1/*
  2 *  PowerPC version 
  3 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  4 *
  5 *  Derived from "arch/i386/kernel/signal.c"
  6 *    Copyright (C) 1991, 1992 Linus Torvalds
  7 *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  8 *
  9 *  This program is free software; you can redistribute it and/or
 10 *  modify it under the terms of the GNU General Public License
 11 *  as published by the Free Software Foundation; either version
 12 *  2 of the License, or (at your option) any later version.
 13 */
 14
 15#include <linux/sched.h>
 16#include <linux/mm.h>
 17#include <linux/smp.h>
 18#include <linux/kernel.h>
 19#include <linux/signal.h>
 20#include <linux/errno.h>
 21#include <linux/wait.h>
 22#include <linux/unistd.h>
 23#include <linux/stddef.h>
 24#include <linux/elf.h>
 25#include <linux/ptrace.h>
 26#include <linux/ratelimit.h>
 27
 28#include <asm/sigcontext.h>
 29#include <asm/ucontext.h>
 30#include <linux/uaccess.h>
 31#include <asm/pgtable.h>
 32#include <asm/unistd.h>
 33#include <asm/cacheflush.h>
 34#include <asm/syscalls.h>
 35#include <asm/vdso.h>
 36#include <asm/switch_to.h>
 37#include <asm/tm.h>
 38#include <asm/asm-prototypes.h>
 39
 40#include "signal.h"
 41
 42
 43#define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
 44#define FP_REGS_SIZE	sizeof(elf_fpregset_t)
 45
 46#define TRAMP_TRACEBACK	3
 47#define TRAMP_SIZE	6
 48
 49/*
 50 * When we have signals to deliver, we set up on the user stack,
 51 * going down from the original stack pointer:
 52 *	1) a rt_sigframe struct which contains the ucontext	
 53 *	2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
 54 *	   frame for the signal handler.
 55 */
 56
 57struct rt_sigframe {
 58	/* sys_rt_sigreturn requires the ucontext be the first field */
 59	struct ucontext uc;
 60#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 61	struct ucontext uc_transact;
 62#endif
 63	unsigned long _unused[2];
 64	unsigned int tramp[TRAMP_SIZE];
 65	struct siginfo __user *pinfo;
 66	void __user *puc;
 67	struct siginfo info;
 68	/* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
 69	char abigap[USER_REDZONE_SIZE];
 70} __attribute__ ((aligned (16)));
 71
 72static const char fmt32[] = KERN_INFO \
 73	"%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
 74static const char fmt64[] = KERN_INFO \
 75	"%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
 76
 77/*
 78 * This computes a quad word aligned pointer inside the vmx_reserve array
 79 * element. For historical reasons sigcontext might not be quad word aligned,
 80 * but the location we write the VMX regs to must be. See the comment in
 81 * sigcontext for more detail.
 82 */
 83#ifdef CONFIG_ALTIVEC
 84static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
 85{
 86	return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
 87}
 88#endif
 89
 90/*
 91 * Set up the sigcontext for the signal frame.
 92 */
 93
 94static long setup_sigcontext(struct sigcontext __user *sc,
 95		struct task_struct *tsk, int signr, sigset_t *set,
 96		unsigned long handler, int ctx_has_vsx_region)
 97{
 98	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
 99	 * process never used altivec yet (MSR_VEC is zero in pt_regs of
100	 * the context). This is very important because we must ensure we
101	 * don't lose the VRSAVE content that may have been set prior to
102	 * the process doing its first vector operation
103	 * Userland shall check AT_HWCAP to know whether it can rely on the
104	 * v_regs pointer or not
105	 */
106#ifdef CONFIG_ALTIVEC
107	elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
108	unsigned long vrsave;
109#endif
110	struct pt_regs *regs = tsk->thread.regs;
111	unsigned long msr = regs->msr;
112	long err = 0;
113	/* Force usr to alway see softe as 1 (interrupts enabled) */
114	unsigned long softe = 0x1;
115
116	BUG_ON(tsk != current);
117
118#ifdef CONFIG_ALTIVEC
119	err |= __put_user(v_regs, &sc->v_regs);
120
121	/* save altivec registers */
122	if (tsk->thread.used_vr) {
123		flush_altivec_to_thread(tsk);
124		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
125		err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
126				      33 * sizeof(vector128));
127		/* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
128		 * contains valid data.
