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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PowerPC version
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 *
6 * Derived from "arch/i386/kernel/signal.c"
7 * Copyright (C) 1991, 1992 Linus Torvalds
8 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
9 */
10
11#include <linux/sched.h>
12#include <linux/mm.h>
13#include <linux/smp.h>
14#include <linux/kernel.h>
15#include <linux/signal.h>
16#include <linux/errno.h>
17#include <linux/wait.h>
18#include <linux/unistd.h>
19#include <linux/stddef.h>
20#include <linux/elf.h>
21#include <linux/ptrace.h>
22#include <linux/ratelimit.h>
23#include <linux/syscalls.h>
24#include <linux/pagemap.h>
25
26#include <asm/sigcontext.h>
27#include <asm/ucontext.h>
28#include <linux/uaccess.h>
29#include <asm/unistd.h>
30#include <asm/cacheflush.h>
31#include <asm/syscalls.h>
32#include <asm/vdso.h>
33#include <asm/switch_to.h>
34#include <asm/tm.h>
35#include <asm/asm-prototypes.h>
36
37#include "signal.h"
38
39
40#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
41#define FP_REGS_SIZE sizeof(elf_fpregset_t)
42
43#define TRAMP_TRACEBACK 4
44#define TRAMP_SIZE 7
45
46/*
47 * When we have signals to deliver, we set up on the user stack,
48 * going down from the original stack pointer:
49 * 1) a rt_sigframe struct which contains the ucontext
50 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
51 * frame for the signal handler.
52 */
53
54struct rt_sigframe {
55 /* sys_rt_sigreturn requires the ucontext be the first field */
56 struct ucontext uc;
57#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
58 struct ucontext uc_transact;
59#endif
60 unsigned long _unused[2];
61 unsigned int tramp[TRAMP_SIZE];
62 struct siginfo __user *pinfo;
63 void __user *puc;
64 struct siginfo info;
65 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
66 char abigap[USER_REDZONE_SIZE];
67} __attribute__ ((aligned (16)));
68
69static const char fmt32[] = KERN_INFO \
70 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
71static const char fmt64[] = KERN_INFO \
72 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
73
74/*
75 * This computes a quad word aligned pointer inside the vmx_reserve array
76 * element. For historical reasons sigcontext might not be quad word aligned,
77 * but the location we write the VMX regs to must be. See the comment in
78 * sigcontext for more detail.
79 */
80#ifdef CONFIG_ALTIVEC
81static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
82{
83 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
84}
85#endif
86
87/*
88 * Set up the sigcontext for the signal frame.
89 */
90
91static long setup_sigcontext(struct sigcontext __user *sc,
92 struct task_struct *tsk, int signr, sigset_t *set,
93 unsigned long handler, int ctx_has_vsx_region)
94{
95 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
96 * process never used altivec yet (MSR_VEC is zero in pt_regs of
97 * the context). This is very important because we must ensure we
98 * don't lose the VRSAVE content that may have been set prior to
99 * the process doing its first vector operation
100 * Userland shall check AT_HWCAP to know whether it can rely on the
101 * v_regs pointer or not
102 */
103#ifdef CONFIG_ALTIVEC
104 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
105 unsigned long vrsave;
106#endif
107 struct pt_regs *regs = tsk->thread.regs;
108 unsigned long msr = regs->msr;
109 long err = 0;
110 /* Force usr to alway see softe as 1 (interrupts enabled) */
111 unsigned long softe = 0x1;
112
113 BUG_ON(tsk != current);
114
115#ifdef CONFIG_ALTIVEC
116 err |= __put_user(v_regs, &sc->v_regs);
117
118 /* save altivec registers */
119 if (tsk->thread.used_vr) {
120 flush_altivec_to_thread(tsk);
121 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
122 err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
123 33 * sizeof(vector128));
124 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
125 * contains valid data.
126 */
127 msr |= MSR_VEC;
128 }
129 /* We always copy to/from vrsave, it's 0 if we don't have or don't
130 * use altivec.
131 */
132 vrsave = 0;
133 if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
134 vrsave = mfspr(SPRN_VRSAVE);
135 tsk->thread.vrsave = vrsave;
136 }
137
138 err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
139#else /* CONFIG_ALTIVEC */
140 err |= __put_user(0, &sc->v_regs);
141#endif /* CONFIG_ALTIVEC */
142 flush_fp_to_thread(tsk);
143 /* copy fpr regs and fpscr */
144 err |= copy_fpr_to_user(&sc->fp_regs, tsk);
145
146 /*
147 * Clear the MSR VSX bit to indicate there is no valid state attached
148 * to this context, except in the specific case below where we set it.
149 */
150 msr &= ~MSR_VSX;
151#ifdef CONFIG_VSX
152 /*
153 * Copy VSX low doubleword to local buffer for formatting,
154 * then out to userspace. Update v_regs to point after the
155 * VMX data.
156 */
157 if (tsk->thread.used_vsr && ctx_has_vsx_region) {
158 flush_vsx_to_thread(tsk);
159 v_regs += ELF_NVRREG;
160 err |= copy_vsx_to_user(v_regs, tsk);
161 /* set MSR_VSX in the MSR value in the frame to
162 * indicate that sc->vs_reg) contains valid data.
