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Commit | Line | Data |
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5526b7e4 | 1 | /* linux/arch/sparc/kernel/signal.c |
1da177e4 LT |
2 | * |
3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
4 | * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) | |
5 | * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx) | |
6 | * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be) | |
7 | */ | |
8 | ||
1da177e4 LT |
9 | #include <linux/sched.h> |
10 | #include <linux/kernel.h> | |
11 | #include <linux/signal.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/wait.h> | |
14 | #include <linux/ptrace.h> | |
15 | #include <linux/unistd.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/tty.h> | |
18 | #include <linux/smp.h> | |
1da177e4 LT |
19 | #include <linux/binfmts.h> /* do_coredum */ |
20 | #include <linux/bitops.h> | |
5a157d5b | 21 | #include <linux/tracehook.h> |
1da177e4 | 22 | |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
1da177e4 | 24 | #include <asm/ptrace.h> |
1da177e4 LT |
25 | #include <asm/pgalloc.h> |
26 | #include <asm/pgtable.h> | |
27 | #include <asm/cacheflush.h> /* flush_sig_insns */ | |
d550bbd4 | 28 | #include <asm/switch_to.h> |
1da177e4 | 29 | |
5598473a | 30 | #include "sigutil.h" |
529b17a9 | 31 | #include "kernel.h" |
5598473a | 32 | |
1da177e4 LT |
33 | extern void fpsave(unsigned long *fpregs, unsigned long *fsr, |
34 | void *fpqueue, unsigned long *fpqdepth); | |
35 | extern void fpload(unsigned long *fpregs, unsigned long *fsr); | |
36 | ||
5526b7e4 | 37 | struct signal_frame { |
1da177e4 | 38 | struct sparc_stackf ss; |
4d7b92ad | 39 | __siginfo32_t info; |
1da177e4 LT |
40 | __siginfo_fpu_t __user *fpu_save; |
41 | unsigned long insns[2] __attribute__ ((aligned (8))); | |
42 | unsigned int extramask[_NSIG_WORDS - 1]; | |
43 | unsigned int extra_size; /* Should be 0 */ | |
5598473a DM |
44 | __siginfo_rwin_t __user *rwin_save; |
45 | } __attribute__((aligned(8))); | |
1da177e4 LT |
46 | |
47 | struct rt_signal_frame { | |
48 | struct sparc_stackf ss; | |
49 | siginfo_t info; | |
50 | struct pt_regs regs; | |
51 | sigset_t mask; | |
52 | __siginfo_fpu_t __user *fpu_save; | |
53 | unsigned int insns[2]; | |
54 | stack_t stack; | |
55 | unsigned int extra_size; /* Should be 0 */ | |
5598473a DM |
56 | __siginfo_rwin_t __user *rwin_save; |
57 | } __attribute__((aligned(8))); | |
1da177e4 LT |
58 | |
59 | /* Align macros */ | |
5526b7e4 | 60 | #define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7))) |
1da177e4 LT |
61 | #define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7))) |
62 | ||
d11c2a0d DM |
63 | /* Checks if the fp is valid. We always build signal frames which are |
64 | * 16-byte aligned, therefore we can always enforce that the restore | |
65 | * frame has that property as well. | |
66 | */ | |
67 | static inline bool invalid_frame_pointer(void __user *fp, int fplen) | |
68 | { | |
69 | if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen)) | |
70 | return true; | |
71 | ||
72 | return false; | |
73 | } | |
74 | ||
5526b7e4 | 75 | asmlinkage void do_sigreturn(struct pt_regs *regs) |
1da177e4 | 76 | { |
d11c2a0d | 77 | unsigned long up_psr, pc, npc, ufp; |
5526b7e4 | 78 | struct signal_frame __user *sf; |
1da177e4 LT |
79 | sigset_t set; |
80 | __siginfo_fpu_t __user *fpu_save; | |
5598473a | 81 | __siginfo_rwin_t __user *rwin_save; |
1da177e4 LT |
82 | int err; |
83 | ||
5526b7e4 | 84 | /* Always make any pending restarted system calls return -EINTR */ |
f56141e3 | 85 | current->restart_block.fn = do_no_restart_syscall; |
5526b7e4 DM |
86 | |
