2 * Common signal handling code for both 32 and 64 bits
4 * Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration
5 * Extracted from signal_32.c and signal_64.c
7 * This file is subject to the terms and conditions of the GNU General
8 * Public License. See the file README.legal in the main directory of
9 * this archive for more details.
12 #include <linux/tracehook.h>
13 #include <linux/signal.h>
14 #include <linux/key.h>
15 #include <asm/hw_breakpoint.h>
16 #include <asm/uaccess.h>
17 #include <asm/unistd.h>
21 /* Log an error when sending an unhandled signal to a process. Controlled
22 * through debug.exception-trace sysctl.
25 int show_unhandled_signals = 0;
28 * Allocate space for the signal frame
30 void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
31 size_t frame_size, int is_32)
33 unsigned long oldsp, newsp;
35 /* Default to using normal stack */
36 oldsp = get_clean_sp(regs, is_32);
38 /* Check for alt stack */
39 if ((ka->sa.sa_flags & SA_ONSTACK) &&
40 current->sas_ss_size && !on_sig_stack(oldsp))
41 oldsp = (current->sas_ss_sp + current->sas_ss_size);
43 /* Get aligned frame */
44 newsp = (oldsp - frame_size) & ~0xFUL;
47 if (!access_ok(VERIFY_WRITE, (void __user *)newsp, oldsp - newsp))
50 return (void __user *)newsp;
55 * Restore the user process's signal mask
57 void restore_sigmask(sigset_t *set)
59 sigdelsetmask(set, ~_BLOCKABLE);
60 set_current_blocked(set);
63 static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
66 unsigned long ret = regs->gpr[3];
70 if (TRAP(regs) != 0x0C00)
73 /* error signalled ? */
74 if (!(regs->ccr & 0x10000000))
78 case ERESTART_RESTARTBLOCK:
80 /* ERESTARTNOHAND means that the syscall should only be
81 * restarted if there was no handler for the signal, and since
82 * we only get here if there is a handler, we dont restart.
84 restart = !has_handler;
87 /* ERESTARTSYS means to restart the syscall if there is no
88 * handler or the handler was registered with SA_RESTART
90 restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0;
93 /* ERESTARTNOINTR means that the syscall should be
94 * called again after the signal handler returns.
101 if (ret == ERESTART_RESTARTBLOCK)
102 regs->gpr[0] = __NR_restart_syscall;
104 regs->gpr[3] = regs->orig_gpr3;
108 regs->result = -EINTR;
109 regs->gpr[3] = EINTR;
110 regs->ccr |= 0x10000000;
114 static int do_signal(struct pt_regs *regs)
119 struct k_sigaction ka;
121 int is32 = is_32bit_task();
123 if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK)
124 oldset = ¤t->saved_sigmask;
126 oldset = ¤t->blocked;
128 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
130 /* Is there any syscall restart business here ? */
131 check_syscall_restart(regs, &ka, signr > 0);
134 struct thread_info *ti = current_thread_info();
135 /* No signal to deliver -- put the saved sigmask back */
136 if (ti->local_flags & _TLF_RESTORE_SIGMASK) {
137 ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
138 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
141 return 0; /* no signals delivered */
144 #ifndef CONFIG_PPC_ADV_DEBUG_REGS
146 * Reenable the DABR before delivering the signal to
147 * user space. The DABR will have been cleared if it
148 * triggered inside the kernel.
150 if (current->thread.dabr)
151 set_dabr(current->thread.dabr);
153 /* Re-enable the breakpoints for the signal stack */
154 thread_change_pc(current, regs);
157 if (ka.sa.sa_flags & SA_SIGINFO)
158 ret = handle_rt_signal32(signr, &ka, &info, oldset,
161 ret = handle_signal32(signr, &ka, &info, oldset,
164 ret = handle_rt_signal64(signr, &ka, &info, oldset, regs);
169 block_sigmask(&ka, signr);
172 * A signal was successfully delivered; the saved sigmask is in
173 * its frame, and we can clear the TLF_RESTORE_SIGMASK flag.
175 current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
178 * Let tracing know that we've done the handler setup.
180 tracehook_signal_handler(signr, &info, &ka, regs,
181 test_thread_flag(TIF_SINGLESTEP));
187 void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
189 if (thread_info_flags & _TIF_SIGPENDING)
192 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
193 clear_thread_flag(TIF_NOTIFY_RESUME);
194 tracehook_notify_resume(regs);
195 if (current->replacement_session_keyring)
196 key_replace_session_keyring();
200 long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
201 unsigned long r5, unsigned long r6, unsigned long r7,
202 unsigned long r8, struct pt_regs *regs)
204 return do_sigaltstack(uss, uoss, regs->gpr[1]);