]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - arch/arm/kernel/signal.c
2 * linux/arch/arm/kernel/signal.c
4 * Copyright (C) 1995-2009 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 #include <linux/errno.h>
11 #include <linux/signal.h>
12 #include <linux/personality.h>
13 #include <linux/uaccess.h>
14 #include <linux/tracehook.h>
17 #include <asm/cacheflush.h>
18 #include <asm/ucontext.h>
19 #include <asm/unistd.h>
25 * For ARM syscalls, we encode the syscall number into the instruction.
27 #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
28 #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
31 * With EABI, the syscall number has to be loaded into r7.
33 #define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
34 #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
37 * For Thumb syscalls, we pass the syscall number via r7. We therefore
38 * need two 16-bit instructions.
40 #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
41 #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
43 const unsigned long sigreturn_codes
[7] = {
44 MOV_R7_NR_SIGRETURN
, SWI_SYS_SIGRETURN
, SWI_THUMB_SIGRETURN
,
45 MOV_R7_NR_RT_SIGRETURN
, SWI_SYS_RT_SIGRETURN
, SWI_THUMB_RT_SIGRETURN
,
49 * atomically swap in the new signal mask, and wait for a signal.
51 asmlinkage
int sys_sigsuspend(int restart
, unsigned long oldmask
, old_sigset_t mask
)
54 siginitset(&blocked
, mask
);
55 return sigsuspend(&blocked
);
59 sys_sigaction(int sig
, const struct old_sigaction __user
*act
,
60 struct old_sigaction __user
*oact
)
62 struct k_sigaction new_ka
, old_ka
;
67 if (!access_ok(VERIFY_READ
, act
, sizeof(*act
)) ||
68 __get_user(new_ka
.sa
.sa_handler
, &act
->sa_handler
) ||
69 __get_user(new_ka
.sa
.sa_restorer
, &act
->sa_restorer
) ||
70 __get_user(new_ka
.sa
.sa_flags
, &act
->sa_flags
) ||
71 __get_user(mask
, &act
->sa_mask
))
73 siginitset(&new_ka
.sa
.sa_mask
, mask
);
76 ret
= do_sigaction(sig
, act
? &new_ka
: NULL
, oact
? &old_ka
: NULL
);
79 if (!access_ok(VERIFY_WRITE
, oact
, sizeof(*oact
)) ||
80 __put_user(old_ka
.sa
.sa_handler
, &oact
->sa_handler
) ||
81 __put_user(old_ka
.sa
.sa_restorer
, &oact
->sa_restorer
) ||
82 __put_user(old_ka
.sa
.sa_flags
, &oact
->sa_flags
) ||
83 __put_user(old_ka
.sa
.sa_mask
.sig
[0], &oact
->sa_mask
))
91 static int preserve_crunch_context(struct crunch_sigframe __user
*frame
)
93 char kbuf
[sizeof(*frame
) + 8];
94 struct crunch_sigframe
*kframe
;
96 /* the crunch context must be 64 bit aligned */
97 kframe
= (struct crunch_sigframe
*)((unsigned long)(kbuf
+ 8) & ~7);
98 kframe
->magic
= CRUNCH_MAGIC
;
99 kframe
->size
= CRUNCH_STORAGE_SIZE
;
100 crunch_task_copy(current_thread_info(), &kframe
->storage
);
101 return __copy_to_user(frame
, kframe
, sizeof(*frame
));
104 static int restore_crunch_context(struct crunch_sigframe __user
*frame
)
106 char kbuf
[sizeof(*frame
) + 8];
107 struct crunch_sigframe
*kframe
;
109 /* the crunch context must be 64 bit aligned */
110 kframe
= (struct crunch_sigframe
*)((unsigned long)(kbuf
+ 8) & ~7);
111 if (__copy_from_user(kframe
, frame
, sizeof(*frame
)))
113 if (kframe
->magic
!= CRUNCH_MAGIC
||
114 kframe
->size
!= CRUNCH_STORAGE_SIZE
)
116 crunch_task_restore(current_thread_info(), &kframe
->storage
);
123 static int preserve_iwmmxt_context(struct iwmmxt_sigframe
*frame
)
125 char kbuf
[sizeof(*frame
) + 8];
126 struct iwmmxt_sigframe
*kframe
;
128 /* the iWMMXt context must be 64 bit aligned */
129 kframe
= (struct iwmmxt_sigframe
*)((unsigned long)(kbuf
+ 8) & ~7);
130 kframe
->magic
= IWMMXT_MAGIC
;
131 kframe