87 | synchronize_user_stack(); | |
88 | ||
89 | sf = (struct signal_frame __user *) regs->u_regs[UREG_FP]; | |
1da177e4 LT |
90 | |
91 | /* 1. Make sure we are not getting garbage from the user */ | |
07b5ab3f | 92 | if (invalid_frame_pointer(sf, sizeof(*sf))) |
d11c2a0d DM |
93 | goto segv_and_exit; |
94 | ||
95 | if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP])) | |
1da177e4 LT |
96 | goto segv_and_exit; |
97 | ||
d11c2a0d | 98 | if (ufp & 0x7) |
1da177e4 LT |
99 | goto segv_and_exit; |
100 | ||
101 | err = __get_user(pc, &sf->info.si_regs.pc); | |
102 | err |= __get_user(npc, &sf->info.si_regs.npc); | |
103 | ||
104 | if ((pc | npc) & 3) | |
105 | goto segv_and_exit; | |
106 | ||
107 | /* 2. Restore the state */ | |
108 | up_psr = regs->psr; | |
109 | err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs)); | |
110 | ||
111 | /* User can only change condition codes and FPU enabling in %psr. */ | |
112 | regs->psr = (up_psr & ~(PSR_ICC | PSR_EF)) | |
113 | | (regs->psr & (PSR_ICC | PSR_EF)); | |
114 | ||
28e61036 DM |
115 | /* Prevent syscall restart. */ |
116 | pt_regs_clear_syscall(regs); | |
117 | ||
1da177e4 | 118 | err |= __get_user(fpu_save, &sf->fpu_save); |
1da177e4 LT |
119 | if (fpu_save) |
120 | err |= restore_fpu_state(regs, fpu_save); | |
5598473a DM |
121 | err |= __get_user(rwin_save, &sf->rwin_save); |
122 | if (rwin_save) | |
123 | err |= restore_rwin_state(rwin_save); | |
1da177e4 LT |
124 | |
125 | /* This is pretty much atomic, no amount locking would prevent | |
126 | * the races which exist anyways. | |
127 | */ | |
128 | err |= __get_user(set.sig[0], &sf->info.si_mask); | |
129 | err |= __copy_from_user(&set.sig[1], &sf->extramask, | |
130 | (_NSIG_WORDS-1) * sizeof(unsigned int)); | |
131 | ||
132 | if (err) | |
133 | goto segv_and_exit; | |
134 | ||
faddf598 | 135 | set_current_blocked(&set); |
1da177e4 LT |
136 | return; |
137 | ||
138 | segv_and_exit: | |
139 | force_sig(SIGSEGV, current); | |
140 | } | |
141 | ||
1da177e4 LT |
142 | asmlinkage void do_rt_sigreturn(struct pt_regs *regs) |
143 | { | |
144 | struct rt_signal_frame __user *sf; | |
d11c2a0d | 145 | unsigned int psr, pc, npc, ufp; |
1da177e4 | 146 | __siginfo_fpu_t __user *fpu_save; |
5598473a | 147 | __siginfo_rwin_t __user *rwin_save; |
1da177e4 | 148 | sigset_t set; |
1da177e4 LT |
149 | int err; |
150 | ||
151 | synchronize_user_stack(); | |
152 | sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP]; | |
07b5ab3f | 153 | if (invalid_frame_pointer(sf, sizeof(*sf))) |
d11c2a0d DM |
154 | goto segv; |
155 | ||
156 | if (get_user(ufp, &sf->regs.u_regs[UREG_FP])) | |
157 | goto segv; | |
158 | ||
159 | if (ufp & 0x7) | |
1da177e4 LT |
160 | goto segv; |
161 | ||
162 | err = __get_user(pc, &sf->regs.pc); | |
163 | err |= __get_user(npc, &sf->regs.npc); | |
164 | err |= ((pc | npc) & 0x03); | |
165 | ||
166 | err |= __get_user(regs->y, &sf->regs.y); | |
167 | err |= __get_user(psr, &sf->regs.psr); | |
168 | ||
169 | err |= __copy_from_user(®s->u_regs[UREG_G1], | |
170 | &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32)); | |
171 | ||
172 | regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC); | |
173 | ||
28e61036 DM |
174 | /* Prevent syscall restart. */ |
175 | pt_regs_clear_syscall(regs); | |
176 | ||
1da177e4 | 177 | err |= __get_user(fpu_save, &sf->fpu_save); |
5598473a | 178 | if (!err && fpu_save) |
1da177e4 LT |
179 | err |= restore_fpu_state(regs, fpu_save); |
180 | err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t)); | |
99b06feb | 181 | err |= restore_altstack(&sf->stack); |
1da177e4 LT |
182 | |
183 | if (err) | |
184 | goto segv; | |
185 | ||
186 | regs->pc = pc; | |
