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 <linux/ptrace.h>
30 #include <linux/module.h>
32 #include <asm/sigcontext.h>
33 #include <asm/ucontext.h>
34 #include <asm/uaccess.h>
35 #include <asm/pgtable.h>
36 #include <asm/unistd.h>
37 #include <asm/cacheflush.h>
42 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
44 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
45 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
47 #define TRAMP_TRACEBACK 3
51 * When we have signals to deliver, we set up on the user stack,
52 * going down from the original stack pointer:
53 * 1) a rt_sigframe struct which contains the ucontext
54 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
55 * frame for the signal handler.
59 /* sys_rt_sigreturn requires the ucontext be the first field */
61 unsigned long _unused
[2];
62 unsigned int tramp
[TRAMP_SIZE
];
63 struct siginfo
*pinfo
;
66 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
68 } __attribute__ ((aligned (16)));
72 * Atomically swap in the new signal mask, and wait for a signal.
74 long sys_rt_sigsuspend(sigset_t __user
*unewset
, size_t sigsetsize
, int p3
, int p4
,
75 int p6
, int p7
, struct pt_regs
*regs
)
77 sigset_t saveset
, newset
;
79 /* XXX: Don't preclude handling different sized sigset_t's. */
80 if (sigsetsize
!= sizeof(sigset_t
))
83 if (copy_from_user(&newset
, unewset
, sizeof(newset
)))
85 sigdelsetmask(&newset
, ~_BLOCKABLE
);
87 spin_lock_irq(¤t
->sighand
->siglock
);
88 saveset
= current
->blocked
;
89 current
->blocked
= newset
;
91 spin_unlock_irq(¤t
->sighand
->siglock
);
93 regs
->result
= -EINTR
;
95 regs
->ccr
|= 0x10000000;
97 current
->state
= TASK_INTERRUPTIBLE
;
99 if (do_signal(&saveset
, regs
)) {
100 set_thread_flag(TIF_RESTOREALL
);
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
+ 15) & ~0xful
);
134 flush_fp_to_thread(current
);
136 #ifdef CONFIG_ALTIVEC
137 err
|= __put_user(v_regs
, &sc
->v_regs
);
139 /* save altivec registers */
140 if (current
->thread
.used_vr
) {
141 flush_altivec_to_thread(current
);
142 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
143 err
|= __copy_to_user(v_regs
, current
->thread
.vr
, 33 * sizeof(vector128
));
144 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
145 * contains valid data.
147 regs
->msr
|= MSR_VEC
;
149 /* We always copy to/from vrsave, it's 0 if we don't have or don't
152 err
|= __put_user(current
->thread
.vrsave
, (u32 __user
*)&v_regs
[33]);
153 #else /* CONFIG_ALTIVEC */
154 err
|= __put_user(0, &sc
->v_regs
);
155 #endif /* CONFIG_ALTIVEC */
156 err
|= __put_user(&sc
->gp_regs
, &sc
->regs
);
157 if (!FULL_REGS(regs
)) {
158 /* Zero out the unsaved GPRs to avoid information
159 leak, and set TIF_SAVE_NVGPRS to ensure that the
160 registers do actually get saved later. */
161 memset(®s
->gpr
[14], 0, 18 * sizeof(unsigned long));
162 set_thread_flag(TIF_SAVE_NVGPRS
);
163 current_thread_info()->nvgprs_frame
= &sc
->gp_regs
;
165 err
|= __copy_to_user(&sc
->gp_regs
, regs
, GP_REGS_SIZE
);
166 err
|= __copy_to_user(&sc
->fp_regs
, ¤t
->thread
.fpr
, FP_REGS_SIZE
);
167 err
|= __put_user(signr
, &sc
->signal
);
168 err
|= __put_user(handler
, &sc
->handler
);
170 err
|= __put_user(set
->sig
[0], &sc
->oldmask
);
176 * Restore the sigcontext from the signal frame.
