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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - arch/powerpc/kernel/signal.c
2 * Common signal handling code for both 32 and 64 bits
4 * Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration
5 * Extracted from signal_32.c and signal_64.c
7 * This file is subject to the terms and conditions of the GNU General
8 * Public License. See the file README.legal in the main directory of
9 * this archive for more details.
12 #include <linux/tracehook.h>
13 #include <linux/signal.h>
14 #include <linux/uprobes.h>
15 #include <linux/key.h>
16 #include <linux/context_tracking.h>
17 #include <asm/hw_breakpoint.h>
18 #include <asm/uaccess.h>
19 #include <asm/unistd.h>
20 #include <asm/debug.h>
24 /* Log an error when sending an unhandled signal to a process. Controlled
25 * through debug.exception-trace sysctl.
28 int show_unhandled_signals
= 1;
31 * Allocate space for the signal frame
33 void __user
* get_sigframe(struct k_sigaction
*ka
, struct pt_regs
*regs
,
34 size_t frame_size
, int is_32
)
36 unsigned long oldsp
, newsp
;
38 /* Default to using normal stack */
39 oldsp
= get_clean_sp(regs
, is_32
);
41 /* Check for alt stack */
42 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) &&
43 current
->sas_ss_size
&& !on_sig_stack(oldsp
))
44 oldsp
= (current
->sas_ss_sp
+ current
->sas_ss_size
);
46 /* Get aligned frame */
47 newsp
= (oldsp
- frame_size
) & ~0xFUL
;
50 if (!access_ok(VERIFY_WRITE
, (void __user
*)newsp
, oldsp
- newsp
))
53 return (void __user
*)newsp
;
56 static void check_syscall_restart(struct pt_regs
*regs
, struct k_sigaction
*ka
,
59 unsigned long ret
= regs
->gpr
[3];
63 if (TRAP(regs
) != 0x0C00)
66 /* error signalled ? */
67 if (!(regs
->ccr
& 0x10000000))
71 case ERESTART_RESTARTBLOCK
:
73 /* ERESTARTNOHAND means that the syscall should only be
74 * restarted if there was no handler for the signal, and since
75 * we only get here if there is a handler, we dont restart.
77 restart
= !has_handler
;
80 /* ERESTARTSYS means to restart the syscall if there is no
81 * handler or the handler was registered with SA_RESTART
83 restart
= !has_handler
|| (ka
->sa
.sa_flags
& SA_RESTART
) != 0;
86 /* ERESTARTNOINTR means that the syscall should be
87 * called again after the signal handler returns.
94 if (ret
== ERESTART_RESTARTBLOCK
)
95 regs
->gpr
[0] = __NR_restart_syscall
;
97 regs
->gpr
[3] = regs
->orig_gpr3
;
101 regs
->result
= -EINTR
;
102 regs
->gpr
[3] = EINTR
;
103 regs
->ccr
|= 0x10000000;
107 static int do_signal(struct pt_regs
*regs
)
109 sigset_t
*oldset
= sigmask_to_save();
112 struct k_sigaction ka
;
114 int is32
= is_32bit_task();
116 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
118 /* Is there any syscall restart business here ? */
119 check_syscall_restart(regs
, &ka
, signr
> 0);
122 /* No signal to deliver -- put the saved sigmask back */
123 restore_saved_sigmask();
125 return 0; /* no signals delivered */
128 #ifndef CONFIG_PPC_ADV_DEBUG_REGS
130 * Reenable the DABR before delivering the signal to
131 * user space. The DABR will have been cleared if it
132 * triggered inside the kernel.
134 if (current
->thread
.hw_brk
.address
&&
135 current
->thread
.hw_brk
.type
)
136 set_breakpoint(¤t
->thread
.hw_brk
);
138 /* Re-enable the breakpoints for the signal stack */
139 thread_change_pc(current
, regs
);
142 if (ka
.sa
.sa_flags
& SA_SIGINFO
)
143 ret
= handle_rt_signal32(signr
, &ka
, &info
, oldset
,
146 ret
= handle_signal32(signr
, &ka
, &info
, oldset
,
149 ret
= handle_rt_signal64(signr
, &ka
, &info
, oldset
, regs
);
154 signal_delivered(signr
, &info
, &ka
, regs
,
155 test_thread_flag(TIF_SINGLESTEP
));
161 void do_notify_resume(struct pt_regs
*regs
, unsigned long thread_info_flags
)
165 if (thread_info_flags
& _TIF_UPROBE
)
166 uprobe_notify_resume(regs
);
168 if (thread_info_flags
& _TIF_SIGPENDING
)
171 if (thread_info_flags
& _TIF_NOTIFY_RESUME
) {
172 clear_thread_flag(TIF_NOTIFY_RESUME
);
173 tracehook_notify_resume(regs
);