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authorStephen Rothwell <sfr@canb.auug.org.au>2005-10-17 21:17:58 -0400
committerStephen Rothwell <sfr@canb.auug.org.au>2005-10-17 21:17:58 -0400
commit81e7009ea46c951860b8716ee427ff4f54dd26fc (patch)
treecd9724dac4d04a2e03f4042adbcc86fdc2d037b7 /arch/ppc
parent55d363397f1bdfa4fe861f0e2fadb058c79dafea (diff)
powerpc: merge ppc signal.c and ppc64 signal32.c
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Diffstat (limited to 'arch/ppc')
-rw-r--r--arch/ppc/kernel/Makefile4
-rw-r--r--arch/ppc/kernel/signal.c771
2 files changed, 2 insertions, 773 deletions
diff --git a/arch/ppc/kernel/Makefile b/arch/ppc/kernel/Makefile
index 87d3be4af820..c178397c50af 100644
--- a/arch/ppc/kernel/Makefile
+++ b/arch/ppc/kernel/Makefile
@@ -13,7 +13,7 @@ extra-$(CONFIG_POWER4) += idle_power4.o
13extra-y += vmlinux.lds 13extra-y += vmlinux.lds
14 14
15obj-y := entry.o traps.o irq.o idle.o time.o misc.o \ 15obj-y := entry.o traps.o irq.o idle.o time.o misc.o \
16 process.o signal.o align.o \ 16 process.o align.o \
17 syscalls.o setup.o \ 17 syscalls.o setup.o \
18 ppc_htab.o perfmon.o 18 ppc_htab.o perfmon.o
19obj-$(CONFIG_6xx) += l2cr.o cpu_setup_6xx.o 19obj-$(CONFIG_6xx) += l2cr.o cpu_setup_6xx.o
@@ -38,7 +38,7 @@ endif
38 38
39else 39else
40obj-y := irq.o idle.o time.o \ 40obj-y := irq.o idle.o time.o \
41 signal.o align.o perfmon.o 41 align.o perfmon.o
42obj-$(CONFIG_6xx) += l2cr.o cpu_setup_6xx.o 42obj-$(CONFIG_6xx) += l2cr.o cpu_setup_6xx.o
43obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o 43obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o
44obj-$(CONFIG_MODULES) += module.o 44obj-$(CONFIG_MODULES) += module.o
diff --git a/arch/ppc/kernel/signal.c b/arch/ppc/kernel/signal.c
deleted file mode 100644
index 2244bf91e593..000000000000
--- a/arch/ppc/kernel/signal.c
+++ /dev/null
@@ -1,771 +0,0 @@
1/*
2 * arch/ppc/kernel/signal.c
3 *
4 * PowerPC version
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 *
7 * Derived from "arch/i386/kernel/signal.c"
8 * Copyright (C) 1991, 1992 Linus Torvalds
9 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
17#include <linux/sched.h>
18#include <linux/mm.h>
19#include <linux/smp.h>
20#include <linux/smp_lock.h>
21#include <linux/kernel.h>
22#include <linux/signal.h>
23#include <linux/errno.h>
24#include <linux/wait.h>
25#include <linux/ptrace.h>
26#include <linux/unistd.h>
27#include <linux/stddef.h>
28#include <linux/elf.h>
29#include <linux/tty.h>
30#include <linux/binfmts.h>
31#include <linux/suspend.h>
32#include <asm/ucontext.h>
33#include <asm/uaccess.h>
34#include <asm/pgtable.h>
35#include <asm/cacheflush.h>
36
37#undef DEBUG_SIG
38
39#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
40
41extern void sigreturn_exit(struct pt_regs *);
42
43#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
44
45int do_signal(sigset_t *oldset, struct pt_regs *regs);
46
47/*
48 * Atomically swap in the new signal mask, and wait for a signal.