129		 */
130		msr |= MSR_VEC;
131	}
132	/* We always copy to/from vrsave, it's 0 if we don't have or don't
133	 * use altivec.
134	 */
135	vrsave = 0;
136	if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
137		vrsave = mfspr(SPRN_VRSAVE);
138		tsk->thread.vrsave = vrsave;
139	}
140
141	err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
142#else /* CONFIG_ALTIVEC */
143	err |= __put_user(0, &sc->v_regs);
144#endif /* CONFIG_ALTIVEC */
145	flush_fp_to_thread(tsk);
146	/* copy fpr regs and fpscr */
147	err |= copy_fpr_to_user(&sc->fp_regs, tsk);
148
149	/*
150	 * Clear the MSR VSX bit to indicate there is no valid state attached
151	 * to this context, except in the specific case below where we set it.
152	 */
153	msr &= ~MSR_VSX;
154#ifdef CONFIG_VSX
155	/*
156	 * Copy VSX low doubleword to local buffer for formatting,
157	 * then out to userspace.  Update v_regs to point after the
158	 * VMX data.
159	 */
160	if (tsk->thread.used_vsr && ctx_has_vsx_region) {
161		flush_vsx_to_thread(tsk);
162		v_regs += ELF_NVRREG;
163		err |= copy_vsx_to_user(v_regs, tsk);
164		/* set MSR_VSX in the MSR value in the frame to
165		 * indicate that sc->vs_reg) contains valid data.
166		 */
167		msr |= MSR_VSX;
168	}
169#endif /* CONFIG_VSX */
170	err |= __put_user(&sc->gp_regs, &sc->regs);
171	WARN_ON(!FULL_REGS(regs));
172	err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
173	err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
174	err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]);
175	err |= __put_user(signr, &sc->signal);
176	err |= __put_user(handler, &sc->handler);
177	if (set != NULL)
178		err |=  __put_user(set->sig[0], &sc->oldmask);
179
180	return err;
181}
182
183#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
184/*
185 * As above, but Transactional Memory is in use, so deliver sigcontexts
186 * containing checkpointed and transactional register states.
187 *
188 * To do this, we treclaim (done before entering here) to gather both sets of
189 * registers and set up the 'normal' sigcontext registers with rolled-back
190 * register values such that a simple signal handler sees a correct
191 * checkpointed register state.  If interested, a TM-aware sighandler can
192 * examine the transactional registers in the 2nd sigcontext to determine the
193 * real origin of the signal.
194 */
195static long setup_tm_sigcontexts(struct sigcontext __user *sc,
196				 struct sigcontext __user *tm_sc,
197				 struct task_struct *tsk,
198				 int signr, sigset_t *set, unsigned long handler)
199{
200	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
201	 * process never used altivec yet (MSR_VEC is zero in pt_regs of
202	 * the context). This is very important because we must ensure we
203	 * don't lose the VRSAVE content that may have been set prior to
204	 * the process doing its first vector operation
205	 * Userland shall check AT_HWCAP to know wether it can rely on the
206	 * v_regs pointer or not.
207	 */
208#ifdef CONFIG_ALTIVEC
209	elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
210	elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
211#endif
212	struct pt_regs *regs = tsk->thread.regs;
213	unsigned long msr = tsk->thread.regs->msr;
214	long err = 0;
215
216	BUG_ON(tsk != current);
217
218	BUG_ON(!MSR_TM_ACTIVE(regs->msr));
219
220	WARN_ON(tm_suspend_disabled);
221
222	/* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as
223	 * it contains the correct FP, VEC, VSX state after we treclaimed
224	 * the transaction and giveup_all() was called on reclaiming.
225	 */
226	msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
227
228	/* Remove TM bits from thread's MSR.  The MSR in the sigcontext
229	 * just indicates to userland that we were doing a transaction, but we
230	 * don't want to return in transactional state.  This also ensures
231	 * that flush_fp_to_thread won't set TIF_RESTORE_TM again.
