1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <linux/module.h>
7#include <linux/ptrace.h>
8#include <linux/sched.h>
9#include <linux/ftrace.h>
10#include <asm/siginfo.h>
11#include <asm/signal.h>
12#include <asm/unistd.h>
13#include <frame_kern.h>
14#include <kern_util.h>
15#include <os.h>
16
17EXPORT_SYMBOL(block_signals);
18EXPORT_SYMBOL(unblock_signals);
19
20void block_signals_trace(void)
21{
22 block_signals();
23 if (current_thread_info())
24 trace_hardirqs_off();
25}
26
27void unblock_signals_trace(void)
28{
29 if (current_thread_info())
30 trace_hardirqs_on();
31 unblock_signals();
32}
33
34void um_trace_signals_on(void)
35{
36 if (current_thread_info())
37 trace_hardirqs_on();
38}
39
40void um_trace_signals_off(void)
41{
42 if (current_thread_info())
43 trace_hardirqs_off();
44}
45
46/*
47 * OK, we're invoking a handler
48 */
49static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
50{
51 sigset_t *oldset = sigmask_to_save();
52 int singlestep = 0;
53 unsigned long sp;
54 int err;
55
56 if (test_thread_flag(TIF_SINGLESTEP) && (current->ptrace & PT_PTRACED))
57 singlestep = 1;
58
59 /* Did we come from a system call? */
60 if (PT_REGS_SYSCALL_NR(regs) >= 0) {
61 /* If so, check system call restarting.. */
62 switch (PT_REGS_SYSCALL_RET(regs)) {
63 case -ERESTART_RESTARTBLOCK:
64 case -ERESTARTNOHAND:
65 PT_REGS_SYSCALL_RET(regs) = -EINTR;
66 break;
67
68 case -ERESTARTSYS:
69 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
70 PT_REGS_SYSCALL_RET(regs) = -EINTR;
71 break;
72 }
73 fallthrough;
74 case -ERESTARTNOINTR:
75 PT_REGS_RESTART_SYSCALL(regs);
76 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
77 break;
78 }
79 }
80
81 sp = PT_REGS_SP(regs);
82 if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
83 sp = current->sas_ss_sp + current->sas_ss_size;
84
85#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
86 if (!(ksig->ka.sa.sa_flags & SA_SIGINFO))
87 err = setup_signal_stack_sc(sp, ksig, regs, oldset);
88 else
89#endif
90 err = setup_signal_stack_si(sp, ksig, regs, oldset);
91
92 signal_setup_done(failed: err, ksig, stepping: singlestep);
93}
94
95void do_signal(struct pt_regs *regs)
96{
97 struct ksignal ksig;
98 int handled_sig = 0;
99
100 while (get_signal(ksig: &ksig)) {
101 handled_sig = 1;
102 /* Whee! Actually deliver the signal. */
103 handle_signal(ksig: &ksig, regs);
104 }
105
106 /* Did we come from a system call? */
107 if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
108 /* Restart the system call - no handlers present */
109 switch (PT_REGS_SYSCALL_RET(regs)) {
110 case -ERESTARTNOHAND:
111 case -ERESTARTSYS:
112 case -ERESTARTNOINTR:
113 PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
114 PT_REGS_RESTART_SYSCALL(regs);
115 break;
116 case -ERESTART_RESTARTBLOCK:
117 PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
118 PT_REGS_RESTART_SYSCALL(regs);
119 break;
120 }
121 }
122
123 /*
124 * if there's no signal to deliver, we just put the saved sigmask
125 * back
126 */
127 if (!handled_sig)
128 restore_saved_sigmask();
129}
130

source code of linux/arch/um/kernel/signal.c