| /* |
| * Common signal handling code for both 32 and 64 bits |
| * |
| * Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration |
| * Extracted from signal_32.c and signal_64.c |
| * |
| * This file is subject to the terms and conditions of the GNU General |
| * Public License. See the file README.legal in the main directory of |
| * this archive for more details. |
| */ |
| |
| #include <linux/ptrace.h> |
| #include <linux/signal.h> |
| #include <asm/uaccess.h> |
| #include <asm/unistd.h> |
| |
| #include "signal.h" |
| |
| /* Log an error when sending an unhandled signal to a process. Controlled |
| * through debug.exception-trace sysctl. |
| */ |
| |
| int show_unhandled_signals = 0; |
| |
| /* |
| * Allocate space for the signal frame |
| */ |
| void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, |
| size_t frame_size) |
| { |
| unsigned long oldsp, newsp; |
| |
| /* Default to using normal stack */ |
| oldsp = regs->gpr[1]; |
| |
| /* Check for alt stack */ |
| if ((ka->sa.sa_flags & SA_ONSTACK) && |
| current->sas_ss_size && !on_sig_stack(oldsp)) |
| oldsp = (current->sas_ss_sp + current->sas_ss_size); |
| |
| /* Get aligned frame */ |
| newsp = (oldsp - frame_size) & ~0xFUL; |
| |
| /* Check access */ |
| if (!access_ok(VERIFY_WRITE, (void __user *)newsp, oldsp - newsp)) |
| return NULL; |
| |
| return (void __user *)newsp; |
| } |
| |
| |
| /* |
| * Restore the user process's signal mask |
| */ |
| void restore_sigmask(sigset_t *set) |
| { |
| sigdelsetmask(set, ~_BLOCKABLE); |
| spin_lock_irq(¤t->sighand->siglock); |
| current->blocked = *set; |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| } |
| |
| static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka, |
| int has_handler) |
| { |
| unsigned long ret = regs->gpr[3]; |
| int restart = 1; |
| |
| /* syscall ? */ |
| if (TRAP(regs) != 0x0C00) |
| return; |
| |
| /* error signalled ? */ |
| if (!(regs->ccr & 0x10000000)) |
| return; |
| |
| switch (ret) { |
| case ERESTART_RESTARTBLOCK: |
| case ERESTARTNOHAND: |
| /* ERESTARTNOHAND means that the syscall should only be |
| * restarted if there was no handler for the signal, and since |
| * we only get here if there is a handler, we dont restart. |
| */ |
| restart = !has_handler; |
| break; |
| case ERESTARTSYS: |
| /* ERESTARTSYS means to restart the syscall if there is no |
| * handler or the handler was registered with SA_RESTART |
| */ |
| restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0; |
| break; |
| case ERESTARTNOINTR: |
| /* ERESTARTNOINTR means that the syscall should be |
| * called again after the signal handler returns. |
| */ |
| break; |
| default: |
| return; |
| } |
| if (restart) { |
| if (ret == ERESTART_RESTARTBLOCK) |
| regs->gpr[0] = __NR_restart_syscall; |
| else |
| regs->gpr[3] = regs->orig_gpr3; |
| regs->nip -= 4; |
| regs->result = 0; |
| } else { |
| regs->result = -EINTR; |
| regs->gpr[3] = EINTR; |
| regs->ccr |= 0x10000000; |
| } |
| } |
| |
| int do_signal(sigset_t *oldset, struct pt_regs *regs) |
| { |
| siginfo_t info; |
| int signr; |
| struct k_sigaction ka; |
| int ret; |
| int is32 = is_32bit_task(); |
| |
| if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK) |
| oldset = ¤t->saved_sigmask; |
| else if (!oldset) |
| oldset = ¤t->blocked; |
| |
| signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| |
| /* Is there any syscall restart business here ? */ |
| check_syscall_restart(regs, &ka, signr > 0); |
| |
| if (signr <= 0) { |
| struct thread_info *ti = current_thread_info(); |
| /* No signal to deliver -- put the saved sigmask back */ |
| if (ti->local_flags & _TLF_RESTORE_SIGMASK) { |
| ti->local_flags &= ~_TLF_RESTORE_SIGMASK; |
| sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
| } |
| return 0; /* no signals delivered */ |
| } |
| |
| /* |
| * Reenable the DABR before delivering the signal to |
| * user space. The DABR will have been cleared if it |
| * triggered inside the kernel. |
| */ |
| if (current->thread.dabr) { |
| set_dabr(current->thread.dabr); |
| #if defined(CONFIG_44x) || defined(CONFIG_BOOKE) |
| mtspr(SPRN_DBCR0, current->thread.dbcr0); |
| #endif |
| } |
| |
| if (is32) { |
| if (ka.sa.sa_flags & SA_SIGINFO) |
| ret = handle_rt_signal32(signr, &ka, &info, oldset, |
| regs); |
| else |
| ret = handle_signal32(signr, &ka, &info, oldset, |
| regs); |
| } else { |
| ret = handle_rt_signal64(signr, &ka, &info, oldset, regs); |
| } |
| |
| if (ret) { |
| spin_lock_irq(¤t->sighand->siglock); |
| sigorsets(¤t->blocked, ¤t->blocked, |
| &ka.sa.sa_mask); |
| if (!(ka.sa.sa_flags & SA_NODEFER)) |
| sigaddset(¤t->blocked, signr); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| /* |
| * A signal was successfully delivered; the saved sigmask is in |
| * its frame, and we can clear the TLF_RESTORE_SIGMASK flag. |
| */ |
| current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK; |
| } |
| |
| return ret; |
| } |
| |
| long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, |
| unsigned long r5, unsigned long r6, unsigned long r7, |
| unsigned long r8, struct pt_regs *regs) |
| { |
| return do_sigaltstack(uss, uoss, regs->gpr[1]); |
| } |