163 */
164 msr |= MSR_VSX;
165 }
166#endif /* CONFIG_VSX */
167 err |= __put_user(&sc->gp_regs, &sc->regs);
168 WARN_ON(!FULL_REGS(regs));
169 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
170 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
171 err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]);
172 err |= __put_user(signr, &sc->signal);
173 err |= __put_user(handler, &sc->handler);
174 if (set != NULL)
175 err |= __put_user(set->sig[0], &sc->oldmask);
176
177 return err;
178}
179
180#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
181/*
182 * As above, but Transactional Memory is in use, so deliver sigcontexts
183 * containing checkpointed and transactional register states.
184 *
185 * To do this, we treclaim (done before entering here) to gather both sets of
186 * registers and set up the 'normal' sigcontext registers with rolled-back
187 * register values such that a simple signal handler sees a correct
188 * checkpointed register state. If interested, a TM-aware sighandler can
189 * examine the transactional registers in the 2nd sigcontext to determine the
190 * real origin of the signal.
191 */
192static long setup_tm_sigcontexts(struct sigcontext __user *sc,
193 struct sigcontext __user *tm_sc,
194 struct task_struct *tsk,
195 int signr, sigset_t *set, unsigned long handler,
196 unsigned long msr)
197{
198 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
199 * process never used altivec yet (MSR_VEC is zero in pt_regs of
200 * the context). This is very important because we must ensure we
201 * don't lose the VRSAVE content that may have been set prior to
202 * the process doing its first vector operation
203 * Userland shall check AT_HWCAP to know wether it can rely on the
204 * v_regs pointer or not.
205 */
206#ifdef CONFIG_ALTIVEC
207 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
208 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
209#endif
210 struct pt_regs *regs = tsk->thread.regs;
211 long err = 0;
212
213 BUG_ON(tsk != current);
214
215 BUG_ON(!MSR_TM_ACTIVE(msr));
216
217 WARN_ON(tm_suspend_disabled);
218
219 /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as
220 * it contains the correct FP, VEC, VSX state after we treclaimed
221 * the transaction and giveup_all() was called on reclaiming.
222 */
223 msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
224
225#ifdef CONFIG_ALTIVEC
226 err |= __put_user(v_regs, &sc->v_regs);
227 err |= __put_user(tm_v_regs, &tm_sc->v_regs);
228
229 /* save altivec registers */
230 if (tsk->thread.used_vr) {
231 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
232 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
233 33 * sizeof(vector128));
234 /* If VEC was enabled there are transactional VRs valid too,
235 * else they're a copy of the checkpointed VRs.
236 */
237 if (msr & MSR_VEC)
238 err |= __copy_to_user(tm_v_regs,
239 &tsk->thread.vr_state,
240 33 * sizeof(vector128));
241 else
242 err |= __copy_to_user(tm_v_regs,
243 &tsk->thread.ckvr_state,
244 33 * sizeof(vector128));
245
246 /* set MSR_VEC in the MSR value in the frame to indicate
247 * that sc->v_reg contains valid data.
248 */
249 msr |= MSR_VEC;
250 }
251 /* We always copy to/from vrsave, it's 0 if we don't have or don't
252 * use altivec.
253 */
254 if (cpu_has_feature(CPU_FTR_ALTIVEC))
255 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
256 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
257 if (msr & MSR_VEC)
258 err |= __put_user(tsk->thread.vrsave,
259 (u32 __user *)&tm_v_regs[33]);
260 else
261 err |= __put_user(tsk->thread.ckvrsave,
262 (u32 __user *)&tm_v_regs[33]);
263
264#else /* CONFIG_ALTIVEC */
265 err |= __put_user(0, &sc->v_regs);
266 err |= __put_user(0, &tm_sc->v_regs);
267#endif /* CONFIG_ALTIVEC */
268
269 /* copy fpr regs and fpscr */
270 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
271 if (msr & MSR_FP)
272 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
273 else
274 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
275
276#ifdef CONFIG_VSX
277 /*
278 * Copy VSX low doubleword to local buffer for formatting,
279 * then out to userspace. Update v_regs to point after the
280 * VMX data.
281 */
282 if (tsk->thread.used_vsr) {
283 v_regs += ELF_NVRREG;
284 tm_v_regs += ELF_NVRREG;
285
286 err |= copy_ckvsx_to_user(v_regs, tsk);
287
288 if (msr & MSR_VSX)
289 err |= copy_vsx_to_user(tm_v_regs, tsk);
290 else
291 err |= copy_ckvsx_to_user(tm_v_regs, tsk);
292
293 /* set MSR_VSX in the MSR value in the frame to
294 * indicate that sc->vs_reg) contains valid data.
295 */
296 msr |= MSR_VSX;
297 }
298#endif /* CONFIG_VSX */
299
300 err |= __put_user(&sc->gp_regs, &sc->regs);
301 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
302 WARN_ON(!FULL_REGS(regs));
303 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
304 err |= __copy_to_user(&sc->gp_regs,
305 &tsk->thread.ckpt_regs, GP_REGS_SIZE);
306 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
307 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
308 err |= __put_user(signr, &sc->signal);
309 err |= __put_user(handler, &sc->handler);
310 if (set != NULL)
311 err |= __put_user(set->sig[0], &sc->oldmask);
312
313 return err;
314}
315#endif
316
317/*
318 * Restore the sigcontext from the signal frame.
