3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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
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.
15 #include <linux/sched.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>
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>
36 #include <asm/switch_to.h>
38 #include <asm/asm-prototypes.h>
43 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
44 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
46 #define TRAMP_TRACEBACK 3
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.
58 /* sys_rt_sigreturn requires the ucontext be the first field */
60 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
61 struct ucontext uc_transact;
63 unsigned long _unused[2];
64 unsigned int tramp[TRAMP_SIZE];
65 struct siginfo __user *pinfo;
68 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
69 char abigap[USER_REDZONE_SIZE];
70 } __attribute__ ((aligned (16)));
72 static const char fmt32[] = KERN_INFO \
73 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
74 static const char fmt64[] = KERN_INFO \
75 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
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.
84 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
86 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
91 * Set up the sigcontext for the signal frame.
94 static 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)
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
106 #ifdef CONFIG_ALTIVEC
107 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
108 unsigned long vrsave;
110 struct pt_regs *regs = tsk->thread.regs;
111 unsigned long msr = regs->msr;
114 BUG_ON(tsk != current);
116 #ifdef CONFIG_ALTIVEC
117 err |= __put_user(v_regs, &sc->v_regs);
119 /* save altivec registers */
120 if (tsk->thread.used_vr) {
121 flush_altivec_to_thread(tsk);
122 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
123 err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
124 33 * sizeof(vector128));
125 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
126 * contains valid data.
130 /* We always copy to/from vrsave, it's 0 if we don't have or don't
134 if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
135 vrsave = mfspr(SPRN_VRSAVE);
136 tsk->thread.vrsave = vrsave;
139 err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
140 #else /* CONFIG_ALTIVEC */
141 err |= __put_user(0, &sc->v_regs);
142 #endif /* CONFIG_ALTIVEC */
143 flush_fp_to_thread(tsk);
144 /* copy fpr regs and fpscr */
145 err |= copy_fpr_to_user(&sc->fp_regs, tsk);
148 * Clear the MSR VSX bit to indicate there is no valid state attached
149 * to this context, except in the specific case below where we set it.
154 * Copy VSX low doubleword to local buffer for formatting,
155 * then out to userspace. Update v_regs to point after the
158 if (tsk->thread.used_vsr && ctx_has_vsx_region) {
159 flush_vsx_to_thread(tsk);
160 v_regs += ELF_NVRREG;
161 err |= copy_vsx_to_user(v_regs, tsk);
162 /* set MSR_VSX in the MSR value in the frame to
163 * indicate that sc->vs_reg) contains valid data.
167 #endif /* CONFIG_VSX */
168 err |= __put_user(&sc->gp_regs, &sc->regs);
169 WARN_ON(!FULL_REGS(regs));
170 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
171 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
172 err |= __put_user(signr, &sc->signal);
173 err |= __put_user(handler, &sc->handler);
175 err |= __put_user(set->sig[0], &sc->oldmask);
180 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
182 * As above, but Transactional Memory is in use, so deliver sigcontexts
183 * containing checkpointed and transactional register states.
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.
192 static 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)
197 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
198 * process never used altivec yet (MSR_VEC is zero in pt_regs of
199 * the context). This is very important because we must ensure we
200 * don't lose the VRSAVE content that may have been set prior to
201 * the process doing its first vector operation
202 * Userland shall check AT_HWCAP to know wether it can rely on the
203 * v_regs pointer or not.
205 #ifdef CONFIG_ALTIVEC
206 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
207 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
209 struct pt_regs *regs = tsk->thread.regs;
210 unsigned long msr = tsk->thread.ckpt_regs.msr;
213 BUG_ON(tsk != current);
215 BUG_ON(!MSR_TM_ACTIVE(regs->msr));
217 /* Remove TM bits from thread's MSR. The MSR in the sigcontext
218 * just indicates to userland that we were doing a transaction, but we
219 * don't want to return in transactional state. This also ensures
220 * that flush_fp_to_thread won't set TIF_RESTORE_TM again.
222 regs->msr &= ~MSR_TS_MASK;
224 #ifdef CONFIG_ALTIVEC
225 err |= __put_user(v_regs, &sc->v_regs);
226 err |= __put_user(tm_v_regs, &tm_sc->v_regs);
228 /* save altivec registers */
229 if (tsk->thread.used_vr) {
230 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
231 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
232 33 * sizeof(vector128));
233 /* If VEC was enabled there are transactional VRs valid too,
234 * else they're a copy of the checkpointed VRs.
