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1 /*
2  * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC
3  *
4  *  PowerPC version
5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6  * Copyright (C) 2001 IBM
7  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
9  *
10  *  Derived from "arch/i386/kernel/signal.c"
11  *    Copyright (C) 1991, 1992 Linus Torvalds
12  *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
13  *
14  *  This program is free software; you can redistribute it and/or
15  *  modify it under the terms of the GNU General Public License
16  *  as published by the Free Software Foundation; either version
17  *  2 of the License, or (at your option) any later version.
18  */
19 
20 #include <linux/sched.h>
21 #include <linux/mm.h>
22 #include <linux/smp.h>
23 #include <linux/kernel.h>
24 #include <linux/signal.h>
25 #include <linux/errno.h>
26 #include <linux/elf.h>
27 #include <linux/ptrace.h>
28 #include <linux/ratelimit.h>
29 #ifdef CONFIG_PPC64
30 #include <linux/syscalls.h>
31 #include <linux/compat.h>
32 #else
33 #include <linux/wait.h>
34 #include <linux/unistd.h>
35 #include <linux/stddef.h>
36 #include <linux/tty.h>
37 #include <linux/binfmts.h>
38 #endif
39 
40 #include <asm/uaccess.h>
41 #include <asm/cacheflush.h>
42 #include <asm/syscalls.h>
43 #include <asm/sigcontext.h>
44 #include <asm/vdso.h>
45 #include <asm/switch_to.h>
46 #include <asm/tm.h>
47 #ifdef CONFIG_PPC64
48 #include "ppc32.h"
49 #include <asm/unistd.h>
50 #else
51 #include <asm/ucontext.h>
52 #include <asm/pgtable.h>
53 #endif
54 
55 #include "signal.h"
56 
57 #undef DEBUG_SIG
58 
59 #ifdef CONFIG_PPC64
60 #define sys_rt_sigreturn	compat_sys_rt_sigreturn
61 #define sys_swapcontext	compat_sys_swapcontext
62 #define sys_sigreturn	compat_sys_sigreturn
63 
64 #define old_sigaction	old_sigaction32
65 #define sigcontext	sigcontext32
66 #define mcontext	mcontext32
67 #define ucontext	ucontext32
68 
69 #define __save_altstack __compat_save_altstack
70 
71 /*
72  * Userspace code may pass a ucontext which doesn't include VSX added
73  * at the end.  We need to check for this case.
74  */
75 #define UCONTEXTSIZEWITHOUTVSX \
76 		(sizeof(struct ucontext) - sizeof(elf_vsrreghalf_t32))
77 
78 /*
79  * Returning 0 means we return to userspace via
80  * ret_from_except and thus restore all user
81  * registers from *regs.  This is what we need
82  * to do when a signal has been delivered.
83  */
84 
85 #define GP_REGS_SIZE	min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))
86 #undef __SIGNAL_FRAMESIZE
87 #define __SIGNAL_FRAMESIZE	__SIGNAL_FRAMESIZE32
88 #undef ELF_NVRREG
89 #define ELF_NVRREG	ELF_NVRREG32
90 
91 /*
92  * Functions for flipping sigsets (thanks to brain dead generic
93  * implementation that makes things simple for little endian only)
94  */
put_sigset_t(compat_sigset_t __user * uset,sigset_t * set)95 static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
96 {
97 	compat_sigset_t	cset;
98 
99 	switch (_NSIG_WORDS) {
100 	case 4: cset.sig[6] = set->sig[3] & 0xffffffffull;
101 		cset.sig[7] = set->sig[3] >> 32;
102 	case 3: cset.sig[4] = set->sig[2] & 0xffffffffull;
103 		cset.sig[5] = set->sig[2] >> 32;
104 	case 2: cset.sig[2] = set->sig[1] & 0xffffffffull;
105 		cset.sig[3] = set->sig[1] >> 32;
106 	case 1: cset.sig[0] = set->sig[0] & 0xffffffffull;
107 		cset.sig[1] = set->sig[0] >> 32;
108 	}
109 	return copy_to_user(uset, &cset, sizeof(*uset));
110 }
111 
get_sigset_t(sigset_t * set,const compat_sigset_t __user * uset)112 static inline int get_sigset_t(sigset_t *set,
113 			       const compat_sigset_t __user *uset)
114 {
115 	compat_sigset_t s32;
116 
117 	if (copy_from_user(&s32, uset, sizeof(*uset)))
118 		return -EFAULT;
119 
120 	/*
121 	 * Swap the 2 words of the 64-bit sigset_t (they are stored
122 	 * in the "wrong" endian in 32-bit user storage).
123 	 */
124 	switch (_NSIG_WORDS) {
125 	case 4: set->sig[3] = s32.sig[6] | (((long)s32.sig[7]) << 32);
126 	case 3: set->sig[2] = s32.sig[4] | (((long)s32.sig[5]) << 32);
127 	case 2: set->sig[1] = s32.sig[2] | (((long)s32.sig[3]) << 32);
128 	case 1: set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
129 	}
130 	return 0;
131 }
132 
133 #define to_user_ptr(p)		ptr_to_compat(p)
134 #define from_user_ptr(p)	compat_ptr(p)
135 
save_general_regs(struct pt_regs * regs,struct mcontext __user * frame)136 static inline int save_general_regs(struct pt_regs *regs,
137 		struct mcontext __user *frame)
138 {
139 	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
140 	int i;
141 
142 	WARN_ON(!FULL_REGS(regs));
143 
144 	for (i = 0; i <= PT_RESULT; i ++) {
145 		if (i == 14 && !FULL_REGS(regs))
146 			i = 32;
147 		if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i]))
148 			return -EFAULT;
149 	}
150 	return 0;
151 }
152 
restore_general_regs(struct pt_regs * regs,struct mcontext __user * sr)153 static inline int restore_general_regs(struct pt_regs *regs,
154 		struct mcontext __user *sr)
155 {
156 	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
157 	int i;
158 
159 	for (i = 0; i <= PT_RESULT; i++) {
160 		if ((i == PT_MSR) || (i == PT_SOFTE))
161 			continue;
162 		if (__get_user(gregs[i], &sr->mc_gregs[i]))
163 			return -EFAULT;
164 	}
165 	return 0;
166 }
167 
168 #else /* CONFIG_PPC64 */
169 
170 #define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
171 
put_sigset_t(sigset_t __user * uset,sigset_t * set)172 static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
173 {
174 	return copy_to_user(uset, set, sizeof(*uset));
175 }
176 
get_sigset_t(sigset_t * set,const sigset_t __user * uset)177 static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
178 {
179 	return copy_from_user(set, uset, sizeof(*uset));
180 }
181 
182 #define to_user_ptr(p)		((unsigned long)(p))
183 #define from_user_ptr(p)	((void __user *)(p))
184 
save_general_regs(struct pt_regs * regs,struct mcontext __user * frame)185 static inline int save_general_regs(struct pt_regs *regs,
186 		struct mcontext __user *frame)
187 {
188 	WARN_ON(!FULL_REGS(regs));
189 	return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
190 }
191 
restore_general_regs(struct pt_regs * regs,struct mcontext __user * sr)192 static inline int restore_general_regs(struct pt_regs *regs,
193 		struct mcontext __user *sr)
194 {
195 	/* copy up to but not including MSR */
196 	if (__copy_from_user(regs, &sr->mc_gregs,
197 				PT_MSR * sizeof(elf_greg_t)))
198 		return -EFAULT;
199 	/* copy from orig_r3 (the word after the MSR) up to the end */
200 	if (__copy_from_user(&regs->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
201 				GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t)))
202 		return -EFAULT;
203 	return 0;
204 }
205 #endif
206 
207 /*
208  * When we have signals to deliver, we set up on the
209  * user stack, going down from the original stack pointer:
210  *	an ABI gap of 56 words
211  *	an mcontext struct
212  *	a sigcontext struct
213  *	a gap of __SIGNAL_FRAMESIZE bytes
214  *
215  * Each of these things must be a multiple of 16 bytes in size. The following
216  * structure represent all of this except the __SIGNAL_FRAMESIZE gap
217  *
218  */
219 struct sigframe {
220 	struct sigcontext sctx;		/* the sigcontext */
221 	struct mcontext	mctx;		/* all the register values */
222 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
223 	struct sigcontext sctx_transact;
224 	struct mcontext	mctx_transact;
225 #endif
226 	/*
227 	 * Programs using the rs6000/xcoff abi can save up to 19 gp
228 	 * regs and 18 fp regs below sp before decrementing it.
