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 | |
17 | EXPORT_SYMBOL(block_signals); |
18 | EXPORT_SYMBOL(unblock_signals); |
19 | |
20 | void block_signals_trace(void) |
21 | { |
22 | block_signals(); |
23 | if (current_thread_info()) |
24 | trace_hardirqs_off(); |
25 | } |
26 | |
27 | void unblock_signals_trace(void) |
28 | { |
29 | if (current_thread_info()) |
30 | trace_hardirqs_on(); |
31 | unblock_signals(); |
32 | } |
33 | |
34 | void um_trace_signals_on(void) |
35 | { |
36 | if (current_thread_info()) |
37 | trace_hardirqs_on(); |
38 | } |
39 | |
40 | void 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 | */ |
49 | static 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 | |
95 | void 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 | |