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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 GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
42 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
44 #define TRAMP_TRACEBACK 3
48 * When we have signals to deliver, we set up on the user stack,
49 * going down from the original stack pointer:
50 * 1) a rt_sigframe struct which contains the ucontext
51 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
52 * frame for the signal handler.
56 /* sys_rt_sigreturn requires the ucontext be the first field */
58 unsigned long _unused
[2];
59 unsigned int tramp
[TRAMP_SIZE
];
60 struct siginfo __user
*pinfo
;
63 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
65 } __attribute__ ((aligned (16)));
68 * Set up the sigcontext for the signal frame.
71 static long setup_sigcontext(struct sigcontext __user
*sc
, struct pt_regs
*regs
,
72 int signr
, sigset_t
*set
, unsigned long handler
)
74 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
75 * process never used altivec yet (MSR_VEC is zero in pt_regs of
76 * the context). This is very important because we must ensure we
77 * don't lose the VRSAVE content that may have been set prior to
78 * the process doing its first vector operation
79 * Userland shall check AT_HWCAP to know wether it can rely on the
80 * v_regs pointer or not
83 elf_vrreg_t __user
*v_regs
= (elf_vrreg_t __user
*)(((unsigned long)sc
->vmx_reserve
+ 15) & ~0xful
);
87 flush_fp_to_thread(current
);
90 err
|= __put_user(v_regs
, &sc
->v_regs
);
92 /* save altivec registers */
93 if (current
->thread
.used_vr
) {
94 flush_altivec_to_thread(current
);
95 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
96 err
|= __copy_to_user(v_regs
, current
->thread
.vr
, 33 * sizeof(vector128
));
97 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
98 * contains valid data.
100 regs
->msr
|= MSR_VEC
;
102 /* We always copy to/from vrsave, it's 0 if we don't have or don't
105 err
|= __put_user(current
->thread
.vrsave
, (u32 __user
*)&v_regs
[33]);
106 #else /* CONFIG_ALTIVEC */
107 err
|= __put_user(0, &sc
->v_regs
);
108 #endif /* CONFIG_ALTIVEC */
109 err
|= __put_user(&sc
->gp_regs
, &sc
->regs
);
110 WARN_ON(!FULL_REGS(regs
));
111 err
|= __copy_to_user(&sc
->gp_regs
, regs
, GP_REGS_SIZE
);
112 err
|= __copy_to_user(&sc
->fp_regs
, ¤t
->thread
.fpr
, FP_REGS_SIZE
);
113 err
|= __put_user(signr
, &sc
->signal
);
114 err
|= __put_user(handler
, &sc
->handler
);
116 err
|= __put_user(set
->sig
[0], &sc
->oldmask
);
122 * Restore the sigcontext from the signal frame.
125 static long restore_sigcontext(struct pt_regs
*regs
, sigset_t
*set
, int sig
,
126 struct sigcontext __user
*sc
)
128 #ifdef CONFIG_ALTIVEC
129 elf_vrreg_t __user
*v_regs
;
131 unsigned long err
= 0;
132 unsigned long save_r13
= 0;
133 elf_greg_t
*gregs
= (elf_greg_t
*)regs
;
137 /* If this is not a signal return, we preserve the TLS in r13 */
139 save_r13
= regs
->gpr
[13];
141 /* copy everything before MSR */
142 err
|= __copy_from_user(regs
, &sc
->gp_regs
,
143 PT_MSR
*sizeof(unsigned long));
145 /* get MSR separately, transfer the LE bit if doing signal return */
146 err
|= __get_user(msr
, &sc
->gp_regs
[PT_MSR
]);
148 regs
->msr
= (regs
->msr
& ~MSR_LE
) | (msr
& MSR_LE
);
151 for (i
= PT_MSR
+1; i
<= PT_RESULT
; i
++) {
154 err
|= __get_user(gregs
[i
], &sc
->gp_regs
[i
]);
158 regs
->gpr
[13] = save_r13
;
160 err
|= __get_user(set
->sig
[0], &sc
->oldmask
);
163 * Do this before updating the thread state in
164 * current->thread.fpr/vr. That way, if we get preempted
165 * and another task grabs the FPU/Altivec, it won't be
166 * tempted to save the current CPU state into the thread_struct
167 * and corrupt what we are writing there.