229 	 */
230 	int			abigap[56];
231 };
232 
233 /* We use the mc_pad field for the signal return trampoline. */
234 #define tramp	mc_pad
235 
236 /*
237  *  When we have rt signals to deliver, we set up on the
238  *  user stack, going down from the original stack pointer:
239  *	one rt_sigframe struct (siginfo + ucontext + ABI gap)
240  *	a gap of __SIGNAL_FRAMESIZE+16 bytes
241  *  (the +16 is to get the siginfo and ucontext in the same
242  *  positions as in older kernels).
243  *
244  *  Each of these things must be a multiple of 16 bytes in size.
245  *
246  */
247 struct rt_sigframe {
248 #ifdef CONFIG_PPC64
249 	compat_siginfo_t info;
250 #else
251 	struct siginfo info;
252 #endif
253 	struct ucontext	uc;
254 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
255 	struct ucontext	uc_transact;
256 #endif
257 	/*
258 	 * Programs using the rs6000/xcoff abi can save up to 19 gp
259 	 * regs and 18 fp regs below sp before decrementing it.
260 	 */
261 	int			abigap[56];
262 };
263 
264 #ifdef CONFIG_VSX
copy_fpr_to_user(void __user * to,struct task_struct * task)265 unsigned long copy_fpr_to_user(void __user *to,
266 			       struct task_struct *task)
267 {
268 	double buf[ELF_NFPREG];
269 	int i;
270 
271 	/* save FPR copy to local buffer then write to the thread_struct */
272 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
273 		buf[i] = task->thread.TS_FPR(i);
274 	memcpy(&buf[i], &task->thread.fpscr, sizeof(double));
275 	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
276 }
277 
copy_fpr_from_user(struct task_struct * task,void __user * from)278 unsigned long copy_fpr_from_user(struct task_struct *task,
279 				 void __user *from)
280 {
281 	double buf[ELF_NFPREG];
282 	int i;
283 
284 	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
285 		return 1;
286 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
287 		task->thread.TS_FPR(i) = buf[i];
288 	memcpy(&task->thread.fpscr, &buf[i], sizeof(double));
289 
290 	return 0;
291 }
292 
copy_vsx_to_user(void __user * to,struct task_struct * task)293 unsigned long copy_vsx_to_user(void __user *to,
294 			       struct task_struct *task)
295 {
296 	double buf[ELF_NVSRHALFREG];
297 	int i;
298 
299 	/* save FPR copy to local buffer then write to the thread_struct */
300 	for (i = 0; i < ELF_NVSRHALFREG; i++)
301 		buf[i] = task->thread.fpr[i][TS_VSRLOWOFFSET];
302 	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
303 }
304 
copy_vsx_from_user(struct task_struct * task,void __user * from)305 unsigned long copy_vsx_from_user(struct task_struct *task,
306 				 void __user *from)
307 {
308 	double buf[ELF_NVSRHALFREG];
309 	int i;
310 
311 	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
312 		return 1;
313 	for (i = 0; i < ELF_NVSRHALFREG ; i++)
314 		task->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];
315 	return 0;
316 }
317 
318 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
copy_transact_fpr_to_user(void __user * to,struct task_struct * task)319 unsigned long copy_transact_fpr_to_user(void __user *to,
320 				  struct task_struct *task)
321 {
322 	double buf[ELF_NFPREG];
323 	int i;
324 
325 	/* save FPR copy to local buffer then write to the thread_struct */
326 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
327 		buf[i] = task->thread.TS_TRANS_FPR(i);
328 	memcpy(&buf[i], &task->thread.transact_fpscr, sizeof(double));
329 	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
330 }
331 
copy_transact_fpr_from_user(struct task_struct * task,void __user * from)332 unsigned long copy_transact_fpr_from_user(struct task_struct *task,
333 					  void __user *from)
334 {
335 	double buf[ELF_NFPREG];
336 	int i;
337 
338 	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
339 		return 1;
340 	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
341 		task->thread.TS_TRANS_FPR(i) = buf[i];
342 	memcpy(&task->thread.transact_fpscr, &buf[i], sizeof(double));
343 
344 	return 0;
345 }
346 
copy_transact_vsx_to_user(void __user * to,struct task_struct * task)347 unsigned long copy_transact_vsx_to_user(void __user *to,
348 				  struct task_struct *task)
349 {
350 	double buf[ELF_NVSRHALFREG];
351 	int i;
352 
353 	/* save FPR copy to local buffer then write to the thread_struct */
354 	for (i = 0; i < ELF_NVSRHALFREG; i++)
355 		buf[i] = task->thread.transact_fpr[i][TS_VSRLOWOFFSET];
356 	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
357 }
358 
copy_transact_vsx_from_user(struct task_struct * task,void __user * from)359 unsigned long copy_transact_vsx_from_user(struct task_struct *task,
360 					  void __user *from)
361 {
362 	double buf[ELF_NVSRHALFREG];
363 	int i;
364 
365 	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
366 		return 1;
367 	for (i = 0; i < ELF_NVSRHALFREG ; i++)
368 		task->thread.transact_fpr[i][TS_VSRLOWOFFSET] = buf[i];
369 	return 0;
370 }
371 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
372 #else
copy_fpr_to_user(void __user * to,struct task_struct * task)373 inline unsigned long copy_fpr_to_user(void __user *to,
374 				      struct task_struct *task)
375 {
376 	return __copy_to_user(to, task->thread.fpr,
377 			      ELF_NFPREG * sizeof(double));
378 }
379 
copy_fpr_from_user(struct task_struct * task,void __user * from)380 inline unsigned long copy_fpr_from_user(struct task_struct *task,
381 					void __user *from)
382 {
383 	return __copy_from_user(task->thread.fpr, from,
384 			      ELF_NFPREG * sizeof(double));
385 }
386 
387 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
copy_transact_fpr_to_user(void __user * to,struct task_struct * task)388 inline unsigned long copy_transact_fpr_to_user(void __user *to,
389 					 struct task_struct *task)
390 {
391 	return __copy_to_user(to, task->thread.transact_fpr,
392 			      ELF_NFPREG * sizeof(double));
393 }
394 
copy_transact_fpr_from_user(struct task_struct * task,void __user * from)395 inline unsigned long copy_transact_fpr_from_user(struct task_struct *task,
396 						 void __user *from)
397 {
398 	return __copy_from_user(task->thread.transact_fpr, from,
399 				ELF_NFPREG * sizeof(double));
400 }
401 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
402 #endif
403 
404 /*
405  * Save the current user registers on the user stack.
