5d2faf0fbf05b0d51388a3cf37cfdfff9f4af7ce
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 * Derived from "arch/i386/kernel/signal.c"
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
15 #include <linux/sched.h>
17 #include <linux/smp.h>
18 #include <linux/kernel.h>
19 #include <linux/signal.h>
20 #include <linux/errno.h>
21 #include <linux/wait.h>
22 #include <linux/unistd.h>
23 #include <linux/stddef.h>
24 #include <linux/elf.h>
25 #include <linux/ptrace.h>
26 #include <linux/module.h>
28 #include <asm/sigcontext.h>
29 #include <asm/ucontext.h>
30 #include <asm/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/unistd.h>
33 #include <asm/cacheflush.h>
34 #include <asm/syscalls.h>
41 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
43 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
44 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
46 #define TRAMP_TRACEBACK 3
50 * When we have signals to deliver, we set up on the user stack,
51 * going down from the original stack pointer:
52 * 1) a rt_sigframe struct which contains the ucontext
53 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
54 * frame for the signal handler.
58 /* sys_rt_sigreturn requires the ucontext be the first field */
60 unsigned long _unused
[2];
61 unsigned int tramp
[TRAMP_SIZE
];
62 struct siginfo __user
*pinfo
;
65 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
67 } __attribute__ ((aligned (16)));
69 long sys_sigaltstack(const stack_t __user
*uss
, stack_t __user
*uoss
, unsigned long r5
,
70 unsigned long r6
, unsigned long r7
, unsigned long r8
,
73 return do_sigaltstack(uss
, uoss
, regs
->gpr
[1]);
78 * Set up the sigcontext for the signal frame.
81 static long setup_sigcontext(struct sigcontext __user
*sc
, struct pt_regs
*regs
,
82 int signr
, sigset_t
*set
, unsigned long handler
)
84 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
85 * process never used altivec yet (MSR_VEC is zero in pt_regs of
86 * the context). This is very important because we must ensure we
87 * don't lose the VRSAVE content that may have been set prior to
88 * the process doing its first vector operation
89 * Userland shall check AT_HWCAP to know wether it can rely on the
90 * v_regs pointer or not
93 elf_vrreg_t __user
*v_regs
= (elf_vrreg_t __user
*)(((unsigned long)sc
->vmx_reserve
+ 15) & ~0xful
);
97 flush_fp_to_thread(current
);
100 err
|= __put_user(v_regs
, &sc
->v_regs
);
102 /* save altivec registers */
103 if (current
->thread
.used_vr
) {
104 flush_altivec_to_thread(current
);
105 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
106 err
|= __copy_to_user(v_regs
, current
->thread
.vr
, 33 * sizeof(vector128
));
107 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
108 * contains valid data.
110 regs
->msr
|= MSR_VEC
;
112 /* We always copy to/from vrsave, it's 0 if we don't have or don't
115 err
|= __put_user(current
->thread
.vrsave
, (u32 __user
*)&v_regs
[33]);
116 #else /* CONFIG_ALTIVEC */
117 err
|= __put_user(0, &sc
->v_regs
);
118 #endif /* CONFIG_ALTIVEC */
119 err
|= __put_user(&sc
->gp_regs
, &sc
->regs
);
120 WARN_ON(!FULL_REGS(regs
));
121 err
|= __copy_to_user(&sc
->gp_regs
, regs
, GP_REGS_SIZE
);
122 err
|= __copy_to_user(&sc
->fp_regs
, ¤t
->thread
.fpr
, FP_REGS_SIZE
);
123 err
|= __put_user(signr
, &sc
->signal
);
124 err
|= __put_user(handler
, &sc
->handler
);
126 err
|= __put_user(set
->sig
[0], &sc
->oldmask
);
132 * Restore the sigcontext from the signal frame.