179 static long restore_sigcontext(struct pt_regs
*regs
, sigset_t
*set
, int sig
,
180 struct sigcontext __user
*sc
)
182 #ifdef CONFIG_ALTIVEC
183 elf_vrreg_t __user
*v_regs
;
185 unsigned long err
= 0;
186 unsigned long save_r13
= 0;
187 elf_greg_t
*gregs
= (elf_greg_t
*)regs
;
188 #ifdef CONFIG_ALTIVEC
193 /* If this is not a signal return, we preserve the TLS in r13 */
195 save_r13
= regs
->gpr
[13];
197 /* copy everything before MSR */
198 err
|= __copy_from_user(regs
, &sc
->gp_regs
,
199 PT_MSR
*sizeof(unsigned long));
201 /* skip MSR and SOFTE */
202 for (i
= PT_MSR
+1; i
<= PT_RESULT
; i
++) {
205 err
|= __get_user(gregs
[i
], &sc
->gp_regs
[i
]);
209 regs
->gpr
[13] = save_r13
;
210 err
|= __copy_from_user(¤t
->thread
.fpr
, &sc
->fp_regs
, FP_REGS_SIZE
);
212 err
|= __get_user(set
->sig
[0], &sc
->oldmask
);
214 #ifdef CONFIG_ALTIVEC
215 err
|= __get_user(v_regs
, &sc
->v_regs
);
216 err
|= __get_user(msr
, &sc
->gp_regs
[PT_MSR
]);
219 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
220 if (v_regs
!= 0 && (msr
& MSR_VEC
) != 0)
221 err
|= __copy_from_user(current
->thread
.vr
, v_regs
,
222 33 * sizeof(vector128
));
223 else if (current
->thread
.used_vr
)
224 memset(current
->thread
.vr
, 0, 33 * sizeof(vector128
));
225 /* Always get VRSAVE back */
227 err
|= __get_user(current
->thread
.vrsave
, (u32 __user
*)&v_regs
[33]);
229 current
->thread
.vrsave
= 0;
230 #endif /* CONFIG_ALTIVEC */
234 if (last_task_used_math
== current
)
235 last_task_used_math
= NULL
;
236 if (last_task_used_altivec
== current
)
237 last_task_used_altivec
= NULL
;
240 /* Force reload of FP/VEC */
241 regs
->msr
&= ~(MSR_FP
| MSR_FE0
| MSR_FE1
| MSR_VEC
);
247 * Allocate space for the signal frame
249 static inline void __user
* get_sigframe(struct k_sigaction
*ka
, struct pt_regs
*regs
,
254 /* Default to using normal stack */
255 newsp
= regs
->gpr
[1];
257 if (ka
->sa
.sa_flags
& SA_ONSTACK
) {
258 if (! on_sig_stack(regs
->gpr
[1]))
259 newsp
= (current
->sas_ss_sp
+ current
->sas_ss_size
);
262 return (void __user
*)((newsp
- frame_size
) & -16ul);
266 * Setup the trampoline code on the stack
268 static long setup_trampoline(unsigned int syscall
, unsigned int __user
*tramp
)
273 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
274 err
|= __put_user(0x38210000UL
| (__SIGNAL_FRAMESIZE
& 0xffff), &tramp
[0]);
275 /* li r0, __NR_[rt_]sigreturn| */
276 err
|= __put_user(0x38000000UL
| (syscall
& 0xffff), &tramp
[1]);
278 err
|= __put_user(0x44000002UL
, &tramp
[2]);
280 /* Minimal traceback info */
281 for (i
=TRAMP_TRACEBACK
; i
< TRAMP_SIZE
;i
++)
282 err
|= __put_user(0, &tramp
[i
]);
285 flush_icache_range((unsigned long) &tramp
[0],
286 (unsigned long) &tramp
[TRAMP_SIZE
]);
292 * Restore the user process's signal mask (also used by signal32.c)
294 void restore_sigmask(sigset_t
*set
)
296 sigdelsetmask(set
, ~_BLOCKABLE
);
297 spin_lock_irq(¤t
->sighand
->siglock
);
298 current
->blocked
= *set
;
300 spin_unlock_irq(¤t
->sighand
->siglock
);
305 * Handle {get,set,swap}_context operations
307 int sys_swapcontext(struct ucontext __user
*old_ctx
,
308 struct ucontext __user
*new_ctx
,
309 long ctx_size
, long r6
, long r7
, long r8
, struct pt_regs
*regs
)
314 /* Context size is for future use. Right now, we only make sure
315 * we are passed something we understand
317 if (ctx_size
< sizeof(struct ucontext
))
320 if (old_ctx
!= NULL
) {
321 if (!access_ok(VERIFY_WRITE
, old_ctx
, sizeof(*old_ctx
))
322 || setup_sigcontext(&old_ctx
->uc_mcontext
, regs
, 0, NULL
, 0)
323 || __copy_to_user(&old_ctx
->uc_sigmask
,
324 ¤t
->blocked
, sizeof(sigset_t
)))
329 if (!access_ok(VERIFY_READ
, new_ctx
, sizeof(*new_ctx
))
330 || __get_user(tmp
, (u8 __user
*) new_ctx
)
331 || __get_user(tmp
, (u8 __user
*) (new_ctx
+ 1) - 1))
335 * If we get a fault copying the context into the kernel's
336 * image of the user's registers, we can't just return -EFAULT
337 * because the user's registers will be corrupted. For instance
338 * the NIP value may have been updated but not some of the
339 * other registers. Given that we have done the access_ok
340 * and successfully read the first and last bytes of the region
341 * above, this should only happen in an out-of-memory situation
342 * or if another thread unmaps the region containing the context.