232	 */
233	regs->msr &= ~MSR_TS_MASK;
234
235#ifdef CONFIG_ALTIVEC
236	err |= __put_user(v_regs, &sc->v_regs);
237	err |= __put_user(tm_v_regs, &tm_sc->v_regs);
238
239	/* save altivec registers */
240	if (tsk->thread.used_vr) {
241		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
242		err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
243				      33 * sizeof(vector128));
244		/* If VEC was enabled there are transactional VRs valid too,
245		 * else they're a copy of the checkpointed VRs.
246		 */
247		if (msr & MSR_VEC)
248			err |= __copy_to_user(tm_v_regs,
249					      &tsk->thread.vr_state,
250					      33 * sizeof(vector128));
251		else
252			err |= __copy_to_user(tm_v_regs,
253					      &tsk->thread.ckvr_state,
254					      33 * sizeof(vector128));
255
256		/* set MSR_VEC in the MSR value in the frame to indicate
257		 * that sc->v_reg contains valid data.
258		 */
259		msr |= MSR_VEC;
260	}
261	/* We always copy to/from vrsave, it's 0 if we don't have or don't
262	 * use altivec.
263	 */
264	if (cpu_has_feature(CPU_FTR_ALTIVEC))
265		tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
266	err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
267	if (msr & MSR_VEC)
268		err |= __put_user(tsk->thread.vrsave,
269				  (u32 __user *)&tm_v_regs[33]);
270	else
271		err |= __put_user(tsk->thread.ckvrsave,
272				  (u32 __user *)&tm_v_regs[33]);
273
274#else /* CONFIG_ALTIVEC */
275	err |= __put_user(0, &sc->v_regs);
276	err |= __put_user(0, &tm_sc->v_regs);
277#endif /* CONFIG_ALTIVEC */
278
279	/* copy fpr regs and fpscr */
280	err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
281	if (msr & MSR_FP)
282		err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
283	else
284		err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
285
286#ifdef CONFIG_VSX
287	/*
288	 * Copy VSX low doubleword to local buffer for formatting,
289	 * then out to userspace.  Update v_regs to point after the
290	 * VMX data.
291	 */
292	if (tsk->thread.used_vsr) {
293		v_regs += ELF_NVRREG;
294		tm_v_regs += ELF_NVRREG;
295
296		err |= copy_ckvsx_to_user(v_regs, tsk);
297
298		if (msr & MSR_VSX)
299			err |= copy_vsx_to_user(tm_v_regs, tsk);
300		else
301			err |= copy_ckvsx_to_user(tm_v_regs, tsk);
302
303		/* set MSR_VSX in the MSR value in the frame to
304		 * indicate that sc->vs_reg) contains valid data.
305		 */
306		msr |= MSR_VSX;
307	}
308#endif /* CONFIG_VSX */
309
310	err |= __put_user(&sc->gp_regs, &sc->regs);
311	err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
312	WARN_ON(!FULL_REGS(regs));
313	err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
314	err |= __copy_to_user(&sc->gp_regs,
315			      &tsk->thread.ckpt_regs, GP_REGS_SIZE);
316	err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
317	err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
318	err |= __put_user(signr, &sc->signal);
319	err |= __put_user(handler, &sc->handler);
320	if (set != NULL)
321		err |=  __put_user(set->sig[0], &sc->oldmask);
322
323	return err;
324}
325#endif
326
327/*
328 * Restore the sigcontext from the signal frame.
329 */
330
331static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
332			      struct sigcontext __user *sc)
333{
334#ifdef CONFIG_ALTIVEC
335	elf_vrreg_t __user *v_regs;
336#endif
337	unsigned long err = 0;
338	unsigned long save_r13 = 0;
339	unsigned long msr;
340	struct pt_regs *regs = tsk->thread.regs;
341#ifdef CONFIG_VSX
342	int i;
343#endif
344
345	BUG_ON(tsk != current);
346
347	/* If this is not a signal return, we preserve the TLS in r13 */
348	if (!sig)
349		save_r13 = regs->gpr[13];
350
351	/* copy the GPRs */
352	err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
353	err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
354	/* get MSR separately, transfer the LE bit if doing signal return */
355	err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
356	if (sig)
357		regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
358	err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
359	err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
360	err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
361	err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
362	err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
363	/* skip SOFTE */
364	regs->trap = 0;
365	err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
366	err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
367	err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
368
369	if (!sig)
370		regs->gpr[13] = save_r13;
371	if (set != NULL)
372		err |=  __get_user(set->sig[0], &sc->oldmask);
373
374	/*
375	 * Force reload of FP/VEC.