406  * We only save the altivec/spe registers if the process has used
407  * altivec/spe instructions at some point.
408  */
save_user_regs(struct pt_regs * regs,struct mcontext __user * frame,int sigret,int ctx_has_vsx_region)409 static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
410 		int sigret, int ctx_has_vsx_region)
411 {
412 	unsigned long msr = regs->msr;
413 
414 	/* Make sure floating point registers are stored in regs */
415 	flush_fp_to_thread(current);
416 
417 	/* save general registers */
418 	if (save_general_regs(regs, frame))
419 		return 1;
420 
421 #ifdef CONFIG_ALTIVEC
422 	/* save altivec registers */
423 	if (current->thread.used_vr) {
424 		flush_altivec_to_thread(current);
425 		if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
426 				   ELF_NVRREG * sizeof(vector128)))
427 			return 1;
428 		/* set MSR_VEC in the saved MSR value to indicate that
429 		   frame->mc_vregs contains valid data */
430 		msr |= MSR_VEC;
431 	}
432 	/* else assert((regs->msr & MSR_VEC) == 0) */
433 
434 	/* We always copy to/from vrsave, it's 0 if we don't have or don't
435 	 * use altivec. Since VSCR only contains 32 bits saved in the least
436 	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
437 	 * most significant bits of that same vector. --BenH
438 	 */
439 	if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
440 		return 1;
441 #endif /* CONFIG_ALTIVEC */
442 	if (copy_fpr_to_user(&frame->mc_fregs, current))
443 		return 1;
444 #ifdef CONFIG_VSX
445 	/*
446 	 * Copy VSR 0-31 upper half from thread_struct to local
447 	 * buffer, then write that to userspace.  Also set MSR_VSX in
448 	 * the saved MSR value to indicate that frame->mc_vregs
449 	 * contains valid data
450 	 */
451 	if (current->thread.used_vsr && ctx_has_vsx_region) {
452 		__giveup_vsx(current);
453 		if (copy_vsx_to_user(&frame->mc_vsregs, current))
454 			return 1;
455 		msr |= MSR_VSX;
456 	}
457 #endif /* CONFIG_VSX */
458 #ifdef CONFIG_SPE
459 	/* save spe registers */
460 	if (current->thread.used_spe) {
461 		flush_spe_to_thread(current);
462 		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
463 				   ELF_NEVRREG * sizeof(u32)))
464 			return 1;
465 		/* set MSR_SPE in the saved MSR value to indicate that
466 		   frame->mc_vregs contains valid data */
467 		msr |= MSR_SPE;
468 	}
469 	/* else assert((regs->msr & MSR_SPE) == 0) */
470 
471 	/* We always copy to/from spefscr */
472 	if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
473 		return 1;
474 #endif /* CONFIG_SPE */
475 
476 	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
477 		return 1;
478 	if (sigret) {
479 		/* Set up the sigreturn trampoline: li r0,sigret; sc */
480 		if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
481 		    || __put_user(0x44000002UL, &frame->tramp[1]))
482 			return 1;
483 		flush_icache_range((unsigned long) &frame->tramp[0],
484 				   (unsigned long) &frame->tramp[2]);
485 	}
486 
487 	return 0;
488 }
489 
490 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
491 /*
492  * Save the current user registers on the user stack.
493  * We only save the altivec/spe registers if the process has used
494  * altivec/spe instructions at some point.
495  * We also save the transactional registers to a second ucontext in the
496  * frame.
497  *
498  * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
499  */
save_tm_user_regs(struct pt_regs * regs,struct mcontext __user * frame,struct mcontext __user * tm_frame,int sigret)500 static int save_tm_user_regs(struct pt_regs *regs,
501 			     struct mcontext __user *frame,
502 			     struct mcontext __user *tm_frame, int sigret)
503 {
504 	unsigned long msr = regs->msr;
505 
506 	/* Make sure floating point registers are stored in regs */
507 	flush_fp_to_thread(current);
508 
509 	/* Save both sets of general registers */
510 	if (save_general_regs(&current->thread.ckpt_regs, frame)
511 	    || save_general_regs(regs, tm_frame))
512 		return 1;
513 
514 	/* Stash the top half of the 64bit MSR into the 32bit MSR word
515 	 * of the transactional mcontext.  This way we have a backward-compatible
516 	 * MSR in the 'normal' (checkpointed) mcontext and additionally one can
517 	 * also look at what type of transaction (T or S) was active at the
518 	 * time of the signal.
519 	 */
520 	if (__put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR]))
521 		return 1;
522 
523 #ifdef CONFIG_ALTIVEC
524 	/* save altivec registers */
525 	if (current->thread.used_vr) {
526 		flush_altivec_to_thread(current);
527 		if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
528 				   ELF_NVRREG * sizeof(vector128)))
529 			return 1;
530 		if (msr & MSR_VEC) {
531 			if (__copy_to_user(&tm_frame->mc_vregs,
532 					   current->thread.transact_vr,
533 					   ELF_NVRREG * sizeof(vector128)))
534 				return 1;
535 		} else {
536 			if (__copy_to_user(&tm_frame->mc_vregs,
537 					   current->thread.vr,
538 					   ELF_NVRREG * sizeof(vector128)))
539 				return 1;
540 		}
541 
542 		/* set MSR_VEC in the saved MSR value to indicate that
543 		 * frame->mc_vregs contains valid data
544 		 */
545 		msr |= MSR_VEC;
546 	}
547 
548 	/* We always copy to/from vrsave, it's 0 if we don't have or don't
549 	 * use altivec. Since VSCR only contains 32 bits saved in the least
550 	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
551 	 * most significant bits of that same vector. --BenH
552 	 */
553 	if (__put_user(current->thread.vrsave,
554 		       (u32 __user *)&frame->mc_vregs[32]))
555 		return 1;
556 	if (msr & MSR_VEC) {
557 		if (__put_user(current->thread.transact_vrsave,
558 			       (u32 __user *)&tm_frame->mc_vregs[32]))
559 			return 1;
560 	} else {
561 		if (__put_user(current->thread.vrsave,
562 			       (u32 __user *)&tm_frame->mc_vregs[32]))
563 			return 1;
564 	}
565 #endif /* CONFIG_ALTIVEC */
566 
567 	if (copy_fpr_to_user(&frame->mc_fregs, current))
568 		return 1;
569 	if (msr & MSR_FP) {
570 		if (copy_transact_fpr_to_user(&tm_frame->mc_fregs, current))
571 			return 1;
572 	} else {
573 		if (copy_fpr_to_user(&tm_frame->mc_fregs, current))
574 			return 1;
575 	}
576 
577 #ifdef CONFIG_VSX
578 	/*
579 	 * Copy VSR 0-31 upper half from thread_struct to local
580 	 * buffer, then write that to userspace.  Also set MSR_VSX in
581 	 * the saved MSR value to indicate that frame->mc_vregs
582 	 * contains valid data
583 	 */
584 	if (current->thread.used_vsr) {
585 		__giveup_vsx(current);
586 		if (copy_vsx_to_user(&frame->mc_vsregs, current))
587 			return 1;
588 		if (msr & MSR_VSX) {
589 			if (copy_transact_vsx_to_user(&tm_frame->mc_vsregs,
590 						      current))
591 				return 1;
592 		} else {
593 			if (copy_vsx_to_user(&tm_frame->mc_vsregs, current))
594 				return 1;
595 		}
596 
597 		msr |= MSR_VSX;
598 	}
599 #endif /* CONFIG_VSX */
600 #ifdef CONFIG_SPE
601 	/* SPE regs are not checkpointed with TM, so this section is
602 	 * simply the same as in save_user_regs().
