xref: /linux/arch/sparc/kernel/signal_64.c (revision e80a48bade619ec5a92230b3d4ae84bfc2746822)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  arch/sparc64/kernel/signal.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  *  Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
7  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
8  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
9  *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
10  */
11 
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/signal.h>
15 #include <linux/errno.h>
16 #include <linux/wait.h>
17 #include <linux/ptrace.h>
18 #include <linux/resume_user_mode.h>
19 #include <linux/unistd.h>
20 #include <linux/mm.h>
21 #include <linux/tty.h>
22 #include <linux/binfmts.h>
23 #include <linux/bitops.h>
24 #include <linux/context_tracking.h>
25 
26 #include <linux/uaccess.h>
27 #include <asm/ptrace.h>
28 #include <asm/fpumacro.h>
29 #include <asm/uctx.h>
30 #include <asm/siginfo.h>
31 #include <asm/visasm.h>
32 #include <asm/switch_to.h>
33 #include <asm/cacheflush.h>
34 
35 #include "sigutil.h"
36 #include "systbls.h"
37 #include "kernel.h"
38 #include "entry.h"
39 
40 /* {set, get}context() needed for 64-bit SparcLinux userland. */
41 asmlinkage void sparc64_set_context(struct pt_regs *regs)
42 {
43 	struct ucontext __user *ucp = (struct ucontext __user *)
44 		regs->u_regs[UREG_I0];
45 	enum ctx_state prev_state = exception_enter();
46 	mc_gregset_t __user *grp;
47 	unsigned long pc, npc, tstate;
48 	unsigned long fp, i7;
49 	unsigned char fenab;
50 	int err;
51 
52 	synchronize_user_stack();
53 	if (get_thread_wsaved()					||
54 	    (((unsigned long)ucp) & (sizeof(unsigned long)-1))	||
55 	    (!__access_ok(ucp, sizeof(*ucp))))
56 		goto do_sigsegv;
57 	grp  = &ucp->uc_mcontext.mc_gregs;
58 	err  = __get_user(pc, &((*grp)[MC_PC]));
59 	err |= __get_user(npc, &((*grp)[MC_NPC]));
60 	if (err || ((pc | npc) & 3))
61 		goto do_sigsegv;
62 	if (regs->u_regs[UREG_I1]) {
63 		sigset_t set;
64 
65 		if (_NSIG_WORDS == 1) {
66 			if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
67 				goto do_sigsegv;
68 		} else {
69 			if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
70 				goto do_sigsegv;
71 		}
72 		set_current_blocked(&set);
73 	}
74 	if (test_thread_flag(TIF_32BIT)) {
75 		pc &= 0xffffffff;
76 		npc &= 0xffffffff;
77 	}
78 	regs->tpc = pc;
79 	regs->tnpc = npc;
80 	err |= __get_user(regs->y, &((*grp)[MC_Y]));
81 	err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
82 	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
83 	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
84 	err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
85 	err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
86 	err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
87 	err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
88 	err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
89 	err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
90 
91 	/* Skip %g7 as that's the thread register in userspace.  */
92 
93 	err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
94 	err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
95 	err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
96 	err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
97 	err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
98 	err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
99 	err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
100 	err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
101 
102 	err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
103 	err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
104 	err |= __put_user(fp,
105 	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
106 	err |= __put_user(i7,
107 	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
108 
109 	err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
110 	if (fenab) {
111 		unsigned long *fpregs = current_thread_info()->fpregs;
112 		unsigned long fprs;
113 
114 		fprs_write(0);
115 		err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
116 		if (fprs & FPRS_DL)
117 			err |= copy_from_user(fpregs,
118 					      &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
119 					      (sizeof(unsigned int) * 32));