343 * We kill the task with a SIGSEGV in this situation.
346 if (__copy_from_user(&set
, &new_ctx
->uc_sigmask
, sizeof(set
)))
348 restore_sigmask(&set
);
349 if (restore_sigcontext(regs
, NULL
, 0, &new_ctx
->uc_mcontext
))
352 /* This returns like rt_sigreturn */
353 set_thread_flag(TIF_RESTOREALL
);
359 * Do a signal return; undo the signal stack.
362 int sys_rt_sigreturn(unsigned long r3
, unsigned long r4
, unsigned long r5
,
363 unsigned long r6
, unsigned long r7
, unsigned long r8
,
364 struct pt_regs
*regs
)
366 struct ucontext __user
*uc
= (struct ucontext __user
*)regs
->gpr
[1];
369 /* Always make any pending restarted system calls return -EINTR */
370 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
372 if (!access_ok(VERIFY_READ
, uc
, sizeof(*uc
)))
375 if (__copy_from_user(&set
, &uc
->uc_sigmask
, sizeof(set
)))
377 restore_sigmask(&set
);
378 if (restore_sigcontext(regs
, NULL
, 1, &uc
->uc_mcontext
))
381 /* do_sigaltstack expects a __user pointer and won't modify
382 * what's in there anyway
384 do_sigaltstack(&uc
->uc_stack
, NULL
, regs
->gpr
[1]);
386 set_thread_flag(TIF_RESTOREALL
);
391 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
392 regs
, uc
, &uc
->uc_mcontext
);
394 force_sig(SIGSEGV
, current
);
398 static int setup_rt_frame(int signr
, struct k_sigaction
*ka
, siginfo_t
*info
,
399 sigset_t
*set
, struct pt_regs
*regs
)
401 /* Handler is *really* a pointer to the function descriptor for
402 * the signal routine. The first entry in the function
403 * descriptor is the entry address of signal and the second
404 * entry is the TOC value we need to use.
406 func_descr_t __user
*funct_desc_ptr
;
407 struct rt_sigframe __user
*frame
;
408 unsigned long newsp
= 0;
411 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
413 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(*frame
)))
416 err
|= __put_user(&frame
->info
, &frame
->pinfo
);
417 err
|= __put_user(&frame
->uc
, &frame
->puc
);
418 err
|= copy_siginfo_to_user(&frame
->info
, info
);
422 /* Create the ucontext. */
423 err
|= __put_user(0, &frame
->uc
.uc_flags
);
424 err
|= __put_user(0, &frame
->uc
.uc_link
);
425 err
|= __put_user(current
->sas_ss_sp
, &frame
->uc
.uc_stack
.ss_sp
);
426 err
|= __put_user(sas_ss_flags(regs
->gpr
[1]),
427 &frame
->uc
.uc_stack
.ss_flags
);
428 err
|= __put_user(current
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
429 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
, regs
, signr
, NULL
,
430 (unsigned long)ka
->sa
.sa_handler
);
431 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
435 /* Make sure signal handler doesn't get spurious FP exceptions */
436 current
->thread
.fpscr
.val
= 0;
438 /* Set up to return from userspace. */
439 if (vdso64_rt_sigtramp
&& current
->thread
.vdso_base
) {
440 regs
->link
= current
->thread
.vdso_base
+ vdso64_rt_sigtramp
;
442 err
|= setup_trampoline(__NR_rt_sigreturn
, &frame
->tramp
[0]);
445 regs
->link
= (unsigned long) &frame
->tramp
[0];
447 funct_desc_ptr
= (func_descr_t __user
*) ka
->sa
.sa_handler
;
449 /* Allocate a dummy caller frame for the signal handler. */
450 newsp
= (unsigned long)frame
- __SIGNAL_FRAMESIZE
;
451 err
|= put_user(regs
->gpr
[1], (unsigned long __user
*)newsp
);
453 /* Set up "regs" so we "return" to the signal handler. */