376	 * This has to be done before copying stuff into tsk->thread.fpr/vr
377	 * for the reasons explained in the previous comment.
378	 */
379	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
380
381#ifdef CONFIG_ALTIVEC
382	err |= __get_user(v_regs, &sc->v_regs);
383	if (err)
384		return err;
385	if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
386		return -EFAULT;
387	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
388	if (v_regs != NULL && (msr & MSR_VEC) != 0) {
389		err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
390					33 * sizeof(vector128));
391		tsk->thread.used_vr = true;
392	} else if (tsk->thread.used_vr) {
393		memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
394	}
395	/* Always get VRSAVE back */
396	if (v_regs != NULL)
397		err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
398	else
399		tsk->thread.vrsave = 0;
400	if (cpu_has_feature(CPU_FTR_ALTIVEC))
401		mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
402#endif /* CONFIG_ALTIVEC */
403	/* restore floating point */
404	err |= copy_fpr_from_user(tsk, &sc->fp_regs);
405#ifdef CONFIG_VSX
406	/*
407	 * Get additional VSX data. Update v_regs to point after the
408	 * VMX data.  Copy VSX low doubleword from userspace to local
409	 * buffer for formatting, then into the taskstruct.
410	 */
411	v_regs += ELF_NVRREG;
412	if ((msr & MSR_VSX) != 0) {
413		err |= copy_vsx_from_user(tsk, v_regs);
414		tsk->thread.used_vsr = true;
415	} else {
416		for (i = 0; i < 32 ; i++)
417			tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
418	}
419#endif
420	return err;
421}
422
423#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
424/*
425 * Restore the two sigcontexts from the frame of a transactional processes.
426 */
427
428static long restore_tm_sigcontexts(struct task_struct *tsk,
429				   struct sigcontext __user *sc,
430				   struct sigcontext __user *tm_sc)
431{
432#ifdef CONFIG_ALTIVEC
433	elf_vrreg_t __user *v_regs, *tm_v_regs;
434#endif
435	unsigned long err = 0;
436	unsigned long msr;
437	struct pt_regs *regs = tsk->thread.regs;
438#ifdef CONFIG_VSX
439	int i;
440#endif
441
442	BUG_ON(tsk != current);
443
444	if (tm_suspend_disabled)
445		return -EINVAL;
446
447	/* copy the GPRs */
448	err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
449	err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
450				sizeof(regs->gpr));
451
452	/*
453	 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
454	 * TEXASR was set by the signal delivery reclaim, as was TFIAR.
455	 * Users doing anything abhorrent like thread-switching w/ signals for
456	 * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
457	 * For the case of getting a signal and simply returning from it,
458	 * we don't need to re-copy them here.
459	 */
460	err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
461	err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
462
463	/* get MSR separately, transfer the LE bit if doing signal return */
464	err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
465	/* Don't allow reserved mode. */
466	if (MSR_TM_RESV(msr))
467		return -EINVAL;
468
469	/* pull in MSR TS bits from user context */
470	regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);
471
472	/*
473	 * Ensure that TM is enabled in regs->msr before we leave the signal
474	 * handler. It could be the case that (a) user disabled the TM bit
475	 * through the manipulation of the MSR bits in uc_mcontext or (b) the
476	 * TM bit was disabled because a sufficient number of context switches
477	 * happened whilst in the signal handler and load_tm overflowed,
478	 * disabling the TM bit. In either case we can end up with an illegal
479	 * TM state leading to a TM Bad Thing when we return to userspace.