120 		if (fprs & FPRS_DU)
121 			err |= copy_from_user(fpregs+16,
122 			 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
123 			 (sizeof(unsigned int) * 32));
124 		err |= __get_user(current_thread_info()->xfsr[0],
125 				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
126 		err |= __get_user(current_thread_info()->gsr[0],
127 				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
128 		regs->tstate &= ~TSTATE_PEF;
129 	}
130 	if (err)
131 		goto do_sigsegv;
132 out:
133 	exception_exit(prev_state);
134 	return;
135 do_sigsegv:
136 	force_sig(SIGSEGV);
137 	goto out;
138 }
139 
140 asmlinkage void sparc64_get_context(struct pt_regs *regs)
141 {
142 	struct ucontext __user *ucp = (struct ucontext __user *)
143 		regs->u_regs[UREG_I0];
144 	enum ctx_state prev_state = exception_enter();
145 	mc_gregset_t __user *grp;
146 	mcontext_t __user *mcp;
147 	unsigned long fp, i7;
148 	unsigned char fenab;
149 	int err;
150 
151 	synchronize_user_stack();
152 	if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
153 		goto do_sigsegv;
154 
155 #if 1
156 	fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
157 #else
158 	fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
159 #endif
160 
161 	mcp = &ucp->uc_mcontext;
162 	grp = &mcp->mc_gregs;
163 
164 	/* Skip over the trap instruction, first. */
165 	if (test_thread_flag(TIF_32BIT)) {
166 		regs->tpc   = (regs->tnpc & 0xffffffff);
167 		regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
168 	} else {
169 		regs->tpc   = regs->tnpc;
170 		regs->tnpc += 4;
171 	}
172 	err = 0;
173 	if (_NSIG_WORDS == 1)
174 		err |= __put_user(current->blocked.sig[0],
175 				  (unsigned long __user *)&ucp->uc_sigmask);
176 	else
177 		err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
178 				      sizeof(sigset_t));
179 
180 	err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
181 	err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
182 	err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
183 	err |= __put_user(regs->y, &((*grp)[MC_Y]));
184 	err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
185 	err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
186 	err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
187 	err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
188 	err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
189 	err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
190 	err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
191 	err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
192 	err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
193 	err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
194 	err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
195 	err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
196 	err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
197 	err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
198 	err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
199 
200 	err |= __get_user(fp,
201 		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
202 	err |= __get_user(i7,
203 		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
204 	err |= __put_user(fp, &(mcp->mc_fp));
205 	err |= __put_user(i7, &(mcp->mc_i7));
206 
207 	err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
208 	if (fenab) {
209 		unsigned long *fpregs = current_thread_info()->fpregs;
210 		unsigned long fprs;
211 
212 		fprs = current_thread_info()->fpsaved[0];
213 		if (fprs & FPRS_DL)
214 			err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
215 					    (sizeof(unsigned int) * 32));
216 		if (fprs & FPRS_DU)
217 			err |= copy_to_user(
218                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
219 			  (sizeof(unsigned int) * 32));
220 		err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
221 		err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
222 		err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
223 	}
224 	if (err)
225 		goto do_sigsegv;
226 out:
227 	exception_exit(prev_state);
228 	return;
229 do_sigsegv:
230 	force_sig(SIGSEGV);
231 	goto out;
232 }
233 
234 /* Checks if the fp is valid.  We always build rt signal frames which
235  * are 16-byte aligned, therefore we can always enforce that the
236  * restore frame has that property as well.
