+++ /dev/null
-/*
- * arch/ubicom32/kernel/signal.c
- * Ubicom32 architecture signal handling implementation.
- *
- * (C) Copyright 2009, Ubicom, Inc.
- * Copyright (C) 1991, 1992 Linus Torvalds
- * Linux/m68k support by Hamish Macdonald
- * 68060 fixes by Jesper Skov
- * 1997-12-01 Modified for POSIX.1b signals by Andreas Schwab
- * mathemu support by Roman Zippel
- * ++roman (07/09/96): implemented signal stacks
- *
- * This file is part of the Ubicom32 Linux Kernel Port.
- *
- * The Ubicom32 Linux Kernel Port is free software: you can redistribute
- * it and/or modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 2 of the
- * License, or (at your option) any later version.
- *
- * The Ubicom32 Linux Kernel Port is distributed in the hope that it
- * will be useful, but WITHOUT ANY WARRANTY; without even the implied
- * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
- * the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with the Ubicom32 Linux Kernel Port. If not,
- * see <http://www.gnu.org/licenses/>.
- *
- * Ubicom32 implementation derived from (with many thanks):
- * arch/m68knommu
- * arch/blackfin
- * arch/parisc
- *
- * mathemu support by Roman Zippel
- * (Note: fpstate in the signal context is completely ignored for the emulator
- * and the internal floating point format is put on stack)
- *
- * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
- * Atari :-) Current limitation: Only one sigstack can be active at one time.
- * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
- * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
- * signal handlers!
- */
-
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/kernel.h>
-#include <linux/signal.h>
-#include <linux/syscalls.h>
-#include <linux/errno.h>
-#include <linux/wait.h>
-#include <linux/ptrace.h>
-#include <linux/unistd.h>
-#include <linux/stddef.h>
-#include <linux/highuid.h>
-#include <linux/tty.h>
-#include <linux/personality.h>
-#include <linux/binfmts.h>
-
-#include <asm/setup.h>
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-#include <asm/traps.h>
-#include <asm/ucontext.h>
-
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
-/*
- * asm signal return handlers.
- */
-void ret_from_user_signal(void);
-void ret_from_user_rt_signal(void);
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs);
-
-/*
- * Common signal suspend implementation
- */
-static int signal_suspend(sigset_t *saveset, struct pt_regs *regs)
-{
- regs->dn[0] = -EINTR;
- while (1) {
- current->state = TASK_INTERRUPTIBLE;
- schedule();
- if (!do_signal(saveset, regs)) {
- continue;
- }
- /*
- * If the current frame type is a signal trampoline we are
- * actually going to call the signal handler so we return the
- * desired d0 as the return value.
- */
- if (regs->frame_type == UBICOM32_FRAME_TYPE_SIGTRAMP) {
- return regs->dn[0];
- }
- return -EINTR;
- }
- /*
- * Should never get here
- */
- BUG();
- return 0;
-}
-
-/*
- * Atomically swap in the new signal mask, and wait for a signal.
- */
-asmlinkage int do_sigsuspend(struct pt_regs *regs)
-{
- old_sigset_t mask = regs->dn[0];
- sigset_t saveset;
-
- mask &= _BLOCKABLE;
- spin_lock_irq(¤t->sighand->siglock);
- saveset = current->blocked;
- siginitset(¤t->blocked, mask);
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- /*
- * Call common handler
- */
- return signal_suspend(&saveset, regs);
-}
-
-asmlinkage int
-do_rt_sigsuspend(struct pt_regs *regs)
-{
- sigset_t *unewset = (sigset_t *)regs->dn[0];
- size_t sigsetsize = (size_t)regs->dn[1];
- sigset_t saveset, newset;
-
- /* XXX: Don't preclude handling different sized sigset_t's. */
- if (sigsetsize != sizeof(sigset_t))
- return -EINVAL;
-
- if (copy_from_user(&newset, unewset, sizeof(newset)))
- return -EFAULT;
- sigdelsetmask(&newset, ~_BLOCKABLE);
-
- spin_lock_irq(¤t->sighand->siglock);
- saveset = current->blocked;
- current->blocked = newset;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- /*
- * Call common handler
- */
- return signal_suspend(&saveset, regs);
-}
-
-asmlinkage int
-sys_sigaction(int sig, const struct old_sigaction *act,
- struct old_sigaction *oact)
-{
- struct k_sigaction new_ka, old_ka;
- int ret;
-
- if (act) {
- old_sigset_t mask;
- if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
- __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
- __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
- return -EFAULT;
- __get_user(new_ka.sa.sa_flags, &act->sa_flags);
- __get_user(mask, &act->sa_mask);
- siginitset(&new_ka.sa.sa_mask, mask);
- }
-
- ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
-
- if (!ret && oact) {
- if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
- __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
- __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
- return -EFAULT;
- __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
- __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
- }
-
- return ret;
-}
-
-asmlinkage int
-do_sys_sigaltstack(struct pt_regs *regs)
-{
- const stack_t *uss = (stack_t *) regs->dn[0];
- stack_t *uoss = (stack_t *)regs->dn[1];
- return do_sigaltstack(uss, uoss, regs->an[7]);
-}
-
-/*
- * fdpic_func_descriptor describes sa_handler when the application is FDPIC
- */
-struct fdpic_func_descriptor {
- unsigned long text;
- unsigned long GOT;
-};
-
-/*
- * rt_sigframe is stored on the user stack immediately before (above)
- * the signal handlers stack.