187 | regs->npc = npc; | |
188 | ||
5598473a DM |
189 | err |= __get_user(rwin_save, &sf->rwin_save); |
190 | if (!err && rwin_save) { | |
191 | if (restore_rwin_state(rwin_save)) | |
192 | goto segv; | |
193 | } | |
194 | ||
faddf598 | 195 | set_current_blocked(&set); |
1da177e4 LT |
196 | return; |
197 | segv: | |
198 | force_sig(SIGSEGV, current); | |
199 | } | |
200 | ||
08f73957 | 201 | static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize) |
1da177e4 | 202 | { |
dc5dc7e6 | 203 | unsigned long sp = regs->u_regs[UREG_FP]; |
1da177e4 | 204 | |
dc5dc7e6 DM |
205 | /* |
206 | * If we are on the alternate signal stack and would overflow it, don't. | |
207 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
208 | */ | |
209 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) | |
210 | return (void __user *) -1L; | |
1da177e4 LT |
211 | |
212 | /* This is the X/Open sanctioned signal stack switching. */ | |
08f73957 | 213 | sp = sigsp(sp, ksig) - framesize; |
f036d9f3 | 214 | |
dc5dc7e6 DM |
215 | /* Always align the stack frame. This handles two cases. First, |
216 | * sigaltstack need not be mindful of platform specific stack | |
217 | * alignment. Second, if we took this signal because the stack | |
218 | * is not aligned properly, we'd like to take the signal cleanly | |
219 | * and report that. | |
220 | */ | |
f036d9f3 | 221 | sp &= ~15UL; |
dc5dc7e6 | 222 | |
f036d9f3 | 223 | return (void __user *) sp; |
1da177e4 LT |
224 | } |
225 | ||
08f73957 AV |
226 | static int setup_frame(struct ksignal *ksig, struct pt_regs *regs, |
227 | sigset_t *oldset) | |
1da177e4 | 228 | { |
5526b7e4 | 229 | struct signal_frame __user *sf; |
5598473a DM |
230 | int sigframe_size, err, wsaved; |
231 | void __user *tail; | |
1da177e4 LT |
232 | |
233 | /* 1. Make sure everything is clean */ | |
234 | synchronize_user_stack(); | |
235 | ||
5598473a DM |
236 | wsaved = current_thread_info()->w_saved; |
237 | ||
238 | sigframe_size = sizeof(*sf); | |
239 | if (used_math()) | |
240 | sigframe_size += sizeof(__siginfo_fpu_t); | |
241 | if (wsaved) | |
242 | sigframe_size += sizeof(__siginfo_rwin_t); | |
1da177e4 | 243 | |
5526b7e4 | 244 | sf = (struct signal_frame __user *) |
08f73957 | 245 | get_sigframe(ksig, regs, sigframe_size); |
1da177e4 | 246 | |
08f73957 AV |
247 | if (invalid_frame_pointer(sf, sigframe_size)) { |
248 | do_exit(SIGILL); | |
249 | return -EINVAL; | |
250 | } | |
1da177e4 | 251 | |
5598473a | 252 | tail = sf + 1; |
1da177e4 LT |
253 | |
254 | /* 2. Save the current process state */ | |
255 | err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs)); | |
256 | ||
257 | err |= __put_user(0, &sf->extra_size); | |
258 | ||
259 | if (used_math()) { | |
5598473a DM |
260 | __siginfo_fpu_t __user *fp = tail; |
261 | tail += sizeof(*fp); | |
262 | err |= save_fpu_state(regs, fp); | |
263 | err |= __put_user(fp, &sf->fpu_save); | |
1da177e4 LT |
264 | } else { |
265 | err |= __put_user(0, &sf->fpu_save); | |
266 | } | |
5598473a DM |
267 | if (wsaved) { |
268 | __siginfo_rwin_t __user *rwp = tail; | |
269 | tail += sizeof(*rwp); | |
270 | err |= save_rwin_state(wsaved, rwp); | |
271 | err |= __put_user(rwp, &sf->rwin_save); | |
272 | } else { | |
273 | err |= __put_user(0, &sf->rwin_save); | |
274 | } | |
1da177e4 LT |
275 | |
276 | err |= __put_user(oldset->sig[0], &sf->info.si_mask); | |
277 | err |= __copy_to_user(sf->extramask, &oldset->sig[1], | |
278 | (_NSIG_WORDS - 1) * sizeof(unsigned int)); | |
5598473a DM |
279 | if (!wsaved) { |
280 | err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], | |
281 | sizeof(struct reg_window32)); | |
282 | } else { | |
283 | struct reg_window32 *rp; | |