603 	 */
604 	if (current->thread.used_spe) {
605 		flush_spe_to_thread(current);
606 		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
607 				   ELF_NEVRREG * sizeof(u32)))
608 			return 1;
609 		/* set MSR_SPE in the saved MSR value to indicate that
610 		 * frame->mc_vregs contains valid data */
611 		msr |= MSR_SPE;
612 	}
613 
614 	/* We always copy to/from spefscr */
615 	if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
616 		return 1;
617 #endif /* CONFIG_SPE */
618 
619 	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
620 		return 1;
621 	if (sigret) {
622 		/* Set up the sigreturn trampoline: li r0,sigret; sc */
623 		if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
624 		    || __put_user(0x44000002UL, &frame->tramp[1]))
625 			return 1;
626 		flush_icache_range((unsigned long) &frame->tramp[0],
627 				   (unsigned long) &frame->tramp[2]);
628 	}
629 
630 	return 0;
631 }
632 #endif
633 
634 /*
635  * Restore the current user register values from the user stack,
636  * (except for MSR).
637  */
restore_user_regs(struct pt_regs * regs,struct mcontext __user * sr,int sig)638 static long restore_user_regs(struct pt_regs *regs,
639 			      struct mcontext __user *sr, int sig)
640 {
641 	long err;
642 	unsigned int save_r2 = 0;
643 	unsigned long msr;
644 #ifdef CONFIG_VSX
645 	int i;
646 #endif
647 
648 	/*
649 	 * restore general registers but not including MSR or SOFTE. Also
650 	 * take care of keeping r2 (TLS) intact if not a signal
651 	 */
652 	if (!sig)
653 		save_r2 = (unsigned int)regs->gpr[2];
654 	err = restore_general_regs(regs, sr);
655 	regs->trap = 0;
656 	err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
657 	if (!sig)
658 		regs->gpr[2] = (unsigned long) save_r2;
659 	if (err)
660 		return 1;
661 
662 	/* if doing signal return, restore the previous little-endian mode */
663 	if (sig)
664 		regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
665 
666 	/*
667 	 * Do this before updating the thread state in
668 	 * current->thread.fpr/vr/evr.  That way, if we get preempted
669 	 * and another task grabs the FPU/Altivec/SPE, it won't be
670 	 * tempted to save the current CPU state into the thread_struct
671 	 * and corrupt what we are writing there.
672 	 */
673 	discard_lazy_cpu_state();
674 
675 #ifdef CONFIG_ALTIVEC
676 	/*
677 	 * Force the process to reload the altivec registers from
678 	 * current->thread when it next does altivec instructions
679 	 */
680 	regs->msr &= ~MSR_VEC;
681 	if (msr & MSR_VEC) {
682 		/* restore altivec registers from the stack */
683 		if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
684 				     sizeof(sr->mc_vregs)))
685 			return 1;
686 	} else if (current->thread.used_vr)
687 		memset(current->thread.vr, 0, ELF_NVRREG * sizeof(vector128));
688 
689 	/* Always get VRSAVE back */
690 	if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
691 		return 1;
692 #endif /* CONFIG_ALTIVEC */
693 	if (copy_fpr_from_user(current, &sr->mc_fregs))
694 		return 1;
695 
696 #ifdef CONFIG_VSX
697 	/*
698 	 * Force the process to reload the VSX registers from
699 	 * current->thread when it next does VSX instruction.
700 	 */
701 	regs->msr &= ~MSR_VSX;
702 	if (msr & MSR_VSX) {
703 		/*
704 		 * Restore altivec registers from the stack to a local
705 		 * buffer, then write this out to the thread_struct
706 		 */
707 		if (copy_vsx_from_user(current, &sr->mc_vsregs))
708 			return 1;
709 	} else if (current->thread.used_vsr)
710 		for (i = 0; i < 32 ; i++)
711 			current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
712 #endif /* CONFIG_VSX */
713 	/*
714 	 * force the process to reload the FP registers from
715 	 * current->thread when it next does FP instructions
716 	 */
717 	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
718 
719 #ifdef CONFIG_SPE
720 	/* force the process to reload the spe registers from
721 	   current->thread when it next does spe instructions */
722 	regs->msr &= ~MSR_SPE;
723 	if (msr & MSR_SPE) {
724 		/* restore spe registers from the stack */
725 		if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
726 				     ELF_NEVRREG * sizeof(u32)))
727 			return 1;
728 	} else if (current->thread.used_spe)
729 		memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
730 
731 	/* Always get SPEFSCR back */
732 	if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG))
733 		return 1;
734 #endif /* CONFIG_SPE */
735 
736 	return 0;
737 }
738 
739 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
740 /*
741  * Restore the current user register values from the user stack, except for
742  * MSR, and recheckpoint the original checkpointed register state for processes
743  * in transactions.
744  */
restore_tm_user_regs(struct pt_regs * regs,struct mcontext __user * sr,struct mcontext __user * tm_sr)745 static long restore_tm_user_regs(struct pt_regs *regs,
746 				 struct mcontext __user *sr,
747 				 struct mcontext __user *tm_sr)
748 {
749 	long err;
750 	unsigned long msr;
751 #ifdef CONFIG_VSX
752 	int i;
753 #endif
754 
755 	/*
756 	 * restore general registers but not including MSR or SOFTE. Also
757 	 * take care of keeping r2 (TLS) intact if not a signal.
758 	 * See comment in signal_64.c:restore_tm_sigcontexts();
759 	 * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR
760 	 * were set by the signal delivery.
761 	 */
762 	err = restore_general_regs(regs, tm_sr);
763 	err |= restore_general_regs(&current->thread.ckpt_regs, sr);
764 
765 	err |= __get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP]);
766 
767 	err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
768 	if (err)
769 		return 1;
770 
771 	/* Restore the previous little-endian mode */
772 	regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
773 
774 	/*
775 	 * Do this before updating the thread state in
776 	 * current->thread.fpr/vr/evr.  That way, if we get preempted
777 	 * and another task grabs the FPU/Altivec/SPE, it won't be
778 	 * tempted to save the current CPU state into the thread_struct
779 	 * and corrupt what we are writing there.
