diff options
Diffstat (limited to 'arch/powerpc/kernel/signal.c')
| -rw-r--r-- | arch/powerpc/kernel/signal.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c new file mode 100644 index 000000000000..c434d6c4e4e6 --- /dev/null +++ b/arch/powerpc/kernel/signal.c @@ -0,0 +1,180 @@ +/* + * 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" + +/* + * 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 (test_thread_flag(TIF_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) { + /* No signal to deliver -- put the saved sigmask back */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) { + clear_thread_flag(TIF_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 (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 TIF_RESTORE_SIGMASK flag. + */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) + clear_thread_flag(TIF_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]); +} |