2 * linux/arch/ppc64/kernel/signal.c
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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
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.
17 #include <linux/config.h>
18 #include <linux/sched.h>
20 #include <linux/smp.h>
21 #include <linux/smp_lock.h>
22 #include <linux/kernel.h>
23 #include <linux/signal.h>
24 #include <linux/errno.h>
25 #include <linux/wait.h>
26 #include <linux/unistd.h>
27 #include <linux/stddef.h>
28 #include <linux/elf.h>
29 #include <asm/ppc32.h>
30 #include <asm/sigcontext.h>
31 #include <asm/ucontext.h>
32 #include <asm/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/ppcdebug.h>
35 #include <asm/unistd.h>
36 #include <asm/cacheflush.h>
40 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
43 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
46 #define GP_REGS_SIZE MIN(sizeof(elf_gregset_t), sizeof(struct pt_regs))
47 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
49 #define TRAMP_TRACEBACK 3
53 * When we have signals to deliver, we set up on the user stack,
54 * going down from the original stack pointer:
55 * 1) a rt_sigframe struct which contains the ucontext
56 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
57 * frame for the signal handler.
61 /* sys_rt_sigreturn requires the ucontext be the first field */
63 unsigned long _unused[2];
64 unsigned int tramp[TRAMP_SIZE];
65 struct siginfo *pinfo;
68 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
74 * Atomically swap in the new signal mask, and wait for a signal.
76 long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, int p3, int p4,
77 int p6, int p7, struct pt_regs *regs)
79 sigset_t saveset, newset;
81 /* XXX: Don't preclude handling different sized sigset_t's. */
82 if (sigsetsize != sizeof(sigset_t))
85 if (copy_from_user(&newset, unewset, sizeof(newset)))
87 sigdelsetmask(&newset, ~_BLOCKABLE);
89 spin_lock_irq(¤t->sighand->siglock);
90 saveset = current->blocked;
91 current->blocked = newset;
93 spin_unlock_irq(¤t->sighand->siglock);
95 regs->result = -EINTR;
97 regs->ccr |= 0x10000000;
99 current->state = TASK_INTERRUPTIBLE;
101 if (do_signal(&saveset, regs))
106 long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, unsigned long r5,
107 unsigned long r6, unsigned long r7, unsigned long r8,
108 struct pt_regs *regs)
110 return do_sigaltstack(uss, uoss, regs->gpr[1]);
115 * Set up the sigcontext for the signal frame.
118 static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
119 int signr, sigset_t *set, unsigned long handler)
121 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
122 * process never used altivec yet (MSR_VEC is zero in pt_regs of
123 * the context). This is very important because we must ensure we
124 * don't lose the VRSAVE content that may have been set prior to
125 * the process doing its first vector operation
126 * Userland shall check AT_HWCAP to know wether it can rely on the
127 * v_regs pointer or not
129 #ifdef CONFIG_ALTIVEC
130 elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve) & ~0xful);
134 if (regs->msr & MSR_FP)
137 /* Make sure signal doesn't get spurrious FP exceptions */
138 current->thread.fpscr = 0;
140 #ifdef CONFIG_ALTIVEC
141 err |= __put_user(v_regs, &sc->v_regs);
143 /* save altivec registers */
144 if (current->thread.used_vr) {
145 if (regs->msr & MSR_VEC)
146 giveup_altivec(current);
147 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
148 err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
149 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
150 * contains valid data.
152 regs->msr |= MSR_VEC;
154 /* We always copy to/from vrsave, it's 0 if we don't have or don't
157 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
158 #else /* CONFIG_ALTIVEC */
159 err |= __put_user(0, &sc->v_regs);
160 #endif /* CONFIG_ALTIVEC */
161 err |= __put_user(&sc->gp_regs, &sc->regs);
162 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
163 err |= __copy_to_user(&sc->fp_regs, ¤t->thread.fpr, FP_REGS_SIZE);
164 err |= __put_user(signr, &sc->signal);
165 err |= __put_user(handler, &sc->handler);
167 err |= __put_user(set->sig[0], &sc->oldmask);
173 * Restore the sigcontext from the signal frame.