780 	 */
781 	discard_lazy_cpu_state();
782 
783 #ifdef CONFIG_ALTIVEC
784 	regs->msr &= ~MSR_VEC;
785 	if (msr & MSR_VEC) {
786 		/* restore altivec registers from the stack */
787 		if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
788 				     sizeof(sr->mc_vregs)) ||
789 		    __copy_from_user(current->thread.transact_vr,
790 				     &tm_sr->mc_vregs,
791 				     sizeof(sr->mc_vregs)))
792 			return 1;
793 	} else if (current->thread.used_vr) {
794 		memset(current->thread.vr, 0, ELF_NVRREG * sizeof(vector128));
795 		memset(current->thread.transact_vr, 0,
796 		       ELF_NVRREG * sizeof(vector128));
797 	}
798 
799 	/* Always get VRSAVE back */
800 	if (__get_user(current->thread.vrsave,
801 		       (u32 __user *)&sr->mc_vregs[32]) ||
802 	    __get_user(current->thread.transact_vrsave,
803 		       (u32 __user *)&tm_sr->mc_vregs[32]))
804 		return 1;
805 #endif /* CONFIG_ALTIVEC */
806 
807 	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
808 
809 	if (copy_fpr_from_user(current, &sr->mc_fregs) ||
810 	    copy_transact_fpr_from_user(current, &tm_sr->mc_fregs))
811 		return 1;
812 
813 #ifdef CONFIG_VSX
814 	regs->msr &= ~MSR_VSX;
815 	if (msr & MSR_VSX) {
816 		/*
817 		 * Restore altivec registers from the stack to a local
818 		 * buffer, then write this out to the thread_struct
819 		 */
820 		if (copy_vsx_from_user(current, &sr->mc_vsregs) ||
821 		    copy_transact_vsx_from_user(current, &tm_sr->mc_vsregs))
822 			return 1;
823 	} else if (current->thread.used_vsr)
824 		for (i = 0; i < 32 ; i++) {
825 			current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
826 			current->thread.transact_fpr[i][TS_VSRLOWOFFSET] = 0;
827 		}
828 #endif /* CONFIG_VSX */
829 
830 #ifdef CONFIG_SPE
831 	/* SPE regs are not checkpointed with TM, so this section is
832 	 * simply the same as in restore_user_regs().
833 	 */
834 	regs->msr &= ~MSR_SPE;
835 	if (msr & MSR_SPE) {
836 		if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
837 				     ELF_NEVRREG * sizeof(u32)))
838 			return 1;
839 	} else if (current->thread.used_spe)
840 		memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
841 
842 	/* Always get SPEFSCR back */
843 	if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs
844 		       + ELF_NEVRREG))
845 		return 1;
846 #endif /* CONFIG_SPE */
847 
848 	/* Now, recheckpoint.  This loads up all of the checkpointed (older)
849 	 * registers, including FP and V[S]Rs.  After recheckpointing, the
850 	 * transactional versions should be loaded.
851 	 */
852 	tm_enable();
853 	/* This loads the checkpointed FP/VEC state, if used */
854 	tm_recheckpoint(&current->thread, msr);
855 	/* The task has moved into TM state S, so ensure MSR reflects this */
856 	regs->msr = (regs->msr & ~MSR_TS_MASK) | MSR_TS_S;
857 
858 	/* This loads the speculative FP/VEC state, if used */
859 	if (msr & MSR_FP) {
860 		do_load_up_transact_fpu(&current->thread);
861 		regs->msr |= (MSR_FP | current->thread.fpexc_mode);
862 	}
863 #ifdef CONFIG_ALTIVEC
864 	if (msr & MSR_VEC) {
865 		do_load_up_transact_altivec(&current->thread);
866 		regs->msr |= MSR_VEC;
867 	}
868 #endif
869 
870 	return 0;
871 }
872 #endif
873 
874 #ifdef CONFIG_PPC64
copy_siginfo_to_user32(struct compat_siginfo __user * d,siginfo_t * s)875 int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s)
876 {
877 	int err;
878 
879 	if (!access_ok (VERIFY_WRITE, d, sizeof(*d)))
880 		return -EFAULT;
881 
882 	/* If you change siginfo_t structure, please be sure
883 	 * this code is fixed accordingly.
884 	 * It should never copy any pad contained in the structure
885 	 * to avoid security leaks, but must copy the generic
886 	 * 3 ints plus the relevant union member.
887 	 * This routine must convert siginfo from 64bit to 32bit as well
888 	 * at the same time.
889 	 */
890 	err = __put_user(s->si_signo, &d->si_signo);
891 	err |= __put_user(s->si_errno, &d->si_errno);
892 	err |= __put_user((short)s->si_code, &d->si_code);
893 	if (s->si_code < 0)
894 		err |= __copy_to_user(&d->_sifields._pad, &s->_sifields._pad,
895 				      SI_PAD_SIZE32);
896 	else switch(s->si_code >> 16) {
897 	case __SI_CHLD >> 16:
898 		err |= __put_user(s->si_pid, &d->si_pid);
899 		err |= __put_user(s->si_uid, &d->si_uid);
900 		err |= __put_user(s->si_utime, &d->si_utime);
901 		err |= __put_user(s->si_stime, &d->si_stime);
902 		err |= __put_user(s->si_status, &d->si_status);
903 		break;
904 	case __SI_FAULT >> 16:
905 		err |= __put_user((unsigned int)(unsigned long)s->si_addr,
906 				  &d->si_addr);
907 		break;
908 	case __SI_POLL >> 16:
909 		err |= __put_user(s->si_band, &d->si_band);
910 		err |= __put_user(s->si_fd, &d->si_fd);
911 		break;
912 	case __SI_TIMER >> 16:
913 		err |= __put_user(s->si_tid, &d->si_tid);
914 		err |= __put_user(s->si_overrun, &d->si_overrun);
915 		err |= __put_user(s->si_int, &d->si_int);
916 		break;
917 	case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
918 	case __SI_MESGQ >> 16:
919 		err |= __put_user(s->si_int, &d->si_int);
920 		/* fallthrough */
921 	case __SI_KILL >> 16:
922 	default:
923 		err |= __put_user(s->si_pid, &d->si_pid);
924 		err |= __put_user(s->si_uid, &d->si_uid);
925 		break;
926 	}
927 	return err;
928 }
929 
930 #define copy_siginfo_to_user	copy_siginfo_to_user32
931 
copy_siginfo_from_user32(siginfo_t * to,struct compat_siginfo __user * from)932 int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
933 {
934 	memset(to, 0, sizeof *to);
935 
936 	if (copy_from_user(to, from, 3*sizeof(int)) ||
937 	    copy_from_user(to->_sifields._pad,
938 			   from->_sifields._pad, SI_PAD_SIZE32))
939 		return -EFAULT;
940 
941 	return 0;
942 }
943 #endif /* CONFIG_PPC64 */
944 
945 /*
946  * Set up a signal frame for a "real-time" signal handler
947  * (one which gets siginfo).