237  */
238 static bool invalid_frame_pointer(void __user *fp)
239 {
240 	if (((unsigned long) fp) & 15)
241 		return true;
242 	return false;
243 }
244 
245 struct rt_signal_frame {
246 	struct sparc_stackf	ss;
247 	siginfo_t		info;
248 	struct pt_regs		regs;
249 	__siginfo_fpu_t __user	*fpu_save;
250 	stack_t			stack;
251 	sigset_t		mask;
252 	__siginfo_rwin_t	*rwin_save;
253 };
254 
255 void do_rt_sigreturn(struct pt_regs *regs)
256 {
257 	unsigned long tpc, tnpc, tstate, ufp;
258 	struct rt_signal_frame __user *sf;
259 	__siginfo_fpu_t __user *fpu_save;
260 	__siginfo_rwin_t __user *rwin_save;
261 	sigset_t set;
262 	int err;
263 
264 	/* Always make any pending restarted system calls return -EINTR */
265 	current->restart_block.fn = do_no_restart_syscall;
266 
267 	synchronize_user_stack ();
268 	sf = (struct rt_signal_frame __user *)
269 		(regs->u_regs [UREG_FP] + STACK_BIAS);
270 
271 	/* 1. Make sure we are not getting garbage from the user */
272 	if (invalid_frame_pointer(sf))
273 		goto segv;
274 
275 	if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
276 		goto segv;
277 
278 	if ((ufp + STACK_BIAS) & 0x7)
279 		goto segv;
280 
281 	err = __get_user(tpc, &sf->regs.tpc);
282 	err |= __get_user(tnpc, &sf->regs.tnpc);
283 	if (test_thread_flag(TIF_32BIT)) {
284 		tpc &= 0xffffffff;
285 		tnpc &= 0xffffffff;
286 	}
287 	err |= ((tpc | tnpc) & 3);
288 
289 	/* 2. Restore the state */
290 	err |= __get_user(regs->y, &sf->regs.y);
291 	err |= __get_user(tstate, &sf->regs.tstate);
292 	err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
293 
294 	/* User can only change condition codes and %asi in %tstate. */
295 	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
296 	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
297 
298 	err |= __get_user(fpu_save, &sf->fpu_save);
299 	if (!err && fpu_save)
300 		err |= restore_fpu_state(regs, fpu_save);
301 
302 	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
303 	err |= restore_altstack(&sf->stack);
304 	if (err)
305 		goto segv;
306 
307 	err |= __get_user(rwin_save, &sf->rwin_save);
308 	if (!err && rwin_save) {
309 		if (restore_rwin_state(rwin_save))
310 			goto segv;
311 	}
312 
313 	regs->tpc = tpc;
314 	regs->tnpc = tnpc;
315 
316 	/* Prevent syscall restart.  */
317 	pt_regs_clear_syscall(regs);
318 
319 	set_current_blocked(&set);
320 	return;
321 segv:
322 	force_sig(SIGSEGV);
323 }
324 
325 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
326 {
327 	unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
328 
329 	/*
330 	 * If we are on the alternate signal stack and would overflow it, don't.
331 	 * Return an always-bogus address instead so we will die with SIGSEGV.
332 	 */
333 	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
334 		return (void __user *) -1L;
335 
336 	/* This is the X/Open sanctioned signal stack switching.  */
337 	sp = sigsp(sp, ksig) - framesize;
338 
339 	/* Always align the stack frame.  This handles two cases.  First,
340 	 * sigaltstack need not be mindful of platform specific stack
341 	 * alignment.  Second, if we took this signal because the stack
342 	 * is not aligned properly, we'd like to take the signal cleanly
343 	 * and report that.
344 	 */
345 	sp &= ~15UL;
346 
347 	return (void __user *) sp;
348 }
349 
350 static inline int
351 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
352 {
353 	struct rt_signal_frame __user *sf;
354 	int wsaved, err, sf_size;
355 	void __user *tail;
356 
357 	/* 1. Make sure everything is clean */
358 	synchronize_user_stack();
359 	save_and_clear_fpu();
360 
361 	wsaved = get_thread_wsaved();
362 
363 	sf_size = sizeof(struct rt_signal_frame);
364 	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
365 		sf_size += sizeof(__siginfo_fpu_t);
366 	if (wsaved)
367 		sf_size += sizeof(__siginfo_rwin_t);
368 	sf = (struct rt_signal_frame __user *)
369 		get_sigframe(ksig, regs, sf_size);
370 
371 	if (invalid_frame_pointer (sf)) {
372 		if (show_unhandled_signals)
373 			pr_info("%s[%d] bad frame in setup_rt_frame: %016lx TPC %016lx O7 %016lx\n",
374 				current->comm, current->pid, (unsigned long)sf,
375 				regs->tpc, regs->u_regs[UREG_I7]);
376 		force_sigsegv(ksig->sig);
377 		return -EINVAL;