49 */
50int
51sys_sigsuspend(old_sigset_t mask, int p2, int p3, int p4, int p6, int p7,
52 struct pt_regs *regs)
53{
54 sigset_t saveset;
55
56 mask &= _BLOCKABLE;
57 spin_lock_irq(&current->sighand->siglock);
58 saveset = current->blocked;
59 siginitset(&current->blocked, mask);
60 recalc_sigpending();
61 spin_unlock_irq(&current->sighand->siglock);
62
63 regs->result = -EINTR;
64 regs->gpr[3] = EINTR;
65 regs->ccr |= 0x10000000;
66 while (1) {
67 current->state = TASK_INTERRUPTIBLE;
68 schedule();
69 if (do_signal(&saveset, regs))
70 sigreturn_exit(regs);
71 }
72}
73
74int
75sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, int p3, int p4,
76 int p6, int p7, struct pt_regs *regs)
77{
78 sigset_t saveset, newset;
79
80 /* XXX: Don't preclude handling different sized sigset_t's. */
81 if (sigsetsize != sizeof(sigset_t))
82 return -EINVAL;
83
84 if (copy_from_user(&newset, unewset, sizeof(newset)))
85 return -EFAULT;
86 sigdelsetmask(&newset, ~_BLOCKABLE);
87
88 spin_lock_irq(&current->sighand->siglock);
89 saveset = current->blocked;
90 current->blocked = newset;
91 recalc_sigpending();
92 spin_unlock_irq(&current->sighand->siglock);
93
94 regs->result = -EINTR;
95 regs->gpr[3] = EINTR;
96 regs->ccr |= 0x10000000;
97 while (1) {
98 current->state = TASK_INTERRUPTIBLE;
99 schedule();
100 if (do_signal(&saveset, regs))
101 sigreturn_exit(regs);
102 }
103}
104
105
106int
107sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, int r5,
108 int r6, int r7, int r8, struct pt_regs *regs)
109{
110 return do_sigaltstack(uss, uoss, regs->gpr[1]);
111}
112
113int
114sys_sigaction(int sig, const struct old_sigaction __user *act,
115 struct old_sigaction __user *oact)
116{
117 struct k_sigaction new_ka, old_ka;
118 int ret;
119
120 if (act) {
121 old_sigset_t mask;
122 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
123 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
124 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
125 return -EFAULT;
126 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
127 __get_user(mask, &act->sa_mask);
128 siginitset(&new_ka.sa.sa_mask, mask);
129 }
130
131 ret = do_sigaction(sig, (act? &new_ka: NULL), (oact? &old_ka: NULL));
132
133 if (!ret && oact) {
134 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
135 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
136 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
137 return -EFAULT;
138 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
139 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
140 }
141
142 return ret;
143}
144
145/*
146 * When we have signals to deliver, we set up on the
147 * user stack, going down from the original stack pointer:
148 * a sigregs struct
149 * a sigcontext struct
150 * a gap of __SIGNAL_FRAMESIZE bytes
151 *
152 * Each of these things must be a multiple of 16 bytes in size.
153 *
154 */
155struct sigregs {
156 struct mcontext mctx; /* all the register values */
157 /* Programs using the rs6000/xcoff abi can save up to 19 gp regs
158 and 18 fp regs below sp before decrementing it. */
159 int abigap[56];
160};
161
162/* We use the mc_pad field for the signal return trampoline. */
163#define tramp mc_pad
164
165/*
166 * When we have rt signals to deliver, we set up on the
167 * user stack, going down from the original stack pointer:
168 * one rt_sigframe struct (siginfo + ucontext + ABI gap)
169 * a gap of __SIGNAL_FRAMESIZE+16 bytes
170 * (the +16 is to get the siginfo and ucontext in the same
171 * positions as in older kernels).
172 *
173 * Each of these things must be a multiple of 16 bytes in size.
174 *
175 */
176struct rt_sigframe
177{
178 struct siginfo info;
179 struct ucontext uc;
180 /* Programs using the rs6000/xcoff abi can save up to 19 gp regs
181 and 18 fp regs below sp before decrementing it. */
182 int abigap[56];
183};
184
185/*
186 * Save the current user registers on the user stack.
187 * We only save the altivec/spe registers if the process has used
188 * altivec/spe instructions at some point.
