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-rw-r--r--arch/um/kernel/signal.c191
1 files changed, 191 insertions, 0 deletions
diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
new file mode 100644
index 000000000000..4aa9808ba264
--- /dev/null
+++ b/arch/um/kernel/signal.c
@@ -0,0 +1,191 @@
1/*
2 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
6#include "linux/config.h"
7#include "linux/stddef.h"
8#include "linux/sys.h"
9#include "linux/sched.h"
10#include "linux/wait.h"
11#include "linux/kernel.h"
12#include "linux/smp_lock.h"
13#include "linux/module.h"
14#include "linux/slab.h"
15#include "linux/tty.h"
16#include "linux/binfmts.h"
17#include "linux/ptrace.h"
18#include "asm/signal.h"
19#include "asm/uaccess.h"
20#include "asm/unistd.h"
21#include "user_util.h"
22#include "asm/ucontext.h"
23#include "kern_util.h"
24#include "signal_kern.h"
25#include "kern.h"
26#include "frame_kern.h"
27#include "sigcontext.h"
28#include "mode.h"
29
30EXPORT_SYMBOL(block_signals);
31EXPORT_SYMBOL(unblock_signals);
32
33#define _S(nr) (1<<((nr)-1))
34
35#define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP)))
36
37/*
38 * OK, we're invoking a handler
39 */
40static int handle_signal(struct pt_regs *regs, unsigned long signr,
41 struct k_sigaction *ka, siginfo_t *info,
42 sigset_t *oldset)
43{
44 unsigned long sp;
45 int err;
46
47 /* Always make any pending restarted system calls return -EINTR */
48 current_thread_info()->restart_block.fn = do_no_restart_syscall;
49
50 /* Did we come from a system call? */
51 if(PT_REGS_SYSCALL_NR(regs) >= 0){
52 /* If so, check system call restarting.. */
53 switch(PT_REGS_SYSCALL_RET(regs)){
54 case -ERESTART_RESTARTBLOCK:
55 case -ERESTARTNOHAND:
56 PT_REGS_SYSCALL_RET(regs) = -EINTR;
57 break;
58
59 case -ERESTARTSYS:
60 if (!(ka->sa.sa_flags & SA_RESTART)) {
61 PT_REGS_SYSCALL_RET(regs) = -EINTR;
62 break;
63 }
64 /* fallthrough */
65 case -ERESTARTNOINTR:
66 PT_REGS_RESTART_SYSCALL(regs);
67 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
68 break;
69 }
70 }
71
72 sp = PT_REGS_SP(regs);
73 if((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
74 sp = current->sas_ss_sp + current->sas_ss_size;
75
76#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
77 if(!(ka->sa.sa_flags & SA_SIGINFO))
78 err = setup_signal_stack_sc(sp, signr, ka, regs, oldset);
79 else
80#endif
81 err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
82
83 if(err){
84 spin_lock_irq(&current->sighand->siglock);
85 current->blocked = *oldset;
86 recalc_sigpending();
87 spin_unlock_irq(&current->sighand->siglock);
88 force_sigsegv(signr, current);
89 } else {
90 spin_lock_irq(&current->sighand->siglock);
91 sigorsets(&current->blocked, &current->blocked,
92 &ka->sa.sa_mask);
93 if(!(ka->sa.sa_flags & SA_NODEFER))
94 sigaddset(&current->blocked, signr);
95 recalc_sigpending();
96 spin_unlock_irq(&current->sighand->siglock);
97 }
98
99 return err;
100}
101
102static int kern_do_signal(struct pt_regs *regs)
103{
104 struct k_sigaction ka_copy;
105 siginfo_t info;
106 sigset_t *oldset;
107 int sig, handled_sig = 0;
108
109 if (test_thread_flag(TIF_RESTORE_SIGMASK))
110 oldset = &current->saved_sigmask;
111 else
112 oldset = &current->blocked;
113
114 while((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0){
115 handled_sig = 1;
116 /* Whee! Actually deliver the signal. */
117 if(!handle_signal(regs, sig, &ka_copy, &info, oldset)){
118 /* a signal was successfully delivered; the saved
119 * sigmask will have been stored in the signal frame,
120 * and will be restored by sigreturn, so we can simply
121 * clear the TIF_RESTORE_SIGMASK flag */
122 if (test_thread_flag(TIF_RESTORE_SIGMASK))
123 clear_thread_flag(TIF_RESTORE_SIGMASK);
124 break;
125 }
126 }
127
128 /* Did we come from a system call? */
129 if(!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)){
130 /* Restart the system call - no handlers present */
131 switch(PT_REGS_SYSCALL_RET(regs)){
132 case -ERESTARTNOHAND:
133 case -ERESTARTSYS:
134 case -ERESTARTNOINTR:
135 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
136 PT_REGS_RESTART_SYSCALL(regs);
137 break;
138 case -ERESTART_RESTARTBLOCK:
139 PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
140 PT_REGS_RESTART_SYSCALL(regs);
141 break;
142 }
143 }
144
145 /* This closes a way to execute a system call on the host. If
146 * you set a breakpoint on a system call instruction and singlestep
147 * from it, the tracing thread used to PTRACE_SINGLESTEP the process
148 * rather than PTRACE_SYSCALL it, allowing the system call to execute
149 * on the host. The tracing thread will check this flag and
150 * PTRACE_SYSCALL if necessary.
151 */
152 if(current->ptrace & PT_DTRACE)
153 current->thread.singlestep_syscall =
154 is_syscall(PT_REGS_IP(&current->thread.regs));
155
156 /* if there's no signal to deliver, we just put the saved sigmask
157 * back */
158 if (!handled_sig && test_thread_flag(TIF_RESTORE_SIGMASK)) {
159 clear_thread_flag(TIF_RESTORE_SIGMASK);
160 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
161 }
162 return(handled_sig);
163}
164
165int do_signal(void)
166{
167 return(kern_do_signal(&current->thread.regs));
168}
169
170/*
171 * Atomically swap in the new signal mask, and wait for a signal.
172 */
173long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
174{
175 mask &= _BLOCKABLE;
176 spin_lock_irq(&current->sighand->siglock);
177 current->saved_sigmask = current->blocked;
178 siginitset(&current->blocked, mask);
179 recalc_sigpending();
180 spin_unlock_irq(&current->sighand->siglock);
181
182 current->state = TASK_INTERRUPTIBLE;
183 schedule();
184 set_thread_flag(TIF_RESTORE_SIGMASK);
185 return -ERESTARTNOHAND;
186}
187
188long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
189{
190 return(do_sigaltstack(uss, uoss, PT_REGS_SP(&current->thread.regs)));
191}
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