2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include <linux/module.h>
7 #include <linux/ptrace.h>
8 #include <linux/sched.h>
9 #include <asm/siginfo.h>
10 #include <asm/signal.h>
11 #include <asm/unistd.h>
12 #include <frame_kern.h>
13 #include <kern_util.h>
15 EXPORT_SYMBOL(block_signals
);
16 EXPORT_SYMBOL(unblock_signals
);
19 * OK, we're invoking a handler
21 static void handle_signal(struct pt_regs
*regs
, unsigned long signr
,
22 struct k_sigaction
*ka
, struct siginfo
*info
)
24 sigset_t
*oldset
= sigmask_to_save();
29 if ((current
->ptrace
& PT_DTRACE
) && (current
->ptrace
& PT_PTRACED
))
32 /* Did we come from a system call? */
33 if (PT_REGS_SYSCALL_NR(regs
) >= 0) {
34 /* If so, check system call restarting.. */
35 switch (PT_REGS_SYSCALL_RET(regs
)) {
36 case -ERESTART_RESTARTBLOCK
:
38 PT_REGS_SYSCALL_RET(regs
) = -EINTR
;
42 if (!(ka
->sa
.sa_flags
& SA_RESTART
)) {
43 PT_REGS_SYSCALL_RET(regs
) = -EINTR
;
48 PT_REGS_RESTART_SYSCALL(regs
);
49 PT_REGS_ORIG_SYSCALL(regs
) = PT_REGS_SYSCALL_NR(regs
);
54 sp
= PT_REGS_SP(regs
);
55 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) && (sas_ss_flags(sp
) == 0))
56 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
58 #ifdef CONFIG_ARCH_HAS_SC_SIGNALS
59 if (!(ka
->sa
.sa_flags
& SA_SIGINFO
))
60 err
= setup_signal_stack_sc(sp
, signr
, ka
, regs
, oldset
);
63 err
= setup_signal_stack_si(sp
, signr
, ka
, regs
, info
, oldset
);
66 force_sigsegv(signr
, current
);
68 signal_delivered(signr
, info
, ka
, regs
, singlestep
);
71 static int kern_do_signal(struct pt_regs
*regs
)
73 struct k_sigaction ka_copy
;
75 int sig
, handled_sig
= 0;
77 while ((sig
= get_signal_to_deliver(&info
, &ka_copy
, regs
, NULL
)) > 0) {
79 /* Whee! Actually deliver the signal. */
80 handle_signal(regs
, sig
, &ka_copy
, &info
);
83 /* Did we come from a system call? */
84 if (!handled_sig
&& (PT_REGS_SYSCALL_NR(regs
) >= 0)) {
85 /* Restart the system call - no handlers present */
86 switch (PT_REGS_SYSCALL_RET(regs
)) {
90 PT_REGS_ORIG_SYSCALL(regs
) = PT_REGS_SYSCALL_NR(regs
);
91 PT_REGS_RESTART_SYSCALL(regs
);
93 case -ERESTART_RESTARTBLOCK
:
94 PT_REGS_ORIG_SYSCALL(regs
) = __NR_restart_syscall
;
95 PT_REGS_RESTART_SYSCALL(regs
);
101 * This closes a way to execute a system call on the host. If
102 * you set a breakpoint on a system call instruction and singlestep
103 * from it, the tracing thread used to PTRACE_SINGLESTEP the process
104 * rather than PTRACE_SYSCALL it, allowing the system call to execute
105 * on the host. The tracing thread will check this flag and
106 * PTRACE_SYSCALL if necessary.
108 if (current
->ptrace
& PT_DTRACE
)
109 current
->thread
.singlestep_syscall
=
110 is_syscall(PT_REGS_IP(¤t
->thread
.regs
));
113 * if there's no signal to deliver, we just put the saved sigmask
117 restore_saved_sigmask();
123 return kern_do_signal(¤t
->thread
.regs
);