948  */
handle_rt_signal32(unsigned long sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * oldset,struct pt_regs * regs)949 int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
950 		siginfo_t *info, sigset_t *oldset,
951 		struct pt_regs *regs)
952 {
953 	struct rt_sigframe __user *rt_sf;
954 	struct mcontext __user *frame;
955 	void __user *addr;
956 	unsigned long newsp = 0;
957 	int sigret;
958 	unsigned long tramp;
959 
960 	/* Set up Signal Frame */
961 	/* Put a Real Time Context onto stack */
962 	rt_sf = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*rt_sf), 1);
963 	addr = rt_sf;
964 	if (unlikely(rt_sf == NULL))
965 		goto badframe;
966 
967 	/* Put the siginfo & fill in most of the ucontext */
968 	if (copy_siginfo_to_user(&rt_sf->info, info)
969 	    || __put_user(0, &rt_sf->uc.uc_flags)
970 	    || __save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1])
971 	    || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext),
972 		    &rt_sf->uc.uc_regs)
973 	    || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
974 		goto badframe;
975 
976 	/* Save user registers on the stack */
977 	frame = &rt_sf->uc.uc_mcontext;
978 	addr = frame;
979 	if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
980 		sigret = 0;
981 		tramp = current->mm->context.vdso_base + vdso32_rt_sigtramp;
982 	} else {
983 		sigret = __NR_rt_sigreturn;
984 		tramp = (unsigned long) frame->tramp;
985 	}
986 
987 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
988 	if (MSR_TM_ACTIVE(regs->msr)) {
989 		if (save_tm_user_regs(regs, &rt_sf->uc.uc_mcontext,
990 				      &rt_sf->uc_transact.uc_mcontext, sigret))
991 			goto badframe;
992 	}
993 	else
994 #endif
995 		if (save_user_regs(regs, frame, sigret, 1))
996 			goto badframe;
997 	regs->link = tramp;
998 
999 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1000 	if (MSR_TM_ACTIVE(regs->msr)) {
1001 		if (__put_user((unsigned long)&rt_sf->uc_transact,
1002 			       &rt_sf->uc.uc_link)
1003 		    || __put_user(to_user_ptr(&rt_sf->uc_transact.uc_mcontext),
1004 				  &rt_sf->uc_transact.uc_regs))
1005 			goto badframe;
1006 	}
1007 	else
1008 #endif
1009 		if (__put_user(0, &rt_sf->uc.uc_link))
1010 			goto badframe;
1011 
1012 	current->thread.fpscr.val = 0;	/* turn off all fp exceptions */
1013 
1014 	/* create a stack frame for the caller of the handler */
1015 	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
1016 	addr = (void __user *)regs->gpr[1];
1017 	if (put_user(regs->gpr[1], (u32 __user *)newsp))
1018 		goto badframe;
1019 
1020 	/* Fill registers for signal handler */
1021 	regs->gpr[1] = newsp;
1022 	regs->gpr[3] = sig;
1023 	regs->gpr[4] = (unsigned long) &rt_sf->info;
1024 	regs->gpr[5] = (unsigned long) &rt_sf->uc;
1025 	regs->gpr[6] = (unsigned long) rt_sf;
1026 	regs->nip = (unsigned long) ka->sa.sa_handler;
1027 	/* enter the signal handler in big-endian mode */
1028 	regs->msr &= ~MSR_LE;
1029 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1030 	/* Remove TM bits from thread's MSR.  The MSR in the sigcontext
1031 	 * just indicates to userland that we were doing a transaction, but we
1032 	 * don't want to return in transactional state:
1033 	 */
1034 	regs->msr &= ~MSR_TS_MASK;
1035 #endif
1036 	return 1;
1037 
1038 badframe:
1039 #ifdef DEBUG_SIG
1040 	printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n",
1041 	       regs, frame, newsp);
1042 #endif
1043 	if (show_unhandled_signals)
1044 		printk_ratelimited(KERN_INFO
1045 				   "%s[%d]: bad frame in handle_rt_signal32: "
1046 				   "%p nip %08lx lr %08lx\n",
1047 				   current->comm, current->pid,
1048 				   addr, regs->nip, regs->link);
1049 
1050 	force_sigsegv(sig, current);
1051 	return 0;
1052 }
1053 
do_setcontext(struct ucontext __user * ucp,struct pt_regs * regs,int sig)1054 static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
1055 {
1056 	sigset_t set;
1057 	struct mcontext __user *mcp;
1058 
1059 	if (get_sigset_t(&set, &ucp->uc_sigmask))
1060 		return -EFAULT;
1061 #ifdef CONFIG_PPC64
1062 	{
1063 		u32 cmcp;
1064 
1065 		if (__get_user(cmcp, &ucp->uc_regs))
1066 			return -EFAULT;
1067 		mcp = (struct mcontext __user *)(u64)cmcp;
1068 		/* no need to check access_ok(mcp), since mcp < 4GB */
1069 	}
1070 #else
1071 	if (__get_user(mcp, &ucp->uc_regs))
1072 		return -EFAULT;
1073 	if (!access_ok(VERIFY_READ, mcp, sizeof(*mcp)))
1074 		return -EFAULT;
1075 #endif
1076 	set_current_blocked(&set);
1077 	if (restore_user_regs(regs, mcp, sig))
1078 		return -EFAULT;
1079 
1080 	return 0;
1081 }
1082 
1083 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
do_setcontext_tm(struct ucontext __user * ucp,struct ucontext __user * tm_ucp,struct pt_regs * regs)1084 static int do_setcontext_tm(struct ucontext __user *ucp,
1085 			    struct ucontext __user *tm_ucp,
1086 			    struct pt_regs *regs)
1087 {
1088 	sigset_t set;
1089 	struct mcontext __user *mcp;
1090 	struct mcontext __user *tm_mcp;
1091 	u32 cmcp;
1092 	u32 tm_cmcp;
1093 
1094 	if (get_sigset_t(&set, &ucp->uc_sigmask))
1095 		return -EFAULT;
1096 
1097 	if (__get_user(cmcp, &ucp->uc_regs) ||
1098 	    __get_user(tm_cmcp, &tm_ucp->uc_regs))
1099 		return -EFAULT;
1100 	mcp = (struct mcontext __user *)(u64)cmcp;
1101 	tm_mcp = (struct mcontext __user *)(u64)tm_cmcp;
1102 	/* no need to check access_ok(mcp), since mcp < 4GB */
1103 
1104 	set_current_blocked(&set);
1105 	if (restore_tm_user_regs(regs, mcp, tm_mcp))
1106 		return -EFAULT;
1107 
1108 	return 0;
1109 }
1110 #endif
1111 
sys_swapcontext(struct ucontext __user * old_ctx,struct ucontext __user * new_ctx,int ctx_size,int r6,int r7,int r8,struct pt_regs * regs)1112 long sys_swapcontext(struct ucontext __user *old_ctx,
1113 		     struct ucontext __user *new_ctx,
1114 		     int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
1115 {
1116 	unsigned char tmp;
1117 	int ctx_has_vsx_region = 0;
1118 
1119 #ifdef CONFIG_PPC64
1120 	unsigned long new_msr = 0;
1121 
1122 	if (new_ctx) {
1123 		struct mcontext __user *mcp;
1124 		u32 cmcp;
1125 
1126 		/*
1127 		 * Get pointer to the real mcontext.  No need for
1128 		 * access_ok since we are dealing with compat
1129 		 * pointers.
1130 		 */
1131 		if (__get_user(cmcp, &new_ctx->uc_regs))
1132 			return -EFAULT;
1133 		mcp = (struct mcontext __user *)(u64)cmcp;
1134 		if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
1135 			return -EFAULT;
1136 	}
1137 	/*
1138 	 * Check that the context is not smaller than the original
1139 	 * size (with VMX but without VSX)
1140 	 */
1141 	if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
1142 		return -EINVAL;
1143 	/*
1144 	 * If the new context state sets the MSR VSX bits but
1145 	 * it doesn't provide VSX state.
