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Diffstat (limited to '')
| -rw-r--r-- | arch/h8300/kernel/signal.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/arch/h8300/kernel/signal.c b/arch/h8300/kernel/signal.c new file mode 100644 index 000000000..75a1c36b1 --- /dev/null +++ b/arch/h8300/kernel/signal.c @@ -0,0 +1,287 @@ +/* + * linux/arch/h8300/kernel/signal.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +/* + * uClinux H8/300 support by Yoshinori Sato <ysato@users.sourceforge.jp> + * and David McCullough <davidm@snapgear.com> + * + * Based on + * Linux/m68k by Hamish Macdonald + */ + +/* + * ++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/sched.h> +#include <linux/sched/task_stack.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/personality.h> +#include <linux/tty.h> +#include <linux/binfmts.h> +#include <linux/tracehook.h> + +#include <asm/setup.h> +#include <linux/uaccess.h> +#include <asm/traps.h> +#include <asm/ucontext.h> + +/* + * Do a signal return; undo the signal stack. + * + * Keep the return code on the stack quadword aligned! + * That makes the cache flush below easier. + */ + +struct rt_sigframe { + long dummy_er0; + long dummy_vector; +#if defined(CONFIG_CPU_H8S) + short dummy_exr; +#endif + long dummy_pc; + char *pretcode; + struct siginfo *pinfo; + void *puc; + unsigned char retcode[8]; + struct siginfo info; + struct ucontext uc; + int sig; +} __packed __aligned(2); + +static inline int +restore_sigcontext(struct sigcontext *usc, int *pd0) +{ + struct pt_regs *regs = current_pt_regs(); + int err = 0; + unsigned int ccr; + unsigned int usp; + unsigned int er0; + + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + /* restore passed registers */ +#define COPY(r) do { err |= get_user(regs->r, &usc->sc_##r); } while (0) + COPY(er1); + COPY(er2); + COPY(er3); + COPY(er5); + COPY(pc); + ccr = regs->ccr & 0x10; + COPY(ccr); +#undef COPY + regs->ccr &= 0xef; + regs->ccr |= ccr; + regs->orig_er0 = -1; /* disable syscall checks */ + err |= __get_user(usp, &usc->sc_usp); + regs->sp = usp; + + err |= __get_user(er0, &usc->sc_er0); + *pd0 = er0; + return err; +} + +asmlinkage int sys_rt_sigreturn(void) +{ + unsigned long usp = rdusp(); + struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4); + sigset_t set; + int er0; + + if (!access_ok(frame, sizeof(*frame))) + goto badframe; + if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) + goto badframe; + + set_current_blocked(&set); + + if (restore_sigcontext(&frame->uc.uc_mcontext, &er0)) + goto badframe; + + if (restore_altstack(&frame->uc.uc_stack)) + goto badframe; + + return er0; + +badframe: + force_sig(SIGSEGV); + return 0; +} + +static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, + unsigned long mask) +{ + int err = 0; + + err |= __put_user(regs->er0, &sc->sc_er0); + err |= __put_user(regs->er1, &sc->sc_er1); + err |= __put_user(regs->er2, &sc->sc_er2); + err |= __put_user(regs->er3, &sc->sc_er3); + err |= __put_user(regs->er4, &sc->sc_er4); + err |= __put_user(regs->er5, &sc->sc_er5); + err |= __put_user(regs->er6, &sc->sc_er6); + err |= __put_user(rdusp(), &sc->sc_usp); + err |= __put_user(regs->pc, &sc->sc_pc); + err |= __put_user(regs->ccr, &sc->sc_ccr); + err |= __put_user(mask, &sc->sc_mask); + + return err; +} + +static inline void __user * +get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size) +{ + return (void __user *)((sigsp(rdusp(), ksig) - frame_size) & -8UL); +} + +static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, + struct pt_regs *regs) +{ + struct rt_sigframe *frame; + int err = 0; + unsigned char *ret; + + frame = get_sigframe(ksig, regs, sizeof(*frame)); + + if (!access_ok(frame, sizeof(*frame))) + return -EFAULT; + + if (ksig->ka.sa.sa_flags & SA_SIGINFO) + err |= copy_siginfo_to_user(&frame->info, &ksig->info); + + /* Create the ucontext. */ + err |= __put_user(0, &frame->uc.uc_flags); + err |= __put_user(0, &frame->uc.uc_link); + err |= __save_altstack(&frame->uc.uc_stack, rdusp()); + err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]); + err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + if (err) + return -EFAULT; + + /* Set up to return from userspace. */ + ret = (unsigned char *)&frame->retcode; + if (ksig->ka.sa.sa_flags & SA_RESTORER) + ret = (unsigned char *)(ksig->ka.sa.sa_restorer); + else { + /* sub.l er0,er0; mov.b #__NR_rt_sigreturn,r0l; trapa #0 */ + err |= __put_user(0x1a80f800 + (__NR_rt_sigreturn & 0xff), + (unsigned long *)(frame->retcode + 0)); + err |= __put_user(0x5700, + (unsigned short *)(frame->retcode + 4)); + } + err |= __put_user(ret, &frame->pretcode); + + if (err) + return -EFAULT; + + /* Set up registers for signal handler */ + regs->sp = (unsigned long)frame; + regs->pc = (unsigned long)ksig->ka.sa.sa_handler; + regs->er0 = ksig->sig; + regs->er1 = (unsigned long)&(frame->info); + regs->er2 = (unsigned long)&frame->uc; + regs->er5 = current->mm->start_data; /* GOT base */ + + return 0; +} + +static void +handle_restart(struct pt_regs *regs, struct k_sigaction *ka) +{ + switch (regs->er0) { + case -ERESTARTNOHAND: + if (!ka) + goto do_restart; + regs->er0 = -EINTR; + break; + case -ERESTART_RESTARTBLOCK: + if (!ka) { + regs->er0 = __NR_restart_syscall; + regs->pc -= 2; + } else + regs->er0 = -EINTR; + break; + case -ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->er0 = -EINTR; + break; + } + fallthrough; + case -ERESTARTNOINTR: +do_restart: + regs->er0 = regs->orig_er0; + regs->pc -= 2; + break; + } +} + +/* + * OK, we're invoking a handler + */ +static void +handle_signal(struct ksignal *ksig, struct pt_regs *regs) +{ + sigset_t *oldset = sigmask_to_save(); + int ret; + /* are we from a system call? */ + if (regs->orig_er0 >= 0) + handle_restart(regs, &ksig->ka); + + ret = setup_rt_frame(ksig, oldset, regs); + + signal_setup_done(ret, ksig, 0); +} + +/* + * 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. + */ +static void do_signal(struct pt_regs *regs) +{ + struct ksignal ksig; + + current->thread.esp0 = (unsigned long) regs; + + if (get_signal(&ksig)) { + /* Whee! Actually deliver the signal. */ + handle_signal(&ksig, regs); + return; + } + /* Did we come from a system call? */ + if (regs->orig_er0 >= 0) + handle_restart(regs, NULL); + + /* If there's no signal to deliver, we just restore the saved mask. */ + restore_saved_sigmask(); +} + +asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) +{ + if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) + do_signal(regs); + + if (thread_info_flags & _TIF_NOTIFY_RESUME) + tracehook_notify_resume(regs); +} |