319 */
320
321static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
322 struct sigcontext __user *sc)
323{
324#ifdef CONFIG_ALTIVEC
325 elf_vrreg_t __user *v_regs;
326#endif
327 unsigned long err = 0;
328 unsigned long save_r13 = 0;
329 unsigned long msr;
330 struct pt_regs *regs = tsk->thread.regs;
331#ifdef CONFIG_VSX
332 int i;
333#endif
334
335 BUG_ON(tsk != current);
336
337 /* If this is not a signal return, we preserve the TLS in r13 */
338 if (!sig)
339 save_r13 = regs->gpr[13];
340
341 /* copy the GPRs */
342 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
343 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
344 /* get MSR separately, transfer the LE bit if doing signal return */
345 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
346 if (sig)
347 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
348 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
349 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
350 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
351 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
352 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
353 /* Don't allow userspace to set SOFTE */
354 set_trap_norestart(regs);
355 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
356 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
357 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
358
359 if (!sig)
360 regs->gpr[13] = save_r13;
361 if (set != NULL)
362 err |= __get_user(set->sig[0], &sc->oldmask);
363
364 /*
365 * Force reload of FP/VEC.
366 * This has to be done before copying stuff into tsk->thread.fpr/vr
367 * for the reasons explained in the previous comment.
368 */
369 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
370
371#ifdef CONFIG_ALTIVEC
372 err |= __get_user(v_regs, &sc->v_regs);
373 if (err)
374 return err;
375 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
376 return -EFAULT;
377 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
378 if (v_regs != NULL && (msr & MSR_VEC) != 0) {
379 err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
380 33 * sizeof(vector128));
381 tsk->thread.used_vr = true;
382 } else if (tsk->thread.used_vr) {
383 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
384 }
385 /* Always get VRSAVE back */
386 if (v_regs != NULL)
387 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
388 else
389 tsk->thread.vrsave = 0;
390 if (cpu_has_feature(CPU_FTR_ALTIVEC))
391 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
392#endif /* CONFIG_ALTIVEC */
393 /* restore floating point */
394 err |= copy_fpr_from_user(tsk, &sc->fp_regs);
395#ifdef CONFIG_VSX
396 /*
397 * Get additional VSX data. Update v_regs to point after the
398 * VMX data. Copy VSX low doubleword from userspace to local
399 * buffer for formatting, then into the taskstruct.
400 */
401 v_regs += ELF_NVRREG;
402 if ((msr & MSR_VSX) != 0) {
403 err |= copy_vsx_from_user(tsk, v_regs);
404 tsk->thread.used_vsr = true;
405 } else {
406 for (i = 0; i < 32 ; i++)
407 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
408 }
409#endif
410 return err;
411}
412
413#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
414/*
415 * Restore the two sigcontexts from the frame of a transactional processes.
416 */
417
418static long restore_tm_sigcontexts(struct task_struct *tsk,
419 struct sigcontext __user *sc,
420 struct sigcontext __user *tm_sc)
421{
422#ifdef CONFIG_ALTIVEC
423 elf_vrreg_t __user *v_regs, *tm_v_regs;
424#endif
425 unsigned long err = 0;
426 unsigned long msr;
427 struct pt_regs *regs = tsk->thread.regs;
428#ifdef CONFIG_VSX
429 int i;
430#endif
431
432 BUG_ON(tsk != current);
433
434 if (tm_suspend_disabled)
435 return -EINVAL;
436
437 /* copy the GPRs */
438 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
439 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
440 sizeof(regs->gpr));
441
442 /*
443 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
444 * TEXASR was set by the signal delivery reclaim, as was TFIAR.
445 * Users doing anything abhorrent like thread-switching w/ signals for
446 * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
447 * For the case of getting a signal and simply returning from it,
448 * we don't need to re-copy them here.
449 */
450 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
451 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
452
453 /* get MSR separately, transfer the LE bit if doing signal return */
454 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
455 /* Don't allow reserved mode. */
456 if (MSR_TM_RESV(msr))
457 return -EINVAL;
458
459 /* pull in MSR LE from user context */
460 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
461
462 /* The following non-GPR non-FPR non-VR state is also checkpointed: */
463 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
464 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
465 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
466 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
467 err |= __get_user(tsk->thread.ckpt_regs.ctr,
468 &sc->gp_regs[PT_CTR]);
469 err |= __get_user(tsk->thread.ckpt_regs.link,
470 &sc->gp_regs[PT_LNK]);
471 err |= __get_user(tsk->thread.ckpt_regs.xer,
472 &sc->gp_regs[PT_XER]);
473 err |= __get_user(tsk->thread.ckpt_regs.ccr,
474 &sc->gp_regs[PT_CCR]);
475 /* Don't allow userspace to set SOFTE */
476 set_trap_norestart(regs);
477 /* These regs are not checkpointed; they can go in 'regs'. */
478 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
479 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
480 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
481
482 /*
483 * Force reload of FP/VEC.
484 * This has to be done before copying stuff into tsk->thread.fpr/vr
485 * for the reasons explained in the previous comment.