135 static long restore_sigcontext(struct pt_regs
*regs
, sigset_t
*set
, int sig
,
136 struct sigcontext __user
*sc
)
138 #ifdef CONFIG_ALTIVEC
139 elf_vrreg_t __user
*v_regs
;
141 unsigned long err
= 0;
142 unsigned long save_r13
= 0;
143 elf_greg_t
*gregs
= (elf_greg_t
*)regs
;
147 /* If this is not a signal return, we preserve the TLS in r13 */
149 save_r13
= regs
->gpr
[13];
151 /* copy everything before MSR */
152 err
|= __copy_from_user(regs
, &sc
->gp_regs
,
153 PT_MSR
*sizeof(unsigned long));
155 /* get MSR separately, transfer the LE bit if doing signal return */
156 err
|= __get_user(msr
, &sc
->gp_regs
[PT_MSR
]);
158 regs
->msr
= (regs
->msr
& ~MSR_LE
) | (msr
& MSR_LE
);
161 for (i
= PT_MSR
+1; i
<= PT_RESULT
; i
++) {
164 err
|= __get_user(gregs
[i
], &sc
->gp_regs
[i
]);
168 regs
->gpr
[13] = save_r13
;
170 err
|= __get_user(set
->sig
[0], &sc
->oldmask
);
173 * Do this before updating the thread state in
174 * current->thread.fpr/vr. That way, if we get preempted
175 * and another task grabs the FPU/Altivec, it won't be
176 * tempted to save the current CPU state into the thread_struct
177 * and corrupt what we are writing there.
179 discard_lazy_cpu_state();
181 err
|= __copy_from_user(¤t
->thread
.fpr
, &sc
->fp_regs
, FP_REGS_SIZE
);
183 #ifdef CONFIG_ALTIVEC
184 err
|= __get_user(v_regs
, &sc
->v_regs
);
187 if (v_regs
&& !access_ok(VERIFY_READ
, v_regs
, 34 * sizeof(vector128
)))
189 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
190 if (v_regs
!= 0 && (msr
& MSR_VEC
) != 0)
191 err
|= __copy_from_user(current
->thread
.vr
, v_regs
,
192 33 * sizeof(vector128
));
193 else if (current
->thread
.used_vr
)
194 memset(current
->thread
.vr
, 0, 33 * sizeof(vector128
));
195 /* Always get VRSAVE back */
197 err
|= __get_user(current
->thread
.vrsave
, (u32 __user
*)&v_regs
[33]);
199 current
->thread
.vrsave
= 0;
200 #endif /* CONFIG_ALTIVEC */
202 /* Force reload of FP/VEC */
203 regs
->msr
&= ~(MSR_FP
| MSR_FE0
| MSR_FE1
| MSR_VEC
);
209 * Allocate space for the signal frame
211 static inline void __user
* get_sigframe(struct k_sigaction
*ka
, struct pt_regs
*regs
,
216 /* Default to using normal stack */
217 newsp
= regs
->gpr
[1];
219 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) && current
->sas_ss_size
) {
220 if (! on_sig_stack(regs
->gpr
[1]))
221 newsp
= (current
->sas_ss_sp
+ current
->sas_ss_size
);
224 return (void __user
*)((newsp
- frame_size
) & -16ul);
228 * Setup the trampoline code on the stack
230 static long setup_trampoline(unsigned int syscall
, unsigned int __user
*tramp
)
235 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
236 err
|= __put_user(0x38210000UL
| (__SIGNAL_FRAMESIZE
& 0xffff), &tramp
[0]);
237 /* li r0, __NR_[rt_]sigreturn| */
238 err
|= __put_user(0x38000000UL
| (syscall
& 0xffff), &tramp
[1]);
240 err
|= __put_user(0x44000002UL
, &tramp
[2]);
242 /* Minimal traceback info */
243 for (i
=TRAMP_TRACEBACK
; i
< TRAMP_SIZE
;i
++)
244 err
|= __put_user(0, &tramp
[i
]);
247 flush_icache_range((unsigned long) &tramp
[0],
248 (unsigned long) &tramp
[TRAMP_SIZE
]);
254 * Restore the user process's signal mask (also used by signal32.c)
256 void restore_sigmask(sigset_t
*set
)
258 sigdelsetmask(set
, ~_BLOCKABLE
);
259 spin_lock_irq(¤t
->sighand
->siglock
);
260 current
->blocked
= *set
;
262 spin_unlock_irq(¤t
->sighand
->siglock
);
267 * Handle {get,set,swap}_context operations
269 int sys_swapcontext(struct ucontext __user
*old_ctx
,
270 struct ucontext __user
*new_ctx
,
271 long ctx_size
, long r6
, long r7
, long r8
, struct pt_regs
*regs
)
276 /* Context size is for future use. Right now, we only make sure
277 * we are passed something we understand
279 if (ctx_size
< sizeof(struct ucontext
))
282 if (old_ctx
!= NULL
) {
283 if (!access_ok(VERIFY_WRITE
, old_ctx
, sizeof(*old_ctx
))
284 || setup_sigcontext(&old_ctx
->uc_mcontext
, regs
, 0, NULL
, 0)
285 || __copy_to_user(&old_ctx
->uc_sigmask
,
286 ¤t
->blocked
, sizeof(sigset_t
)))
291 if (!access_ok(VERIFY_READ
, new_ctx
, sizeof(*new_ctx
))
292 || __get_user(tmp
, (u8 __user
*) new_ctx
)
293 || __get_user(tmp
, (u8 __user
*) (new_ctx
+ 1) - 1))
297 * If we get a fault copying the context into the kernel's
298 * image of the user's registers, we can't just return -EFAULT
299 * because the user's registers will be corrupted. For instance
300 * the NIP value may have been updated but not some of the
301 * other registers. Given that we have done the access_ok
302 * and successfully read the first and last bytes of the region
303 * above, this should only happen in an out-of-memory situation
304 * or if another thread unmaps the region containing the context.