237 err |= __copy_to_user(tm_v_regs,
238 &tsk->thread.vr_state,
239 33 * sizeof(vector128));
241 err |= __copy_to_user(tm_v_regs,
242 &tsk->thread.ckvr_state,
243 33 * sizeof(vector128));
245 /* set MSR_VEC in the MSR value in the frame to indicate
246 * that sc->v_reg contains valid data.
250 /* We always copy to/from vrsave, it's 0 if we don't have or don't
253 if (cpu_has_feature(CPU_FTR_ALTIVEC))
254 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
255 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
257 err |= __put_user(tsk->thread.vrsave,
258 (u32 __user *)&tm_v_regs[33]);
260 err |= __put_user(tsk->thread.ckvrsave,
261 (u32 __user *)&tm_v_regs[33]);
263 #else /* CONFIG_ALTIVEC */
264 err |= __put_user(0, &sc->v_regs);
265 err |= __put_user(0, &tm_sc->v_regs);
266 #endif /* CONFIG_ALTIVEC */
268 /* copy fpr regs and fpscr */
269 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
271 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
273 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
277 * Copy VSX low doubleword to local buffer for formatting,
278 * then out to userspace. Update v_regs to point after the
281 if (tsk->thread.used_vsr) {
282 v_regs += ELF_NVRREG;
283 tm_v_regs += ELF_NVRREG;
285 err |= copy_ckvsx_to_user(v_regs, tsk);
288 err |= copy_vsx_to_user(tm_v_regs, tsk);
290 err |= copy_ckvsx_to_user(tm_v_regs, tsk);
292 /* set MSR_VSX in the MSR value in the frame to
293 * indicate that sc->vs_reg) contains valid data.
297 #endif /* CONFIG_VSX */
299 err |= __put_user(&sc->gp_regs, &sc->regs);
300 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
301 WARN_ON(!FULL_REGS(regs));
302 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
303 err |= __copy_to_user(&sc->gp_regs,
304 &tsk->thread.ckpt_regs, GP_REGS_SIZE);
305 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
306 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
307 err |= __put_user(signr, &sc->signal);
308 err |= __put_user(handler, &sc->handler);
310 err |= __put_user(set->sig[0], &sc->oldmask);
317 * Restore the sigcontext from the signal frame.
320 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
321 struct sigcontext __user *sc)
323 #ifdef CONFIG_ALTIVEC
324 elf_vrreg_t __user *v_regs;
326 unsigned long err = 0;
327 unsigned long save_r13 = 0;
329 struct pt_regs *regs = tsk->thread.regs;
334 BUG_ON(tsk != current);
336 /* If this is not a signal return, we preserve the TLS in r13 */
338 save_r13 = regs->gpr[13];
341 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
342 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
343 /* get MSR separately, transfer the LE bit if doing signal return */
344 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
346 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
347 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
348 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
349 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
350 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
351 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
354 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
355 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
356 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
359 regs->gpr[13] = save_r13;
361 err |= __get_user(set->sig[0], &sc->oldmask);
364 * Force reload of FP/VEC.
365 * This has to be done before copying stuff into tsk->thread.fpr/vr
366 * for the reasons explained in the previous comment.
368 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
370 #ifdef CONFIG_ALTIVEC
371 err |= __get_user(v_regs, &sc->v_regs);
374 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
376 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
377 if (v_regs != NULL && (msr & MSR_VEC) != 0) {
378 err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
379 33 * sizeof(vector128));
380 tsk->thread.used_vr = true;
381 } else if (tsk->thread.used_vr) {
382 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
384 /* Always get VRSAVE back */
386 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
388 tsk->thread.vrsave = 0;
389 if (cpu_has_feature(CPU_FTR_ALTIVEC))
390 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
391 #endif /* CONFIG_ALTIVEC */
392 /* restore floating point */
393 err |= copy_fpr_from_user(tsk, &sc->fp_regs);
396 * Get additional VSX data. Update v_regs to point after the
397 * VMX data. Copy VSX low doubleword from userspace to local
398 * buffer for formatting, then into the taskstruct.
400 v_regs += ELF_NVRREG;
401 if ((msr & MSR_VSX) != 0) {
402 err |= copy_vsx_from_user(tsk, v_regs);
403 tsk->thread.used_vsr = true;
405 for (i = 0; i < 32 ; i++)
406 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
412 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
414 * Restore the two sigcontexts from the frame of a transactional processes.