189 */
190static int
191save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, int sigret)
192{
193 /* save general and floating-point registers */
194 CHECK_FULL_REGS(regs);
195 preempt_disable();
196 if (regs->msr & MSR_FP)
197 giveup_fpu(current);
198#ifdef CONFIG_ALTIVEC
199 if (current->thread.used_vr && (regs->msr & MSR_VEC))
200 giveup_altivec(current);
201#endif /* CONFIG_ALTIVEC */
202#ifdef CONFIG_SPE
203 if (current->thread.used_spe && (regs->msr & MSR_SPE))
204 giveup_spe(current);
205#endif /* CONFIG_ALTIVEC */
206 preempt_enable();
207
208 if (__copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE)
209 || __copy_to_user(&frame->mc_fregs, current->thread.fpr,
210 ELF_NFPREG * sizeof(double)))
211 return 1;
212
213 current->thread.fpscr = 0; /* turn off all fp exceptions */
214
215#ifdef CONFIG_ALTIVEC
216 /* save altivec registers */
217 if (current->thread.used_vr) {
218 if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
219 ELF_NVRREG * sizeof(vector128)))
220 return 1;
221 /* set MSR_VEC in the saved MSR value to indicate that
222 frame->mc_vregs contains valid data */
223 if (__put_user(regs->msr | MSR_VEC, &frame->mc_gregs[PT_MSR]))
224 return 1;
225 }
226 /* else assert((regs->msr & MSR_VEC) == 0) */
227
228 /* We always copy to/from vrsave, it's 0 if we don't have or don't
229 * use altivec. Since VSCR only contains 32 bits saved in the least
230 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
231 * most significant bits of that same vector. --BenH
232 */
233 if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
234 return 1;
235#endif /* CONFIG_ALTIVEC */
236
237#ifdef CONFIG_SPE
238 /* save spe registers */
239 if (current->thread.used_spe) {
240 if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
241 ELF_NEVRREG * sizeof(u32)))
242 return 1;
243 /* set MSR_SPE in the saved MSR value to indicate that
244 frame->mc_vregs contains valid data */
245 if (__put_user(regs->msr | MSR_SPE, &frame->mc_gregs[PT_MSR]))
246 return 1;
247 }
248 /* else assert((regs->msr & MSR_SPE) == 0) */
249
250 /* We always copy to/from spefscr */
251 if (__put_user(current->thread.spefscr, (u32 *)&frame->mc_vregs + ELF_NEVRREG))
252 return 1;
253#endif /* CONFIG_SPE */
254
255 if (sigret) {
256 /* Set up the sigreturn trampoline: li r0,sigret; sc */
257 if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
258 || __put_user(0x44000002UL, &frame->tramp[1]))
259 return 1;
260 flush_icache_range((unsigned long) &frame->tramp[0],
261 (unsigned long) &frame->tramp[2]);
262 }
263
264 return 0;
265}
266
267/*
268 * Restore the current user register values from the user stack,
269 * (except for MSR).