480	 */
481	regs->msr |= MSR_TM;
482
483	/* pull in MSR LE from user context */
484	regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
485
486	/* The following non-GPR non-FPR non-VR state is also checkpointed: */
487	err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
488	err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
489	err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
490	err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
491	err |= __get_user(tsk->thread.ckpt_regs.ctr,
492			  &sc->gp_regs[PT_CTR]);
493	err |= __get_user(tsk->thread.ckpt_regs.link,
494			  &sc->gp_regs[PT_LNK]);
495	err |= __get_user(tsk->thread.ckpt_regs.xer,
496			  &sc->gp_regs[PT_XER]);
497	err |= __get_user(tsk->thread.ckpt_regs.ccr,
498			  &sc->gp_regs[PT_CCR]);
499
500	/* These regs are not checkpointed; they can go in 'regs'. */
501	err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
502	err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
503	err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
504	err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
505
506	/*
507	 * Force reload of FP/VEC.
508	 * This has to be done before copying stuff into tsk->thread.fpr/vr
509	 * for the reasons explained in the previous comment.
510	 */
511	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
512
513#ifdef CONFIG_ALTIVEC
514	err |= __get_user(v_regs, &sc->v_regs);
515	err |= __get_user(tm_v_regs, &tm_sc->v_regs);
516	if (err)
517		return err;
518	if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
519		return -EFAULT;
520	if (tm_v_regs && !access_ok(VERIFY_READ,
521				    tm_v_regs, 34 * sizeof(vector128)))
522		return -EFAULT;
523	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
524	if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
525		err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs,
526					33 * sizeof(vector128));
527		err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
528					33 * sizeof(vector128));
529		current->thread.used_vr = true;
530	}
531	else if (tsk->thread.used_vr) {
532		memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
533		memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
534	}
535	/* Always get VRSAVE back */
536	if (v_regs != NULL && tm_v_regs != NULL) {
537		err |= __get_user(tsk->thread.ckvrsave,
538				  (u32 __user *)&v_regs[33]);
539		err |= __get_user(tsk->thread.vrsave,
540				  (u32 __user *)&tm_v_regs[33]);
541	}
542	else {
543		tsk->thread.vrsave = 0;
544		tsk->thread.ckvrsave = 0;
545	}
546	if (cpu_has_feature(CPU_FTR_ALTIVEC))
547		mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
548#endif /* CONFIG_ALTIVEC */
549	/* restore floating point */
550	err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
551	err |= copy_ckfpr_from_user(tsk, &sc->fp_regs);
552#ifdef CONFIG_VSX
553	/*
554	 * Get additional VSX data. Update v_regs to point after the
555	 * VMX data.  Copy VSX low doubleword from userspace to local
556	 * buffer for formatting, then into the taskstruct.
557	 */
558	if (v_regs && ((msr & MSR_VSX) != 0)) {
559		v_regs += ELF_NVRREG;
560		tm_v_regs += ELF_NVRREG;
561		err |= copy_vsx_from_user(tsk, tm_v_regs);
562		err |= copy_ckvsx_from_user(tsk, v_regs);
563		tsk->thread.used_vsr = true;
564	} else {
565		for (i = 0; i < 32 ; i++) {
566			tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
567			tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
568		}
569	}
570#endif
571	tm_enable();
572	/* Make sure the transaction is marked as failed */
573	tsk->thread.tm_texasr |= TEXASR_FS;
574	/* This loads the checkpointed FP/VEC state, if used */
575	tm_recheckpoint(&tsk->thread);
576
577	msr_check_and_set(msr & (MSR_FP | MSR_VEC));
578	if (msr & MSR_FP) {
579		load_fp_state(&tsk->thread.fp_state);
580		regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
581	}
582	if (msr & MSR_VEC) {
583		load_vr_state(&tsk->thread.vr_state);
584		regs->msr |= MSR_VEC;
585	}
586
587	return err;
588}
589#endif
590
591/*
592 * Setup the trampoline code on the stack
593 */
594static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
595{
596	int i;
597	long err = 0;
598
599	/* addi r1, r1, __SIGNAL_FRAMESIZE  # Pop the dummy stackframe */
600	err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
601	/* li r0, __NR_[rt_]sigreturn| */
602	err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
603	/* sc */
604	err |= __put_user(0x44000002UL, &tramp[2]);
605
606	/* Minimal traceback info */
607	for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
608		err |= __put_user(0, &tramp[i]);
609
610	if (!err)
611		flush_icache_range((unsigned long) &tramp[0],
612			   (unsigned long) &tramp[TRAMP_SIZE]);
613
614	return err;
615}
616
617/*
618 * Userspace code may pass a ucontext which doesn't include VSX added
619 * at the end.  We need to check for this case.