1146 	 */
1147 	if ((ctx_size < sizeof(struct ucontext)) &&
1148 	    (new_msr & MSR_VSX))
1149 		return -EINVAL;
1150 	/* Does the context have enough room to store VSX data? */
1151 	if (ctx_size >= sizeof(struct ucontext))
1152 		ctx_has_vsx_region = 1;
1153 #else
1154 	/* Context size is for future use. Right now, we only make sure
1155 	 * we are passed something we understand
1156 	 */
1157 	if (ctx_size < sizeof(struct ucontext))
1158 		return -EINVAL;
1159 #endif
1160 	if (old_ctx != NULL) {
1161 		struct mcontext __user *mctx;
1162 
1163 		/*
1164 		 * old_ctx might not be 16-byte aligned, in which
1165 		 * case old_ctx->uc_mcontext won't be either.
1166 		 * Because we have the old_ctx->uc_pad2 field
1167 		 * before old_ctx->uc_mcontext, we need to round down
1168 		 * from &old_ctx->uc_mcontext to a 16-byte boundary.
1169 		 */
1170 		mctx = (struct mcontext __user *)
1171 			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
1172 		if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
1173 		    || save_user_regs(regs, mctx, 0, ctx_has_vsx_region)
1174 		    || put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
1175 		    || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
1176 			return -EFAULT;
1177 	}
1178 	if (new_ctx == NULL)
1179 		return 0;
1180 	if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
1181 	    || __get_user(tmp, (u8 __user *) new_ctx)
1182 	    || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
1183 		return -EFAULT;
1184 
1185 	/*
1186 	 * If we get a fault copying the context into the kernel's
1187 	 * image of the user's registers, we can't just return -EFAULT
1188 	 * because the user's registers will be corrupted.  For instance
1189 	 * the NIP value may have been updated but not some of the
1190 	 * other registers.  Given that we have done the access_ok
1191 	 * and successfully read the first and last bytes of the region
1192 	 * above, this should only happen in an out-of-memory situation
1193 	 * or if another thread unmaps the region containing the context.
1194 	 * We kill the task with a SIGSEGV in this situation.
1195 	 */
1196 	if (do_setcontext(new_ctx, regs, 0))
1197 		do_exit(SIGSEGV);
1198 
1199 	set_thread_flag(TIF_RESTOREALL);
1200 	return 0;
1201 }
1202 
sys_rt_sigreturn(int r3,int r4,int r5,int r6,int r7,int r8,struct pt_regs * regs)1203 long sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
1204 		     struct pt_regs *regs)
1205 {
1206 	struct rt_sigframe __user *rt_sf;
1207 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1208 	struct ucontext __user *uc_transact;
1209 	unsigned long msr_hi;
1210 	unsigned long tmp;
1211 	int tm_restore = 0;
1212 #endif
1213 	/* Always make any pending restarted system calls return -EINTR */
1214 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
1215 
1216 	rt_sf = (struct rt_sigframe __user *)
1217 		(regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
1218 	if (!access_ok(VERIFY_READ, rt_sf, sizeof(*rt_sf)))
1219 		goto bad;
1220 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1221 	if (__get_user(tmp, &rt_sf->uc.uc_link))
1222 		goto bad;
1223 	uc_transact = (struct ucontext __user *)(uintptr_t)tmp;
1224 	if (uc_transact) {
1225 		u32 cmcp;
1226 		struct mcontext __user *mcp;
1227 
1228 		if (__get_user(cmcp, &uc_transact->uc_regs))
1229 			return -EFAULT;
1230 		mcp = (struct mcontext __user *)(u64)cmcp;
1231 		/* The top 32 bits of the MSR are stashed in the transactional
1232 		 * ucontext. */
1233 		if (__get_user(msr_hi, &mcp->mc_gregs[PT_MSR]))
1234 			goto bad;
1235 
1236 		if (MSR_TM_SUSPENDED(msr_hi<<32)) {
1237 			/* We only recheckpoint on return if we're
1238 			 * transaction.
1239 			 */
1240 			tm_restore = 1;
1241 			if (do_setcontext_tm(&rt_sf->uc, uc_transact, regs))
1242 				goto bad;
1243 		}
1244 	}
1245 	if (!tm_restore)
1246 		/* Fall through, for non-TM restore */
1247 #endif
1248 	if (do_setcontext(&rt_sf->uc, regs, 1))
1249 		goto bad;
1250 
1251 	/*
1252 	 * It's not clear whether or why it is desirable to save the
1253 	 * sigaltstack setting on signal delivery and restore it on
1254 	 * signal return.  But other architectures do this and we have
1255 	 * always done it up until now so it is probably better not to
1256 	 * change it.  -- paulus
1257 	 */
1258 #ifdef CONFIG_PPC64
1259 	if (compat_restore_altstack(&rt_sf->uc.uc_stack))
1260 		goto bad;
1261 #else
1262 	if (restore_altstack(&rt_sf->uc.uc_stack))
1263 		goto bad;
1264 #endif
1265 	set_thread_flag(TIF_RESTOREALL);
1266 	return 0;
1267 
1268  bad:
1269 	if (show_unhandled_signals)
1270 		printk_ratelimited(KERN_INFO
1271 				   "%s[%d]: bad frame in sys_rt_sigreturn: "
1272 				   "%p nip %08lx lr %08lx\n",
1273 				   current->comm, current->pid,
1274 				   rt_sf, regs->nip, regs->link);
1275 
1276 	force_sig(SIGSEGV, current);
1277 	return 0;
1278 }
1279 
1280 #ifdef CONFIG_PPC32
sys_debug_setcontext(struct ucontext __user * ctx,int ndbg,struct sig_dbg_op __user * dbg,int r6,int r7,int r8,struct pt_regs * regs)1281 int sys_debug_setcontext(struct ucontext __user *ctx,
1282 			 int ndbg, struct sig_dbg_op __user *dbg,
1283 			 int r6, int r7, int r8,
1284 			 struct pt_regs *regs)
1285 {
1286 	struct sig_dbg_op op;
1287 	int i;
1288 	unsigned char tmp;
1289 	unsigned long new_msr = regs->msr;
1290 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1291 	unsigned long new_dbcr0 = current->thread.dbcr0;
1292 #endif
1293 
1294 	for (i=0; i<ndbg; i++) {
1295 		if (copy_from_user(&op, dbg + i, sizeof(op)))
1296 			return -EFAULT;
1297 		switch (op.dbg_type) {
1298 		case SIG_DBG_SINGLE_STEPPING:
1299 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1300 			if (op.dbg_value) {
1301 				new_msr |= MSR_DE;
1302 				new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
1303 			} else {
1304 				new_dbcr0 &= ~DBCR0_IC;
1305 				if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
1306 						current->thread.dbcr1)) {
1307 					new_msr &= ~MSR_DE;
1308 					new_dbcr0 &= ~DBCR0_IDM;
1309 				}
1310 			}
1311 #else
1312 			if (op.dbg_value)
1313 				new_msr |= MSR_SE;
1314 			else
1315 				new_msr &= ~MSR_SE;
1316 #endif
1317 			break;
1318 		case SIG_DBG_BRANCH_TRACING:
1319 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1320 			return -EINVAL;
1321 #else
1322 			if (op.dbg_value)
1323 				new_msr |= MSR_BE;
1324 			else
1325 				new_msr &= ~MSR_BE;
1326 #endif
1327 			break;
1328 
1329 		default:
1330 			return -EINVAL;
1331 		}
1332 	}
1333 
1334 	/* We wait until here to actually install the values in the
1335 	   registers so if we fail in the above loop, it will not
1336 	   affect the contents of these registers.  After this point,
1337 	   failure is a problem, anyway, and it's very unlikely unless
1338 	   the user is really doing something wrong. */
1339 	regs->msr = new_msr;
1340 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1341 	current->thread.dbcr0 = new_dbcr0;
1342 #endif
1343 
1344 	if (!access_ok(VERIFY_READ, ctx, sizeof(*ctx))
1345 	    || __get_user(tmp, (u8 __user *) ctx)
1346 	    || __get_user(tmp, (u8 __user *) (ctx + 1) - 1))
1347 		return -EFAULT;
1348 
1349 	/*
1350 	 * If we get a fault copying the context into the kernel's
1351 	 * image of the user's registers, we can't just return -EFAULT
1352 	 * because the user's registers will be corrupted.  For instance
1353 	 * the NIP value may have been updated but not some of the
1354 	 * other registers.  Given that we have done the access_ok
1355 	 * and successfully read the first and last bytes of the region
1356 	 * above, this should only happen in an out-of-memory situation
1357 	 * or if another thread unmaps the region containing the context.