486 */
487 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
488
489#ifdef CONFIG_ALTIVEC
490 err |= __get_user(v_regs, &sc->v_regs);
491 err |= __get_user(tm_v_regs, &tm_sc->v_regs);
492 if (err)
493 return err;
494 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
495 return -EFAULT;
496 if (tm_v_regs && !access_ok(tm_v_regs, 34 * sizeof(vector128)))
497 return -EFAULT;
498 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
499 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
500 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs,
501 33 * sizeof(vector128));
502 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
503 33 * sizeof(vector128));
504 current->thread.used_vr = true;
505 }
506 else if (tsk->thread.used_vr) {
507 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
508 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
509 }
510 /* Always get VRSAVE back */
511 if (v_regs != NULL && tm_v_regs != NULL) {
512 err |= __get_user(tsk->thread.ckvrsave,
513 (u32 __user *)&v_regs[33]);
514 err |= __get_user(tsk->thread.vrsave,
515 (u32 __user *)&tm_v_regs[33]);
516 }
517 else {
518 tsk->thread.vrsave = 0;
519 tsk->thread.ckvrsave = 0;
520 }
521 if (cpu_has_feature(CPU_FTR_ALTIVEC))
522 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
523#endif /* CONFIG_ALTIVEC */
524 /* restore floating point */
525 err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
526 err |= copy_ckfpr_from_user(tsk, &sc->fp_regs);
527#ifdef CONFIG_VSX
528 /*
529 * Get additional VSX data. Update v_regs to point after the
530 * VMX data. Copy VSX low doubleword from userspace to local
531 * buffer for formatting, then into the taskstruct.
532 */
533 if (v_regs && ((msr & MSR_VSX) != 0)) {
534 v_regs += ELF_NVRREG;
535 tm_v_regs += ELF_NVRREG;
536 err |= copy_vsx_from_user(tsk, tm_v_regs);
537 err |= copy_ckvsx_from_user(tsk, v_regs);
538 tsk->thread.used_vsr = true;
539 } else {
540 for (i = 0; i < 32 ; i++) {
541 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
542 tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
543 }
544 }
545#endif
546 tm_enable();
547 /* Make sure the transaction is marked as failed */
548 tsk->thread.tm_texasr |= TEXASR_FS;
549
550 /*
551 * Disabling preemption, since it is unsafe to be preempted
552 * with MSR[TS] set without recheckpointing.
553 */
554 preempt_disable();
555
556 /* pull in MSR TS bits from user context */
557 regs->msr |= msr & MSR_TS_MASK;
558
559 /*
560 * Ensure that TM is enabled in regs->msr before we leave the signal
561 * handler. It could be the case that (a) user disabled the TM bit
562 * through the manipulation of the MSR bits in uc_mcontext or (b) the
563 * TM bit was disabled because a sufficient number of context switches
564 * happened whilst in the signal handler and load_tm overflowed,
565 * disabling the TM bit. In either case we can end up with an illegal
566 * TM state leading to a TM Bad Thing when we return to userspace.
567 *
568 * CAUTION:
569 * After regs->MSR[TS] being updated, make sure that get_user(),
570 * put_user() or similar functions are *not* called. These
571 * functions can generate page faults which will cause the process
572 * to be de-scheduled with MSR[TS] set but without calling
573 * tm_recheckpoint(). This can cause a bug.
574 */
575 regs->msr |= MSR_TM;
576
577 /* This loads the checkpointed FP/VEC state, if used */
578 tm_recheckpoint(&tsk->thread);
579
580 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
581 if (msr & MSR_FP) {
582 load_fp_state(&tsk->thread.fp_state);
583 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
584 }
585 if (msr & MSR_VEC) {
586 load_vr_state(&tsk->thread.vr_state);
587 regs->msr |= MSR_VEC;
588 }
589
590 preempt_enable();
591
592 return err;
593}
594#endif
595
596/*
597 * Setup the trampoline code on the stack
598 */
599static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
600{
601 int i;
602 long err = 0;
603
604 /* bctrl # call the handler */
605 err |= __put_user(PPC_INST_BCTRL, &tramp[0]);
606 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
607 err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) |
608 (__SIGNAL_FRAMESIZE & 0xffff), &tramp[1]);
609 /* li r0, __NR_[rt_]sigreturn| */
610 err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[2]);
611 /* sc */
612 err |= __put_user(PPC_INST_SC, &tramp[3]);
613
614 /* Minimal traceback info */
615 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
616 err |= __put_user(0, &tramp[i]);
617
618 if (!err)
619 flush_icache_range((unsigned long) &tramp[0],
620 (unsigned long) &tramp[TRAMP_SIZE]);
621
622 return err;
623}
624
625/*
626 * Userspace code may pass a ucontext which doesn't include VSX added
627 * at the end. We need to check for this case.
628 */
629#define UCONTEXTSIZEWITHOUTVSX \
630 (sizeof(struct ucontext) - 32*sizeof(long))
631
632/*
633 * Handle {get,set,swap}_context operations
634 */
635SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
636 struct ucontext __user *, new_ctx, long, ctx_size)
637{
638 sigset_t set;
639 unsigned long new_msr = 0;
640 int ctx_has_vsx_region = 0;
641
642 if (new_ctx &&
643 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
644 return -EFAULT;
645 /*
646 * Check that the context is not smaller than the original
647 * size (with VMX but without VSX)
648 */
649 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
650 return -EINVAL;
651 /*
652 * If the new context state sets the MSR VSX bits but
653 * it doesn't provide VSX state.