620 */
621#define UCONTEXTSIZEWITHOUTVSX \
622		(sizeof(struct ucontext) - 32*sizeof(long))
623
624/*
625 * Handle {get,set,swap}_context operations
626 */
627int sys_swapcontext(struct ucontext __user *old_ctx,
628		    struct ucontext __user *new_ctx,
629		    long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
630{
631	unsigned char tmp;
632	sigset_t set;
633	unsigned long new_msr = 0;
634	int ctx_has_vsx_region = 0;
635
636	BUG_ON(regs != current->thread.regs);
637
638	if (new_ctx &&
639	    get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
640		return -EFAULT;
641	/*
642	 * Check that the context is not smaller than the original
643	 * size (with VMX but without VSX)
644	 */
645	if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
646		return -EINVAL;
647	/*
648	 * If the new context state sets the MSR VSX bits but
649	 * it doesn't provide VSX state.
650	 */
651	if ((ctx_size < sizeof(struct ucontext)) &&
652	    (new_msr & MSR_VSX))
653		return -EINVAL;
654	/* Does the context have enough room to store VSX data? */
655	if (ctx_size >= sizeof(struct ucontext))
656		ctx_has_vsx_region = 1;
657
658	if (old_ctx != NULL) {
659		if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
660		    || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
661					ctx_has_vsx_region)
662		    || __copy_to_user(&old_ctx->uc_sigmask,
663				      &current->blocked, sizeof(sigset_t)))
664			return -EFAULT;
665	}
666	if (new_ctx == NULL)
667		return 0;
668	if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
669	    || __get_user(tmp, (u8 __user *) new_ctx)
670	    || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
671		return -EFAULT;
672
673	/*
674	 * If we get a fault copying the context into the kernel's
675	 * image of the user's registers, we can't just return -EFAULT
676	 * because the user's registers will be corrupted.  For instance
677	 * the NIP value may have been updated but not some of the
678	 * other registers.  Given that we have done the access_ok
679	 * and successfully read the first and last bytes of the region
680	 * above, this should only happen in an out-of-memory situation
681	 * or if another thread unmaps the region containing the context.
682	 * We kill the task with a SIGSEGV in this situation.
683	 */
684
685	if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
686		do_exit(SIGSEGV);
687	set_current_blocked(&set);
688	if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
689		do_exit(SIGSEGV);
690
691	/* This returns like rt_sigreturn */
692	set_thread_flag(TIF_RESTOREALL);
693	return 0;
694}
695
696
697/*
698 * Do a signal return; undo the signal stack.
699 */
700
701int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
702		     unsigned long r6, unsigned long r7, unsigned long r8,
703		     struct pt_regs *regs)
704{
705	struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
706	sigset_t set;
707#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
708	unsigned long msr;
709#endif
710
711	BUG_ON(current->thread.regs != regs);
712
713	/* Always make any pending restarted system calls return -EINTR */
714	current->restart_block.fn = do_no_restart_syscall;
715
716	if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
717		goto badframe;
718
719	if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
720		goto badframe;
721	set_current_blocked(&set);
722
723#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
724	/*
725	 * If there is a transactional state then throw it away.
726	 * The purpose of a sigreturn is to destroy all traces of the
727	 * signal frame, this includes any transactional state created
728	 * within in. We only check for suspended as we can never be
729	 * active in the kernel, we are active, there is nothing better to
730	 * do than go ahead and Bad Thing later.
731	 * The cause is not important as there will never be a
732	 * recheckpoint so it's not user visible.
