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" |
3be311e3 | 14 | #include <sysdep/sigcontext.h> |
1da177e4 LT |
15 | |
16 | EXPORT_SYMBOL(block_signals); | |
17 | EXPORT_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 | |
1d3468a6 | 25 | */ |
1da177e4 LT |
26 | static 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? */ | |
ba180fd4 | 37 | if (PT_REGS_SYSCALL_NR(regs) >= 0) { |
1da177e4 | 38 | /* If so, check system call restarting.. */ |
c5d4bb17 | 39 | switch (PT_REGS_SYSCALL_RET(regs)) { |
1da177e4 LT |
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); | |
ba180fd4 | 59 | if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0)) |
1da177e4 LT |
60 | sp = current->sas_ss_sp + current->sas_ss_size; |
61 | ||
62 | #ifdef CONFIG_ARCH_HAS_SC_SIGNALS | |
ba180fd4 | 63 | if (!(ka->sa.sa_flags & SA_SIGINFO)) |
1da177e4 LT |
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 | ||
ba180fd4 | 69 | if (err) { |
1da177e4 LT |
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); | |
69be8f18 | 75 | } else { |
1da177e4 | 76 | spin_lock_irq(¤t->sighand->siglock); |
1d3468a6 | 77 | sigorsets(¤t->blocked, ¤t->blocked, |
1da177e4 | 78 | &ka->sa.sa_mask); |
ba180fd4 | 79 | if (!(ka->sa.sa_flags & SA_NODEFER)) |
69be8f18 | 80 | sigaddset(¤t->blocked, signr); |
1da177e4 LT |
81 | recalc_sigpending(); |
82 | spin_unlock_irq(¤t->sighand->siglock); | |
83 | } | |
84 | ||
85 | return err; | |
86 | } | |
87 | ||
2fc10620 | 88 | static int kern_do_signal(struct pt_regs *regs) |
1da177e4 LT |
89 | { |
90 | struct k_sigaction ka_copy; | |
91 | siginfo_t info; | |
2fc10620 | 92 | sigset_t *oldset; |
1da177e4 LT |
93 | int sig, handled_sig = 0; |
94 | ||
2fc10620 JD |
95 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
96 | oldset = ¤t->saved_sigmask; | |
97 | else | |
98 | oldset = ¤t->blocked; | |
99 | ||
ba180fd4 | 100 | while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) { |
1da177e4 LT |
101 | handled_sig = 1; |
102 | /* Whee! Actually deliver the signal. */ | |
ba180fd4 JD |
103 | if (!handle_signal(regs, sig, &ka_copy, &info, oldset)) { |
104 | /* | |
105 | * a signal was successfully delivered; the saved | |
2fc10620 JD |
106 | * sigmask will have been stored in the signal frame, |
107 | * and will be restored by sigreturn, so we can simply | |
ba180fd4 JD |
108 | * clear the TIF_RESTORE_SIGMASK flag |
109 | */ | |
2fc10620 JD |
110 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
111 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
1da177e4 | 112 | break; |
2fc10620 | 113 | } |
1da177e4 LT |
114 | } |
115 | ||
116 | /* Did we come from a system call? */ | |
ba180fd4 | 117 | if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) { |
1da177e4 | 118 | /* Restart the system call - no handlers present */ |
c5d4bb17 | 119 | switch (PT_REGS_SYSCALL_RET(regs)) { |
2fc10620 JD |
120 | case -ERESTARTNOHAND: |
121 | case -ERESTARTSYS: | |
122 | case -ERESTARTNOINTR: | |
1da177e4 LT |
123 | PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); |
124 | PT_REGS_RESTART_SYSCALL(regs); | |
2fc10620 JD |
125 | break; |
126 | case -ERESTART_RESTARTBLOCK: | |
1d3468a6 | 127 | PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall; |
1da177e4 | 128 | PT_REGS_RESTART_SYSCALL(regs); |
2fc10620 | 129 | break; |
ba180fd4 | 130 | } |
1da177e4 LT |
131 | } |
132 | ||
ba180fd4 JD |
133 | /* |
134 | * This closes a way to execute a system call on the host. If | |
1da177e4 LT |
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 | |
1d3468a6 | 138 | * on the host. The tracing thread will check this flag and |
1da177e4 LT |
139 | * PTRACE_SYSCALL if necessary. |
140 | */ | |
ba180fd4 | 141 | if (current->ptrace & PT_DTRACE) |
1da177e4 LT |
142 | current->thread.singlestep_syscall = |
143 | is_syscall(PT_REGS_IP(¤t->thread.regs)); | |
2fc10620 | 144 | |
ba180fd4 JD |
145 | /* |
146 | * if there's no signal to deliver, we just put the saved sigmask | |
147 | * back | |
148 | */ | |
2fc10620 JD |
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 | } | |
7c7a8949 | 153 | return handled_sig; |
1da177e4 LT |
154 | } |
155 | ||
156 | int do_signal(void) | |
157 | { | |
7c7a8949 | 158 | return kern_do_signal(¤t->thread.regs); |
1da177e4 LT |
159 | } |
160 | ||
161 | /* | |
162 | * Atomically swap in the new signal mask, and wait for a signal. | |
163 | */ | |
164 | long sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
165 | { | |
1da177e4 LT |
166 | mask &= _BLOCKABLE; |
167 | spin_lock_irq(¤t->sighand->siglock); | |
2fc10620 | 168 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
169 | siginitset(¤t->blocked, mask); |
170 | recalc_sigpending(); | |
171 | spin_unlock_irq(¤t->sighand->siglock); | |
172 | ||
2fc10620 JD |
173 | current->state = TASK_INTERRUPTIBLE; |
174 | schedule(); | |
175 | set_thread_flag(TIF_RESTORE_SIGMASK); | |
176 | return -ERESTARTNOHAND; | |
1da177e4 LT |
177 | } |
178 | ||
1da177e4 LT |
179 | long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss) |
180 | { | |
7c7a8949 | 181 | return do_sigaltstack(uss, uoss, PT_REGS_SP(¤t->thread.regs)); |
1da177e4 | 182 | } |