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(to: &set, from: &ucp->uc_sigmask, n: 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(to: fpregs, |
118 | from: &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs), |
119 | n: (sizeof(unsigned int) * 32)); |
120 | if (fprs & FPRS_DU) |
121 | err |= copy_from_user(to: fpregs+16, |
122 | from: ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16, |
123 | n: (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_ctx: 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(to: &ucp->uc_sigmask, from: ¤t->blocked, |
178 | n: 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_ctx: 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(fp: 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(to: regs->u_regs, from: sf->regs.u_regs, n: 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(to: &set, from: &sf->mask, n: 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, framesize: sf_size); |
370 | |
371 | if (invalid_frame_pointer (fp: 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(sig: ksig->sig); |
377 | return -EINVAL; |
378 | } |
379 | |
380 | tail = (sf + 1); |
381 | |
382 | /* 2. Save the current process state */ |
383 | err = copy_to_user(to: &sf->regs, from: regs, n: 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(to: &sf->mask, from: sigmask_to_save(), n: 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 = ¤t_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(to: &sf->info, from: &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 its 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: &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, sa: &ksig.ka.sa); |
523 | signal_setup_done(failed: setup_rt_frame(ksig: &ksig, regs), ksig: &ksig, stepping: 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 == 10); |
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 | |