270 */
271static int
272restore_user_regs(struct pt_regs *regs, struct mcontext __user *sr, int sig)
273{
274 unsigned long save_r2 = 0;
275#if defined(CONFIG_ALTIVEC) || defined(CONFIG_SPE)
276 unsigned long msr;
277#endif
278
279 /* backup/restore the TLS as we don't want it to be modified */
280 if (!sig)
281 save_r2 = regs->gpr[2];
282 /* copy up to but not including MSR */
283 if (__copy_from_user(regs, &sr->mc_gregs, PT_MSR * sizeof(elf_greg_t)))
284 return 1;
285 /* copy from orig_r3 (the word after the MSR) up to the end */
286 if (__copy_from_user(&regs->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
287 GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t)))
288 return 1;
289 if (!sig)
290 regs->gpr[2] = save_r2;
291
292 /* force the process to reload the FP registers from
293 current->thread when it next does FP instructions */
294 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
295 if (__copy_from_user(current->thread.fpr, &sr->mc_fregs,
296 sizeof(sr->mc_fregs)))
297 return 1;
298
299#ifdef CONFIG_ALTIVEC
300 /* force the process to reload the altivec registers from
301 current->thread when it next does altivec instructions */
302 regs->msr &= ~MSR_VEC;
303 if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_VEC) != 0) {
304 /* restore altivec registers from the stack */
305 if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
306 sizeof(sr->mc_vregs)))
307 return 1;
308 } else if (current->thread.used_vr)
309 memset(&current->thread.vr, 0, ELF_NVRREG * sizeof(vector128));
310
311 /* Always get VRSAVE back */
312 if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
313 return 1;
314#endif /* CONFIG_ALTIVEC */
315
316#ifdef CONFIG_SPE
317 /* force the process to reload the spe registers from
318 current->thread when it next does spe instructions */
319 regs->msr &= ~MSR_SPE;
320 if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_SPE) != 0) {
321 /* restore spe registers from the stack */
322 if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
323 ELF_NEVRREG * sizeof(u32)))
324 return 1;
325 } else if (current->thread.used_spe)
326 memset(&current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
327
328 /* Always get SPEFSCR back */
329 if (__get_user(current->thread.spefscr, (u32 *)&sr->mc_vregs + ELF_NEVRREG))
330 return 1;
331#endif /* CONFIG_SPE */
332
333#ifndef CONFIG_SMP
334 preempt_disable();
335 if (last_task_used_math == current)
336 last_task_used_math = NULL;
337 if (last_task_used_altivec == current)
338 last_task_used_altivec = NULL;
339 if (last_task_used_spe == current)
340 last_task_used_spe = NULL;
341 preempt_enable();
342#endif
343 return 0;
344}
345
346/*
347 * Restore the user process's signal mask
348 */
349static void
350restore_sigmask(sigset_t *set)
351{
352 sigdelsetmask(set, ~_BLOCKABLE);
353 spin_lock_irq(&current->sighand->siglock);
354 current->blocked = *set;
355 recalc_sigpending();
356 spin_unlock_irq(&current->sighand->siglock);
357}
358
359/*
360 * Set up a signal frame for a "real-time" signal handler
361 * (one which gets siginfo).
362 */
363static void
364handle_rt_signal(unsigned long sig, struct k_sigaction *ka,
365 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs,
366 unsigned long newsp)
367{
368 struct rt_sigframe __user *rt_sf;
369 struct mcontext __user *frame;
370 unsigned long origsp = newsp;
371
372 /* Set up Signal Frame */
373 /* Put a Real Time Context onto stack */
374 newsp -= sizeof(*rt_sf);
375 rt_sf = (struct rt_sigframe __user *) newsp;
376
377 /* create a stack frame for the caller of the handler */
378 newsp -= __SIGNAL_FRAMESIZE + 16;
379
380 if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp))
381 goto badframe;
382
383 /* Put the siginfo & fill in most of the ucontext */
384 if (copy_siginfo_to_user(&rt_sf->info, info)
385 || __put_user(0, &rt_sf->uc.uc_flags)
386 || __put_user(0, &rt_sf->uc.uc_link)
387 || __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp)
388 || __put_user(sas_ss_flags(regs->gpr[1]),
389 &rt_sf->uc.uc_stack.ss_flags)
390 || __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size)
391 || __put_user(&rt_sf->uc.uc_mcontext, &rt_sf->uc.uc_regs)
