1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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
11 #include <linux/sched.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>
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>
33 #include <asm/switch_to.h>
35 #include <asm/asm-prototypes.h>
40 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
41 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
43 #define TRAMP_TRACEBACK 4
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.
55 /* sys_rt_sigreturn requires the ucontext be the first field */
57 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
58 struct ucontext uc_transact;
60 unsigned long _unused[2];
61 unsigned int tramp[TRAMP_SIZE];
62 struct siginfo __user *pinfo;
65 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
66 char abigap[USER_REDZONE_SIZE];
67 } __attribute__ ((aligned (16)));
70 * This computes a quad word aligned pointer inside the vmx_reserve array
71 * element. For historical reasons sigcontext might not be quad word aligned,
72 * but the location we write the VMX regs to must be. See the comment in
73 * sigcontext for more detail.
76 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
78 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
82 static void prepare_setup_sigcontext(struct task_struct *tsk)
85 /* save altivec registers */
86 if (tsk->thread.used_vr)
87 flush_altivec_to_thread(tsk);
88 if (cpu_has_feature(CPU_FTR_ALTIVEC))
89 tsk->thread.vrsave = mfspr(SPRN_VRSAVE);
90 #endif /* CONFIG_ALTIVEC */
92 flush_fp_to_thread(tsk);
95 if (tsk->thread.used_vsr)
96 flush_vsx_to_thread(tsk);
97 #endif /* CONFIG_VSX */
101 * Set up the sigcontext for the signal frame.
104 static long setup_sigcontext(struct sigcontext __user *sc,
105 struct task_struct *tsk, int signr, sigset_t *set,
106 unsigned long handler, int ctx_has_vsx_region)
108 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
109 * process never used altivec yet (MSR_VEC is zero in pt_regs of
110 * the context). This is very important because we must ensure we
111 * don't lose the VRSAVE content that may have been set prior to
112 * the process doing its first vector operation
113 * Userland shall check AT_HWCAP to know whether it can rely on the
114 * v_regs pointer or not
116 #ifdef CONFIG_ALTIVEC
117 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
119 struct pt_regs *regs = tsk->thread.regs;
120 unsigned long msr = regs->msr;
122 /* Force usr to alway see softe as 1 (interrupts enabled) */
123 unsigned long softe = 0x1;
125 BUG_ON(tsk != current);
127 #ifdef CONFIG_ALTIVEC
128 err |= __put_user(v_regs, &sc->v_regs);
130 /* save altivec registers */
131 if (tsk->thread.used_vr) {
132 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
133 err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
134 33 * sizeof(vector128));
135 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
136 * contains valid data.
140 /* We always copy to/from vrsave, it's 0 if we don't have or don't
143 err |= __put_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
144 #else /* CONFIG_ALTIVEC */
145 err |= __put_user(0, &sc->v_regs);
146 #endif /* CONFIG_ALTIVEC */
147 /* copy fpr regs and fpscr */
148 err |= copy_fpr_to_user(&sc->fp_regs, tsk);
151 * Clear the MSR VSX bit to indicate there is no valid state attached
152 * to this context, except in the specific case below where we set it.
157 * Copy VSX low doubleword to local buffer for formatting,
158 * then out to userspace. Update v_regs to point after the
161 if (tsk->thread.used_vsr && ctx_has_vsx_region) {
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.
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);
178 err |= __put_user(set->sig[0], &sc->oldmask);
183 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
185 * As above, but Transactional Memory is in use, so deliver sigcontexts
186 * containing checkpointed and transactional register states.
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.
195 static 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,
201 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
202 * process never used altivec yet (MSR_VEC is zero in pt_regs of
203 * the context). This is very important because we must ensure we
204 * don't lose the VRSAVE content that may have been set prior to
205 * the process doing its first vector operation
206 * Userland shall check AT_HWCAP to know wether it can rely on the
207 * v_regs pointer or not.
209 #ifdef CONFIG_ALTIVEC
210 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
211 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
213 struct pt_regs *regs = tsk->thread.regs;
216 BUG_ON(tsk != current);
218 BUG_ON(!MSR_TM_ACTIVE(msr));
220 WARN_ON(tm_suspend_disabled);
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.