654 */
655 if ((ctx_size < sizeof(struct ucontext)) &&
656 (new_msr & MSR_VSX))
657 return -EINVAL;
658 /* Does the context have enough room to store VSX data? */
659 if (ctx_size >= sizeof(struct ucontext))
660 ctx_has_vsx_region = 1;
661
662 if (old_ctx != NULL) {
663 if (!access_ok(old_ctx, ctx_size)
664 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
665 ctx_has_vsx_region)
666 || __copy_to_user(&old_ctx->uc_sigmask,
667 ¤t->blocked, sizeof(sigset_t)))
668 return -EFAULT;
669 }
670 if (new_ctx == NULL)
671 return 0;
672 if (!access_ok(new_ctx, ctx_size) ||
673 fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
674 return -EFAULT;
675
676 /*
677 * If we get a fault copying the context into the kernel's
678 * image of the user's registers, we can't just return -EFAULT
679 * because the user's registers will be corrupted. For instance
680 * the NIP value may have been updated but not some of the
681 * other registers. Given that we have done the access_ok
682 * and successfully read the first and last bytes of the region
683 * above, this should only happen in an out-of-memory situation
684 * or if another thread unmaps the region containing the context.
685 * We kill the task with a SIGSEGV in this situation.
686 */
687
688 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
689 do_exit(SIGSEGV);
690 set_current_blocked(&set);
691 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
692 do_exit(SIGSEGV);
693
694 /* This returns like rt_sigreturn */
695 set_thread_flag(TIF_RESTOREALL);
696 return 0;
697}
698
699
700/*
701 * Do a signal return; undo the signal stack.
702 */
703
704SYSCALL_DEFINE0(rt_sigreturn)
705{
706 struct pt_regs *regs = current_pt_regs();
707 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
708 sigset_t set;
709#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
710 unsigned long msr;
711#endif
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(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 /*
738 * Disable MSR[TS] bit also, so, if there is an exception in the
739 * code below (as a page fault in copy_ckvsx_to_user()), it does
740 * not recheckpoint this task if there was a context switch inside
741 * the exception.
742 *
743 * A major page fault can indirectly call schedule(). A reschedule
744 * process in the middle of an exception can have a side effect
745 * (Changing the CPU MSR[TS] state), since schedule() is called
746 * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended
747 * (switch_to() calls tm_recheckpoint() for the 'new' process). In
748 * this case, the process continues to be the same in the CPU, but
749 * the CPU state just changed.
750 *
751 * This can cause a TM Bad Thing, since the MSR in the stack will
752 * have the MSR[TS]=0, and this is what will be used to RFID.
753 *
754 * Clearing MSR[TS] state here will avoid a recheckpoint if there
755 * is any process reschedule in kernel space. The MSR[TS] state
756 * does not need to be saved also, since it will be replaced with
757 * the MSR[TS] that came from user context later, at
758 * restore_tm_sigcontexts.
759 */
760 regs->msr &= ~MSR_TS_MASK;
761
762 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
763 goto badframe;
764 if (MSR_TM_ACTIVE(msr)) {
765 /* We recheckpoint on return. */
766 struct ucontext __user *uc_transact;
767
768 /* Trying to start TM on non TM system */
769 if (!cpu_has_feature(CPU_FTR_TM))
770 goto badframe;
771
772 if (__get_user(uc_transact, &uc->uc_link))
773 goto badframe;
774 if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
775 &uc_transact->uc_mcontext))
776 goto badframe;
777 } else
778#endif
779 {
780 /*
781 * Fall through, for non-TM restore
782 *
783 * Unset MSR[TS] on the thread regs since MSR from user
784 * context does not have MSR active, and recheckpoint was
785 * not called since restore_tm_sigcontexts() was not called
786 * also.
787 *
788 * If not unsetting it, the code can RFID to userspace with
789 * MSR[TS] set, but without CPU in the proper state,
790 * causing a TM bad thing.
791 */
792 current->thread.regs->msr &= ~MSR_TS_MASK;
793 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
794 goto badframe;
795 }
796
797 if (restore_altstack(&uc->uc_stack))
798 goto badframe;
799
800 set_thread_flag(TIF_RESTOREALL);
801 return 0;
802
803badframe:
804 if (show_unhandled_signals)
805 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
806 current->comm, current->pid, "rt_sigreturn",
807 (long)uc, regs->nip, regs->link);
808
809 force_sig(SIGSEGV);
810 return 0;
811}
812
813int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
814 struct task_struct *tsk)
815{
816 struct rt_sigframe __user *frame;
817 unsigned long newsp = 0;
818 long err = 0;
819 struct pt_regs *regs = tsk->thread.regs;
820#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
821 /* Save the thread's msr before get_tm_stackpointer() changes it */
822 unsigned long msr = regs->msr;
823#endif
824
825 BUG_ON(tsk != current);
826
827 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
828 if (unlikely(frame == NULL))
829 goto badframe;
830
831 err |= __put_user(&frame->info, &frame->pinfo);
832 err |= __put_user(&frame->uc, &frame->puc);
833 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
834 if (err)
835 goto badframe;
836
837 /* Create the ucontext. */
838 err |= __put_user(0, &frame->uc.uc_flags);
839 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
840#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
841 if (MSR_TM_ACTIVE(msr)) {
842 /* The ucontext_t passed to userland points to the second
843 * ucontext_t (for transactional state) with its uc_link ptr.