176 static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
177 struct sigcontext __user *sc)
179 #ifdef CONFIG_ALTIVEC
180 elf_vrreg_t __user *v_regs;
182 unsigned long err = 0;
183 unsigned long save_r13;
184 elf_greg_t *gregs = (elf_greg_t *)regs;
187 /* If this is not a signal return, we preserve the TLS in r13 */
189 save_r13 = regs->gpr[13];
191 /* copy everything before MSR */
192 err |= __copy_from_user(regs, &sc->gp_regs,
193 PT_MSR*sizeof(unsigned long));
195 /* skip MSR and SOFTE */
196 for (i = PT_MSR+1; i <= PT_RESULT; i++) {
199 err |= __get_user(gregs[i], &sc->gp_regs[i]);
203 regs->gpr[13] = save_r13;
204 err |= __copy_from_user(¤t->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
206 err |= __get_user(set->sig[0], &sc->oldmask);
208 #ifdef CONFIG_ALTIVEC
209 err |= __get_user(v_regs, &sc->v_regs);
212 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
213 if (v_regs != 0 && (regs->msr & MSR_VEC) != 0)
214 err |= __copy_from_user(current->thread.vr, v_regs, 33 * sizeof(vector128));
215 else if (current->thread.used_vr)
216 memset(¤t->thread.vr, 0, 33);
217 /* Always get VRSAVE back */
219 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
221 current->thread.vrsave = 0;
222 #endif /* CONFIG_ALTIVEC */
224 /* Force reload of FP/VEC */
225 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC);
231 * Allocate space for the signal frame
233 static inline void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
238 /* Default to using normal stack */
239 newsp = regs->gpr[1];
241 if (ka->sa.sa_flags & SA_ONSTACK) {
242 if (! on_sig_stack(regs->gpr[1]))
243 newsp = (current->sas_ss_sp + current->sas_ss_size);
246 return (void __user *)((newsp - frame_size) & -8ul);
250 * Setup the trampoline code on the stack
252 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
257 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
258 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
259 /* li r0, __NR_[rt_]sigreturn| */
260 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
262 err |= __put_user(0x44000002UL, &tramp[2]);
264 /* Minimal traceback info */
265 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
266 err |= __put_user(0, &tramp[i]);
269 flush_icache_range((unsigned long) &tramp[0],
270 (unsigned long) &tramp[TRAMP_SIZE]);
276 * Restore the user process's signal mask (also used by signal32.c)
278 void restore_sigmask(sigset_t *set)
280 sigdelsetmask(set, ~_BLOCKABLE);
281 spin_lock_irq(¤t->sighand->siglock);
282 current->blocked = *set;
284 spin_unlock_irq(¤t->sighand->siglock);
289 * Handle {get,set,swap}_context operations
291 int sys_swapcontext(struct ucontext __user *old_ctx,
292 struct ucontext __user *new_ctx,
293 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
298 /* Context size is for future use. Right now, we only make sure
299 * we are passed something we understand
301 if (ctx_size < sizeof(struct ucontext))
304 if (old_ctx != NULL) {
305 if (verify_area(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
306 || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
307 || __copy_to_user(&old_ctx->uc_sigmask,
308 ¤t->blocked, sizeof(sigset_t)))
313 if (verify_area(VERIFY_READ, new_ctx, sizeof(*new_ctx))
314 || __get_user(tmp, (u8 __user *) new_ctx)
315 || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
319 * If we get a fault copying the context into the kernel's
320 * image of the user's registers, we can't just return -EFAULT
321 * because the user's registers will be corrupted. For instance
322 * the NIP value may have been updated but not some of the
323 * other registers. Given that we have done the verify_area
324 * and successfully read the first and last bytes of the region
325 * above, this should only happen in an out-of-memory situation
326 * or if another thread unmaps the region containing the context.
327 * We kill the task with a SIGSEGV in this situation.
330 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
332 restore_sigmask(&set);
333 if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
336 /* This returns like rt_sigreturn */
342 * Do a signal return; undo the signal stack.
345 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
346 unsigned long r6, unsigned long r7, unsigned long r8,
347 struct pt_regs *regs)
349 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
352 /* Always make any pending restarted system calls return -EINTR */
353 current_thread_info()->restart_block.fn = do_no_restart_syscall;
355 if (verify_area(VERIFY_READ, uc, sizeof(*uc)))
358 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
360 restore_sigmask(&set);
361 if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
364 /* do_sigaltstack expects a __user pointer and won't modify
365 * what's in there anyway
367 do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
373 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
374 regs, uc, &uc->uc_mcontext);
379 static void setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
380 sigset_t *set, struct pt_regs *regs)
382 /* Handler is *really* a pointer to the function descriptor for
383 * the signal routine. The first entry in the function
384 * descriptor is the entry address of signal and the second
385 * entry is the TOC value we need to use.