226 msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
228 #ifdef CONFIG_ALTIVEC
229 err |= __put_user(v_regs, &sc->v_regs);
230 err |= __put_user(tm_v_regs, &tm_sc->v_regs);
232 /* save altivec registers */
233 if (tsk->thread.used_vr) {
234 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
235 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
236 33 * sizeof(vector128));
237 /* If VEC was enabled there are transactional VRs valid too,
238 * else they're a copy of the checkpointed VRs.
241 err |= __copy_to_user(tm_v_regs,
242 &tsk->thread.vr_state,
243 33 * sizeof(vector128));
245 err |= __copy_to_user(tm_v_regs,
246 &tsk->thread.ckvr_state,
247 33 * sizeof(vector128));
249 /* set MSR_VEC in the MSR value in the frame to indicate
250 * that sc->v_reg contains valid data.
254 /* We always copy to/from vrsave, it's 0 if we don't have or don't
257 if (cpu_has_feature(CPU_FTR_ALTIVEC))
258 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
259 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
261 err |= __put_user(tsk->thread.vrsave,
262 (u32 __user *)&tm_v_regs[33]);
264 err |= __put_user(tsk->thread.ckvrsave,
265 (u32 __user *)&tm_v_regs[33]);
267 #else /* CONFIG_ALTIVEC */
268 err |= __put_user(0, &sc->v_regs);
269 err |= __put_user(0, &tm_sc->v_regs);
270 #endif /* CONFIG_ALTIVEC */
272 /* copy fpr regs and fpscr */
273 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
275 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
277 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
281 * Copy VSX low doubleword to local buffer for formatting,
282 * then out to userspace. Update v_regs to point after the
285 if (tsk->thread.used_vsr) {
286 v_regs += ELF_NVRREG;
287 tm_v_regs += ELF_NVRREG;
289 err |= copy_ckvsx_to_user(v_regs, tsk);
292 err |= copy_vsx_to_user(tm_v_regs, tsk);
294 err |= copy_ckvsx_to_user(tm_v_regs, tsk);
296 /* set MSR_VSX in the MSR value in the frame to
297 * indicate that sc->vs_reg) contains valid data.
301 #endif /* CONFIG_VSX */
303 err |= __put_user(&sc->gp_regs, &sc->regs);
304 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
305 WARN_ON(!FULL_REGS(regs));
306 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
307 err |= __copy_to_user(&sc->gp_regs,
308 &tsk->thread.ckpt_regs, GP_REGS_SIZE);
309 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
310 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
311 err |= __put_user(signr, &sc->signal);
312 err |= __put_user(handler, &sc->handler);
314 err |= __put_user(set->sig[0], &sc->oldmask);
321 * Restore the sigcontext from the signal frame.
324 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
325 struct sigcontext __user *sc)
327 #ifdef CONFIG_ALTIVEC
328 elf_vrreg_t __user *v_regs;
330 unsigned long err = 0;
331 unsigned long save_r13 = 0;
333 struct pt_regs *regs = tsk->thread.regs;
338 BUG_ON(tsk != current);
340 /* If this is not a signal return, we preserve the TLS in r13 */
342 save_r13 = regs->gpr[13];
345 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
346 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
347 /* get MSR separately, transfer the LE bit if doing signal return */
348 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
350 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
351 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
352 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
353 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
354 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
355 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
356 /* Don't allow userspace to set SOFTE */
357 set_trap_norestart(regs);
358 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
359 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
360 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
363 regs->gpr[13] = save_r13;
365 err |= __get_user(set->sig[0], &sc->oldmask);
368 * Force reload of FP/VEC.
369 * This has to be done before copying stuff into tsk->thread.fpr/vr
370 * for the reasons explained in the previous comment.
372 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
374 #ifdef CONFIG_ALTIVEC
375 err |= __get_user(v_regs, &sc->v_regs);
378 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
380 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
381 if (v_regs != NULL && (msr & MSR_VEC) != 0) {
382 err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
383 33 * sizeof(vector128));
384 tsk->thread.used_vr = true;
385 } else if (tsk->thread.used_vr) {
386 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
388 /* Always get VRSAVE back */
390 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
392 tsk->thread.vrsave = 0;
393 if (cpu_has_feature(CPU_FTR_ALTIVEC))
394 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
395 #endif /* CONFIG_ALTIVEC */
396 /* restore floating point */
397 err |= copy_fpr_from_user(tsk, &sc->fp_regs);
400 * Get additional VSX data. Update v_regs to point after the
401 * VMX data. Copy VSX low doubleword from userspace to local
402 * buffer for formatting, then into the taskstruct.