392 || __copy_to_user(&rt_sf->uc.uc_sigmask, oldset, sizeof(*oldset)))
393 goto badframe;
394
395 /* Save user registers on the stack */
396 frame = &rt_sf->uc.uc_mcontext;
397 if (save_user_regs(regs, frame, __NR_rt_sigreturn))
398 goto badframe;
399
400 if (put_user(regs->gpr[1], (unsigned long __user *)newsp))
401 goto badframe;
402 regs->gpr[1] = newsp;
403 regs->gpr[3] = sig;
404 regs->gpr[4] = (unsigned long) &rt_sf->info;
405 regs->gpr[5] = (unsigned long) &rt_sf->uc;
406 regs->gpr[6] = (unsigned long) rt_sf;
407 regs->nip = (unsigned long) ka->sa.sa_handler;
408 regs->link = (unsigned long) frame->tramp;
409 regs->trap = 0;
410
411 return;
412
413badframe:
414#ifdef DEBUG_SIG
415 printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n",
416 regs, frame, newsp);
417#endif
418 force_sigsegv(sig, current);
419}
420
421static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
422{
423 sigset_t set;
424 struct mcontext __user *mcp;
425
426 if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(set))
427 || __get_user(mcp, &ucp->uc_regs))
428 return -EFAULT;
429 restore_sigmask(&set);
430 if (restore_user_regs(regs, mcp, sig))
431 return -EFAULT;
432
433 return 0;
434}
435
436int sys_swapcontext(struct ucontext __user *old_ctx,
437 struct ucontext __user *new_ctx,
438 int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
439{
440 unsigned char tmp;
441
442 /* Context size is for future use. Right now, we only make sure
443 * we are passed something we understand
444 */
445 if (ctx_size < sizeof(struct ucontext))
446 return -EINVAL;
447
448 if (old_ctx != NULL) {
449 if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
450 || save_user_regs(regs, &old_ctx->uc_mcontext, 0)
451 || __copy_to_user(&old_ctx->uc_sigmask,
452 &current->blocked, sizeof(sigset_t))
453 || __put_user(&old_ctx->uc_mcontext, &old_ctx->uc_regs))
454 return -EFAULT;
455 }
456 if (new_ctx == NULL)
457 return 0;
458 if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
459 || __get_user(tmp, (u8 __user *) new_ctx)
460 || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
461 return -EFAULT;
462
463 /*
464 * If we get a fault copying the context into the kernel's
465 * image of the user's registers, we can't just return -EFAULT
466 * because the user's registers will be corrupted. For instance
467 * the NIP value may have been updated but not some of the
468 * other registers. Given that we have done the access_ok
469 * and successfully read the first and last bytes of the region
470 * above, this should only happen in an out-of-memory situation
471 * or if another thread unmaps the region containing the context.
472 * We kill the task with a SIGSEGV in this situation.
473 */
474 if (do_setcontext(new_ctx, regs, 0))
475 do_exit(SIGSEGV);
476 sigreturn_exit(regs);
477 /* doesn't actually return back to here */
478 return 0;
479}
480
481int sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
482 struct pt_regs *regs)
483{
484 struct rt_sigframe __user *rt_sf;
485
486 /* Always make any pending restarted system calls return -EINTR */
487 current_thread_info()->restart_block.fn = do_no_restart_syscall;
488
489 rt_sf = (struct rt_sigframe __user *)
490 (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
491 if (!access_ok(VERIFY_READ, rt_sf, sizeof(struct rt_sigframe)))
492 goto bad;
493 if (do_setcontext(&rt_sf->uc, regs, 1))
494 goto bad;
495
496 /*
497 * It's not clear whether or why it is desirable to save the
498 * sigaltstack setting on signal delivery and restore it on
499 * signal return. But other architectures do this and we have
500 * always done it up until now so it is probably better not to
501 * change it. -- paulus
502 */
503 do_sigaltstack(&rt_sf->uc.uc_stack, NULL, regs->gpr[1]);
504
505 sigreturn_exit(regs); /* doesn't return here */
506 return 0;
507
508 bad:
509 force_sig(SIGSEGV, current);
510 return 0;
511}
512
513int sys_debug_setcontext(struct ucontext __user *ctx,
514 int ndbg, struct sig_dbg_op __user *dbg,
515 int r6, int r7, int r8,
516 struct pt_regs *regs)
517{
518 struct sig_dbg_op op;
519 int i;
520 unsigned long new_msr = regs->msr;
521#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