417 static long restore_tm_sigcontexts(struct task_struct *tsk,
418 struct sigcontext __user *sc,
419 struct sigcontext __user *tm_sc)
421 #ifdef CONFIG_ALTIVEC
422 elf_vrreg_t __user *v_regs, *tm_v_regs;
424 unsigned long err = 0;
426 struct pt_regs *regs = tsk->thread.regs;
431 BUG_ON(tsk != current);
434 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
435 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
439 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
440 * TEXASR was set by the signal delivery reclaim, as was TFIAR.
441 * Users doing anything abhorrent like thread-switching w/ signals for
442 * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
443 * For the case of getting a signal and simply returning from it,
444 * we don't need to re-copy them here.
446 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
447 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
449 /* get MSR separately, transfer the LE bit if doing signal return */
450 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
451 /* Don't allow reserved mode. */
452 if (MSR_TM_RESV(msr))
455 /* pull in MSR TM from user context */
456 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);
458 /* pull in MSR LE from user context */
459 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
461 /* The following non-GPR non-FPR non-VR state is also checkpointed: */
462 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
463 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
464 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
465 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
466 err |= __get_user(tsk->thread.ckpt_regs.ctr,
467 &sc->gp_regs[PT_CTR]);
468 err |= __get_user(tsk->thread.ckpt_regs.link,
469 &sc->gp_regs[PT_LNK]);
470 err |= __get_user(tsk->thread.ckpt_regs.xer,
471 &sc->gp_regs[PT_XER]);
472 err |= __get_user(tsk->thread.ckpt_regs.ccr,
473 &sc->gp_regs[PT_CCR]);
475 /* These regs are not checkpointed; they can go in 'regs'. */
476 err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
477 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
478 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
479 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
482 * Force reload of FP/VEC.
483 * This has to be done before copying stuff into tsk->thread.fpr/vr
484 * for the reasons explained in the previous comment.
486 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
488 #ifdef CONFIG_ALTIVEC
489 err |= __get_user(v_regs, &sc->v_regs);
490 err |= __get_user(tm_v_regs, &tm_sc->v_regs);
493 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
495 if (tm_v_regs && !access_ok(VERIFY_READ,
496 tm_v_regs, 34 * sizeof(vector128)))
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;
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));
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]);
518 tsk->thread.vrsave = 0;
519 tsk->thread.ckvrsave = 0;
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);
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.
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;
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;
547 /* Make sure the transaction is marked as failed */
548 tsk->thread.tm_texasr |= TEXASR_FS;
549 /* This loads the checkpointed FP/VEC state, if used */
550 tm_recheckpoint(&tsk->thread, msr);
552 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
554 load_fp_state(&tsk->thread.fp_state);
555 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
558 load_vr_state(&tsk->thread.vr_state);
559 regs->msr |= MSR_VEC;
567 * Setup the trampoline code on the stack
569 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
574 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
575 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
576 /* li r0, __NR_[rt_]sigreturn| */
577 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
579 err |= __put_user(0x44000002UL, &tramp[2]);
581 /* Minimal traceback info */
582 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
583 err |= __put_user(0, &tramp[i]);
586 flush_icache_range((unsigned long) &tramp[0],
587 (unsigned long) &tramp[TRAMP_SIZE]);
593 * Userspace code may pass a ucontext which doesn't include VSX added
594 * at the end. We need to check for this case.
596 #define UCONTEXTSIZEWITHOUTVSX \
597 (sizeof(struct ucontext) - 32*sizeof(long))
600 * Handle {get,set,swap}_context operations
602 int sys_swapcontext(struct ucontext __user *old_ctx,
603 struct ucontext __user *new_ctx,
604 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
608 unsigned long new_msr = 0;
609 int ctx_has_vsx_region = 0;
611 BUG_ON(regs != current->thread.regs);
614 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
617 * Check that the context is not smaller than the original
618 * size (with VMX but without VSX)
620 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
623 * If the new context state sets the MSR VSX bits but
624 * it doesn't provide VSX state.
626 if ((ctx_size < sizeof(struct ucontext)) &&
629 /* Does the context have enough room to store VSX data? */
630 if (ctx_size >= sizeof(struct ucontext))
631 ctx_has_vsx_region = 1;
633 if (old_ctx != NULL) {
634 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
635 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
637 || __copy_to_user(&old_ctx->uc_sigmask,
638 ¤t->blocked, sizeof(sigset_t)))
643 if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
644 || __get_user(tmp, (u8 __user *) new_ctx)
645 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
649 * If we get a fault copying the context into the kernel's
650 * image of the user's registers, we can't just return -EFAULT
651 * because the user's registers will be corrupted. For instance
652 * the NIP value may have been updated but not some of the
653 * other registers. Given that we have done the access_ok
654 * and successfully read the first and last bytes of the region
655 * above, this should only happen in an out-of-memory situation
656 * or if another thread unmaps the region containing the context.