378 	}
379 
380 	tail = (sf + 1);
381 
382 	/* 2. Save the current process state */
383 	err = copy_to_user(&sf->regs, regs, sizeof (*regs));
384 
385 	if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
386 		__siginfo_fpu_t __user *fpu_save = tail;
387 		tail += sizeof(__siginfo_fpu_t);
388 		err |= save_fpu_state(regs, fpu_save);
389 		err |= __put_user((u64)fpu_save, &sf->fpu_save);
390 	} else {
391 		err |= __put_user(0, &sf->fpu_save);
392 	}
393 	if (wsaved) {
394 		__siginfo_rwin_t __user *rwin_save = tail;
395 		tail += sizeof(__siginfo_rwin_t);
396 		err |= save_rwin_state(wsaved, rwin_save);
397 		err |= __put_user((u64)rwin_save, &sf->rwin_save);
398 		set_thread_wsaved(0);
399 	} else {
400 		err |= __put_user(0, &sf->rwin_save);
401 	}
402 
403 	/* Setup sigaltstack */
404 	err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
405 
406 	err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
407 
408 	if (!wsaved) {
409 		err |= raw_copy_in_user((u64 __user *)sf,
410 					(u64 __user *)(regs->u_regs[UREG_FP] +
411 					   STACK_BIAS),
412 					sizeof(struct reg_window));
413 	} else {
414 		struct reg_window *rp;
415 
416 		rp = &current_thread_info()->reg_window[wsaved - 1];
417 		err |= copy_to_user(sf, rp, sizeof(struct reg_window));
418 	}
419 	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
420 		err |= copy_siginfo_to_user(&sf->info, &ksig->info);
421 	else {
422 		err |= __put_user(ksig->sig, &sf->info.si_signo);
423 		err |= __put_user(SI_NOINFO, &sf->info.si_code);
424 	}
425 	if (err)
426 		return err;
427 
428 	/* 3. signal handler back-trampoline and parameters */
429 	regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
430 	regs->u_regs[UREG_I0] = ksig->sig;
431 	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
432 
433 	/* The sigcontext is passed in this way because of how it
434 	 * is defined in GLIBC's /usr/include/bits/sigcontext.h
435 	 * for sparc64.  It includes the 128 bytes of siginfo_t.
436 	 */
437 	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
438 
439 	/* 5. signal handler */
440 	regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
441 	regs->tnpc = (regs->tpc + 4);
442 	if (test_thread_flag(TIF_32BIT)) {
443 		regs->tpc &= 0xffffffff;
444 		regs->tnpc &= 0xffffffff;
445 	}
446 	/* 4. return to kernel instructions */
447 	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
448 	return 0;
449 }
450 
451 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
452 				   struct sigaction *sa)
453 {
454 	switch (regs->u_regs[UREG_I0]) {
455 	case ERESTART_RESTARTBLOCK:
456 	case ERESTARTNOHAND:
457 	no_system_call_restart:
458 		regs->u_regs[UREG_I0] = EINTR;
459 		regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
460 		break;
461 	case ERESTARTSYS:
462 		if (!(sa->sa_flags & SA_RESTART))
463 			goto no_system_call_restart;
464 		fallthrough;
465 	case ERESTARTNOINTR:
466 		regs->u_regs[UREG_I0] = orig_i0;
467 		regs->tpc -= 4;
468 		regs->tnpc -= 4;
469 	}
470 }
471 
472 /* Note that 'init' is a special process: it doesn't get signals it doesn't
473  * want to handle. Thus you cannot kill init even with a SIGKILL even by
474  * mistake.
475  */
476 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
477 {
478 	struct ksignal ksig;
479 	int restart_syscall;
480 	bool has_handler;
481 
482 	/* It's a lot of work and synchronization to add a new ptrace
483 	 * register for GDB to save and restore in order to get
484 	 * orig_i0 correct for syscall restarts when debugging.
485 	 *
486 	 * Although it should be the case that most of the global
487 	 * registers are volatile across a system call, glibc already
488 	 * depends upon that fact that we preserve them.  So we can't
489 	 * just use any global register to save away the orig_i0 value.
490 	 *
491 	 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
492 	 * preserved across a system call trap by various pieces of
493 	 * code in glibc.
494 	 *
495 	 * %g7 is used as the "thread register".   %g6 is not used in
496 	 * any fixed manner.  %g6 is used as a scratch register and
497 	 * a compiler temporary, but it's value is never used across
498 	 * a system call.  Therefore %g6 is usable for orig_i0 storage.
