Commit | Line | Data |
---|---|---|
1d3468a6 | 1 | /* |
ba180fd4 | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | */ | |
5 | ||
c5d4bb17 JD |
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> | |
1da177e4 | 12 | #include "frame_kern.h" |
ba180fd4 | 13 | #include "kern_util.h" |
1da177e4 LT |
14 | |
15 | EXPORT_SYMBOL(block_signals); | |
16 | EXPORT_SYMBOL(unblock_signals); | |
17 | ||
18 | #define _S(nr) (1<<((nr)-1)) | |
19 | ||
20 | #define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP))) | |
21 | ||
22 | /* | |
23 | * OK, we're invoking a handler | |
1d3468a6 | 24 | */ |
1da177e4 LT |
25 | static int handle_signal(struct pt_regs *regs, unsigned long signr, |
26 | struct k_sigaction *ka, siginfo_t *info, | |
27 | sigset_t *oldset) | |
28 | { | |
29 | unsigned long sp; | |
30 | int err; | |
31 | ||
32 | /* Always make any pending restarted system calls return -EINTR */ | |
33 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
34 | ||
35 | /* Did we come from a system call? */ | |
ba180fd4 | 36 | if (PT_REGS_SYSCALL_NR(regs) >= 0) { |
1da177e4 | 37 | /* If so, check system call restarting.. */ |
c5d4bb17 | 38 | switch (PT_REGS_SYSCALL_RET(regs)) { |
1da177e4 LT |
39 | case -ERESTART_RESTARTBLOCK: |
40 | case -ERESTARTNOHAND: | |
41 | PT_REGS_SYSCALL_RET(regs) = -EINTR; | |
42 | break; | |
43 | ||
44 | case -ERESTARTSYS: | |
45 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
46 | PT_REGS_SYSCALL_RET(regs) = -EINTR; | |
47 | break; | |
48 | } | |
49 | /* fallthrough */ | |
50 | case -ERESTARTNOINTR: | |
51 | PT_REGS_RESTART_SYSCALL(regs); | |
52 | PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); | |
53 | break; | |
54 | } | |
55 | } | |
56 | ||
57 | sp = PT_REGS_SP(regs); | |
ba180fd4 | 58 | if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0)) |
1da177e4 LT |
59 | sp = current->sas_ss_sp + current->sas_ss_size; |
60 | ||
61 | #ifdef CONFIG_ARCH_HAS_SC_SIGNALS | |
ba180fd4 | 62 | if (!(ka->sa.sa_flags & SA_SIGINFO)) |
1da177e4 LT |
63 | err = setup_signal_stack_sc(sp, signr, ka, regs, oldset); |
64 | else | |
65 | #endif | |
66 | err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset); | |
67 | ||
f6adb9a6 | 68 | if (err) |
1da177e4 | 69 | force_sigsegv(signr, current); |
d982d595 MF |
70 | else |
71 | block_sigmask(ka, signr); | |
1da177e4 LT |
72 | |
73 | return err; | |
74 | } | |
75 | ||
2fc10620 | 76 | static int kern_do_signal(struct pt_regs *regs) |
1da177e4 LT |
77 | { |
78 | struct k_sigaction ka_copy; | |
79 | siginfo_t info; | |
2fc10620 | 80 | sigset_t *oldset; |
1da177e4 LT |
81 | int sig, handled_sig = 0; |
82 | ||
2fc10620 JD |
83 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
84 | oldset = ¤t->saved_sigmask; | |
85 | else | |
86 | oldset = ¤t->blocked; | |
87 | ||
ba180fd4 | 88 | while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) { |
1da177e4 LT |
89 | handled_sig = 1; |
90 | /* Whee! Actually deliver the signal. */ | |
ba180fd4 JD |
91 | if (!handle_signal(regs, sig, &ka_copy, &info, oldset)) { |
92 | /* | |
93 | * a signal was successfully delivered; the saved | |
2fc10620 JD |
94 | * sigmask will have been stored in the signal frame, |
95 | * and will be restored by sigreturn, so we can simply | |
ba180fd4 JD |
96 | * clear the TIF_RESTORE_SIGMASK flag |
97 | */ | |
2fc10620 JD |
98 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
99 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
1da177e4 | 100 | break; |
2fc10620 | 101 | } |
1da177e4 LT |
102 | } |
103 | ||
104 | /* Did we come from a system call? */ | |
ba180fd4 | 105 | if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) { |
1da177e4 | 106 | /* Restart the system call - no handlers present */ |
c5d4bb17 | 107 | switch (PT_REGS_SYSCALL_RET(regs)) { |
2fc10620 JD |
108 | case -ERESTARTNOHAND: |
109 | case -ERESTARTSYS: | |
110 | case -ERESTARTNOINTR: | |
1da177e4 LT |
111 | PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); |
112 | PT_REGS_RESTART_SYSCALL(regs); | |
2fc10620 JD |
113 | break; |
114 | case -ERESTART_RESTARTBLOCK: | |
1d3468a6 | 115 | PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall; |
1da177e4 | 116 | PT_REGS_RESTART_SYSCALL(regs); |
2fc10620 | 117 | break; |
ba180fd4 | 118 | } |
1da177e4 LT |
119 | } |
120 | ||
ba180fd4 JD |
121 | /* |
122 | * This closes a way to execute a system call on the host. If | |
1da177e4 LT |
123 | * you set a breakpoint on a system call instruction and singlestep |
124 | * from it, the tracing thread used to PTRACE_SINGLESTEP the process | |
125 | * rather than PTRACE_SYSCALL it, allowing the system call to execute | |
1d3468a6 | 126 | * on the host. The tracing thread will check this flag and |
1da177e4 LT |
127 | * PTRACE_SYSCALL if necessary. |
128 | */ | |
ba180fd4 | 129 | if (current->ptrace & PT_DTRACE) |
1da177e4 LT |
130 | current->thread.singlestep_syscall = |
131 | is_syscall(PT_REGS_IP(¤t->thread.regs)); | |
2fc10620 | 132 | |
ba180fd4 JD |
133 | /* |
134 | * if there's no signal to deliver, we just put the saved sigmask | |
135 | * back | |
136 | */ | |
2fc10620 JD |
137 | if (!handled_sig && test_thread_flag(TIF_RESTORE_SIGMASK)) { |
138 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
139 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
140 | } | |
7c7a8949 | 141 | return handled_sig; |
1da177e4 LT |
142 | } |
143 | ||
144 | int do_signal(void) | |
145 | { | |
7c7a8949 | 146 | return kern_do_signal(¤t->thread.regs); |
1da177e4 LT |
147 | } |
148 | ||
149 | /* | |
150 | * Atomically swap in the new signal mask, and wait for a signal. | |
151 | */ | |
152 | long sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
153 | { | |
d982d595 MF |
154 | sigset_t blocked; |
155 | ||
1da177e4 | 156 | mask &= _BLOCKABLE; |
d982d595 MF |
157 | siginitset(&blocked, mask); |
158 | set_current_blocked(&blocked); | |
1da177e4 | 159 | |
2fc10620 JD |
160 | current->state = TASK_INTERRUPTIBLE; |
161 | schedule(); | |
162 | set_thread_flag(TIF_RESTORE_SIGMASK); | |
163 | return -ERESTARTNOHAND; | |
1da177e4 LT |
164 | } |
165 | ||
1da177e4 LT |
166 | long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss) |
167 | { | |
7c7a8949 | 168 | return do_sigaltstack(uss, uoss, PT_REGS_SP(¤t->thread.regs)); |
1da177e4 | 169 | } |