169 discard_lazy_cpu_state();
172 * Force reload of FP/VEC.
173 * This has to be done before copying stuff into current->thread.fpr/vr
174 * for the reasons explained in the previous comment.
176 regs
->msr
&= ~(MSR_FP
| MSR_FE0
| MSR_FE1
| MSR_VEC
);
178 err
|= __copy_from_user(¤t
->thread
.fpr
, &sc
->fp_regs
, FP_REGS_SIZE
);
180 #ifdef CONFIG_ALTIVEC
181 err
|= __get_user(v_regs
, &sc
->v_regs
);
184 if (v_regs
&& !access_ok(VERIFY_READ
, v_regs
, 34 * sizeof(vector128
)))
186 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
187 if (v_regs
!= 0 && (msr
& MSR_VEC
) != 0)
188 err
|= __copy_from_user(current
->thread
.vr
, v_regs
,
189 33 * sizeof(vector128
));
190 else if (current
->thread
.used_vr
)
191 memset(current
->thread
.vr
, 0, 33 * sizeof(vector128
));
192 /* Always get VRSAVE back */
194 err
|= __get_user(current
->thread
.vrsave
, (u32 __user
*)&v_regs
[33]);
196 current
->thread
.vrsave
= 0;
197 #endif /* CONFIG_ALTIVEC */
203 * Setup the trampoline code on the stack
205 static long setup_trampoline(unsigned int syscall
, unsigned int __user
*tramp
)
210 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
211 err
|= __put_user(0x38210000UL
| (__SIGNAL_FRAMESIZE
& 0xffff), &tramp
[0]);
212 /* li r0, __NR_[rt_]sigreturn| */
213 err
|= __put_user(0x38000000UL
| (syscall
& 0xffff), &tramp
[1]);
215 err
|= __put_user(0x44000002UL
, &tramp
[2]);
217 /* Minimal traceback info */
218 for (i
=TRAMP_TRACEBACK
; i
< TRAMP_SIZE
;i
++)
219 err
|= __put_user(0, &tramp
[i
]);
222 flush_icache_range((unsigned long) &tramp
[0],
223 (unsigned long) &tramp
[TRAMP_SIZE
]);
229 * Handle {get,set,swap}_context operations
231 int sys_swapcontext(struct ucontext __user
*old_ctx
,
232 struct ucontext __user
*new_ctx
,
233 long ctx_size
, long r6
, long r7
, long r8
, struct pt_regs
*regs
)
238 /* Context size is for future use. Right now, we only make sure
239 * we are passed something we understand
241 if (ctx_size
< sizeof(struct ucontext
))
244 if (old_ctx
!= NULL
) {
245 if (!access_ok(VERIFY_WRITE
, old_ctx
, sizeof(*old_ctx
))
246 || setup_sigcontext(&old_ctx
->uc_mcontext
, regs
, 0, NULL
, 0)
247 || __copy_to_user(&old_ctx
->uc_sigmask
,
248 ¤t
->blocked
, sizeof(sigset_t
)))
253 if (!access_ok(VERIFY_READ
, new_ctx
, sizeof(*new_ctx
))
254 || __get_user(tmp
, (u8 __user
*) new_ctx
)
255 || __get_user(tmp
, (u8 __user
*) (new_ctx
+ 1) - 1))
259 * If we get a fault copying the context into the kernel's
260 * image of the user's registers, we can't just return -EFAULT
261 * because the user's registers will be corrupted. For instance
262 * the NIP value may have been updated but not some of the
263 * other registers. Given that we have done the access_ok
264 * and successfully read the first and last bytes of the region
265 * above, this should only happen in an out-of-memory situation
266 * or if another thread unmaps the region containing the context.
267 * We kill the task with a SIGSEGV in this situation.
270 if (__copy_from_user(&set
, &new_ctx
->uc_sigmask
, sizeof(set
)))
272 restore_sigmask(&set
);
273 if (restore_sigcontext(regs
, NULL
, 0, &new_ctx
->uc_mcontext
))
276 /* This returns like rt_sigreturn */
277 set_thread_flag(TIF_RESTOREALL
);
283 * Do a signal return; undo the signal stack.