844 */
845 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
846 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
847 &frame->uc_transact.uc_mcontext,
848 tsk, ksig->sig, NULL,
849 (unsigned long)ksig->ka.sa.sa_handler,
850 msr);
851 } else
852#endif
853 {
854 err |= __put_user(0, &frame->uc.uc_link);
855 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
856 NULL, (unsigned long)ksig->ka.sa.sa_handler,
857 1);
858 }
859 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
860 if (err)
861 goto badframe;
862
863 /* Make sure signal handler doesn't get spurious FP exceptions */
864 tsk->thread.fp_state.fpscr = 0;
865
866 /* Set up to return from userspace. */
867 if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
868 regs->nip = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
869 } else {
870 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
871 if (err)
872 goto badframe;
873 regs->nip = (unsigned long) &frame->tramp[0];
874 }
875
876 /* Allocate a dummy caller frame for the signal handler. */
877 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
878 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
879
880 /* Set up "regs" so we "return" to the signal handler. */
881 if (is_elf2_task()) {
882 regs->ctr = (unsigned long) ksig->ka.sa.sa_handler;
883 regs->gpr[12] = regs->ctr;
884 } else {
885 /* Handler is *really* a pointer to the function descriptor for
886 * the signal routine. The first entry in the function
887 * descriptor is the entry address of signal and the second
888 * entry is the TOC value we need to use.
889 */
890 func_descr_t __user *funct_desc_ptr =
891 (func_descr_t __user *) ksig->ka.sa.sa_handler;
892
893 err |= get_user(regs->ctr, &funct_desc_ptr->entry);
894 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
895 }
896
897 /* enter the signal handler in native-endian mode */
898 regs->msr &= ~MSR_LE;
899 regs->msr |= (MSR_KERNEL & MSR_LE);
900 regs->gpr[1] = newsp;
901 regs->gpr[3] = ksig->sig;
902 regs->result = 0;
903 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
904 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
905 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
906 regs->gpr[6] = (unsigned long) frame;
907 } else {
908 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
909 }
910 if (err)
911 goto badframe;
912
913 return 0;
914
915badframe:
916 if (show_unhandled_signals)
917 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
918 tsk->comm, tsk->pid, "setup_rt_frame",
919 (long)frame, regs->nip, regs->link);
920
921 return 1;
922}
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 <asm/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
38#include "signal.h"
39
40#define DEBUG_SIG 0
41
42#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
43#define FP_REGS_SIZE sizeof(elf_fpregset_t)
44
45#define TRAMP_TRACEBACK 3
46#define TRAMP_SIZE 6
47
48/*
49 * When we have signals to deliver, we set up on the user stack,
50 * going down from the original stack pointer:
51 * 1) a rt_sigframe struct which contains the ucontext
52 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
53 * frame for the signal handler.
54 */
55
56struct rt_sigframe {
57 /* sys_rt_sigreturn requires the ucontext be the first field */
58 struct ucontext uc;
59 unsigned long _unused[2];
60 unsigned int tramp[TRAMP_SIZE];
61 struct siginfo __user *pinfo;
62 void __user *puc;
63 struct siginfo info;
64 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
65 char abigap[288];
66} __attribute__ ((aligned (16)));
67
68static const char fmt32[] = KERN_INFO \
69 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
70static const char fmt64[] = KERN_INFO \
71 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
72
73/*
74 * Set up the sigcontext for the signal frame.
75 */
76
77static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
78 int signr, sigset_t *set, unsigned long handler,
79 int ctx_has_vsx_region)
80{
81 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
82 * process never used altivec yet (MSR_VEC is zero in pt_regs of
83 * the context). This is very important because we must ensure we
84 * don't lose the VRSAVE content that may have been set prior to
85 * the process doing its first vector operation
86 * Userland shall check AT_HWCAP to know wether it can rely on the
87 * v_regs pointer or not
88 */
89#ifdef CONFIG_ALTIVEC
90 elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
91#endif
92 unsigned long msr = regs->msr;
93 long err = 0;
94
95 flush_fp_to_thread(current);
96
97#ifdef CONFIG_ALTIVEC
98 err |= __put_user(v_regs, &sc->v_regs);
99
100 /* save altivec registers */
101 if (current->thread.used_vr) {
102 flush_altivec_to_thread(current);
103 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
104 err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
105 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
106 * contains valid data.
107 */
108 msr |= MSR_VEC;
109 }
110 /* We always copy to/from vrsave, it's 0 if we don't have or don't
111 * use altivec.
112 */
113 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
114#else /* CONFIG_ALTIVEC */
115 err |= __put_user(0, &sc->v_regs);
116#endif /* CONFIG_ALTIVEC */
117 flush_fp_to_thread(current);
118 /* copy fpr regs and fpscr */
119 err |= copy_fpr_to_user(&sc->fp_regs, current);
120#ifdef CONFIG_VSX
121 /*
122 * Copy VSX low doubleword to local buffer for formatting,
123 * then out to userspace. Update v_regs to point after the
124 * VMX data.
