9a23 | 220 | struct pt_regs *regs = task_pt_regs(current); |
80703617 MS |
221 | struct sigframe __user *frame = |
222 | (struct sigframe __user *) regs->gprs[15]; | |
1da177e4 LT |
223 | sigset_t set; |
224 | ||
1da177e4 LT |
225 | if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE)) |
226 | goto badframe; | |
391c62fe | 227 | set_current_blocked(&set); |
d0164ee2 | 228 | save_fpu_regs(); |
1da177e4 LT |
229 | if (restore_sigregs(regs, &frame->sregs)) |
230 | goto badframe; | |
80703617 MS |
231 | if (restore_sigregs_ext(regs, &frame->sregs_ext)) |
232 | goto badframe; | |
233 | load_sigregs(); | |
1da177e4 | 234 | return regs->gprs[2]; |
1da177e4 | 235 | badframe: |
3cf5d076 | 236 | force_sig(SIGSEGV); |
1da177e4 LT |
237 | return 0; |
238 | } | |
239 | ||
26689452 | 240 | SYSCALL_DEFINE0(rt_sigreturn) |
1da177e4 | 241 | { |
03ff9a23 | 242 | struct pt_regs *regs = task_pt_regs(current); |
80703617 MS |
243 | struct rt_sigframe __user *frame = |
244 | (struct rt_sigframe __user *)regs->gprs[15]; | |
1da177e4 LT |
245 | sigset_t set; |
246 | ||
1da177e4 LT |
247 | if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set))) |
248 | goto badframe; | |
391c62fe | 249 | set_current_blocked(&set); |
80703617 MS |
250 | if (restore_altstack(&frame->uc.uc_stack)) |
251 | goto badframe; | |
d0164ee2 | 252 | save_fpu_regs(); |
1da177e4 LT |
253 | if (restore_sigregs(regs, &frame->uc.uc_mcontext)) |
254 | goto badframe; | |
80703617 | 255 | if (restore_sigregs_ext(regs, &frame->uc.uc_mcontext_ext)) |
4e3df37e | 256 | goto badframe; |
80703617 | 257 | load_sigregs(); |
1da177e4 | 258 | return regs->gprs[2]; |
1da177e4 | 259 | badframe: |
3cf5d076 | 260 | force_sig(SIGSEGV); |
1da177e4 LT |
261 | return 0; |
262 | } | |
263 | ||
1da177e4 LT |
264 | /* |
265 | * Determine which stack to use.. | |
266 | */ | |
267 | static inline void __user * | |
268 | get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) | |
269 | { | |
270 | unsigned long sp; | |
271 | ||
272 | /* Default to using normal stack */ | |
273 | sp = regs->gprs[15]; | |
274 | ||
de553438 HC |
275 | /* Overflow on alternate signal stack gives SIGSEGV. */ |
276 | if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL)) | |
277 | return (void __user *) -1UL; | |
278 | ||
1da177e4 LT |
279 | /* This is the X/Open sanctioned signal stack switching. */ |
280 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
281 | if (! sas_ss_flags(sp)) | |
282 | sp = current->sas_ss_sp + current->sas_ss_size; | |
283 | } | |
284 | ||
1da177e4 LT |
285 | return (void __user *)((sp - frame_size) & -8ul); |
286 | } | |
287 | ||
54dfe5dd HC |
288 | static int setup_frame(int sig, struct k_sigaction *ka, |
289 | sigset_t *set, struct pt_regs * regs) | |
1da177e4 | 290 | { |
80703617 MS |
291 | struct sigframe __user *frame; |
292 | struct sigcontext sc; | |
293 | unsigned long restorer; | |
294 | size_t frame_size; | |
295 | ||
296 | /* | |
297 | * gprs_high are only present for a 31-bit task running on | |
298 | * a 64-bit kernel (see compat_signal.c) but the space for | |
299 | * gprs_high need to be allocated if vector registers are | |
300 | * included in the signal frame on a 31-bit system. | |
301 | */ | |
302 | frame_size = sizeof(*frame) - sizeof(frame->sregs_ext); | |
303 | if (MACHINE_HAS_VX) | |
304 | frame_size += sizeof(frame->sregs_ext); | |