305 * We kill the task with a SIGSEGV in this situation.
308 if (__copy_from_user(&set
, &new_ctx
->uc_sigmask
, sizeof(set
)))
310 restore_sigmask(&set
);
311 if (restore_sigcontext(regs
, NULL
, 0, &new_ctx
->uc_mcontext
))
314 /* This returns like rt_sigreturn */
315 set_thread_flag(TIF_RESTOREALL
);
321 * Do a signal return; undo the signal stack.
324 int sys_rt_sigreturn(unsigned long r3
, unsigned long r4
, unsigned long r5
,
325 unsigned long r6
, unsigned long r7
, unsigned long r8
,
326 struct pt_regs
*regs
)
328 struct ucontext __user
*uc
= (struct ucontext __user
*)regs
->gpr
[1];
331 /* Always make any pending restarted system calls return -EINTR */
332 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
334 if (!access_ok(VERIFY_READ
, uc
, sizeof(*uc
)))
337 if (__copy_from_user(&set
, &uc
->uc_sigmask
, sizeof(set
)))
339 restore_sigmask(&set
);
340 if (restore_sigcontext(regs
, NULL
, 1, &uc
->uc_mcontext
))
343 /* do_sigaltstack expects a __user pointer and won't modify
344 * what's in there anyway
346 do_sigaltstack(&uc
->uc_stack
, NULL
, regs
->gpr
[1]);
348 set_thread_flag(TIF_RESTOREALL
);
353 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
354 regs
, uc
, &uc
->uc_mcontext
);
356 force_sig(SIGSEGV
, current
);
360 static int setup_rt_frame(int signr
, struct k_sigaction
*ka
, siginfo_t
*info
,
361 sigset_t
*set
, struct pt_regs
*regs
)
363 /* Handler is *really* a pointer to the function descriptor for
364 * the signal routine. The first entry in the function
365 * descriptor is the entry address of signal and the second
366 * entry is the TOC value we need to use.