125 */
126 if (current->thread.used_vsr && ctx_has_vsx_region) {
127 __giveup_vsx(current);
128 v_regs += ELF_NVRREG;
129 err |= copy_vsx_to_user(v_regs, current);
130 /* set MSR_VSX in the MSR value in the frame to
131 * indicate that sc->vs_reg) contains valid data.
132 */
133 msr |= MSR_VSX;
134 }
135#endif /* CONFIG_VSX */
136 err |= __put_user(&sc->gp_regs, &sc->regs);
137 WARN_ON(!FULL_REGS(regs));
138 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
139 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
140 err |= __put_user(signr, &sc->signal);
141 err |= __put_user(handler, &sc->handler);
142 if (set != NULL)
143 err |= __put_user(set->sig[0], &sc->oldmask);
144
145 return err;
146}
147
148/*
149 * Restore the sigcontext from the signal frame.
150 */
151
152static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
153 struct sigcontext __user *sc)
154{
155#ifdef CONFIG_ALTIVEC
156 elf_vrreg_t __user *v_regs;
157#endif
158 unsigned long err = 0;
159 unsigned long save_r13 = 0;
160 unsigned long msr;
161#ifdef CONFIG_VSX
162 int i;
163#endif
164
165 /* If this is not a signal return, we preserve the TLS in r13 */
166 if (!sig)
167 save_r13 = regs->gpr[13];
168
169 /* copy the GPRs */
170 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
171 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
172 /* get MSR separately, transfer the LE bit if doing signal return */
173 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
174 if (sig)
175 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
176 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
177 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
178 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
179 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
180 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
181 /* skip SOFTE */
182 regs->trap = 0;
183 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
184 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
185 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
186
187 if (!sig)
188 regs->gpr[13] = save_r13;
189 if (set != NULL)
190 err |= __get_user(set->sig[0], &sc->oldmask);
191
192 /*
193 * Do this before updating the thread state in
194 * current->thread.fpr/vr. That way, if we get preempted
195 * and another task grabs the FPU/Altivec, it won't be
196 * tempted to save the current CPU state into the thread_struct
197 * and corrupt what we are writing there.
198 */
199 discard_lazy_cpu_state();
200
201 /*
202 * Force reload of FP/VEC.
203 * This has to be done before copying stuff into current->thread.fpr/vr
204 * for the reasons explained in the previous comment.
205 */
206 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
207
208#ifdef CONFIG_ALTIVEC
209 err |= __get_user(v_regs, &sc->v_regs);
210 if (err)
211 return err;
212 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
213 return -EFAULT;
214 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
215 if (v_regs != 0 && (msr & MSR_VEC) != 0)
216 err |= __copy_from_user(current->thread.vr, v_regs,
217 33 * sizeof(vector128));
218 else if (current->thread.used_vr)
219 memset(current->thread.vr, 0, 33 * sizeof(vector128));
220 /* Always get VRSAVE back */
221 if (v_regs != 0)
222 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
223 else
224 current->thread.vrsave = 0;
225#endif /* CONFIG_ALTIVEC */
226 /* restore floating point */
227 err |= copy_fpr_from_user(current, &sc->fp_regs);
228#ifdef CONFIG_VSX
229 /*
230 * Get additional VSX data. Update v_regs to point after the
231 * VMX data. Copy VSX low doubleword from userspace to local
232 * buffer for formatting, then into the taskstruct.
233 */
234 v_regs += ELF_NVRREG;
235 if ((msr & MSR_VSX) != 0)
236 err |= copy_vsx_from_user(current, v_regs);
237 else
238 for (i = 0; i < 32 ; i++)
239 current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
240#endif
241 return err;
242}
243
244/*
245 * Setup the trampoline code on the stack
246 */
247static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
248{
249 int i;
250 long err = 0;
251
252 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
253 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
254 /* li r0, __NR_[rt_]sigreturn| */
255 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
256 /* sc */
257 err |= __put_user(0x44000002UL, &tramp[2]);
258
259 /* Minimal traceback info */
260 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
261 err |= __put_user(0, &tramp[i]);
262
263 if (!err)
264 flush_icache_range((unsigned long) &tramp[0],
265 (unsigned long) &tramp[TRAMP_SIZE]);
266
267 return err;
268}
269
270/*
271 * Userspace code may pass a ucontext which doesn't include VSX added
272 * at the end. We need to check for this case.
273 */
274#define UCONTEXTSIZEWITHOUTVSX \
275 (sizeof(struct ucontext) - 32*sizeof(long))
276
277/*
278 * Handle {get,set,swap}_context operations
279 */
280int sys_swapcontext(struct ucontext __user *old_ctx,
281 struct ucontext __user *new_ctx,
282 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
283{
284 unsigned char tmp;
285 sigset_t set;
286 unsigned long new_msr = 0;
287 int ctx_has_vsx_region = 0;
288
289 if (new_ctx &&
290 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
291 return -EFAULT;
292 /*
293 * Check that the context is not smaller than the original
294 * size (with VMX but without VSX)
295 */
296 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
297 return -EINVAL;
298 /*
299 * If the new context state sets the MSR VSX bits but
300 * it doesn't provide VSX state.