305 | frame = get_sigframe(ka, regs, frame_size); | |
de553438 | 306 | if (frame == (void __user *) -1UL) |
067bf2d4 | 307 | return -EFAULT; |
de553438 | 308 | |
80703617 MS |
309 | /* Set up backchain. */ |
310 | if (__put_user(regs->gprs[15], (addr_t __user *) frame)) | |
067bf2d4 | 311 | return -EFAULT; |
1da177e4 | 312 | |
80703617 MS |
313 | /* Create struct sigcontext on the signal stack */ |
314 | memcpy(&sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE); | |
315 | sc.sregs = (_sigregs __user __force *) &frame->sregs; | |
316 | if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc))) | |
317 | return -EFAULT; | |
318 | ||
319 | /* Store registers needed to create the signal frame */ | |
320 | store_sigregs(); | |
321 | ||
322 | /* Create _sigregs on the signal stack */ | |
1da177e4 | 323 | if (save_sigregs(regs, &frame->sregs)) |
067bf2d4 | 324 | return -EFAULT; |
80703617 MS |
325 | |
326 | /* Place signal number on stack to allow backtrace from handler. */ | |
327 | if (__put_user(regs->gprs[2], (int __user *) &frame->signo)) | |
328 | return -EFAULT; | |
329 | ||
330 | /* Create _sigregs_ext on the signal stack */ | |
331 | if (save_sigregs_ext(regs, &frame->sregs_ext)) | |
067bf2d4 | 332 | return -EFAULT; |
1da177e4 LT |
333 | |
334 | /* Set up to return from userspace. If provided, use a stub | |
335 | already in userspace. */ | |
df29a744 | 336 | if (ka->sa.sa_flags & SA_RESTORER) |
fecc868a | 337 | restorer = (unsigned long) ka->sa.sa_restorer; |
df29a744 SS |
338 | else |
339 | restorer = VDSO64_SYMBOL(current, sigreturn); | |
1da177e4 | 340 | |
1da177e4 | 341 | /* Set up registers for signal handler */ |
80703617 | 342 | regs->gprs[14] = restorer; |
1da177e4 | 343 | regs->gprs[15] = (unsigned long) frame; |
fa968ee2 MS |
344 | /* Force default amode and default user address space control. */ |
345 | regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA | | |
e258d719 | 346 | (PSW_USER_BITS & PSW_MASK_ASC) | |
fa968ee2 | 347 | (regs->psw.mask & ~PSW_MASK_ASC); |
fecc868a | 348 | regs->psw.addr = (unsigned long) ka->sa.sa_handler; |
1da177e4 | 349 | |
6a32591a | 350 | regs->gprs[2] = sig; |
1da177e4 LT |
351 | regs->gprs[3] = (unsigned long) &frame->sc; |
352 | ||
353 | /* We forgot to include these in the sigcontext. | |
354 | To avoid breaking binary compatibility, they are passed as args. */ | |
aa33c8cb MS |
355 | if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL || |
356 | sig == SIGTRAP || sig == SIGFPE) { | |
357 | /* set extra registers only for synchronous signals */ | |
358 | regs->gprs[4] = regs->int_code & 127; | |
359 | regs->gprs[5] = regs->int_parm_long; | |
ef280c85 | 360 | regs->gprs[6] = current->thread.last_break; |
aa33c8cb | 361 | } |
54dfe5dd | 362 | return 0; |
1da177e4 LT |
363 | } |
364 | ||
067bf2d4 RW |
365 | static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
366 | struct pt_regs *regs) | |
1da177e4 | 367 | { |
80703617 MS |
368 | struct rt_sigframe __user *frame; |
369 | unsigned long uc_flags, restorer; | |
370 | size_t frame_size; | |
371 | ||
372 | frame_size = sizeof(struct rt_sigframe) - sizeof(_sigregs_ext); | |
373 | /* | |
374 | * gprs_high are only present for a 31-bit task running on | |
375 | * a 64-bit kernel (see compat_signal.c) but the space for | |
376 | * gprs_high need to be allocated if vector registers are | |
