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> | |
37185b33 AV |
12 | #include <frame_kern.h> |
13 | #include <kern_util.h> | |
1da177e4 LT |
14 | |
15 | EXPORT_SYMBOL(block_signals); | |
16 | EXPORT_SYMBOL(unblock_signals); | |
17 | ||
1da177e4 LT |
18 | /* |
19 | * OK, we're invoking a handler | |
1d3468a6 | 20 | */ |
307627ee | 21 | static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 22 | { |
b7f9a11a | 23 | sigset_t *oldset = sigmask_to_save(); |
f9a38eac | 24 | int singlestep = 0; |
1da177e4 LT |
25 | unsigned long sp; |
26 | int err; | |
27 | ||
f9a38eac AV |
28 | if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) |
29 | singlestep = 1; | |
30 | ||
1da177e4 | 31 | /* Did we come from a system call? */ |
ba180fd4 | 32 | if (PT_REGS_SYSCALL_NR(regs) >= 0) { |
1da177e4 | 33 | /* If so, check system call restarting.. */ |
c5d4bb17 | 34 | switch (PT_REGS_SYSCALL_RET(regs)) { |
1da177e4 LT |
35 | case -ERESTART_RESTARTBLOCK: |
36 | case -ERESTARTNOHAND: | |
37 | PT_REGS_SYSCALL_RET(regs) = -EINTR; | |
38 | break; | |
39 | ||
40 | case -ERESTARTSYS: | |
307627ee | 41 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
1da177e4 LT |
42 | PT_REGS_SYSCALL_RET(regs) = -EINTR; |
43 | break; | |
44 | } | |
45 | /* fallthrough */ | |
46 | case -ERESTARTNOINTR: | |
47 | PT_REGS_RESTART_SYSCALL(regs); | |
48 | PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); | |
49 | break; | |
50 | } | |
51 | } | |
52 | ||
53 | sp = PT_REGS_SP(regs); | |
307627ee | 54 | if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0)) |
1da177e4 LT |
55 | sp = current->sas_ss_sp + current->sas_ss_size; |
56 | ||
57 | #ifdef CONFIG_ARCH_HAS_SC_SIGNALS | |
307627ee RW |
58 | if (!(ksig->ka.sa.sa_flags & SA_SIGINFO)) |
59 | err = setup_signal_stack_sc(sp, ksig, regs, oldset); | |
1da177e4 LT |
60 | else |
61 | #endif | |
307627ee | 62 | err = setup_signal_stack_si(sp, ksig, regs, oldset); |
1da177e4 | 63 | |
307627ee | 64 | signal_setup_done(err, ksig, singlestep); |
1da177e4 LT |
65 | } |
66 | ||
ccaee5f8 | 67 | void do_signal(struct pt_regs *regs) |
1da177e4 | 68 | { |
307627ee RW |
69 | struct ksignal ksig; |
70 | int handled_sig = 0; | |
1da177e4 | 71 | |
307627ee | 72 | while (get_signal(&ksig)) { |
1da177e4 LT |
73 | handled_sig = 1; |
74 | /* Whee! Actually deliver the signal. */ | |
307627ee | 75 | handle_signal(&ksig, regs); |
1da177e4 LT |
76 | } |
77 | ||
78 | /* Did we come from a system call? */ | |
ba180fd4 | 79 | if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) { |
1da177e4 | 80 | /* Restart the system call - no handlers present */ |
c5d4bb17 | 81 | switch (PT_REGS_SYSCALL_RET(regs)) { |
2fc10620 JD |
82 | case -ERESTARTNOHAND: |
83 | case -ERESTARTSYS: | |
84 | case -ERESTARTNOINTR: | |
1da177e4 LT |
85 | PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); |
86 | PT_REGS_RESTART_SYSCALL(regs); | |
2fc10620 JD |
87 | break; |
88 | case -ERESTART_RESTARTBLOCK: | |
1d3468a6 | 89 | PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall; |
1da177e4 | 90 | PT_REGS_RESTART_SYSCALL(regs); |
2fc10620 | 91 | break; |
ba180fd4 | 92 | } |
1da177e4 LT |
93 | } |
94 | ||
ba180fd4 JD |
95 | /* |
96 | * This closes a way to execute a system call on the host. If | |
1da177e4 LT |
97 | * you set a breakpoint on a system call instruction and singlestep |
98 | * from it, the tracing thread used to PTRACE_SINGLESTEP the process | |
99 | * rather than PTRACE_SYSCALL it, allowing the system call to execute | |
1d3468a6 | 100 | * on the host. The tracing thread will check this flag and |
1da177e4 LT |
101 | * PTRACE_SYSCALL if necessary. |
102 | */ | |
ba180fd4 | 103 | if (current->ptrace & PT_DTRACE) |
1da177e4 LT |
104 | current->thread.singlestep_syscall = |
105 | is_syscall(PT_REGS_IP(¤t->thread.regs)); | |
2fc10620 | 106 | |
ba180fd4 JD |
107 | /* |
108 | * if there's no signal to deliver, we just put the saved sigmask | |
109 | * back | |
110 | */ | |
51a7b448 AV |
111 | if (!handled_sig) |
112 | restore_saved_sigmask(); | |
1da177e4 | 113 | } |