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 flush_fp_to_thread(current);
136 /* Make sure signal doesn't get spurrious FP exceptions */
137 current->thread.fpscr = 0;
139 #ifdef CONFIG_ALTIVEC
140 err |= __put_user(v_regs, &sc->v_regs);
142 /* save altivec registers */
143 if (current->thread.used_vr) {
144 flush_altivec_to_thread(current);
145 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
146 err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
147 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
148 * contains valid data.
150 regs->msr |= MSR_VEC;
152 /* We always copy to/from vrsave, it's 0 if we don't have or don't
155 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
156 #else /* CONFIG_ALTIVEC */
157 err |= __put_user(0, &sc->v_regs);
158 #endif /* CONFIG_ALTIVEC */
159 err |= __put_user(&sc->gp_regs, &sc->regs);
160 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
161 err |= __copy_to_user(&sc->fp_regs, ¤t->thread.fpr, FP_REGS_SIZE);
162 err |= __put_user(signr, &sc->signal);
163 err |= __put_user(handler, &sc->handler);
165 err |= __put_user(set->sig[0], &sc->oldmask);
171 * Restore the sigcontext from the signal frame.
174 static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
175 struct sigcontext __user *sc)
177 #ifdef CONFIG_ALTIVEC
178 elf_vrreg_t __user *v_regs;
180 unsigned long err = 0;
181 unsigned long save_r13;
182 elf_greg_t *gregs = (elf_greg_t *)regs;
185 /* If this is not a signal return, we preserve the TLS in r13 */
187 save_r13 = regs->gpr[13];
189 /* copy everything before MSR */
190 err |= __copy_from_user(regs, &sc->gp_regs,
191 PT_MSR*sizeof(unsigned long));
193 /* skip MSR and SOFTE */
194 for (i = PT_MSR+1; i <= PT_RESULT; i++) {
197 err |= __get_user(gregs[i], &sc->gp_regs[i]);
201 regs->gpr[13] = save_r13;
202 err |= __copy_from_user(¤t->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
204 err |= __get_user(set->sig[0], &sc->oldmask);
206 #ifdef CONFIG_ALTIVEC
207 err |= __get_user(v_regs, &sc->v_regs);
210 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
211 if (v_regs != 0 && (regs->msr & MSR_VEC) != 0)
212 err |= __copy_from_user(current->thread.vr, v_regs, 33 * sizeof(vector128));
213 else if (current->thread.used_vr)
214 memset(¤t->thread.vr, 0, 33);
215 /* Always get VRSAVE back */
217 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
219 current->thread.vrsave = 0;
220 #endif /* CONFIG_ALTIVEC */
222 /* Force reload of FP/VEC */
223 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC);
229 * Allocate space for the signal frame
231 static inline void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
236 /* Default to using normal stack */
237 newsp = regs->gpr[1];
239 if (ka->sa.sa_flags & SA_ONSTACK) {
240 if (! on_sig_stack(regs->gpr[1]))
241 newsp = (current->sas_ss_sp + current->sas_ss_size);
244 return (void __user *)((newsp - frame_size) & -8ul);
248 * Setup the trampoline code on the stack
250 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
255 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
256 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
257 /* li r0, __NR_[rt_]sigreturn| */
258 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
260 err |= __put_user(0x44000002UL, &tramp[2]);
262 /* Minimal traceback info */
263 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
264 err |= __put_user(0, &tramp[i]);
267 flush_icache_range((unsigned long) &tramp[0],
268 (unsigned long) &tramp[TRAMP_SIZE]);
274 * Restore the user process's signal mask (also used by signal32.c)
276 void restore_sigmask(sigset_t *set)
278 sigdelsetmask(set, ~_BLOCKABLE);
279 spin_lock_irq(¤t->sighand->siglock);
280 current->blocked = *set;
282 spin_unlock_irq(¤t->sighand->siglock);
287 * Handle {get,set,swap}_context operations
289 int sys_swapcontext(struct ucontext __user *old_ctx,
290 struct ucontext __user *new_ctx,
291 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
296 /* Context size is for future use. Right now, we only make sure
297 * we are passed something we understand
299 if (ctx_size < sizeof(struct ucontext))
302 if (old_ctx != NULL) {
303 if (verify_area(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
304 || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
305 || __copy_to_user(&old_ctx->uc_sigmask,
306 ¤t->blocked, sizeof(sigset_t)))
311 if (verify_area(VERIFY_READ, new_ctx, sizeof(*new_ctx))
312 || __get_user(tmp, (u8 __user *) new_ctx)
313 || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
317 * If we get a fault copying the context into the kernel's
318 * image of the user's registers, we can't just return -EFAULT
319 * because the user's registers will be corrupted. For instance
320 * the NIP value may have been updated but not some of the
321 * other registers. Given that we have done the verify_area
322 * and successfully read the first and last bytes of the region
323 * above, this should only happen in an out-of-memory situation
324 * or if another thread unmaps the region containing the context.
325 * We kill the task with a SIGSEGV in this situation.
328 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
330 restore_sigmask(&set);
331 if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
334 /* This returns like rt_sigreturn */
340 * Do a signal return; undo the signal stack.