733	 */
734	if (MSR_TM_SUSPENDED(mfmsr()))
735		tm_reclaim_current(0);
736
737	if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
738		goto badframe;
739	if (MSR_TM_ACTIVE(msr)) {
740		/* We recheckpoint on return. */
741		struct ucontext __user *uc_transact;
742		if (__get_user(uc_transact, &uc->uc_link))
743			goto badframe;
744		if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
745					   &uc_transact->uc_mcontext))
746			goto badframe;
747	}
748	else
749	/* Fall through, for non-TM restore */
750#endif
751	if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
752		goto badframe;
753
754	if (restore_altstack(&uc->uc_stack))
755		goto badframe;
756
757	set_thread_flag(TIF_RESTOREALL);
758	return 0;
759
760badframe:
761	if (show_unhandled_signals)
762		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
763				   current->comm, current->pid, "rt_sigreturn",
764				   (long)uc, regs->nip, regs->link);
765
766	force_sig(SIGSEGV, current);
767	return 0;
768}
769
770int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
771		struct task_struct *tsk)
772{
773	struct rt_sigframe __user *frame;
774	unsigned long newsp = 0;
775	long err = 0;
776	struct pt_regs *regs = tsk->thread.regs;
777
778	BUG_ON(tsk != current);
779
780	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
781	if (unlikely(frame == NULL))
782		goto badframe;
783
784	err |= __put_user(&frame->info, &frame->pinfo);
785	err |= __put_user(&frame->uc, &frame->puc);
786	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
787	if (err)
788		goto badframe;
789
790	/* Create the ucontext.  */
791	err |= __put_user(0, &frame->uc.uc_flags);
792	err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
793#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
794	if (MSR_TM_ACTIVE(regs->msr)) {
795		/* The ucontext_t passed to userland points to the second
796		 * ucontext_t (for transactional state) with its uc_link ptr.
797		 */
798		err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
799		err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
800					    &frame->uc_transact.uc_mcontext,
801					    tsk, ksig->sig, NULL,
802					    (unsigned long)ksig->ka.sa.sa_handler);
803	} else
804#endif
805	{
806		err |= __put_user(0, &frame->uc.uc_link);
807		err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
808					NULL, (unsigned long)ksig->ka.sa.sa_handler,
809					1);
810	}
811	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
812	if (err)
813		goto badframe;
814
815	/* Make sure signal handler doesn't get spurious FP exceptions */
816	tsk->thread.fp_state.fpscr = 0;
817
818	/* Set up to return from userspace. */
819	if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
820		regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
821	} else {
822		err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
823		if (err)
824			goto badframe;
825		regs->link = (unsigned long) &frame->tramp[0];
826	}
827
828	/* Allocate a dummy caller frame for the signal handler. */
829	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
830	err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
831
832	/* Set up "regs" so we "return" to the signal handler. */
833	if (is_elf2_task()) {
834		regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
835		regs->gpr[12] = regs->nip;
836	} else {
837		/* Handler is *really* a pointer to the function descriptor for
838		 * the signal routine.  The first entry in the function
839		 * descriptor is the entry address of signal and the second
840		 * entry is the TOC value we need to use.
841		 */
842		func_descr_t __user *funct_desc_ptr =
843			(func_descr_t __user *) ksig->ka.sa.sa_handler;
844
845		err |= get_user(regs->nip, &funct_desc_ptr->entry);
846		err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
847	}
848
849	/* enter the signal handler in native-endian mode */
850	regs->msr &= ~MSR_LE;
851	regs->msr |= (MSR_KERNEL & MSR_LE);
852	regs->gpr[1] = newsp;
853	regs->gpr[3] = ksig->sig;
854	regs->result = 0;
855	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
856		err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
857		err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
858		regs->gpr[6] = (unsigned long) frame;
859	} else {
860		regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
861	}
862	if (err)
863		goto badframe;
864
865	return 0;
866
867badframe:
868	if (show_unhandled_signals)
869		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
870				   tsk->comm, tsk->pid, "setup_rt_frame",
871				   (long)frame, regs->nip, regs->link);
872
873	return 1;
874}