377 | * included in the signal frame on a 31-bit system. | |
378 | */ | |
379 | uc_flags = 0; | |
80703617 MS |
380 | if (MACHINE_HAS_VX) { |
381 | frame_size += sizeof(_sigregs_ext); | |
b5510d9b | 382 | uc_flags |= UC_VXRS; |
80703617 | 383 | } |
80703617 | 384 | frame = get_sigframe(&ksig->ka, regs, frame_size); |
de553438 | 385 | if (frame == (void __user *) -1UL) |
067bf2d4 | 386 | return -EFAULT; |
de553438 | 387 | |
80703617 MS |
388 | /* Set up backchain. */ |
389 | if (__put_user(regs->gprs[15], (addr_t __user *) frame)) | |
067bf2d4 | 390 | return -EFAULT; |
1da177e4 LT |
391 | |
392 | /* Set up to return from userspace. If provided, use a stub | |
393 | already in userspace. */ | |
df29a744 | 394 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
fecc868a | 395 | restorer = (unsigned long) ksig->ka.sa.sa_restorer; |
df29a744 SS |
396 | else |
397 | restorer = VDSO64_SYMBOL(current, rt_sigreturn); | |
1da177e4 | 398 | |
80703617 MS |
399 | /* Create siginfo on the signal stack */ |
400 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) | |
401 | return -EFAULT; | |
402 | ||
403 | /* Store registers needed to create the signal frame */ | |
404 | store_sigregs(); | |
405 | ||
406 | /* Create ucontext on the signal stack. */ | |
407 | if (__put_user(uc_flags, &frame->uc.uc_flags) || | |
408 | __put_user(NULL, &frame->uc.uc_link) || | |
409 | __save_altstack(&frame->uc.uc_stack, regs->gprs[15]) || | |
410 | save_sigregs(regs, &frame->uc.uc_mcontext) || | |
411 | __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)) || | |
412 | save_sigregs_ext(regs, &frame->uc.uc_mcontext_ext)) | |
067bf2d4 | 413 | return -EFAULT; |
1da177e4 LT |
414 | |
415 | /* Set up registers for signal handler */ | |
80703617 | 416 | regs->gprs[14] = restorer; |
1da177e4 | 417 | regs->gprs[15] = (unsigned long) frame; |
fa968ee2 MS |
418 | /* Force default amode and default user address space control. */ |
419 | regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA | | |
e258d719 | 420 | (PSW_USER_BITS & PSW_MASK_ASC) | |
fa968ee2 | 421 | (regs->psw.mask & ~PSW_MASK_ASC); |
fecc868a | 422 | regs->psw.addr = (unsigned long) ksig->ka.sa.sa_handler; |
1da177e4 | 423 | |
6a32591a | 424 | regs->gprs[2] = ksig->sig; |
1da177e4 LT |
425 | regs->gprs[3] = (unsigned long) &frame->info; |
426 | regs->gprs[4] = (unsigned long) &frame->uc; | |
ef280c85 | 427 | regs->gprs[5] = current->thread.last_break; |
54dfe5dd | 428 | return 0; |
1da177e4 LT |
429 | } |
430 | ||
067bf2d4 RW |
431 | static void handle_signal(struct ksignal *ksig, sigset_t *oldset, |
432 | struct pt_regs *regs) | |
1da177e4 | 433 | { |
54dfe5dd HC |
434 | int ret; |
435 | ||
1da177e4 | 436 | /* Set up the stack frame */ |
067bf2d4 RW |
437 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
438 | ret = setup_rt_frame(ksig, oldset, regs); | |
1da177e4 | 439 | else |
067bf2d4 RW |
440 | ret = setup_frame(ksig->sig, &ksig->ka, oldset, regs); |
441 | ||
442 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP)); | |
1da177e4 LT |
443 | } |
444 | ||
445 | /* | |
446 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
447 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
448 | * mistake. | |
449 | * | |
450 | * Note that we go through the signals twice: once to check the signals that | |
451 | * the kernel can handle, and then we build all the user-level signal handling | |