->size
= IWMMXT_STORAGE_SIZE
;
132 iwmmxt_task_copy(current_thread_info(), &kframe
->storage
);
133 return __copy_to_user(frame
, kframe
, sizeof(*frame
));
136 static int restore_iwmmxt_context(struct iwmmxt_sigframe
*frame
)
138 char kbuf
[sizeof(*frame
) + 8];
139 struct iwmmxt_sigframe
*kframe
;
141 /* the iWMMXt context must be 64 bit aligned */
142 kframe
= (struct iwmmxt_sigframe
*)((unsigned long)(kbuf
+ 8) & ~7);
143 if (__copy_from_user(kframe
, frame
, sizeof(*frame
)))
145 if (kframe
->magic
!= IWMMXT_MAGIC
||
146 kframe
->size
!= IWMMXT_STORAGE_SIZE
)
148 iwmmxt_task_restore(current_thread_info(), &kframe
->storage
);
156 static int preserve_vfp_context(struct vfp_sigframe __user
*frame
)
158 const unsigned long magic
= VFP_MAGIC
;
159 const unsigned long size
= VFP_STORAGE_SIZE
;
162 __put_user_error(magic
, &frame
->magic
, err
);
163 __put_user_error(size
, &frame
->size
, err
);
168 return vfp_preserve_user_clear_hwstate(&frame
->ufp
, &frame
->ufp_exc
);
171 static int restore_vfp_context(struct vfp_sigframe __user
*frame
)
177 __get_user_error(magic
, &frame
->magic
, err
);
178 __get_user_error(size
, &frame
->size
, err
);
182 if (magic
!= VFP_MAGIC
|| size
!= VFP_STORAGE_SIZE
)
185 return vfp_restore_user_hwstate(&frame
->ufp
, &frame
->ufp_exc
);
191 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
195 unsigned long retcode
[2];
203 static int restore_sigframe(struct pt_regs
*regs
, struct sigframe __user
*sf
)
205 struct aux_sigframe __user
*aux
;
209 err
= __copy_from_user(&set
, &sf
->uc
.uc_sigmask
, sizeof(set
));
211 set_current_blocked(&set
);
213 __get_user_error(regs
->ARM_r0
, &sf
->uc
.uc_mcontext
.arm_r0
, err
);
214 __get_user_error(regs
->ARM_r1
, &sf
->uc
.uc_mcontext
.arm_r1
, err
);
215 __get_user_error(regs
->ARM_r2
, &sf
->uc
.uc_mcontext
.arm_r2
, err
);
216 __get_user_error(regs
->ARM_r3
, &sf
->uc
.uc_mcontext
.arm_r3
, err
);
217 __get_user_error(regs
->ARM_r4
, &sf
->uc
.uc_mcontext
.arm_r4
, err
);
218 __get_user_error(regs
->ARM_r5
, &sf
->uc
.uc_mcontext
.arm_r5
, err
);
219 __get_user_error(regs
->ARM_r6
, &sf
->uc
.uc_mcontext
.arm_r6
, err
);
220 __get_user_error(regs
->ARM_r7
, &sf
->uc
.uc_mcontext
.arm_r7
, err
);
221 __get_user_error(regs
->ARM_r8
, &sf
->uc
.uc_mcontext
.arm_r8
, err
);
222 __get_user_error(regs
->ARM_r9
, &sf
->uc
.uc_mcontext
.arm_r9
, err
);
223 __get_user_error(regs
->ARM_r10
, &sf
->uc
.uc_mcontext
.arm_r10
, err
);
224 __get_user_error(regs
->ARM_fp
, &sf
->uc
.uc_mcontext
.arm_fp
, err
);
225 __get_user_error(regs
->ARM_ip
, &sf
->uc
.uc_mcontext
.arm_ip
, err
);
226 __get_user_error(regs
->ARM_sp
, &sf
->uc
.uc_mcontext
.arm_sp
, err
);
227 __get_user_error(regs
->ARM_lr
, &sf
->uc
.uc_mcontext
.arm_lr
, err
);
228 __get_user_error(regs
->ARM_pc
, &sf
->uc
.uc_mcontext
.arm_pc
, err
);
229 __get_user_error(regs
->ARM_cpsr
, &sf
->uc
.uc_mcontext
.arm_cpsr
, err
);
231 err
|= !valid_user_regs(regs
);
233 aux
= (struct aux_sigframe __user
*) sf
->uc
.uc_regspace
;
236 err
|= restore_crunch_context(&aux
->crunch
);
239 if (err
== 0 && test_thread_flag(TIF_USING_IWMMXT
))
240 err
|= restore_iwmmxt_context(&aux
->iwmmxt
);
244 err
|= restore_vfp_context(&aux
->vfp
);
250 asmlinkage
int sys_sigreturn(struct pt_regs
*regs
)
252 struct sigframe __user
*frame
;
254 /* Always make any pending restarted system calls return -EINTR */
255 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
258 * Since we stacked the signal on a 64-bit boundary,
259 * then 'sp' should be word aligned here. If it's
260 * not, then the user is trying to mess with us.