- */
-struct rt_sigframe
-{
- unsigned long syscall_number; /* This holds __NR_rt_sigreturn. */
- unsigned long restore_all_regs; /* This field gets set to 1 if the frame
- * type is TRAP or INTERRUPT. */
- siginfo_t *info;
- struct ucontext uc;
- int sig;
- void *pretcode;
-};
-
-/*
- * Do a signal return; undo the signal stack.
- */
-asmlinkage int do_sigreturn(unsigned long __unused)
-{
- BUG();
- return 0;
-}
-
-asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
-{
- unsigned long usp = regs->an[7];
- struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
- sigset_t set;
-
- if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
- goto badframe;
- if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
- goto badframe;
-
- sigdelsetmask(&set, ~_BLOCKABLE);
- spin_lock_irq(¤t->sighand->siglock);
- current->blocked = set;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- if (copy_from_user(regs, &frame->uc.uc_mcontext, sizeof(struct pt_regs)))
- goto badframe;
- return regs->dn[0];
-
-badframe:
- force_sig(SIGSEGV, current);
- return 0;
-}
-
-static inline void *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
-{
- unsigned long usp;
-
- /* Default to using normal stack. */
- usp = regs->an[7];
-
- /* This is the X/Open sanctioned signal stack switching. */
- if (ka->sa.sa_flags & SA_ONSTACK) {
- if (!sas_ss_flags(usp))
- usp = current->sas_ss_sp + current->sas_ss_size;
- }
- return (void *)((usp - frame_size) & ~0x3);
-}
-
-/*
- * signal_trampoline: Defined in ubicom32_syscall.S
- */
-asmlinkage void signal_trampoline(void)__attribute__((naked));
-
-static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
- sigset_t *set, struct pt_regs *regs)
-{
- struct rt_sigframe *frame;
- int err = 0;
-
- frame = (struct rt_sigframe *) get_sigframe(ka, regs, sizeof(*frame));
-
- /*
- * The 'err |=' have been may criticized as bad code style, but I
- * strongly suspect that we want this code to be fast. So for
- * now it stays as is.
- */
- err |= __put_user( ( (current_thread_info()->exec_domain)
- && (current_thread_info()->exec_domain->signal_invmap)
- && (sig < 32) )
- ? current_thread_info()->exec_domain->signal_invmap[sig]
- : sig, &frame->sig);
- err |= __put_user(info, &frame->info);
-
- /* Create the ucontext. */
- err |= __put_user(0, &frame->uc.uc_flags);
- err |= __put_user(0, &frame->uc.uc_link);
- err |= __put_user((void *)current->sas_ss_sp,
- &frame->uc.uc_stack.ss_sp);
- err |= __put_user(sas_ss_flags(regs->an[7]),
- &frame->uc.uc_stack.ss_flags);
- err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
- err |= __put_user(__NR_rt_sigreturn, &frame->syscall_number);
- if ((regs->frame_type == UBICOM32_FRAME_TYPE_TRAP) ||
- (regs->frame_type == UBICOM32_FRAME_TYPE_INTERRUPT)) {
- err |= __put_user(1, &frame->restore_all_regs);
- } else {
- err |= __put_user(0, &frame->restore_all_regs);
- }
- err |= copy_to_user (&frame->uc.uc_mcontext.sc_regs, regs, sizeof(struct pt_regs));
- err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
-
- if (err)
- goto give_sigsegv;
-
- /*
- * Set up registers for signal handler NOTE: Do not modify dn[14], it
- * contains the userspace tls pointer, so it important that it carries
- * over to the signal handler.