657 * We kill the task with a SIGSEGV in this situation.
660 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
662 set_current_blocked(&set);
663 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
666 /* This returns like rt_sigreturn */
667 set_thread_flag(TIF_RESTOREALL);
673 * Do a signal return; undo the signal stack.
676 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
677 unsigned long r6, unsigned long r7, unsigned long r8,
678 struct pt_regs *regs)
680 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
682 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
686 BUG_ON(current->thread.regs != regs);
688 /* Always make any pending restarted system calls return -EINTR */
689 current->restart_block.fn = do_no_restart_syscall;
691 if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
694 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
696 set_current_blocked(&set);
698 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
700 * If there is a transactional state then throw it away.
701 * The purpose of a sigreturn is to destroy all traces of the
702 * signal frame, this includes any transactional state created
703 * within in. We only check for suspended as we can never be
704 * active in the kernel, we are active, there is nothing better to
705 * do than go ahead and Bad Thing later.
706 * The cause is not important as there will never be a
707 * recheckpoint so it's not user visible.
709 if (MSR_TM_SUSPENDED(mfmsr()))
710 tm_reclaim_current(0);
712 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
714 if (MSR_TM_ACTIVE(msr)) {
715 /* We recheckpoint on return. */
716 struct ucontext __user *uc_transact;
717 if (__get_user(uc_transact, &uc->uc_link))
719 if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
720 &uc_transact->uc_mcontext))
724 /* Fall through, for non-TM restore */
726 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
729 if (restore_altstack(&uc->uc_stack))
732 set_thread_flag(TIF_RESTOREALL);
736 if (show_unhandled_signals)
737 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
738 current->comm, current->pid, "rt_sigreturn",
739 (long)uc, regs->nip, regs->link);
741 force_sig(SIGSEGV, current);
745 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
746 struct task_struct *tsk)
748 struct rt_sigframe __user *frame;
749 unsigned long newsp = 0;
751 struct pt_regs *regs = tsk->thread.regs;
753 BUG_ON(tsk != current);
755 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
756 if (unlikely(frame == NULL))
759 err |= __put_user(&frame->info, &frame->pinfo);
760 err |= __put_user(&frame->uc, &frame->puc);
761 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
765 /* Create the ucontext. */
766 err |= __put_user(0, &frame->uc.uc_flags);
767 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
768 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
769 if (MSR_TM_ACTIVE(regs->msr)) {
770 /* The ucontext_t passed to userland points to the second
771 * ucontext_t (for transactional state) with its uc_link ptr.
773 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
774 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
775 &frame->uc_transact.uc_mcontext,
776 tsk, ksig->sig, NULL,
777 (unsigned long)ksig->ka.sa.sa_handler);
781 err |= __put_user(0, &frame->uc.uc_link);
782 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
783 NULL, (unsigned long)ksig->ka.sa.sa_handler,
786 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
790 /* Make sure signal handler doesn't get spurious FP exceptions */
791 tsk->thread.fp_state.fpscr = 0;
793 /* Set up to return from userspace. */
794 if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
795 regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
797 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
800 regs->link = (unsigned long) &frame->tramp[0];
803 /* Allocate a dummy caller frame for the signal handler. */
804 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
805 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
807 /* Set up "regs" so we "return" to the signal handler. */
808 if (is_elf2_task()) {
809 regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
810 regs->gpr[12] = regs->nip;
812 /* Handler is *really* a pointer to the function descriptor for
813 * the signal routine. The first entry in the function
814 * descriptor is the entry address of signal and the second
815 * entry is the TOC value we need to use.
817 func_descr_t __user *funct_desc_ptr =
818 (func_descr_t __user *) ksig->ka.sa.sa_handler;
820 err |= get_user(regs->nip, &funct_desc_ptr->entry);
821 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
824 /* enter the signal handler in native-endian mode */
825 regs->msr &= ~MSR_LE;
826 regs->msr |= (MSR_KERNEL & MSR_LE);
827 regs->gpr[1] = newsp;
828 regs->gpr[3] = ksig->sig;
830 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
831 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
832 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
833 regs->gpr[6] = (unsigned long) frame;
835 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
843 if (show_unhandled_signals)
844 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
845 tsk->comm, tsk->pid, "setup_rt_frame",
846 (long)frame, regs->nip, regs->link);