262 if (regs
->ARM_sp
& 7)
265 frame
= (struct sigframe __user
*)regs
->ARM_sp
;
267 if (!access_ok(VERIFY_READ
, frame
, sizeof (*frame
)))
270 if (restore_sigframe(regs
, frame
))
276 force_sig(SIGSEGV
, current
);
280 asmlinkage
int sys_rt_sigreturn(struct pt_regs
*regs
)
282 struct rt_sigframe __user
*frame
;
284 /* Always make any pending restarted system calls return -EINTR */
285 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
288 * Since we stacked the signal on a 64-bit boundary,
289 * then 'sp' should be word aligned here. If it's
290 * not, then the user is trying to mess with us.
292 if (regs
->ARM_sp
& 7)
295 frame
= (struct rt_sigframe __user
*)regs
->ARM_sp
;
297 if (!access_ok(VERIFY_READ
, frame
, sizeof (*frame
)))
300 if (restore_sigframe(regs
, &frame
->sig
))
303 if (do_sigaltstack(&frame
->sig
.uc
.uc_stack
, NULL
, regs
->ARM_sp
) == -EFAULT
)
309 force_sig(SIGSEGV
, current
);
314 setup_sigframe(struct sigframe __user
*sf
, struct pt_regs
*regs
, sigset_t
*set
)
316 struct aux_sigframe __user
*aux
;
319 __put_user_error(regs
->ARM_r0
, &sf
->uc
.uc_mcontext
.arm_r0
, err
);
320 __put_user_error(regs
->ARM_r1
, &sf
->uc
.uc_mcontext
.arm_r1
, err
);
321 __put_user_error(regs
->ARM_r2
, &sf
->uc
.uc_mcontext
.arm_r2
, err
);
322 __put_user_error(regs
->ARM_r3
, &sf
->uc
.uc_mcontext
.arm_r3
, err
);
323 __put_user_error(regs
->ARM_r4
, &sf
->uc
.uc_mcontext
.arm_r4
, err
);
324 __put_user_error(regs
->ARM_r5
, &sf
->uc
.uc_mcontext
.arm_r5
, err
);
325 __put_user_error(regs
->ARM_r6
, &sf
->uc
.uc_mcontext
.arm_r6
, err
);
326 __put_user_error(regs
->ARM_r7
, &sf
->uc
.uc_mcontext
.arm_r7
, err
);
327 __put_user_error(regs
->ARM_r8
, &sf
->uc
.uc_mcontext
.arm_r8
, err
);
328 __put_user_error(regs
->ARM_r9
, &sf
->uc
.uc_mcontext
.arm_r9
, err
);
329 __put_user_error(regs
->ARM_r10
, &sf
->uc
.uc_mcontext
.arm_r10
, err
);
330 __put_user_error(regs
->ARM_fp
, &sf
->uc
.uc_mcontext
.arm_fp
, err
);
331 __put_user_error(regs
->ARM_ip
, &sf
->uc
.uc_mcontext
.arm_ip
, err
);
332 __put_user_error(regs
->ARM_sp
, &sf
->uc
.uc_mcontext
.arm_sp
, err
);
333 __put_user_error(regs
->ARM_lr
, &sf
->uc
.uc_mcontext
.arm_lr
, err
);
334 __put_user_error(regs
->ARM_pc
, &sf
->uc
.uc_mcontext
.arm_pc
, err
);
335 __put_user_error(regs
->ARM_cpsr
, &sf
->uc
.uc_mcontext
.arm_cpsr
, err
);
337 __put_user_error(current
->thread
.trap_no
, &sf
->uc
.uc_mcontext
.trap_no
, err
);
338 __put_user_error(current
->thread
.error_code
, &sf
->uc
.uc_mcontext
.error_code
, err
);
339 __put_user_error(current
->thread
.address
, &sf
->uc
.uc_mcontext
.fault_address
, err
);
340 __put_user_error(set
->sig
[0], &sf
->uc
.uc_mcontext
.oldmask
, err
);
342 err
|= __copy_to_user(&sf
->uc
.uc_sigmask
, set
, sizeof(*set
));
344 aux
= (struct aux_sigframe __user
*) sf
->uc
.uc_regspace
;
347 err
|= preserve_crunch_context(&aux
->crunch
);
350 if (err
== 0 && test_thread_flag(TIF_USING_IWMMXT
))
351 err
|= preserve_iwmmxt_context(&aux
->iwmmxt
);
355 err
|= preserve_vfp_context(&aux
->vfp
);
357 __put_user_error(0, &aux
->end_magic
, err
);
362 static inline void __user
*
363 get_sigframe(struct k_sigaction
*ka
, struct pt_regs
*regs
, int framesize
)
365 unsigned long sp
= regs
->ARM_sp
;
369 * This is the X/Open sanctioned signal stack switching.