404 v_regs += ELF_NVRREG;
405 if ((msr & MSR_VSX) != 0) {
406 err |= copy_vsx_from_user(tsk, v_regs);
407 tsk->thread.used_vsr = true;
409 for (i = 0; i < 32 ; i++)
410 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
416 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
418 * Restore the two sigcontexts from the frame of a transactional processes.
421 static long restore_tm_sigcontexts(struct task_struct *tsk,
422 struct sigcontext __user *sc,
423 struct sigcontext __user *tm_sc)
425 #ifdef CONFIG_ALTIVEC
426 elf_vrreg_t __user *v_regs, *tm_v_regs;
428 unsigned long err = 0;
430 struct pt_regs *regs = tsk->thread.regs;
435 BUG_ON(tsk != current);
437 if (tm_suspend_disabled)
441 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
442 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
446 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
447 * TEXASR was set by the signal delivery reclaim, as was TFIAR.
448 * Users doing anything abhorrent like thread-switching w/ signals for
449 * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
450 * For the case of getting a signal and simply returning from it,
451 * we don't need to re-copy them here.
453 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
454 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
456 /* get MSR separately, transfer the LE bit if doing signal return */
457 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
458 /* Don't allow reserved mode. */
459 if (MSR_TM_RESV(msr))
462 /* pull in MSR LE from user context */
463 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
465 /* The following non-GPR non-FPR non-VR state is also checkpointed: */
466 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
467 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
468 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
469 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
470 err |= __get_user(tsk->thread.ckpt_regs.ctr,
471 &sc->gp_regs[PT_CTR]);
472 err |= __get_user(tsk->thread.ckpt_regs.link,
473 &sc->gp_regs[PT_LNK]);
474 err |= __get_user(tsk->thread.ckpt_regs.xer,
475 &sc->gp_regs[PT_XER]);
476 err |= __get_user(tsk->thread.ckpt_regs.ccr,
477 &sc->gp_regs[PT_CCR]);
478 /* Don't allow userspace to set SOFTE */
479 set_trap_norestart(regs);
480 /* These regs are not checkpointed; they can go in 'regs'. */
481 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
482 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
483 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
486 * Force reload of FP/VEC.
487 * This has to be done before copying stuff into tsk->thread.fpr/vr
488 * for the reasons explained in the previous comment.
490 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
492 #ifdef CONFIG_ALTIVEC
493 err |= __get_user(v_regs, &sc->v_regs);
494 err |= __get_user(tm_v_regs, &tm_sc->v_regs);
497 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
499 if (tm_v_regs && !access_ok(tm_v_regs, 34 * sizeof(vector128)))
501 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
502 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
503 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs,
504 33 * sizeof(vector128));
505 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
506 33 * sizeof(vector128));
507 current->thread.used_vr = true;
509 else if (tsk->thread.used_vr) {
510 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
511 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
513 /* Always get VRSAVE back */
514 if (v_regs != NULL && tm_v_regs != NULL) {
515 err |= __get_user(tsk->thread.ckvrsave,
516 (u32 __user *)&v_regs[33]);
517 err |= __get_user(tsk->thread.vrsave,
518 (u32 __user *)&tm_v_regs[33]);
521 tsk->thread.vrsave = 0;
522 tsk->thread.ckvrsave = 0;
524 if (cpu_has_feature(CPU_FTR_ALTIVEC))
525 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
526 #endif /* CONFIG_ALTIVEC */
527 /* restore floating point */
528 err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
529 err |= copy_ckfpr_from_user(tsk, &sc->fp_regs);
532 * Get additional VSX data. Update v_regs to point after the
533 * VMX data. Copy VSX low doubleword from userspace to local
534 * buffer for formatting, then into the taskstruct.
536 if (v_regs && ((msr & MSR_VSX) != 0)) {
537 v_regs += ELF_NVRREG;
538 tm_v_regs += ELF_NVRREG;
539 err |= copy_vsx_from_user(tsk, tm_v_regs);
540 err |= copy_ckvsx_from_user(tsk, v_regs);
541 tsk->thread.used_vsr = true;
543 for (i = 0; i < 32 ; i++) {
544 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
545 tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
550 /* Make sure the transaction is marked as failed */
551 tsk->thread.tm_texasr |= TEXASR_FS;
554 * Disabling preemption, since it is unsafe to be preempted
555 * with MSR[TS] set without recheckpointing.