368 func_descr_t __user
*funct_desc_ptr
;
369 struct rt_sigframe __user
*frame
;
370 unsigned long newsp
= 0;
373 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
375 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(*frame
)))
378 err
|= __put_user(&frame
->info
, &frame
->pinfo
);
379 err
|= __put_user(&frame
->uc
, &frame
->puc
);
380 err
|= copy_siginfo_to_user(&frame
->info
, info
);
384 /* Create the ucontext. */
385 err
|= __put_user(0, &frame
->uc
.uc_flags
);
386 err
|= __put_user(0, &frame
->uc
.uc_link
);
387 err
|= __put_user(current
->sas_ss_sp
, &frame
->uc
.uc_stack
.ss_sp
);
388 err
|= __put_user(sas_ss_flags(regs
->gpr
[1]),
389 &frame
->uc
.uc_stack
.ss_flags
);
390 err
|= __put_user(current
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
391 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
, regs
, signr
, NULL
,
392 (unsigned long)ka
->sa
.sa_handler
);
393 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
397 /* Make sure signal handler doesn't get spurious FP exceptions */
398 current
->thread
.fpscr
.val
= 0;
400 /* Set up to return from userspace. */
401 if (vdso64_rt_sigtramp
&& current
->mm
->context
.vdso_base
) {
402 regs
->link
= current
->mm
->context
.vdso_base
+ vdso64_rt_sigtramp
;
404 err
|= setup_trampoline(__NR_rt_sigreturn
, &frame
->tramp
[0]);
407 regs
->link
= (unsigned long) &frame
->tramp
[0];
409 funct_desc_ptr
= (func_descr_t __user
*) ka
->sa
.sa_handler
;
411 /* Allocate a dummy caller frame for the signal handler. */
412 newsp
= (unsigned long)frame
- __SIGNAL_FRAMESIZE
;
413 err
|= put_user(regs
->gpr
[1], (unsigned long __user
*)newsp
);
415 /* Set up "regs" so we "return" to the signal handler. */
416 err
|= get_user(regs
->nip
, &funct_desc_ptr
->entry
);
417 /* enter the signal handler in big-endian mode */
418 regs
->msr
&= ~MSR_LE
;
419 regs
->gpr
[1] = newsp
;
420 err
|= get_user(regs
->gpr
[2], &funct_desc_ptr
->toc
);
421 regs
->gpr
[3] = signr
;
423 if (ka
->sa
.sa_flags
& SA_SIGINFO
) {
424 err
|= get_user(regs
->gpr
[4], (unsigned long __user
*)&frame
->pinfo
);
425 err
|= get_user(regs
->gpr
[5], (unsigned long __user
*)&frame
->puc
);
426 regs
->gpr
[6] = (unsigned long) frame
;
428 regs
->gpr
[4] = (unsigned long)&frame
->uc
.uc_mcontext
;
437 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
440 force_sigsegv(signr
, current
);
446 * OK, we're invoking a handler
448 static int handle_signal(unsigned long sig
, struct k_sigaction
*ka
,
449 siginfo_t
*info
, sigset_t
*oldset
, struct pt_regs
*regs
)
453 /* Set up Signal Frame */
454 ret
= setup_rt_frame(sig
, ka
, info
, oldset
, regs
);
457 spin_lock_irq(¤t
->sighand
->siglock
);
458 sigorsets(¤t
->blocked
, ¤t
->blocked
, &ka
->sa
.sa_mask
);
459 if (!(ka
->sa
.sa_flags
& SA_NODEFER
))
460 sigaddset(¤t
->blocked
,sig
);
462 spin_unlock_irq(¤t
->sighand
->siglock
);
469 * Note that 'init' is a special process: it doesn't get signals it doesn't
470 * want to handle. Thus you cannot kill init even with a SIGKILL even by
473 int do_signal(sigset_t
*oldset
, struct pt_regs
*regs
)
477 struct k_sigaction ka
;
480 * If the current thread is 32 bit - invoke the
481 * 32 bit signal handling code
483 if (test_thread_flag(TIF_32BIT
))
484 return do_signal32(oldset
, regs
);
486 if (test_thread_flag(TIF_RESTORE_SIGMASK
))
487 oldset
= ¤t
->saved_sigmask
;
489 oldset
= ¤t
->blocked
;
491 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
493 /* Is there any syscall restart business here ? */
494 check_syscall_restart(regs
, &ka
, signr
> 0);
500 * Reenable the DABR before delivering the signal to
501 * user space. The DABR will have been cleared if it
502 * triggered inside the kernel.
504 if (current
->thread
.dabr
)
505 set_dabr(current
->thread
.dabr
);
507 /* Whee! Actually deliver the signal. */
508 ret
= handle_signal(signr
, &ka
, &info
, oldset
, regs
);
510 /* If a signal was successfully delivered, the saved sigmask is in
511 its frame, and we can clear the TIF_RESTORE_SIGMASK flag */
512 if (ret
&& test_thread_flag(TIF_RESTORE_SIGMASK
))
513 clear_thread_flag(TIF_RESTORE_SIGMASK
);
518 /* No signal to deliver -- put the saved sigmask back */
519 if (test_thread_flag(TIF_RESTORE_SIGMASK
)) {
520 clear_thread_flag(TIF_RESTORE_SIGMASK
);
521 sigprocmask(SIG_SETMASK
, ¤t
->saved_sigmask
, NULL
);
526 EXPORT_SYMBOL(do_signal
);
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