284 | ||
285 | rp = ¤t_thread_info()->reg_window[wsaved - 1]; | |
286 | err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); | |
287 | } | |
1da177e4 | 288 | if (err) |
08f73957 | 289 | return err; |
1da177e4 LT |
290 | |
291 | /* 3. signal handler back-trampoline and parameters */ | |
292 | regs->u_regs[UREG_FP] = (unsigned long) sf; | |
08f73957 | 293 | regs->u_regs[UREG_I0] = ksig->sig; |
1da177e4 LT |
294 | regs->u_regs[UREG_I1] = (unsigned long) &sf->info; |
295 | regs->u_regs[UREG_I2] = (unsigned long) &sf->info; | |
296 | ||
297 | /* 4. signal handler */ | |
08f73957 | 298 | regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
1da177e4 LT |
299 | regs->npc = (regs->pc + 4); |
300 | ||
301 | /* 5. return to kernel instructions */ | |
08f73957 AV |
302 | if (ksig->ka.ka_restorer) |
303 | regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; | |
1da177e4 LT |
304 | else { |
305 | regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); | |
306 | ||
307 | /* mov __NR_sigreturn, %g1 */ | |
308 | err |= __put_user(0x821020d8, &sf->insns[0]); | |
309 | ||
310 | /* t 0x10 */ | |
311 | err |= __put_user(0x91d02010, &sf->insns[1]); | |
312 | if (err) | |
08f73957 | 313 | return err; |
1da177e4 LT |
314 | |
315 | /* Flush instruction space. */ | |
316 | flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); | |
317 | } | |
392c2180 | 318 | return 0; |
1da177e4 LT |
319 | } |
320 | ||
08f73957 AV |
321 | static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs, |
322 | sigset_t *oldset) | |
1da177e4 LT |
323 | { |
324 | struct rt_signal_frame __user *sf; | |
5598473a DM |
325 | int sigframe_size, wsaved; |
326 | void __user *tail; | |
1da177e4 LT |
327 | unsigned int psr; |
328 | int err; | |
329 | ||
330 | synchronize_user_stack(); | |
5598473a DM |
331 | wsaved = current_thread_info()->w_saved; |
332 | sigframe_size = sizeof(*sf); | |
333 | if (used_math()) | |
334 | sigframe_size += sizeof(__siginfo_fpu_t); | |
335 | if (wsaved) | |
336 | sigframe_size += sizeof(__siginfo_rwin_t); | |
1da177e4 | 337 | sf = (struct rt_signal_frame __user *) |
08f73957 AV |
338 | get_sigframe(ksig, regs, sigframe_size); |
339 | if (invalid_frame_pointer(sf, sigframe_size)) { | |
340 | do_exit(SIGILL); | |
341 | return -EINVAL; | |
342 | } | |
1da177e4 | 343 | |
5598473a | 344 | tail = sf + 1; |
1da177e4 LT |
345 | err = __put_user(regs->pc, &sf->regs.pc); |
346 | err |= __put_user(regs->npc, &sf->regs.npc); | |
347 | err |= __put_user(regs->y, &sf->regs.y); | |
348 | psr = regs->psr; | |
349 | if (used_math()) | |
350 | psr |= PSR_EF; | |
351 | err |= __put_user(psr, &sf->regs.psr); | |
352 | err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs)); | |
353 | err |= __put_user(0, &sf->extra_size); | |
354 | ||
355 | if (psr & PSR_EF) { | |
529b17a9 | 356 | __siginfo_fpu_t __user *fp = tail; |
5598473a DM |
357 | tail += sizeof(*fp); |
358 | err |= save_fpu_state(regs, fp); | |
359 | err |= __put_user(fp, &sf->fpu_save); | |
1da177e4 LT |
360 | } else { |
361 | err |= __put_user(0, &sf->fpu_save); | |
362 | } | |
5598473a | 363 | if (wsaved) { |
529b17a9 | 364 | __siginfo_rwin_t __user *rwp = tail; |
5598473a DM |
365 | tail += sizeof(*rwp); |
366 | err |= save_rwin_state(wsaved, rwp); | |
367 | err |= __put_user(rwp, &sf->rwin_save); | |
368 | } else { | |
369 | err |= __put_user(0, &sf->rwin_save); | |
370 | } | |
1da177e4 LT |
371 | err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t)); |
372 | ||
373 | /* Setup sigaltstack */ | |
99b06feb | 374 | err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]); |
1da177e4 | 375 | |
5598473a DM |
376 | if (!wsaved) { |