371 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) && !sas_ss_flags(sp
))
372 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
375 * ATPCS B01 mandates 8-byte alignment
377 frame
= (void __user
*)((sp
- framesize
) & ~7);
380 * Check that we can actually write to the signal frame.
382 if (!access_ok(VERIFY_WRITE
, frame
, framesize
))
389 setup_return(struct pt_regs
*regs
, struct k_sigaction
*ka
,
390 unsigned long __user
*rc
, void __user
*frame
, int usig
)
392 unsigned long handler
= (unsigned long)ka
->sa
.sa_handler
;
393 unsigned long retcode
;
395 unsigned long cpsr
= regs
->ARM_cpsr
& ~(PSR_f
| PSR_E_BIT
);
397 cpsr
|= PSR_ENDSTATE
;
400 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
402 if (ka
->sa
.sa_flags
& SA_THIRTYTWO
)
403 cpsr
= (cpsr
& ~MODE_MASK
) | USR_MODE
;
405 #ifdef CONFIG_ARM_THUMB
406 if (elf_hwcap
& HWCAP_THUMB
) {
408 * The LSB of the handler determines if we're going to
409 * be using THUMB or ARM mode for this signal handler.
415 #if __LINUX_ARM_ARCH__ >= 7
416 /* clear the If-Then Thumb-2 execution state */
417 cpsr
&= ~PSR_IT_MASK
;
424 if (ka
->sa
.sa_flags
& SA_RESTORER
) {
425 retcode
= (unsigned long)ka
->sa
.sa_restorer
;
427 unsigned int idx
= thumb
<< 1;
429 if (ka
->sa
.sa_flags
& SA_SIGINFO
)
432 if (__put_user(sigreturn_codes
[idx
], rc
) ||
433 __put_user(sigreturn_codes
[idx
+1], rc
+1))
436 if (cpsr
& MODE32_BIT
) {
438 * 32-bit code can use the new high-page
439 * signal return code support.
441 retcode
= KERN_SIGRETURN_CODE
+ (idx
<< 2) + thumb
;
444 * Ensure that the instruction cache sees
445 * the return code written onto the stack.
447 flush_icache_range((unsigned long)rc
,
448 (unsigned long)(rc
+ 2));
450 retcode
= ((unsigned long)rc
) + thumb
;
455 regs
->ARM_sp
= (unsigned long)frame
;
456 regs
->ARM_lr
= retcode
;
457 regs
->ARM_pc
= handler
;
458 regs
->ARM_cpsr
= cpsr
;
464 setup_frame(int usig
, struct k_sigaction
*ka
, sigset_t
*set
, struct pt_regs
*regs
)
466 struct sigframe __user
*frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
473 * Set uc.uc_flags to a value which sc.trap_no would never have.
475 __put_user_error(0x5ac3c35a, &frame
->uc
.uc_flags
, err
);
477 err
|= setup_sigframe(frame
, regs
, set
);
479 err
= setup_return(regs
, ka
, frame
->retcode
, frame
, usig
);
485 setup_rt_frame(int usig
, struct k_sigaction
*ka
, siginfo_t
*info
,
486 sigset_t
*set
, struct pt_regs
*regs
)
488 struct rt_sigframe __user
*frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
495 err
|= copy_siginfo_to_user(&frame
->info
, info
);
497 __put_user_error(0, &frame
->sig
.uc
.uc_flags
, err
);
498 __put_user_error(NULL
, &frame
->sig
.uc
.uc_link
, err
);
500 memset(&stack
, 0, sizeof(stack
));
501 stack
.ss_sp
= (void __user
*)current
->sas_ss_sp
;
502 stack
.ss_flags
= sas_ss_flags(regs
->ARM_sp
);
503 stack
.ss_size
= current
->sas_ss_size
;
504 err
|= __copy_to_user(&frame
->sig
.uc
.uc_stack
, &stack
, sizeof(stack
));
506 err
|= setup_sigframe(&frame
->sig
, regs
, set
);
508 err
= setup_return(regs
, ka
, frame
->sig
.retcode
, frame
, usig
);
512 * For realtime signals we must also set the second and third
513 * arguments for the signal handler.