559 /* pull in MSR TS bits from user context */
560 regs->msr |= msr & MSR_TS_MASK;
563 * Ensure that TM is enabled in regs->msr before we leave the signal
564 * handler. It could be the case that (a) user disabled the TM bit
565 * through the manipulation of the MSR bits in uc_mcontext or (b) the
566 * TM bit was disabled because a sufficient number of context switches
567 * happened whilst in the signal handler and load_tm overflowed,
568 * disabling the TM bit. In either case we can end up with an illegal
569 * TM state leading to a TM Bad Thing when we return to userspace.
572 * After regs->MSR[TS] being updated, make sure that get_user(),
573 * put_user() or similar functions are *not* called. These
574 * functions can generate page faults which will cause the process
575 * to be de-scheduled with MSR[TS] set but without calling
576 * tm_recheckpoint(). This can cause a bug.
580 /* This loads the checkpointed FP/VEC state, if used */
581 tm_recheckpoint(&tsk->thread);
583 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
585 load_fp_state(&tsk->thread.fp_state);
586 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
589 load_vr_state(&tsk->thread.vr_state);
590 regs->msr |= MSR_VEC;
600 * Setup the trampoline code on the stack
602 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
607 /* bctrl # call the handler */
608 err |= __put_user(PPC_INST_BCTRL, &tramp[0]);
609 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
610 err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) |
611 (__SIGNAL_FRAMESIZE & 0xffff), &tramp[1]);
612 /* li r0, __NR_[rt_]sigreturn| */
613 err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[2]);
615 err |= __put_user(PPC_INST_SC, &tramp[3]);
617 /* Minimal traceback info */
618 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
619 err |= __put_user(0, &tramp[i]);
622 flush_icache_range((unsigned long) &tramp[0],
623 (unsigned long) &tramp[TRAMP_SIZE]);
629 * Userspace code may pass a ucontext which doesn't include VSX added
630 * at the end. We need to check for this case.
632 #define UCONTEXTSIZEWITHOUTVSX \
633 (sizeof(struct ucontext) - 32*sizeof(long))
636 * Handle {get,set,swap}_context operations
638 SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
639 struct ucontext __user *, new_ctx, long, ctx_size)
642 unsigned long new_msr = 0;
643 int ctx_has_vsx_region = 0;
646 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
649 * Check that the context is not smaller than the original
650 * size (with VMX but without VSX)
652 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
655 * If the new context state sets the MSR VSX bits but
656 * it doesn't provide VSX state.
658 if ((ctx_size < sizeof(struct ucontext)) &&
661 /* Does the context have enough room to store VSX data? */
662 if (ctx_size >= sizeof(struct ucontext))
663 ctx_has_vsx_region = 1;
665 if (old_ctx != NULL) {
666 prepare_setup_sigcontext(current);
667 if (!access_ok(old_ctx, ctx_size)
668 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
670 || __copy_to_user(&old_ctx->uc_sigmask,
671 ¤t->blocked, sizeof(sigset_t)))
676 if (!access_ok(new_ctx, ctx_size) ||
677 fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
681 * If we get a fault copying the context into the kernel's
682 * image of the user's registers, we can't just return -EFAULT
683 * because the user's registers will be corrupted. For instance
684 * the NIP value may have been updated but not some of the
685 * other registers. Given that we have done the access_ok
686 * and successfully read the first and last bytes of the region
687 * above, this should only happen in an out-of-memory situation
688 * or if another thread unmaps the region containing the context.
689 * We kill the task with a SIGSEGV in this situation.
692 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
694 set_current_blocked(&set);
695 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
698 /* This returns like rt_sigreturn */
699 set_thread_flag(TIF_RESTOREALL);
705 * Do a signal return; undo the signal stack.
708 SYSCALL_DEFINE0(rt_sigreturn)
710 struct pt_regs *regs = current_pt_regs();
711 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
713 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
717 /* Always make any pending restarted system calls return -EINTR */
718 current->restart_block.fn = do_no_restart_syscall;
720 if (!access_ok(uc, sizeof(*uc)))
723 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
725 set_current_blocked(&set);
727 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
729 * If there is a transactional state then throw it away.