499 	 */
500 	if (pt_regs_is_syscall(regs) &&
501 	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
502 		regs->u_regs[UREG_G6] = orig_i0;
503 
504 #ifdef CONFIG_COMPAT
505 	if (test_thread_flag(TIF_32BIT)) {
506 		do_signal32(regs);
507 		return;
508 	}
509 #endif
510 
511 	has_handler = get_signal(&ksig);
512 
513 	restart_syscall = 0;
514 	if (pt_regs_is_syscall(regs) &&
515 	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
516 		restart_syscall = 1;
517 		orig_i0 = regs->u_regs[UREG_G6];
518 	}
519 
520 	if (has_handler) {
521 		if (restart_syscall)
522 			syscall_restart(orig_i0, regs, &ksig.ka.sa);
523 		signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
524 	} else {
525 		if (restart_syscall) {
526 			switch (regs->u_regs[UREG_I0]) {
527 			case ERESTARTNOHAND:
528 	     		case ERESTARTSYS:
529 			case ERESTARTNOINTR:
530 				/* replay the system call when we are done */
531 				regs->u_regs[UREG_I0] = orig_i0;
532 				regs->tpc -= 4;
533 				regs->tnpc -= 4;
534 				pt_regs_clear_syscall(regs);
535 				fallthrough;
536 			case ERESTART_RESTARTBLOCK:
537 				regs->u_regs[UREG_G1] = __NR_restart_syscall;
538 				regs->tpc -= 4;
539 				regs->tnpc -= 4;
540 				pt_regs_clear_syscall(regs);
541 			}
542 		}
543 		restore_saved_sigmask();
544 	}
545 }
546 
547 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
548 {
549 	user_exit();
550 	if (thread_info_flags & _TIF_UPROBE)
551 		uprobe_notify_resume(regs);
552 	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
553 		do_signal(regs, orig_i0);
554 	if (thread_info_flags & _TIF_NOTIFY_RESUME)
555 		resume_user_mode_work(regs);
556 	user_enter();
557 }
558 
559 /*
560  * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
561  * changes likely come with new fields that should be added below.
562  */
563 static_assert(NSIGILL	== 11);
564 static_assert(NSIGFPE	== 15);
565 static_assert(NSIGSEGV	== 9);
566 static_assert(NSIGBUS	== 5);
567 static_assert(NSIGTRAP	== 6);
568 static_assert(NSIGCHLD	== 6);
569 static_assert(NSIGSYS	== 2);
570 static_assert(sizeof(siginfo_t) == 128);
571 static_assert(__alignof__(siginfo_t) == 8);
572 static_assert(offsetof(siginfo_t, si_signo)	== 0x00);
573 static_assert(offsetof(siginfo_t, si_errno)	== 0x04);
574 static_assert(offsetof(siginfo_t, si_code)	== 0x08);
575 static_assert(offsetof(siginfo_t, si_pid)	== 0x10);
576 static_assert(offsetof(siginfo_t, si_uid)	== 0x14);
577 static_assert(offsetof(siginfo_t, si_tid)	== 0x10);
578 static_assert(offsetof(siginfo_t, si_overrun)	== 0x14);
579 static_assert(offsetof(siginfo_t, si_status)	== 0x18);
580 static_assert(offsetof(siginfo_t, si_utime)	== 0x20);
581 static_assert(offsetof(siginfo_t, si_stime)	== 0x28);
582 static_assert(offsetof(siginfo_t, si_value)	== 0x18);
583 static_assert(offsetof(siginfo_t, si_int)	== 0x18);
584 static_assert(offsetof(siginfo_t, si_ptr)	== 0x18);
585 static_assert(offsetof(siginfo_t, si_addr)	== 0x10);
586 static_assert(offsetof(siginfo_t, si_trapno)	== 0x18);
587 static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x18);
588 static_assert(offsetof(siginfo_t, si_lower)	== 0x20);
589 static_assert(offsetof(siginfo_t, si_upper)	== 0x28);
590 static_assert(offsetof(siginfo_t, si_pkey)	== 0x20);
591 static_assert(offsetof(siginfo_t, si_perf_data)	== 0x18);
592 static_assert(offsetof(siginfo_t, si_perf_type)	== 0x20);
593 static_assert(offsetof(siginfo_t, si_perf_flags) == 0x24);
594 static_assert(offsetof(siginfo_t, si_band)	== 0x10);
595 static_assert(offsetof(siginfo_t, si_fd)	== 0x14);
596