452 | * stack-frames in one go after that. | |
453 | */ | |
56e62a73 | 454 | |
8ba62d37 | 455 | void arch_do_signal_or_restart(struct pt_regs *regs) |
1da177e4 | 456 | { |
067bf2d4 | 457 | struct ksignal ksig; |
b7f9a11a | 458 | sigset_t *oldset = sigmask_to_save(); |
1da177e4 | 459 | |
20b40a79 MS |
460 | /* |
461 | * Get signal to deliver. When running under ptrace, at this point | |
462 | * the debugger may change all our registers, including the system | |
463 | * call information. | |
464 | */ | |
f8fc82b4 | 465 | current->thread.system_call = |
d3a73acb | 466 | test_pt_regs_flag(regs, PIF_SYSCALL) ? regs->int_code : 0; |
1da177e4 | 467 | |
8ba62d37 | 468 | if (get_signal(&ksig)) { |
1da177e4 | 469 | /* Whee! Actually deliver the signal. */ |
f8fc82b4 MS |
470 | if (current->thread.system_call) { |
471 | regs->int_code = current->thread.system_call; | |
20b40a79 MS |
472 | /* Check for system call restarting. */ |
473 | switch (regs->gprs[2]) { | |
474 | case -ERESTART_RESTARTBLOCK: | |
475 | case -ERESTARTNOHAND: | |
476 | regs->gprs[2] = -EINTR; | |
477 | break; | |
478 | case -ERESTARTSYS: | |
067bf2d4 | 479 | if (!(ksig.ka.sa.sa_flags & SA_RESTART)) { |
20b40a79 MS |
480 | regs->gprs[2] = -EINTR; |
481 | break; | |
482 | } | |
2c7749b9 | 483 | fallthrough; |
20b40a79 MS |
484 | case -ERESTARTNOINTR: |
485 | regs->gprs[2] = regs->orig_gpr2; | |
ccf45caf MS |
486 | regs->psw.addr = |
487 | __rewind_psw(regs->psw, | |
aa33c8cb | 488 | regs->int_code >> 16); |
20b40a79 MS |
489 | break; |
490 | } | |
20b40a79 | 491 | } |
d9ae6772 | 492 | /* No longer in a system call */ |
d3a73acb | 493 | clear_pt_regs_flag(regs, PIF_SYSCALL); |
df29a744 | 494 | |
9d6d99e3 | 495 | rseq_signal_deliver(&ksig, regs); |
a610d6e6 | 496 | if (is_compat_task()) |
067bf2d4 | 497 | handle_signal32(&ksig, oldset, regs); |
a610d6e6 | 498 | else |
067bf2d4 | 499 | handle_signal(&ksig, oldset, regs); |
54dfe5dd HC |
500 | return; |
501 | } | |
502 | ||
20b40a79 | 503 | /* No handlers present - check for system call restart */ |
d3a73acb | 504 | clear_pt_regs_flag(regs, PIF_SYSCALL); |
f8fc82b4 MS |
505 | if (current->thread.system_call) { |
506 | regs->int_code = current->thread.system_call; | |
20b40a79 MS |
507 | switch (regs->gprs[2]) { |
508 | case -ERESTART_RESTARTBLOCK: | |
509 | /* Restart with sys_restart_syscall */ | |
df29a744 SS |
510 | regs->gprs[2] = regs->orig_gpr2; |
511 | current->restart_block.arch_data = regs->psw.addr; | |
512 | if (is_compat_task()) | |
513 | regs->psw.addr = VDSO32_SYMBOL(current, restart_syscall); | |
514 | else | |
515 | regs->psw.addr = VDSO64_SYMBOL(current, restart_syscall); | |
516 | if (test_thread_flag(TIF_SINGLE_STEP)) | |
517 | clear_thread_flag(TIF_PER_TRAP); | |
518 | break; | |
20b40a79 MS |
519 | case -ERESTARTNOHAND: |
520 | case -ERESTARTSYS: | |
521 | case -ERESTARTNOINTR: | |
20b40a79 | 522 | regs->gprs[2] = regs->orig_gpr2; |
df29a744 | 523 | regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16); |
39efd4ec | 524 | if (test_thread_flag(TIF_SINGLE_STEP)) |
56e62a73 | 525 | clear_thread_flag(TIF_PER_TRAP); |
b6ef5bb3 | 526 | break; |
20b40a79 MS |
527 | } |
528 | } | |
529 | ||
54dfe5dd HC |
530 | /* |
531 | * If there's no signal to deliver, we just put the saved sigmask back. | |
532 | */ | |
51a7b448 | 533 | restore_saved_sigmask(); |
1da177e4 | 534 | } |