387 func_descr_t __user *funct_desc_ptr;
388 struct rt_sigframe __user *frame;
389 unsigned long newsp = 0;
392 frame = get_sigframe(ka, regs, sizeof(*frame));
394 if (verify_area(VERIFY_WRITE, frame, sizeof(*frame)))
397 err |= __put_user(&frame->info, &frame->pinfo);
398 err |= __put_user(&frame->uc, &frame->puc);
399 err |= copy_siginfo_to_user(&frame->info, info);
403 /* Create the ucontext. */
404 err |= __put_user(0, &frame->uc.uc_flags);
405 err |= __put_user(0, &frame->uc.uc_link);
406 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
407 err |= __put_user(sas_ss_flags(regs->gpr[1]),
408 &frame->uc.uc_stack.ss_flags);
409 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
410 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
411 (unsigned long)ka->sa.sa_handler);
412 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
416 /* Set up to return from userspace. */
417 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
421 funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;
423 /* Allocate a dummy caller frame for the signal handler. */
424 newsp = (unsigned long)frame - __SIGNAL_FRAMESIZE;
425 err |= put_user(0, (unsigned long __user *)newsp);
427 /* Set up "regs" so we "return" to the signal handler. */
428 err |= get_user(regs->nip, &funct_desc_ptr->entry);
429 regs->link = (unsigned long) &frame->tramp[0];
430 regs->gpr[1] = newsp;
431 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
432 regs->gpr[3] = signr;
434 if (ka->sa.sa_flags & SA_SIGINFO) {
435 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
436 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
437 regs->gpr[6] = (unsigned long) frame;
439 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
448 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
456 * OK, we're invoking a handler
458 static void handle_signal(unsigned long sig, struct k_sigaction *ka,
459 siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
461 /* Set up Signal Frame */
462 setup_rt_frame(sig, ka, info, oldset, regs);
464 if (ka->sa.sa_flags & SA_ONESHOT)
465 ka->sa.sa_handler = SIG_DFL;
467 if (!(ka->sa.sa_flags & SA_NODEFER)) {
468 spin_lock_irq(¤t->sighand->siglock);
469 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
470 sigaddset(¤t->blocked,sig);
472 spin_unlock_irq(¤t->sighand->siglock);
477 static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
479 switch ((int)regs->result) {
480 case -ERESTART_RESTARTBLOCK:
481 case -ERESTARTNOHAND:
482 /* ERESTARTNOHAND means that the syscall should only be
483 * restarted if there was no handler for the signal, and since
484 * we only get here if there is a handler, we dont restart.
486 regs->result = -EINTR;
489 /* ERESTARTSYS means to restart the syscall if there is no
490 * handler or the handler was registered with SA_RESTART
492 if (!(ka->sa.sa_flags & SA_RESTART)) {
493 regs->result = -EINTR;
497 case -ERESTARTNOINTR:
498 /* ERESTARTNOINTR means that the syscall should be
499 * called again after the signal handler returns.
501 regs->gpr[3] = regs->orig_gpr3;
509 * Note that 'init' is a special process: it doesn't get signals it doesn't
510 * want to handle. Thus you cannot kill init even with a SIGKILL even by
513 int do_signal(sigset_t *oldset, struct pt_regs *regs)
519 * If the current thread is 32 bit - invoke the
520 * 32 bit signal handling code
522 if (test_thread_flag(TIF_32BIT))
523 return do_signal32(oldset, regs);
526 oldset = ¤t->blocked;
528 signr = get_signal_to_deliver(&info, regs, NULL);
530 struct k_sigaction *ka = ¤t->sighand->action[signr-1];
532 /* Whee! Actually deliver the signal. */
533 if (regs->trap == 0x0C00)
534 syscall_restart(regs, ka);
535 handle_signal(signr, ka, &info, oldset, regs);
539 if (regs->trap == 0x0C00) { /* System Call! */
540 if ((int)regs->result == -ERESTARTNOHAND ||
541 (int)regs->result == -ERESTARTSYS ||
542 (int)regs->result == -ERESTARTNOINTR) {
543 regs->gpr[3] = regs->orig_gpr3;
544 regs->nip -= 4; /* Back up & retry system call */
546 } else if ((int)regs->result == -ERESTART_RESTARTBLOCK) {
547 regs->gpr[0] = __NR_restart_syscall;