377 | err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], | |
378 | sizeof(struct reg_window32)); | |
379 | } else { | |
380 | struct reg_window32 *rp; | |
381 | ||
382 | rp = ¤t_thread_info()->reg_window[wsaved - 1]; | |
383 | err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); | |
384 | } | |
1da177e4 | 385 | |
08f73957 | 386 | err |= copy_siginfo_to_user(&sf->info, &ksig->info); |
1da177e4 LT |
387 | |
388 | if (err) | |
08f73957 | 389 | return err; |
1da177e4 LT |
390 | |
391 | regs->u_regs[UREG_FP] = (unsigned long) sf; | |
08f73957 | 392 | regs->u_regs[UREG_I0] = ksig->sig; |
1da177e4 LT |
393 | regs->u_regs[UREG_I1] = (unsigned long) &sf->info; |
394 | regs->u_regs[UREG_I2] = (unsigned long) &sf->regs; | |
395 | ||
08f73957 | 396 | regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
1da177e4 LT |
397 | regs->npc = (regs->pc + 4); |
398 | ||
08f73957 AV |
399 | if (ksig->ka.ka_restorer) |
400 | regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; | |
1da177e4 LT |
401 | else { |
402 | regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); | |
403 | ||
404 | /* mov __NR_sigreturn, %g1 */ | |
405 | err |= __put_user(0x821020d8, &sf->insns[0]); | |
406 | ||
407 | /* t 0x10 */ | |
408 | err |= __put_user(0x91d02010, &sf->insns[1]); | |
409 | if (err) | |
08f73957 | 410 | return err; |
1da177e4 LT |
411 | |
412 | /* Flush instruction space. */ | |
413 | flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); | |
414 | } | |
392c2180 | 415 | return 0; |
1da177e4 LT |
416 | } |
417 | ||
a610d6e6 | 418 | static inline void |
08f73957 | 419 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 420 | { |
b7f9a11a | 421 | sigset_t *oldset = sigmask_to_save(); |
392c2180 DM |
422 | int err; |
423 | ||
08f73957 AV |
424 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
425 | err = setup_rt_frame(ksig, regs, oldset); | |
ec98c6b9 | 426 | else |
08f73957 AV |
427 | err = setup_frame(ksig, regs, oldset); |
428 | signal_setup_done(err, ksig, 0); | |
1da177e4 LT |
429 | } |
430 | ||
431 | static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs, | |
432 | struct sigaction *sa) | |
433 | { | |
434 | switch(regs->u_regs[UREG_I0]) { | |
435 | case ERESTART_RESTARTBLOCK: | |
436 | case ERESTARTNOHAND: | |
437 | no_system_call_restart: | |
438 | regs->u_regs[UREG_I0] = EINTR; | |
439 | regs->psr |= PSR_C; | |
440 | break; | |
441 | case ERESTARTSYS: | |
442 | if (!(sa->sa_flags & SA_RESTART)) | |
443 | goto no_system_call_restart; | |
444 | /* fallthrough */ | |
445 | case ERESTARTNOINTR: | |
446 | regs->u_regs[UREG_I0] = orig_i0; | |
447 | regs->pc -= 4; | |
448 | regs->npc -= 4; | |
449 | } | |
450 | } | |
451 | ||
452 | /* Note that 'init' is a special process: it doesn't get signals it doesn't | |
453 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
454 | * mistake. | |
455 | */ | |
5a157d5b | 456 | static void do_signal(struct pt_regs *regs, unsigned long orig_i0) |
1da177e4 | 457 | { |
08f73957 | 458 | struct ksignal ksig; |
28e61036 | 459 | int restart_syscall; |
08f73957 | 460 | bool has_handler; |
1da177e4 | 461 | |
1d299bc7 DM |
462 | /* It's a lot of work and synchronization to add a new ptrace |
463 | * register for GDB to save and restore in order to get | |
464 | * orig_i0 correct for syscall restarts when debugging. | |
465 | * | |
e88d2468 DM |
466 | * Although it should be the case that most of the global |
467 | * registers are volatile across a system call, glibc already | |
468 | * depends upon that fact that we preserve them. So we can't | |
469 | * just use any global register to save away the orig_i0 value. | |
470 | * | |
