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 <asm/hw_breakpoint.h>
15 #include <asm/uaccess.h>
16 #include <asm/unistd.h>
20 /* Log an error when sending an unhandled signal to a process. Controlled
21 * through debug.exception-trace sysctl.
24 int show_unhandled_signals = 0;
27 * Allocate space for the signal frame
29 void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
30 size_t frame_size, int is_32)
32 unsigned long oldsp, newsp;
34 /* Default to using normal stack */
35 oldsp = get_clean_sp(regs, is_32);
37 /* Check for alt stack */
38 if ((ka->sa.sa_flags & SA_ONSTACK) &&
39 current->sas_ss_size && !on_sig_stack(oldsp))
40 oldsp = (current->sas_ss_sp + current->sas_ss_size);
42 /* Get aligned frame */
43 newsp = (oldsp - frame_size) & ~0xFUL;
46 if (!access_ok(VERIFY_WRITE, (void __user *)newsp, oldsp - newsp))
49 return (void __user *)newsp;
54 * Restore the user process's signal mask
56 void restore_sigmask(sigset_t *set)
58 sigdelsetmask(set, ~_BLOCKABLE);
59 spin_lock_irq(¤t->sighand->siglock);
60 current->blocked = *set;
62 spin_unlock_irq(¤t->sighand->siglock);
65 static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
68 unsigned long ret = regs->gpr[3];
72 if (TRAP(regs) != 0x0C00)
75 /* error signalled ? */
76 if (!(regs->ccr & 0x10000000))
80 case ERESTART_RESTARTBLOCK:
82 /* ERESTARTNOHAND means that the syscall should only be
83 * restarted if there was no handler for the signal, and since
84 * we only get here if there is a handler, we dont restart.
86 restart = !has_handler;
89 /* ERESTARTSYS means to restart the syscall if there is no
90 * handler or the handler was registered with SA_RESTART
92 restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0;
95 /* ERESTARTNOINTR means that the syscall should be
96 * called again after the signal handler returns.
103 if (ret == ERESTART_RESTARTBLOCK)
104 regs->gpr[0] = __NR_restart_syscall;
106 regs->gpr[3] = regs->orig_gpr3;
110 regs->result = -EINTR;
111 regs->gpr[3] = EINTR;
112 regs->ccr |= 0x10000000;
116 static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs)
120 struct k_sigaction ka;
122 int is32 = is_32bit_task();
124 if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK)
125 oldset = ¤t->saved_sigmask;
127 oldset = ¤t->blocked;
129 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
131 /* Is there any syscall restart business here ? */
132 check_syscall_restart(regs, &ka, signr > 0);
135 struct thread_info *ti = current_thread_info();
136 /* No signal to deliver -- put the saved sigmask back */
137 if (ti->local_flags & _TLF_RESTORE_SIGMASK) {
138 ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
139 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
142 return 0; /* no signals delivered */
145 #ifndef CONFIG_PPC_ADV_DEBUG_REGS
147 * Reenable the DABR before delivering the signal to
148 * user space. The DABR will have been cleared if it
149 * triggered inside the kernel.
151 if (current->thread.dabr)
152 set_dabr(current->thread.dabr);
154 /* Re-enable the breakpoints for the signal stack */
155 thread_change_pc(current, regs);
158 if (ka.sa.sa_flags & SA_SIGINFO)
159 ret = handle_rt_signal32(signr, &ka, &info, oldset,
162 ret = handle_signal32(signr, &ka, &info, oldset,
165 ret = handle_rt_signal64(signr, &ka, &info, oldset, regs);
170 spin_lock_irq(¤t->sighand->siglock);
171 sigorsets(¤t->blocked, ¤t->blocked,
173 if (!(ka.sa.sa_flags & SA_NODEFER))
174 sigaddset(¤t->blocked, signr);
176 spin_unlock_irq(¤t->sighand->siglock);
179 * A signal was successfully delivered; the saved sigmask is in
180 * its frame, and we can clear the TLF_RESTORE_SIGMASK flag.
182 current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
185 * Let tracing know that we've done the handler setup.
187 tracehook_signal_handler(signr, &info, &ka, regs,
188 test_thread_flag(TIF_SINGLESTEP));
194 void do_signal(struct pt_regs *regs, unsigned long thread_info_flags)
196 if (thread_info_flags & _TIF_SIGPENDING)
197 do_signal_pending(NULL, regs);
199 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
200 clear_thread_flag(TIF_NOTIFY_RESUME);
201 tracehook_notify_resume(regs);
205 long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
206 unsigned long r5, unsigned long r6, unsigned long r7,
207 unsigned long r8, struct pt_regs *regs)
209 return do_sigaltstack(uss, uoss, regs->gpr[1]);