514 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
516 regs
->ARM_r1
= (unsigned long)&frame
->info
;
517 regs
->ARM_r2
= (unsigned long)&frame
->sig
.uc
;
524 * OK, we're invoking a handler
527 handle_signal(unsigned long sig
, struct k_sigaction
*ka
,
528 siginfo_t
*info
, struct pt_regs
*regs
)
530 struct thread_info
*thread
= current_thread_info();
531 struct task_struct
*tsk
= current
;
532 sigset_t
*oldset
= sigmask_to_save();
537 * translate the signal
539 if (usig
< 32 && thread
->exec_domain
&& thread
->exec_domain
->signal_invmap
)
540 usig
= thread
->exec_domain
->signal_invmap
[usig
];
543 * Set up the stack frame
545 if (ka
->sa
.sa_flags
& SA_SIGINFO
)
546 ret
= setup_rt_frame(usig
, ka
, info
, oldset
, regs
);
548 ret
= setup_frame(usig
, ka
, oldset
, regs
);
551 * Check that the resulting registers are actually sane.
553 ret
|= !valid_user_regs(regs
);
556 force_sigsegv(sig
, tsk
);
559 signal_delivered(sig
, info
, ka
, regs
, 0);
563 * Note that 'init' is a special process: it doesn't get signals it doesn't
564 * want to handle. Thus you cannot kill init even with a SIGKILL even by
567 * Note that we go through the signals twice: once to check the signals that
568 * the kernel can handle, and then we build all the user-level signal handling
569 * stack-frames in one go after that.
571 static int do_signal(struct pt_regs
*regs
, int syscall
)
573 unsigned int retval
= 0, continue_addr
= 0, restart_addr
= 0;
574 struct k_sigaction ka
;
580 * If we were from a system call, check for system call restarting...
583 continue_addr
= regs
->ARM_pc
;
584 restart_addr
= continue_addr
- (thumb_mode(regs
) ? 2 : 4);
585 retval
= regs
->ARM_r0
;
588 * Prepare for system call restart. We do this here so that a
589 * debugger will see the already changed PSW.
592 case -ERESTART_RESTARTBLOCK
:
594 case -ERESTARTNOHAND
:
596 case -ERESTARTNOINTR
:
598 regs
->ARM_r0
= regs
->ARM_ORIG_r0
;
599 regs
->ARM_pc
= restart_addr
;
605 * Get the signal to deliver. When running under ptrace, at this
606 * point the debugger may change all our registers ...
608 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
610 * Depending on the signal settings we may need to revert the
611 * decision to restart the system call. But skip this if a
612 * debugger has chosen to restart at a different PC.
614 if (regs
->ARM_pc
!= restart_addr
)
617 if (unlikely(restart
)) {
618 if (retval
== -ERESTARTNOHAND
||
619 retval
== -ERESTART_RESTARTBLOCK
620 || (retval
== -ERESTARTSYS
621 && !(ka
.sa
.sa_flags
& SA_RESTART
))) {
622 regs
->ARM_r0
= -EINTR
;
623 regs
->ARM_pc
= continue_addr
;
627 handle_signal(signr
, &ka
, &info
, regs
);
631 restore_saved_sigmask();
632 if (unlikely(restart
))
633 regs
->ARM_pc
= continue_addr
;
638 do_work_pending(struct pt_regs
*regs
, unsigned int thread_flags
, int syscall
)
641 if (likely(thread_flags
& _TIF_NEED_RESCHED
)) {
644 if (unlikely(!user_mode(regs
)))
647 if (thread_flags
& _TIF_SIGPENDING
) {
648 int restart
= do_signal(regs
, syscall
);
649 if (unlikely(restart
)) {
651 * Restart without handlers.
652 * Deal with it without leaving
659 clear_thread_flag(TIF_NOTIFY_RESUME
);
660 tracehook_notify_resume(regs
);
664 thread_flags
= current_thread_info()->flags
;
665 } while (thread_flags
& _TIF_WORK_MASK
);