522 unsigned long new_dbcr0 = current->thread.dbcr0;
523#endif
524
525 for (i=0; i<ndbg; i++) {
526 if (__copy_from_user(&op, dbg, sizeof(op)))
527 return -EFAULT;
528 switch (op.dbg_type) {
529 case SIG_DBG_SINGLE_STEPPING:
530#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
531 if (op.dbg_value) {
532 new_msr |= MSR_DE;
533 new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
534 } else {
535 new_msr &= ~MSR_DE;
536 new_dbcr0 &= ~(DBCR0_IDM | DBCR0_IC);
537 }
538#else
539 if (op.dbg_value)
540 new_msr |= MSR_SE;
541 else
542 new_msr &= ~MSR_SE;
543#endif
544 break;
545 case SIG_DBG_BRANCH_TRACING:
546#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
547 return -EINVAL;
548#else
549 if (op.dbg_value)
550 new_msr |= MSR_BE;
551 else
552 new_msr &= ~MSR_BE;
553#endif
554 break;
555
556 default:
557 return -EINVAL;
558 }
559 }
560
561 /* We wait until here to actually install the values in the
562 registers so if we fail in the above loop, it will not
563 affect the contents of these registers. After this point,
564 failure is a problem, anyway, and it's very unlikely unless
565 the user is really doing something wrong. */
566 regs->msr = new_msr;
567#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
568 current->thread.dbcr0 = new_dbcr0;
569#endif
570
571 /*
572 * If we get a fault copying the context into the kernel's
573 * image of the user's registers, we can't just return -EFAULT
574 * because the user's registers will be corrupted. For instance
575 * the NIP value may have been updated but not some of the
576 * other registers. Given that we have done the access_ok
577 * and successfully read the first and last bytes of the region
578 * above, this should only happen in an out-of-memory situation
579 * or if another thread unmaps the region containing the context.
580 * We kill the task with a SIGSEGV in this situation.
581 */
582 if (do_setcontext(ctx, regs, 1)) {
583 force_sig(SIGSEGV, current);
584 goto out;
585 }
586
587 /*
588 * It's not clear whether or why it is desirable to save the
589 * sigaltstack setting on signal delivery and restore it on
590 * signal return. But other architectures do this and we have
591 * always done it up until now so it is probably better not to
592 * change it. -- paulus
593 */
594 do_sigaltstack(&ctx->uc_stack, NULL, regs->gpr[1]);
595
596 sigreturn_exit(regs);
597 /* doesn't actually return back to here */
598
599 out:
600 return 0;
601}
602
603/*
604 * OK, we're invoking a handler
605 */
606static void
607handle_signal(unsigned long sig, struct k_sigaction *ka,
608 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs,
609 unsigned long newsp)
610{
611 struct sigcontext __user *sc;
612 struct sigregs __user *frame;
613 unsigned long origsp = newsp;
614
615 /* Set up Signal Frame */
616 newsp -= sizeof(struct sigregs);
617 frame = (struct sigregs __user *) newsp;
618
619 /* Put a sigcontext on the stack */
620 newsp -= sizeof(*sc);
621 sc = (struct sigcontext __user *) newsp;
622
623 /* create a stack frame for the caller of the handler */
624 newsp -= __SIGNAL_FRAMESIZE;
625
626 if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp))
627 goto badframe;
628
629#if _NSIG != 64
630#error "Please adjust handle_signal()"
631#endif
632 if (__put_user((unsigned long) ka->sa.sa_handler, &sc->handler)
633 || __put_user(oldset->sig[0], &sc->oldmask)
634 || __put_user(oldset->sig[1], &sc->_unused[3])
635 || __put_user((struct pt_regs __user *)frame, &sc->regs)
636 || __put_user(sig, &sc->signal))
637 goto badframe;
638
639 if (save_user_regs(regs, &frame->mctx, __NR_sigreturn))
640 goto badframe;
641
642 if (put_user(regs->gpr[1], (unsigned long __user *)newsp))
643 goto badframe;
644 regs->gpr[1] = newsp;
645 regs->gpr[3] = sig;
646 regs->gpr[4] = (unsigned long) sc;
647 regs->nip = (unsigned long) ka->sa.sa_handler;
648 regs->link = (unsigned long) frame->mctx.tramp;
649 regs->trap = 0;
650
651 return;
652
653badframe:
654#ifdef DEBUG_SIG
655 printk("badframe in handle_signal, regs=%p frame=%p newsp=%lx\n",
656 regs, frame, newsp);
657#endif
658 force_sigsegv(sig, current);
659}
660
661/*
662 * Do a signal return; undo the signal stack.
