Jeff Dike | 1d3468a | 2006-07-10 04:45:13 -0700 | [diff] [blame] | 1 | /* |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * Licensed under the GPL |
| 4 | */ |
| 5 | |
Jeff Dike | c5d4bb1 | 2008-02-04 22:31:14 -0800 | [diff] [blame] | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include "frame_kern.h" |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 13 | #include "kern_util.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | |
| 15 | EXPORT_SYMBOL(block_signals); |
| 16 | EXPORT_SYMBOL(unblock_signals); |
| 17 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | /* |
| 19 | * OK, we're invoking a handler |
Jeff Dike | 1d3468a | 2006-07-10 04:45:13 -0700 | [diff] [blame] | 20 | */ |
Al Viro | a610d6e | 2012-05-21 23:42:15 -0400 | [diff] [blame] | 21 | static void handle_signal(struct pt_regs *regs, unsigned long signr, |
Al Viro | b7f9a11 | 2012-05-02 09:59:21 -0400 | [diff] [blame] | 22 | struct k_sigaction *ka, siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | { |
Al Viro | b7f9a11 | 2012-05-02 09:59:21 -0400 | [diff] [blame] | 24 | sigset_t *oldset = sigmask_to_save(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | unsigned long sp; |
| 26 | int err; |
| 27 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | /* Did we come from a system call? */ |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 29 | if (PT_REGS_SYSCALL_NR(regs) >= 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | /* If so, check system call restarting.. */ |
Jeff Dike | c5d4bb1 | 2008-02-04 22:31:14 -0800 | [diff] [blame] | 31 | switch (PT_REGS_SYSCALL_RET(regs)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | case -ERESTART_RESTARTBLOCK: |
| 33 | case -ERESTARTNOHAND: |
| 34 | PT_REGS_SYSCALL_RET(regs) = -EINTR; |
| 35 | break; |
| 36 | |
| 37 | case -ERESTARTSYS: |
| 38 | if (!(ka->sa.sa_flags & SA_RESTART)) { |
| 39 | PT_REGS_SYSCALL_RET(regs) = -EINTR; |
| 40 | break; |
| 41 | } |
| 42 | /* fallthrough */ |
| 43 | case -ERESTARTNOINTR: |
| 44 | PT_REGS_RESTART_SYSCALL(regs); |
| 45 | PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); |
| 46 | break; |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | sp = PT_REGS_SP(regs); |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 51 | if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | sp = current->sas_ss_sp + current->sas_ss_size; |
| 53 | |
| 54 | #ifdef CONFIG_ARCH_HAS_SC_SIGNALS |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 55 | if (!(ka->sa.sa_flags & SA_SIGINFO)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | err = setup_signal_stack_sc(sp, signr, ka, regs, oldset); |
| 57 | else |
| 58 | #endif |
| 59 | err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset); |
| 60 | |
Matt Fleming | f6adb9a | 2012-03-23 15:01:49 -0700 | [diff] [blame] | 61 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | force_sigsegv(signr, current); |
Matt Fleming | d982d59 | 2012-03-23 15:01:50 -0700 | [diff] [blame] | 63 | else |
Al Viro | efee984 | 2012-04-28 02:04:15 -0400 | [diff] [blame] | 64 | signal_delivered(signr, info, ka, regs, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | } |
| 66 | |
Jeff Dike | 2fc1062 | 2006-01-18 17:44:02 -0800 | [diff] [blame] | 67 | static int kern_do_signal(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | { |
| 69 | struct k_sigaction ka_copy; |
| 70 | siginfo_t info; |
| 71 | int sig, handled_sig = 0; |
| 72 | |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 73 | while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | handled_sig = 1; |
| 75 | /* Whee! Actually deliver the signal. */ |
Al Viro | a610d6e | 2012-05-21 23:42:15 -0400 | [diff] [blame] | 76 | handle_signal(regs, sig, &ka_copy, &info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | } |
| 78 | |
| 79 | /* Did we come from a system call? */ |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 80 | if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | /* Restart the system call - no handlers present */ |
Jeff Dike | c5d4bb1 | 2008-02-04 22:31:14 -0800 | [diff] [blame] | 82 | switch (PT_REGS_SYSCALL_RET(regs)) { |
Jeff Dike | 2fc1062 | 2006-01-18 17:44:02 -0800 | [diff] [blame] | 83 | case -ERESTARTNOHAND: |
| 84 | case -ERESTARTSYS: |
| 85 | case -ERESTARTNOINTR: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); |
| 87 | PT_REGS_RESTART_SYSCALL(regs); |
Jeff Dike | 2fc1062 | 2006-01-18 17:44:02 -0800 | [diff] [blame] | 88 | break; |
| 89 | case -ERESTART_RESTARTBLOCK: |
Jeff Dike | 1d3468a | 2006-07-10 04:45:13 -0700 | [diff] [blame] | 90 | PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | PT_REGS_RESTART_SYSCALL(regs); |
Jeff Dike | 2fc1062 | 2006-01-18 17:44:02 -0800 | [diff] [blame] | 92 | break; |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 93 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | } |
| 95 | |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 96 | /* |
| 97 | * This closes a way to execute a system call on the host. If |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | * you set a breakpoint on a system call instruction and singlestep |
| 99 | * from it, the tracing thread used to PTRACE_SINGLESTEP the process |
| 100 | * rather than PTRACE_SYSCALL it, allowing the system call to execute |
Jeff Dike | 1d3468a | 2006-07-10 04:45:13 -0700 | [diff] [blame] | 101 | * on the host. The tracing thread will check this flag and |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | * PTRACE_SYSCALL if necessary. |
| 103 | */ |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 104 | if (current->ptrace & PT_DTRACE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | current->thread.singlestep_syscall = |
| 106 | is_syscall(PT_REGS_IP(¤t->thread.regs)); |
Jeff Dike | 2fc1062 | 2006-01-18 17:44:02 -0800 | [diff] [blame] | 107 | |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 108 | /* |
| 109 | * if there's no signal to deliver, we just put the saved sigmask |
| 110 | * back |
| 111 | */ |
Al Viro | 51a7b44 | 2012-05-21 23:33:55 -0400 | [diff] [blame] | 112 | if (!handled_sig) |
| 113 | restore_saved_sigmask(); |
Jeff Dike | 7c7a894 | 2007-03-06 01:42:18 -0800 | [diff] [blame] | 114 | return handled_sig; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | } |
| 116 | |
| 117 | int do_signal(void) |
| 118 | { |
Jeff Dike | 7c7a894 | 2007-03-06 01:42:18 -0800 | [diff] [blame] | 119 | return kern_do_signal(¤t->thread.regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | } |
| 121 | |
| 122 | /* |
| 123 | * Atomically swap in the new signal mask, and wait for a signal. |
| 124 | */ |
| 125 | long sys_sigsuspend(int history0, int history1, old_sigset_t mask) |
| 126 | { |
Matt Fleming | d982d59 | 2012-03-23 15:01:50 -0700 | [diff] [blame] | 127 | sigset_t blocked; |
Matt Fleming | d982d59 | 2012-03-23 15:01:50 -0700 | [diff] [blame] | 128 | siginitset(&blocked, mask); |
Al Viro | 68f3f16 | 2012-05-21 21:42:32 -0400 | [diff] [blame] | 129 | return sigsuspend(&blocked); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | } |
| 131 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss) |
| 133 | { |
Jeff Dike | 7c7a894 | 2007-03-06 01:42:18 -0800 | [diff] [blame] | 134 | return do_sigaltstack(uss, uoss, PT_REGS_SP(¤t->thread.regs)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | } |