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1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
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>
14
15EXPORT_SYMBOL(block_signals);
16EXPORT_SYMBOL(unblock_signals);
17
18/*
19 * OK, we're invoking a handler
20 */
21static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
22{
23 sigset_t *oldset = sigmask_to_save();
24 int singlestep = 0;
25 unsigned long sp;
26 int err;
27
28 if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
29 singlestep = 1;
30
31 /* Did we come from a system call? */
32 if (PT_REGS_SYSCALL_NR(regs) >= 0) {
33 /* If so, check system call restarting.. */
34 switch (PT_REGS_SYSCALL_RET(regs)) {
35 case -ERESTART_RESTARTBLOCK:
36 case -ERESTARTNOHAND:
37 PT_REGS_SYSCALL_RET(regs) = -EINTR;
38 break;
39
40 case -ERESTARTSYS:
41 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
42 PT_REGS_SYSCALL_RET(regs) = -EINTR;
43 break;
44 }
45 /* fallthrough */
46 case -ERESTARTNOINTR:
47 PT_REGS_RESTART_SYSCALL(regs);
48 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
49 break;
50 }
51 }
52
53 sp = PT_REGS_SP(regs);
54 if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
55 sp = current->sas_ss_sp + current->sas_ss_size;
56
57#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
58 if (!(ksig->ka.sa.sa_flags & SA_SIGINFO))
59 err = setup_signal_stack_sc(sp, ksig, regs, oldset);
60 else
61#endif
62 err = setup_signal_stack_si(sp, ksig, regs, oldset);
63
64 signal_setup_done(err, ksig, singlestep);
65}
66
67void do_signal(struct pt_regs *regs)
68{
69 struct ksignal ksig;
70 int handled_sig = 0;
71
72 while (get_signal(&ksig)) {
73 handled_sig = 1;
74 /* Whee! Actually deliver the signal. */
75 handle_signal(&ksig, regs);
76 }
77
78 /* Did we come from a system call? */
79 if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
80 /* Restart the system call - no handlers present */
81 switch (PT_REGS_SYSCALL_RET(regs)) {
82 case -ERESTARTNOHAND:
83 case -ERESTARTSYS:
84 case -ERESTARTNOINTR:
85 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
86 PT_REGS_RESTART_SYSCALL(regs);
87 break;
88 case -ERESTART_RESTARTBLOCK:
89 PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
90 PT_REGS_RESTART_SYSCALL(regs);
91 break;
92 }
93 }
94
95 /*
96 * This closes a way to execute a system call on the host. If
97 * you set a breakpoint on a system call instruction and singlestep
98 * from it, the tracing thread used to PTRACE_SINGLESTEP the process
99 * rather than PTRACE_SYSCALL it, allowing the system call to execute
100 * on the host. The tracing thread will check this flag and
101 * PTRACE_SYSCALL if necessary.
102 */
103 if (current->ptrace & PT_DTRACE)
104 current->thread.singlestep_syscall =
105 is_syscall(PT_REGS_IP(¤t->thread.regs));
106
107 /*
108 * if there's no signal to deliver, we just put the saved sigmask
109 * back
110 */
111 if (!handled_sig)
112 restore_saved_sigmask();
113}
1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
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>
14
15EXPORT_SYMBOL(block_signals);
16EXPORT_SYMBOL(unblock_signals);
17
18/*
19 * OK, we're invoking a handler
20 */
21static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
22{
23 sigset_t *oldset = sigmask_to_save();
24 int singlestep = 0;
25 unsigned long sp;
26 int err;
27
28 if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
29 singlestep = 1;
30
31 /* Did we come from a system call? */
32 if (PT_REGS_SYSCALL_NR(regs) >= 0) {
33 /* If so, check system call restarting.. */
34 switch (PT_REGS_SYSCALL_RET(regs)) {
35 case -ERESTART_RESTARTBLOCK:
36 case -ERESTARTNOHAND:
37 PT_REGS_SYSCALL_RET(regs) = -EINTR;
38 break;
39
40 case -ERESTARTSYS:
41 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
42 PT_REGS_SYSCALL_RET(regs) = -EINTR;
43 break;
44 }
45 /* fallthrough */
46 case -ERESTARTNOINTR:
47 PT_REGS_RESTART_SYSCALL(regs);
48 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
49 break;
50 }
51 }
52
53 sp = PT_REGS_SP(regs);
54 if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
55 sp = current->sas_ss_sp + current->sas_ss_size;
56
57#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
58 if (!(ksig->ka.sa.sa_flags & SA_SIGINFO))
59 err = setup_signal_stack_sc(sp, ksig, regs, oldset);
60 else
61#endif
62 err = setup_signal_stack_si(sp, ksig, regs, oldset);
63
64 signal_setup_done(err, ksig, singlestep);
65}
66
67void do_signal(struct pt_regs *regs)
68{
69 struct ksignal ksig;
70 int handled_sig = 0;
71
72 while (get_signal(&ksig)) {
73 handled_sig = 1;
74 /* Whee! Actually deliver the signal. */
75 handle_signal(&ksig, regs);
76 }
77
78 /* Did we come from a system call? */
79 if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
80 /* Restart the system call - no handlers present */
81 switch (PT_REGS_SYSCALL_RET(regs)) {
82 case -ERESTARTNOHAND:
83 case -ERESTARTSYS:
84 case -ERESTARTNOINTR:
85 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
86 PT_REGS_RESTART_SYSCALL(regs);
87 break;
88 case -ERESTART_RESTARTBLOCK:
89 PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
90 PT_REGS_RESTART_SYSCALL(regs);
91 break;
92 }
93 }
94
95 /*
96 * This closes a way to execute a system call on the host. If
97 * you set a breakpoint on a system call instruction and singlestep
98 * from it, the tracing thread used to PTRACE_SINGLESTEP the process
99 * rather than PTRACE_SYSCALL it, allowing the system call to execute
100 * on the host. The tracing thread will check this flag and
101 * PTRACE_SYSCALL if necessary.
102 */
103 if (current->ptrace & PT_DTRACE)
104 current->thread.singlestep_syscall =
105 is_syscall(PT_REGS_IP(¤t->thread.regs));
106
107 /*
108 * if there's no signal to deliver, we just put the saved sigmask
109 * back
110 */
111 if (!handled_sig)
112 restore_saved_sigmask();
113}