454 err
|= get_user(regs
->nip
, &funct_desc_ptr
->entry
);
455 regs
->gpr
[1] = newsp
;
456 err
|= get_user(regs
->gpr
[2], &funct_desc_ptr
->toc
);
457 regs
->gpr
[3] = signr
;
459 if (ka
->sa
.sa_flags
& SA_SIGINFO
) {
460 err
|= get_user(regs
->gpr
[4], (unsigned long __user
*)&frame
->pinfo
);
461 err
|= get_user(regs
->gpr
[5], (unsigned long __user
*)&frame
->puc
);
462 regs
->gpr
[6] = (unsigned long) frame
;
464 regs
->gpr
[4] = (unsigned long)&frame
->uc
.uc_mcontext
;
473 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
476 force_sigsegv(signr
, current
);
482 * OK, we're invoking a handler
484 static int handle_signal(unsigned long sig
, struct k_sigaction
*ka
,
485 siginfo_t
*info
, sigset_t
*oldset
, struct pt_regs
*regs
)
489 /* Set up Signal Frame */
490 ret
= setup_rt_frame(sig
, ka
, info
, oldset
, regs
);
493 spin_lock_irq(¤t
->sighand
->siglock
);
494 sigorsets(¤t
->blocked
, ¤t
->blocked
, &ka
->sa
.sa_mask
);
495 if (!(ka
->sa
.sa_flags
& SA_NODEFER
))
496 sigaddset(¤t
->blocked
,sig
);
498 spin_unlock_irq(¤t
->sighand
->siglock
);
504 static inline void syscall_restart(struct pt_regs
*regs
, struct k_sigaction
*ka
)
506 switch ((int)regs
->result
) {
507 case -ERESTART_RESTARTBLOCK
:
508 case -ERESTARTNOHAND
:
509 /* ERESTARTNOHAND means that the syscall should only be
510 * restarted if there was no handler for the signal, and since
511 * we only get here if there is a handler, we dont restart.
513 regs
->result
= -EINTR
;
514 regs
->gpr
[3] = EINTR
;
515 regs
->ccr
|= 0x10000000;
518 /* ERESTARTSYS means to restart the syscall if there is no
519 * handler or the handler was registered with SA_RESTART
521 if (!(ka
->sa
.sa_flags
& SA_RESTART
)) {
522 regs
->result
= -EINTR
;
523 regs
->gpr
[3] = EINTR
;
524 regs
->ccr
|= 0x10000000;
528 case -ERESTARTNOINTR
:
529 /* ERESTARTNOINTR means that the syscall should be
530 * called again after the signal handler returns.
532 regs
->gpr
[3] = regs
->orig_gpr3
;
540 * Note that 'init' is a special process: it doesn't get signals it doesn't
541 * want to handle. Thus you cannot kill init even with a SIGKILL even by
544 int do_signal(sigset_t
*oldset
, struct pt_regs
*regs
)
548 struct k_sigaction ka
;
551 * If the current thread is 32 bit - invoke the
552 * 32 bit signal handling code
554 if (test_thread_flag(TIF_32BIT
))
555 return do_signal32(oldset
, regs
);
558 oldset
= ¤t
->blocked
;
560 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
562 /* Whee! Actually deliver the signal. */
563 if (TRAP(regs
) == 0x0C00)
564 syscall_restart(regs
, &ka
);
567 * Reenable the DABR before delivering the signal to
568 * user space. The DABR will have been cleared if it
569 * triggered inside the kernel.
571 if (current
->thread
.dabr
)
572 set_dabr(current
->thread
.dabr
);
574 return handle_signal(signr
, &ka
, &info
, oldset
, regs
);
577 if (TRAP(regs
) == 0x0C00) { /* System Call! */
578 if ((int)regs
->result
== -ERESTARTNOHAND
||
579 (int)regs
->result
== -ERESTARTSYS
||
580 (int)regs
->result
== -ERESTARTNOINTR
) {
581 regs
->gpr
[3] = regs
->orig_gpr3
;
582 regs
->nip
-= 4; /* Back up & retry system call */
584 } else if ((int)regs
->result
== -ERESTART_RESTARTBLOCK
) {
585 regs
->gpr
[0] = __NR_restart_syscall
;
593 EXPORT_SYMBOL(do_signal
);