- */
- regs->an[7] = (unsigned long)frame;
- regs->pc = (unsigned long) signal_trampoline;
- regs->an[5] = (unsigned long) signal_trampoline;
- regs->dn[0] = sig;
- regs->dn[1] = (unsigned long) frame->info;
- regs->dn[2] = (unsigned int) &frame->uc;
-
- /*
- * If this is FDPIC then the signal handler is actually a function
- * descriptor.
- */
- if (current->personality & FDPIC_FUNCPTRS) {
- struct fdpic_func_descriptor __user *funcptr =
- (struct fdpic_func_descriptor *) ka->sa.sa_handler;
- err |= __get_user(regs->dn[3], &funcptr->text);
- err |= __get_user(regs->an[0], &funcptr->GOT);
- if (err)
- goto give_sigsegv;
-
- /*
- * The funcdesc must be in a3 as this is required for the lazy
- * resolver in ld.so, if the application is not FDPIC a3 is not
- * used.
- */
- regs->an[3] = (unsigned long) funcptr;
-
- } else {
- regs->dn[3] = (unsigned long)ka->sa.sa_handler;
- regs->an[0] = 0;
- }
-
- regs->frame_type = UBICOM32_FRAME_TYPE_SIGTRAMP;
-
- return;
-
-give_sigsegv:
- /* user space exception */
- force_sigsegv(sig, current);
-}
-
-static inline void
-handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
-{
- switch (regs->dn[0]) {
- case -ERESTARTNOHAND:
- if (!has_handler)
- goto do_restart;
- regs->dn[0] = -EINTR;
- break;
-
- case -ERESTARTSYS:
- if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
- regs->dn[0] = -EINTR;
- break;
- }
- /* fallthrough */
- case -ERESTARTNOINTR:
- do_restart:
- regs->dn[0] = regs->original_dn_0;
- regs->pc -= 8;
- regs->an[5] -= 8;
- break;
- }
-}
-
-/*
- * OK, we're invoking a handler
- */
-static void
-handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
- sigset_t *oldset, struct pt_regs *regs)
-{
- /* are we from a system call? */
- if (regs->frame_type == -1)
- /* If so, check system call restarting.. */
- handle_restart(regs, ka, 1);
-
- /* set up the stack frame */
- setup_rt_frame(sig, ka, info, oldset, regs);
-
- if (ka->sa.sa_flags & SA_ONESHOT)
- ka->sa.sa_handler = SIG_DFL;
-
- 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,sig);
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-}
-
-/*
- * Note that 'init' is a special process: it doesn't get signals it doesn't
- * want to handle. Thus you cannot kill init even with a SIGKILL even by
- * mistake.
- */
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
-{
- struct k_sigaction ka;
- siginfo_t info;
- int signr;
-
- /*
- * We want the common case to go fast, which
- * is why we may in certain cases get here from
- * kernel mode. Just return without doing anything
- * if so.
- */
- if (!user_mode(regs))
- return 1;
-
- if (!oldset)
- oldset = ¤t->blocked;
-
- signr = get_signal_to_deliver(&info, &ka, regs, NULL);
- if (signr > 0) {
- /* Whee! Actually deliver the signal. */
- handle_signal(signr, &ka, &info, oldset, regs);
- return 1;
- }
-
- /* Did we come from a system call? */
- if (regs->frame_type == -1) {
- /* Restart the system call - no handlers present */
- handle_restart(regs, NULL, 0);
- }
-
- return 0;
-}
-
-/*
- * sys_sigreturn()
- * Return handler for signal clean-up.
- *
- * NOTE: Ubicom32 does not use this syscall. Instead we rely
- * on do_rt_sigreturn().
- */
-asmlinkage long sys_sigreturn(void)
-{
- return -ENOSYS;
-}
projects / openwrt / svn-archive / archive.git / blobdiff