286 int sys_rt_sigreturn(unsigned long r3
, unsigned long r4
, unsigned long r5
,
287 unsigned long r6
, unsigned long r7
, unsigned long r8
,
288 struct pt_regs
*regs
)
290 struct ucontext __user
*uc
= (struct ucontext __user
*)regs
->gpr
[1];
293 /* Always make any pending restarted system calls return -EINTR */
294 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
296 if (!access_ok(VERIFY_READ
, uc
, sizeof(*uc
)))
299 if (__copy_from_user(&set
, &uc
->uc_sigmask
, sizeof(set
)))
301 restore_sigmask(&set
);
302 if (restore_sigcontext(regs
, NULL
, 1, &uc
->uc_mcontext
))
305 /* do_sigaltstack expects a __user pointer and won't modify
306 * what's in there anyway
308 do_sigaltstack(&uc
->uc_stack
, NULL
, regs
->gpr
[1]);
310 set_thread_flag(TIF_RESTOREALL
);
315 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
316 regs
, uc
, &uc
->uc_mcontext
);
318 force_sig(SIGSEGV
, current
);
322 int handle_rt_signal64(int signr
, struct k_sigaction
*ka
, siginfo_t
*info
,
323 sigset_t
*set
, struct pt_regs
*regs
)
325 /* Handler is *really* a pointer to the function descriptor for
326 * the signal routine. The first entry in the function
327 * descriptor is the entry address of signal and the second
328 * entry is the TOC value we need to use.
330 func_descr_t __user
*funct_desc_ptr
;
331 struct rt_sigframe __user
*frame
;
332 unsigned long newsp
= 0;
335 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
336 if (unlikely(frame
== NULL
))
339 err
|= __put_user(&frame
->info
, &frame
->pinfo
);
340 err
|= __put_user(&frame
->uc
, &frame
->puc
);
341 err
|= copy_siginfo_to_user(&frame
->info
, info
);
345 /* Create the ucontext. */
346 err
|= __put_user(0, &frame
->uc
.uc_flags
);
347 err
|= __put_user(0, &frame
->uc
.uc_link
);
348 err
|= __put_user(current
->sas_ss_sp
, &frame
->uc
.uc_stack
.ss_sp
);
349 err
|= __put_user(sas_ss_flags(regs
->gpr
[1]),
350 &frame
->uc
.uc_stack
.ss_flags
);
351 err
|= __put_user(current
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
352 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
, regs
, signr
, NULL
,
353 (unsigned long)ka
->sa
.sa_handler
);
354 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
358 /* Make sure signal handler doesn't get spurious FP exceptions */
359 current
->thread
.fpscr
.val
= 0;
361 /* Set up to return from userspace. */
362 if (vdso64_rt_sigtramp
&& current
->mm
->context
.vdso_base
) {
363 regs
->link
= current
->mm
->context
.vdso_base
+ vdso64_rt_sigtramp
;
365 err
|= setup_trampoline(__NR_rt_sigreturn
, &frame
->tramp
[0]);
368 regs
->link
= (unsigned long) &frame
->tramp
[0];
370 funct_desc_ptr
= (func_descr_t __user
*) ka
->sa
.sa_handler
;
372 /* Allocate a dummy caller frame for the signal handler. */
373 newsp
= ((unsigned long)frame
) - __SIGNAL_FRAMESIZE
;
374 err
|= put_user(regs
->gpr
[1], (unsigned long __user
*)newsp
);
376 /* Set up "regs" so we "return" to the signal handler. */
377 err
|= get_user(regs
->nip
, &funct_desc_ptr
->entry
);
378 /* enter the signal handler in big-endian mode */
379 regs
->msr
&= ~MSR_LE
;
380 regs
->gpr
[1] = newsp
;
381 err
|= get_user(regs
->gpr
[2], &funct_desc_ptr
->toc
);
382 regs
->gpr
[3] = signr
;
384 if (ka
->sa
.sa_flags
& SA_SIGINFO
) {
385 err
|= get_user(regs
->gpr
[4], (unsigned long __user
*)&frame
->pinfo
);
386 err
|= get_user(regs
->gpr
[5], (unsigned long __user
*)&frame
->puc
);
387 regs
->gpr
[6] = (unsigned long) frame
;
389 regs
->gpr
[4] = (unsigned long)&frame
->uc
.uc_mcontext
;
398 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
401 force_sigsegv(signr
, current
);