730 * The purpose of a sigreturn is to destroy all traces of the
731 * signal frame, this includes any transactional state created
732 * within in. We only check for suspended as we can never be
733 * active in the kernel, we are active, there is nothing better to
734 * do than go ahead and Bad Thing later.
735 * The cause is not important as there will never be a
736 * recheckpoint so it's not user visible.
738 if (MSR_TM_SUSPENDED(mfmsr()))
739 tm_reclaim_current(0);
742 * Disable MSR[TS] bit also, so, if there is an exception in the
743 * code below (as a page fault in copy_ckvsx_to_user()), it does
744 * not recheckpoint this task if there was a context switch inside
747 * A major page fault can indirectly call schedule(). A reschedule
748 * process in the middle of an exception can have a side effect
749 * (Changing the CPU MSR[TS] state), since schedule() is called
750 * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended
751 * (switch_to() calls tm_recheckpoint() for the 'new' process). In
752 * this case, the process continues to be the same in the CPU, but
753 * the CPU state just changed.
755 * This can cause a TM Bad Thing, since the MSR in the stack will
756 * have the MSR[TS]=0, and this is what will be used to RFID.
758 * Clearing MSR[TS] state here will avoid a recheckpoint if there
759 * is any process reschedule in kernel space. The MSR[TS] state
760 * does not need to be saved also, since it will be replaced with
761 * the MSR[TS] that came from user context later, at
762 * restore_tm_sigcontexts.
764 regs->msr &= ~MSR_TS_MASK;
766 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
768 if (MSR_TM_ACTIVE(msr)) {
769 /* We recheckpoint on return. */
770 struct ucontext __user *uc_transact;
772 /* Trying to start TM on non TM system */
773 if (!cpu_has_feature(CPU_FTR_TM))
776 if (__get_user(uc_transact, &uc->uc_link))
778 if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
779 &uc_transact->uc_mcontext))
785 * Fall through, for non-TM restore
787 * Unset MSR[TS] on the thread regs since MSR from user
788 * context does not have MSR active, and recheckpoint was
789 * not called since restore_tm_sigcontexts() was not called
792 * If not unsetting it, the code can RFID to userspace with
793 * MSR[TS] set, but without CPU in the proper state,
794 * causing a TM bad thing.
796 current->thread.regs->msr &= ~MSR_TS_MASK;
797 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
801 if (restore_altstack(&uc->uc_stack))
804 set_thread_flag(TIF_RESTOREALL);
808 signal_fault(current, regs, "rt_sigreturn", uc);
814 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
815 struct task_struct *tsk)
817 struct rt_sigframe __user *frame;
818 unsigned long newsp = 0;
820 struct pt_regs *regs = tsk->thread.regs;
821 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
822 /* Save the thread's msr before get_tm_stackpointer() changes it */
823 unsigned long msr = regs->msr;
826 frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
827 if (!access_ok(frame, sizeof(*frame)))
830 err |= __put_user(&frame->info, &frame->pinfo);
831 err |= __put_user(&frame->uc, &frame->puc);
832 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
836 /* Create the ucontext. */
837 err |= __put_user(0, &frame->uc.uc_flags);
838 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
839 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
840 if (MSR_TM_ACTIVE(msr)) {
841 /* The ucontext_t passed to userland points to the second
842 * ucontext_t (for transactional state) with its uc_link ptr.
844 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
845 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
846 &frame->uc_transact.uc_mcontext,
847 tsk, ksig->sig, NULL,
848 (unsigned long)ksig->ka.sa.sa_handler,
853 err |= __put_user(0, &frame->uc.uc_link);
854 prepare_setup_sigcontext(tsk);
855 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
856 NULL, (unsigned long)ksig->ka.sa.sa_handler,
859 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
863 /* Make sure signal handler doesn't get spurious FP exceptions */
864 tsk->thread.fp_state.fpscr = 0;
866 /* Set up to return from userspace. */
867 if (tsk->mm->context.vdso) {
868 regs->nip = VDSO64_SYMBOL(tsk->mm->context.vdso, sigtramp_rt64);
870 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
873 regs->nip = (unsigned long) &frame->tramp[0];
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);
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;
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.
890 func_descr_t __user *funct_desc_ptr =
891 (func_descr_t __user *) ksig->ka.sa.sa_handler;
893 err |= get_user(regs->ctr, &funct_desc_ptr->entry);
894 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
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;
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;
908 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
916 signal_fault(current, regs, "handle_rt_signal64", frame);