343 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
344 unsigned long r6, unsigned long r7, unsigned long r8,
345 struct pt_regs *regs)
347 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
350 /* Always make any pending restarted system calls return -EINTR */
351 current_thread_info()->restart_block.fn = do_no_restart_syscall;
353 if (verify_area(VERIFY_READ, uc, sizeof(*uc)))
356 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
358 restore_sigmask(&set);
359 if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
362 /* do_sigaltstack expects a __user pointer and won't modify
363 * what's in there anyway
365 do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
371 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
372 regs, uc, &uc->uc_mcontext);
377 static void setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
378 sigset_t *set, struct pt_regs *regs)
380 /* Handler is *really* a pointer to the function descriptor for
381 * the signal routine. The first entry in the function
382 * descriptor is the entry address of signal and the second
383 * entry is the TOC value we need to use.
385 func_descr_t __user *funct_desc_ptr;
386 struct rt_sigframe __user *frame;
387 unsigned long newsp = 0;
390 frame = get_sigframe(ka, regs, sizeof(*frame));
392 if (verify_area(VERIFY_WRITE, frame, sizeof(*frame)))
395 err |= __put_user(&frame->info, &frame->pinfo);
396 err |= __put_user(&frame->uc, &frame->puc);
397 err |= copy_siginfo_to_user(&frame->info, info);
401 /* Create the ucontext. */
402 err |= __put_user(0, &frame->uc.uc_flags);
403 err |= __put_user(0, &frame->uc.uc_link);
404 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
405 err |= __put_user(sas_ss_flags(regs->gpr[1]),
406 &frame->uc.uc_stack.ss_flags);
407 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
408 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
409 (unsigned long)ka->sa.sa_handler);
410 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
414 /* Set up to return from userspace. */
415 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
419 funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;
421 /* Allocate a dummy caller frame for the signal handler. */
422 newsp = (unsigned long)frame - __SIGNAL_FRAMESIZE;
423 err |= put_user(0, (unsigned long __user *)newsp);
425 /* Set up "regs" so we "return" to the signal handler. */
426 err |= get_user(regs->nip, &funct_desc_ptr->entry);
427 regs->link = (unsigned long) &frame->tramp[0];
428 regs->gpr[1] = newsp;
429 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
430 regs->gpr[3] = signr;
432 if (ka->sa.sa_flags & SA_SIGINFO) {
433 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
434 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
435 regs->gpr[6] = (unsigned long) frame;
437 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
446 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
454 * OK, we're invoking a handler
456 static void handle_signal(unsigned long sig, struct k_sigaction *ka,
457 siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
459 /* Set up Signal Frame */
460 setup_rt_frame(sig, ka, info, oldset, regs);
462 if (ka->sa.sa_flags & SA_ONESHOT)
463 ka->sa.sa_handler = SIG_DFL;
465 if (!(ka->sa.sa_flags & SA_NODEFER)) {
466 spin_lock_irq(¤t->sighand->siglock);
467 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
468 sigaddset(¤t->blocked,sig);
470 spin_unlock_irq(¤t->sighand->siglock);
475 static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
477 switch ((int)regs->result) {
478 case -ERESTART_RESTARTBLOCK:
479 case -ERESTARTNOHAND:
480 /* ERESTARTNOHAND means that the syscall should only be
481 * restarted if there was no handler for the signal, and since
482 * we only get here if there is a handler, we dont restart.
484 regs->result = -EINTR;
487 /* ERESTARTSYS means to restart the syscall if there is no
488 * handler or the handler was registered with SA_RESTART
490 if (!(ka->sa.sa_flags & SA_RESTART)) {
491 regs->result = -EINTR;
495 case -ERESTARTNOINTR:
496 /* ERESTARTNOINTR means that the syscall should be
497 * called again after the signal handler returns.
499 regs->gpr[3] = regs->orig_gpr3;
507 * Note that 'init' is a special process: it doesn't get signals it doesn't
508 * want to handle. Thus you cannot kill init even with a SIGKILL even by
511 int do_signal(sigset_t *oldset, struct pt_regs *regs)
517 * If the current thread is 32 bit - invoke the
518 * 32 bit signal handling code
520 if (test_thread_flag(TIF_32BIT))
521 return do_signal32(oldset, regs);
524 oldset = ¤t->blocked;
526 signr = get_signal_to_deliver(&info, regs, NULL);
528 struct k_sigaction *ka = ¤t->sighand->action[signr-1];
530 /* Whee! Actually deliver the signal. */
531 if (TRAP(regs) == 0x0C00)
532 syscall_restart(regs, ka);
533 handle_signal(signr, ka, &info, oldset, regs);
537 if (TRAP(regs) == 0x0C00) { /* System Call! */
538 if ((int)regs->result == -ERESTARTNOHAND ||
539 (int)regs->result == -ERESTARTSYS ||
540 (int)regs->result == -ERESTARTNOINTR) {
541 regs->gpr[3] = regs->orig_gpr3;
542 regs->nip -= 4; /* Back up & retry system call */
544 } else if ((int)regs->result == -ERESTART_RESTARTBLOCK) {
545 regs->gpr[0] = __NR_restart_syscall;