301 */
302 if ((ctx_size < sizeof(struct ucontext)) &&
303 (new_msr & MSR_VSX))
304 return -EINVAL;
305 /* Does the context have enough room to store VSX data? */
306 if (ctx_size >= sizeof(struct ucontext))
307 ctx_has_vsx_region = 1;
308
309 if (old_ctx != NULL) {
310 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
311 || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
312 ctx_has_vsx_region)
313 || __copy_to_user(&old_ctx->uc_sigmask,
314 ¤t->blocked, sizeof(sigset_t)))
315 return -EFAULT;
316 }
317 if (new_ctx == NULL)
318 return 0;
319 if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
320 || __get_user(tmp, (u8 __user *) new_ctx)
321 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
322 return -EFAULT;
323
324 /*
325 * If we get a fault copying the context into the kernel's
326 * image of the user's registers, we can't just return -EFAULT
327 * because the user's registers will be corrupted. For instance
328 * the NIP value may have been updated but not some of the
329 * other registers. Given that we have done the access_ok
330 * and successfully read the first and last bytes of the region
331 * above, this should only happen in an out-of-memory situation
332 * or if another thread unmaps the region containing the context.
333 * We kill the task with a SIGSEGV in this situation.
334 */
335
336 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
337 do_exit(SIGSEGV);
338 set_current_blocked(&set);
339 if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
340 do_exit(SIGSEGV);
341
342 /* This returns like rt_sigreturn */
343 set_thread_flag(TIF_RESTOREALL);
344 return 0;
345}
346
347
348/*
349 * Do a signal return; undo the signal stack.
350 */
351
352int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
353 unsigned long r6, unsigned long r7, unsigned long r8,
354 struct pt_regs *regs)
355{
356 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
357 sigset_t set;
358
359 /* Always make any pending restarted system calls return -EINTR */
360 current_thread_info()->restart_block.fn = do_no_restart_syscall;
361
362 if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
363 goto badframe;
364
365 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
366 goto badframe;
367 set_current_blocked(&set);
368 if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
369 goto badframe;
370
371 /* do_sigaltstack expects a __user pointer and won't modify
372 * what's in there anyway
373 */
374 do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
375
376 set_thread_flag(TIF_RESTOREALL);
377 return 0;
378
379badframe:
380#if DEBUG_SIG
381 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
382 regs, uc, &uc->uc_mcontext);
383#endif
384 if (show_unhandled_signals)
385 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
386 current->comm, current->pid, "rt_sigreturn",
387 (long)uc, regs->nip, regs->link);
388
389 force_sig(SIGSEGV, current);
390 return 0;
391}
392
393int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
394 sigset_t *set, struct pt_regs *regs)
395{
396 /* Handler is *really* a pointer to the function descriptor for
397 * the signal routine. The first entry in the function
398 * descriptor is the entry address of signal and the second
399 * entry is the TOC value we need to use.
400 */
401 func_descr_t __user *funct_desc_ptr;
402 struct rt_sigframe __user *frame;
403 unsigned long newsp = 0;
404 long err = 0;
405
406 frame = get_sigframe(ka, regs, sizeof(*frame), 0);
407 if (unlikely(frame == NULL))
408 goto badframe;
409
410 err |= __put_user(&frame->info, &frame->pinfo);
411 err |= __put_user(&frame->uc, &frame->puc);
412 err |= copy_siginfo_to_user(&frame->info, info);
413 if (err)
414 goto badframe;
415
416 /* Create the ucontext. */
417 err |= __put_user(0, &frame->uc.uc_flags);
418 err |= __put_user(0, &frame->uc.uc_link);
419 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
420 err |= __put_user(sas_ss_flags(regs->gpr[1]),
421 &frame->uc.uc_stack.ss_flags);
422 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
423 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
424 (unsigned long)ka->sa.sa_handler, 1);
425 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
426 if (err)
427 goto badframe;
428
429 /* Make sure signal handler doesn't get spurious FP exceptions */
430 current->thread.fpscr.val = 0;
431
432 /* Set up to return from userspace. */
433 if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
434 regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
435 } else {
436 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
437 if (err)
438 goto badframe;
439 regs->link = (unsigned long) &frame->tramp[0];
440 }
441 funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;
442
443 /* Allocate a dummy caller frame for the signal handler. */
444 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
445 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
446
447 /* Set up "regs" so we "return" to the signal handler. */
448 err |= get_user(regs->nip, &funct_desc_ptr->entry);
449 /* enter the signal handler in big-endian mode */
450 regs->msr &= ~MSR_LE;
451 regs->gpr[1] = newsp;
452 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
453 regs->gpr[3] = signr;
454 regs->result = 0;
455 if (ka->sa.sa_flags & SA_SIGINFO) {
456 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
457 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
458 regs->gpr[6] = (unsigned long) frame;
459 } else {
460 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
461 }
462 if (err)
463 goto badframe;
464
465 return 1;
466
467badframe:
468#if DEBUG_SIG
469 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
470 regs, frame, newsp);
471#endif
472 if (show_unhandled_signals)
473 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
474 current->comm, current->pid, "setup_rt_frame",
475 (long)frame, regs->nip, regs->link);
476
477 force_sigsegv(signr, current);
478 return 0;
479}