1358 	 * We kill the task with a SIGSEGV in this situation.
1359 	 */
1360 	if (do_setcontext(ctx, regs, 1)) {
1361 		if (show_unhandled_signals)
1362 			printk_ratelimited(KERN_INFO "%s[%d]: bad frame in "
1363 					   "sys_debug_setcontext: %p nip %08lx "
1364 					   "lr %08lx\n",
1365 					   current->comm, current->pid,
1366 					   ctx, regs->nip, regs->link);
1367 
1368 		force_sig(SIGSEGV, current);
1369 		goto out;
1370 	}
1371 
1372 	/*
1373 	 * It's not clear whether or why it is desirable to save the
1374 	 * sigaltstack setting on signal delivery and restore it on
1375 	 * signal return.  But other architectures do this and we have
1376 	 * always done it up until now so it is probably better not to
1377 	 * change it.  -- paulus
1378 	 */
1379 	restore_altstack(&ctx->uc_stack);
1380 
1381 	set_thread_flag(TIF_RESTOREALL);
1382  out:
1383 	return 0;
1384 }
1385 #endif
1386 
1387 /*
1388  * OK, we're invoking a handler
1389  */
handle_signal32(unsigned long sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * oldset,struct pt_regs * regs)1390 int handle_signal32(unsigned long sig, struct k_sigaction *ka,
1391 		    siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
1392 {
1393 	struct sigcontext __user *sc;
1394 	struct sigframe __user *frame;
1395 	unsigned long newsp = 0;
1396 	int sigret;
1397 	unsigned long tramp;
1398 
1399 	/* Set up Signal Frame */
1400 	frame = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*frame), 1);
1401 	if (unlikely(frame == NULL))
1402 		goto badframe;
1403 	sc = (struct sigcontext __user *) &frame->sctx;
1404 
1405 #if _NSIG != 64
1406 #error "Please adjust handle_signal()"
1407 #endif
1408 	if (__put_user(to_user_ptr(ka->sa.sa_handler), &sc->handler)
1409 	    || __put_user(oldset->sig[0], &sc->oldmask)
1410 #ifdef CONFIG_PPC64
1411 	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
1412 #else
1413 	    || __put_user(oldset->sig[1], &sc->_unused[3])
1414 #endif
1415 	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
1416 	    || __put_user(sig, &sc->signal))
1417 		goto badframe;
1418 
1419 	if (vdso32_sigtramp && current->mm->context.vdso_base) {
1420 		sigret = 0;
1421 		tramp = current->mm->context.vdso_base + vdso32_sigtramp;
1422 	} else {
1423 		sigret = __NR_sigreturn;
1424 		tramp = (unsigned long) frame->mctx.tramp;
1425 	}
1426 
1427 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1428 	if (MSR_TM_ACTIVE(regs->msr)) {
1429 		if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
1430 				      sigret))
1431 			goto badframe;
1432 	}
1433 	else
1434 #endif
1435 		if (save_user_regs(regs, &frame->mctx, sigret, 1))
1436 			goto badframe;
1437 
1438 	regs->link = tramp;
1439 
1440 	current->thread.fpscr.val = 0;	/* turn off all fp exceptions */
1441 
1442 	/* create a stack frame for the caller of the handler */
1443 	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
1444 	if (put_user(regs->gpr[1], (u32 __user *)newsp))
1445 		goto badframe;
1446 
1447 	regs->gpr[1] = newsp;
1448 	regs->gpr[3] = sig;
1449 	regs->gpr[4] = (unsigned long) sc;
1450 	regs->nip = (unsigned long) ka->sa.sa_handler;
1451 	/* enter the signal handler in big-endian mode */
1452 	regs->msr &= ~MSR_LE;
1453 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1454 	/* Remove TM bits from thread's MSR.  The MSR in the sigcontext
1455 	 * just indicates to userland that we were doing a transaction, but we
1456 	 * don't want to return in transactional state:
1457 	 */
1458 	regs->msr &= ~MSR_TS_MASK;
1459 #endif
1460 	return 1;
1461 
1462 badframe:
1463 #ifdef DEBUG_SIG
1464 	printk("badframe in handle_signal, regs=%p frame=%p newsp=%lx\n",
1465 	       regs, frame, newsp);
1466 #endif
1467 	if (show_unhandled_signals)
1468 		printk_ratelimited(KERN_INFO
1469 				   "%s[%d]: bad frame in handle_signal32: "
1470 				   "%p nip %08lx lr %08lx\n",
1471 				   current->comm, current->pid,
1472 				   frame, regs->nip, regs->link);
1473 
1474 	force_sigsegv(sig, current);
1475 	return 0;
1476 }
1477 
1478 /*
1479  * Do a signal return; undo the signal stack.
1480  */
sys_sigreturn(int r3,int r4,int r5,int r6,int r7,int r8,struct pt_regs * regs)1481 long sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
1482 		       struct pt_regs *regs)
1483 {
1484 	struct sigcontext __user *sc;
1485 	struct sigcontext sigctx;
1486 	struct mcontext __user *sr;
1487 	void __user *addr;
1488 	sigset_t set;
1489 
1490 	/* Always make any pending restarted system calls return -EINTR */
1491 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
1492 
1493 	sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
1494 	addr = sc;
1495 	if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
1496 		goto badframe;
1497 
1498 #ifdef CONFIG_PPC64
1499 	/*
1500 	 * Note that PPC32 puts the upper 32 bits of the sigmask in the
1501 	 * unused part of the signal stackframe
1502 	 */
1503 	set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32);
1504 #else
1505 	set.sig[0] = sigctx.oldmask;
1506 	set.sig[1] = sigctx._unused[3];
1507 #endif
1508 	set_current_blocked(&set);
1509 
1510 	sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
1511 	addr = sr;
1512 	if (!access_ok(VERIFY_READ, sr, sizeof(*sr))
1513 	    || restore_user_regs(regs, sr, 1))
1514 		goto badframe;
1515 
1516 	set_thread_flag(TIF_RESTOREALL);
1517 	return 0;
1518 
1519 badframe:
1520 	if (show_unhandled_signals)
1521 		printk_ratelimited(KERN_INFO
1522 				   "%s[%d]: bad frame in sys_sigreturn: "
1523 				   "%p nip %08lx lr %08lx\n",
1524 				   current->comm, current->pid,
1525 				   addr, regs->nip, regs->link);
1526 
1527 	force_sig(SIGSEGV, current);
1528 	return 0;
1529 }
1530