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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#include <sysdep/sigcontext.h>
15
16EXPORT_SYMBOL(block_signals);
17EXPORT_SYMBOL(unblock_signals);
18
19#define _S(nr) (1<<((nr)-1))
20
21#define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP)))
22
23/*
24 * OK, we're invoking a handler
25 */
26static int handle_signal(struct pt_regs *regs, unsigned long signr,
27 struct k_sigaction *ka, siginfo_t *info,
28 sigset_t *oldset)
29{
30 unsigned long sp;
31 int err;
32
33 /* Always make any pending restarted system calls return -EINTR */
34 current_thread_info()->restart_block.fn = do_no_restart_syscall;
35
36 /* Did we come from a system call? */
37 if (PT_REGS_SYSCALL_NR(regs) >= 0) {
38 /* If so, check system call restarting.. */
39 switch (PT_REGS_SYSCALL_RET(regs)) {
40 case -ERESTART_RESTARTBLOCK:
41 case -ERESTARTNOHAND:
42 PT_REGS_SYSCALL_RET(regs) = -EINTR;
43 break;
44
45 case -ERESTARTSYS:
46 if (!(ka->sa.sa_flags & SA_RESTART)) {
47 PT_REGS_SYSCALL_RET(regs) = -EINTR;
48 break;
49 }
50 /* fallthrough */
51 case -ERESTARTNOINTR:
52 PT_REGS_RESTART_SYSCALL(regs);
53 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
54 break;
55 }
56 }
57
58 sp = PT_REGS_SP(regs);
59 if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
60 sp = current->sas_ss_sp + current->sas_ss_size;
61
62#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
63 if (!(ka->sa.sa_flags & SA_SIGINFO))
64 err = setup_signal_stack_sc(sp, signr, ka, regs, oldset);
65 else
66#endif
67 err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
68
69 if (err) {
70 spin_lock_irq(¤t->sighand->siglock);
71 current->blocked = *oldset;
72 recalc_sigpending();
73 spin_unlock_irq(¤t->sighand->siglock);
74 force_sigsegv(signr, current);
75 } else {
76 spin_lock_irq(¤t->sighand->siglock);
77 sigorsets(¤t->blocked, ¤t->blocked,
78 &ka->sa.sa_mask);
79 if (!(ka->sa.sa_flags & SA_NODEFER))
80 sigaddset(¤t->blocked, signr);
81 recalc_sigpending();
82 spin_unlock_irq(¤t->sighand->siglock);
83 }
84
85 return err;
86}
87
88static int kern_do_signal(struct pt_regs *regs)
89{
90 struct k_sigaction ka_copy;
91 siginfo_t info;
92 sigset_t *oldset;
93 int sig, handled_sig = 0;
94
95 if (test_thread_flag(TIF_RESTORE_SIGMASK))
96 oldset = ¤t->saved_sigmask;
97 else
98 oldset = ¤t->blocked;
99
100 while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) {
101 handled_sig = 1;
102 /* Whee! Actually deliver the signal. */
103 if (!handle_signal(regs, sig, &ka_copy, &info, oldset)) {
104 /*
105 * a signal was successfully delivered; the saved
106 * sigmask will have been stored in the signal frame,
107 * and will be restored by sigreturn, so we can simply
108 * clear the TIF_RESTORE_SIGMASK flag
109 */
110 if (test_thread_flag(TIF_RESTORE_SIGMASK))
111 clear_thread_flag(TIF_RESTORE_SIGMASK);
112 break;
113 }
114 }
115
116 /* Did we come from a system call? */
117 if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
118 /* Restart the system call - no handlers present */
119 switch (PT_REGS_SYSCALL_RET(regs)) {
120 case -ERESTARTNOHAND:
121 case -ERESTARTSYS:
122 case -ERESTARTNOINTR:
123 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
124 PT_REGS_RESTART_SYSCALL(regs);
125 break;
126 case -ERESTART_RESTARTBLOCK:
127 PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
128 PT_REGS_RESTART_SYSCALL(regs);
129 break;
130 }
131 }
132
133 /*
134 * This closes a way to execute a system call on the host. If
135 * you set a breakpoint on a system call instruction and singlestep
136 * from it, the tracing thread used to PTRACE_SINGLESTEP the process
137 * rather than PTRACE_SYSCALL it, allowing the system call to execute
138 * on the host. The tracing thread will check this flag and
139 * PTRACE_SYSCALL if necessary.
140 */
141 if (current->ptrace & PT_DTRACE)
142 current->thread.singlestep_syscall =
143 is_syscall(PT_REGS_IP(¤t->thread.regs));
144
145 /*
146 * if there's no signal to deliver, we just put the saved sigmask
147 * back
148 */
149 if (!handled_sig && test_thread_flag(TIF_RESTORE_SIGMASK)) {
150 clear_thread_flag(TIF_RESTORE_SIGMASK);
151 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
152 }
153 return handled_sig;
154}
155
156int do_signal(void)
157{
158 return kern_do_signal(¤t->thread.regs);
159}
160
161/*
162 * Atomically swap in the new signal mask, and wait for a signal.
163 */
164long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
165{
166 mask &= _BLOCKABLE;
167 spin_lock_irq(¤t->sighand->siglock);
168 current->saved_sigmask = current->blocked;
169 siginitset(¤t->blocked, mask);
170 recalc_sigpending();
171 spin_unlock_irq(¤t->sighand->siglock);
172
173 current->state = TASK_INTERRUPTIBLE;
174 schedule();
175 set_thread_flag(TIF_RESTORE_SIGMASK);
176 return -ERESTARTNOHAND;
177}
178
179long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
180{
181 return do_sigaltstack(uss, uoss, PT_REGS_SP(¤t->thread.regs));
182}