663 */
664int sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
665 struct pt_regs *regs)
666{
667 struct sigcontext __user *sc;
668 struct sigcontext sigctx;
669 struct mcontext __user *sr;
670 sigset_t set;
671
672 /* Always make any pending restarted system calls return -EINTR */
673 current_thread_info()->restart_block.fn = do_no_restart_syscall;
674
675 sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
676 if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
677 goto badframe;
678
679 set.sig[0] = sigctx.oldmask;
680 set.sig[1] = sigctx._unused[3];
681 restore_sigmask(&set);
682
683 sr = (struct mcontext __user *) sigctx.regs;
684 if (!access_ok(VERIFY_READ, sr, sizeof(*sr))
685 || restore_user_regs(regs, sr, 1))
686 goto badframe;
687
688 sigreturn_exit(regs); /* doesn't return */
689 return 0;
690
691badframe:
692 force_sig(SIGSEGV, current);
693 return 0;
694}
695
696/*
697 * Note that 'init' is a special process: it doesn't get signals it doesn't
698 * want to handle. Thus you cannot kill init even with a SIGKILL even by
699 * mistake.
700 */
701int do_signal(sigset_t *oldset, struct pt_regs *regs)
702{
703 siginfo_t info;
704 struct k_sigaction ka;
705 unsigned long frame, newsp;
706 int signr, ret;
707
708 if (try_to_freeze()) {
709 signr = 0;
710 if (!signal_pending(current))
711 goto no_signal;
712 }
713
714 if (!oldset)
715 oldset = &current->blocked;
716
717 newsp = frame = 0;
718
719 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
720 no_signal:
721 if (TRAP(regs) == 0x0C00 /* System Call! */
722 && regs->ccr & 0x10000000 /* error signalled */
723 && ((ret = regs->gpr[3]) == ERESTARTSYS
724 || ret == ERESTARTNOHAND || ret == ERESTARTNOINTR
725 || ret == ERESTART_RESTARTBLOCK)) {
726
727 if (signr > 0
728 && (ret == ERESTARTNOHAND || ret == ERESTART_RESTARTBLOCK
729 || (ret == ERESTARTSYS
730 && !(ka.sa.sa_flags & SA_RESTART)))) {
731 /* make the system call return an EINTR error */
732 regs->result = -EINTR;
733 regs->gpr[3] = EINTR;
734 /* note that the cr0.SO bit is already set */
735 } else {
736 regs->nip -= 4; /* Back up & retry system call */
737 regs->result = 0;
738 regs->trap = 0;
739 if (ret == ERESTART_RESTARTBLOCK)
740 regs->gpr[0] = __NR_restart_syscall;
741 else
742 regs->gpr[3] = regs->orig_gpr3;
743 }
744 }
745
746 if (signr == 0)
747 return 0; /* no signals delivered */
748
749 if ((ka.sa.sa_flags & SA_ONSTACK) && current->sas_ss_size
750 && !on_sig_stack(regs->gpr[1]))
751 newsp = current->sas_ss_sp + current->sas_ss_size;
752 else
753 newsp = regs->gpr[1];
754 newsp &= ~0xfUL;
755
756 /* Whee! Actually deliver the signal. */
757 if (ka.sa.sa_flags & SA_SIGINFO)
758 handle_rt_signal(signr, &ka, &info, oldset, regs, newsp);
759 else
760 handle_signal(signr, &ka, &info, oldset, regs, newsp);
761
762 spin_lock_irq(&current->sighand->siglock);
763 sigorsets(&current->blocked,&current->blocked,&ka.sa.sa_mask);
764 if (!(ka.sa.sa_flags & SA_NODEFER))
765 sigaddset(&current->blocked, signr);
766 recalc_sigpending();
767 spin_unlock_irq(&current->sighand->siglock);
768
769 return 1;
770}
771
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-24 08:43:06 -0500