471 | * In particular %g2, %g3, %g4, and %g5 are all assumed to be | |
472 | * preserved across a system call trap by various pieces of | |
473 | * code in glibc. | |
474 | * | |
475 | * %g7 is used as the "thread register". %g6 is not used in | |
476 | * any fixed manner. %g6 is used as a scratch register and | |
477 | * a compiler temporary, but it's value is never used across | |
478 | * a system call. Therefore %g6 is usable for orig_i0 storage. | |
1d299bc7 | 479 | */ |
28e61036 | 480 | if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) |
e88d2468 | 481 | regs->u_regs[UREG_G6] = orig_i0; |
1da177e4 | 482 | |
08f73957 | 483 | has_handler = get_signal(&ksig); |
28e61036 DM |
484 | |
485 | /* If the debugger messes with the program counter, it clears | |
486 | * the software "in syscall" bit, directing us to not perform | |
487 | * a syscall restart. | |
488 | */ | |
1d299bc7 DM |
489 | restart_syscall = 0; |
490 | if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) { | |
491 | restart_syscall = 1; | |
e88d2468 | 492 | orig_i0 = regs->u_regs[UREG_G6]; |
1d299bc7 DM |
493 | } |
494 | ||
08f73957 | 495 | if (has_handler) { |
28e61036 | 496 | if (restart_syscall) |
08f73957 AV |
497 | syscall_restart(orig_i0, regs, &ksig.ka.sa); |
498 | handle_signal(&ksig, regs); | |
499 | } else { | |
500 | if (restart_syscall) { | |
501 | switch (regs->u_regs[UREG_I0]) { | |
502 | case ERESTARTNOHAND: | |
503 | case ERESTARTSYS: | |
504 | case ERESTARTNOINTR: | |
505 | /* replay the system call when we are done */ | |
506 | regs->u_regs[UREG_I0] = orig_i0; | |
507 | regs->pc -= 4; | |
508 | regs->npc -= 4; | |
509 | pt_regs_clear_syscall(regs); | |
510 | case ERESTART_RESTARTBLOCK: | |
511 | regs->u_regs[UREG_G1] = __NR_restart_syscall; | |
512 | regs->pc -= 4; | |
513 | regs->npc -= 4; | |
514 | pt_regs_clear_syscall(regs); | |
515 | } | |
516 | } | |
517 | restore_saved_sigmask(); | |
1da177e4 | 518 | } |
1da177e4 LT |
519 | } |
520 | ||
5a157d5b DM |
521 | void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, |
522 | unsigned long thread_info_flags) | |
523 | { | |
6fd84c08 | 524 | if (thread_info_flags & _TIF_SIGPENDING) |
5a157d5b DM |
525 | do_signal(regs, orig_i0); |
526 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { | |
527 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
528 | tracehook_notify_resume(regs); | |
529 | } | |
530 | } | |
531 | ||
529b17a9 SR |
532 | asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr, |
533 | struct sigstack __user *ossptr, | |
534 | unsigned long sp) | |
1da177e4 LT |
535 | { |
536 | int ret = -EFAULT; | |
537 | ||
538 | /* First see if old state is wanted. */ | |
539 | if (ossptr) { | |
540 | if (put_user(current->sas_ss_sp + current->sas_ss_size, | |
541 | &ossptr->the_stack) || | |
542 | __put_user(on_sig_stack(sp), &ossptr->cur_status)) | |
543 | goto out; | |
544 | } | |
545 | ||
546 | /* Now see if we want to update the new state. */ | |
547 | if (ssptr) { | |
548 | char *ss_sp; | |
549 | ||
550 | if (get_user(ss_sp, &ssptr->the_stack)) | |
551 | goto out; | |
552 | /* If the current stack was set with sigaltstack, don't | |
553 | swap stacks while we are on it. */ | |
554 | ret = -EPERM; | |
555 | if (current->sas_ss_sp && on_sig_stack(sp)) | |
556 | goto out; | |
557 | ||
558 | /* Since we don't know the extent of the stack, and we don't | |
559 | track onstack-ness, but rather calculate it, we must | |
560 | presume a size. Ho hum this interface is lossy. */ | |
561 | current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ; | |
562 | current->sas_ss_size = SIGSTKSZ; | |
563 | } | |
564 | ret = 0; | |
565 | out: | |
566 | return ret; | |
567 | } |