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 spin_lock_irq(¤t->sighand->siglock);
61 current->blocked = *set;
63 spin_unlock_irq(¤t->sighand->siglock);
66 static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
69 unsigned long ret = regs->gpr[3];
73 if (TRAP(regs) != 0x0C00)
76 /* error signalled ? */
77 if (!(regs->ccr & 0x10000000))
81 case ERESTART_RESTARTBLOCK:
83 /* ERESTARTNOHAND means that the syscall should only be
84 * restarted if there was no handler for the signal, and since
85 * we only get here if there is a handler, we dont restart.
87 restart = !has_handler;
90 /* ERESTARTSYS means to restart the syscall if there is no
91 * handler or the handler was registered with SA_RESTART
93 restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0;
96 /* ERESTARTNOINTR means that the syscall should be
97 * called again after the signal handler returns.
104 if (ret == ERESTART_RESTARTBLOCK)
105 regs->gpr[0] = __NR_restart_syscall;
107 regs->gpr[3] = regs->orig_gpr3;
111 regs->result = -EINTR;
112 regs->gpr[3] = EINTR;
113 regs->ccr |= 0x10000000;
117 static int do_signal(struct pt_regs *regs)
122 struct k_sigaction ka;
124 int is32 = is_32bit_task();
126 if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK)
127 oldset = ¤t->saved_sigmask;
129 oldset = ¤t->blocked;
131 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
133 /* Is there any syscall restart business here ? */
134 check_syscall_restart(regs, &ka, signr > 0);
137 struct thread_info *ti = current_thread_info();
138 /* No signal to deliver -- put the saved sigmask back */
139 if (ti->local_flags & _TLF_RESTORE_SIGMASK) {
140 ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
141 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
144 return 0; /* no signals delivered */
147 #ifndef CONFIG_PPC_ADV_DEBUG_REGS
149 * Reenable the DABR before delivering the signal to
150 * user space. The DABR will have been cleared if it
151 * triggered inside the kernel.
153 if (current->thread.dabr)
154 set_dabr(current->thread.dabr);
156 /* Re-enable the breakpoints for the signal stack */
157 thread_change_pc(current, regs);
160 if (ka.sa.sa_flags & SA_SIGINFO)
161 ret = handle_rt_signal32(signr, &ka, &info, oldset,
164 ret = handle_signal32(signr, &ka, &info, oldset,
167 ret = handle_rt_signal64(signr, &ka, &info, oldset, regs);
172 spin_lock_irq(¤t->sighand->siglock);
173 sigorsets(¤t->blocked, ¤t->blocked,
175 if (!(ka.sa.sa_flags & SA_NODEFER))
176 sigaddset(¤t->blocked, signr);
178 spin_unlock_irq(¤t->sighand->siglock);
181 * A signal was successfully delivered; the saved sigmask is in
182 * its frame, and we can clear the TLF_RESTORE_SIGMASK flag.
184 current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
187 * Let tracing know that we've done the handler setup.
189 tracehook_signal_handler(signr, &info, &ka, regs,
190 test_thread_flag(TIF_SINGLESTEP));
196 void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
198 if (thread_info_flags & _TIF_SIGPENDING)
201 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
202 clear_thread_flag(TIF_NOTIFY_RESUME);
203 tracehook_notify_resume(regs);
204 if (current->replacement_session_keyring)
205 key_replace_session_keyring();
209 long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
210 unsigned long r5, unsigned long r6, unsigned long r7,
211 unsigned long r8, struct pt_regs *regs)
213 return do_sigaltstack(uss, uoss, regs->gpr[1]);