diff options
Diffstat (limited to 'target/linux/ubicom32/files/arch/ubicom32/kernel/signal.c')
| -rw-r--r-- | target/linux/ubicom32/files/arch/ubicom32/kernel/signal.c | 458 |
1 files changed, 458 insertions, 0 deletions
diff --git a/target/linux/ubicom32/files/arch/ubicom32/kernel/signal.c b/target/linux/ubicom32/files/arch/ubicom32/kernel/signal.c new file mode 100644 index 000000000..f6ccbe3a7 --- /dev/null +++ b/target/linux/ubicom32/files/arch/ubicom32/kernel/signal.c @@ -0,0 +1,458 @@ +/* + * 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; +} |