diff options
Diffstat (limited to 'arch/arm26/kernel/signal.c')
| -rw-r--r-- | arch/arm26/kernel/signal.c | 540 |
1 files changed, 540 insertions, 0 deletions
diff --git a/arch/arm26/kernel/signal.c b/arch/arm26/kernel/signal.c new file mode 100644 index 00000000000..356d9809cc0 --- /dev/null +++ b/arch/arm26/kernel/signal.c @@ -0,0 +1,540 @@ +/* + * linux/arch/arm26/kernel/signal.c + * + * Copyright (C) 1995-2002 Russell King + * Copyright (C) 2003 Ian Molton (ARM26) + * + * FIXME!!! This is probably very broken (13/05/2003) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/config.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/wait.h> +#include <linux/ptrace.h> +#include <linux/personality.h> +#include <linux/tty.h> +#include <linux/binfmts.h> +#include <linux/elf.h> + +#include <asm/pgalloc.h> +#include <asm/ucontext.h> +#include <asm/uaccess.h> +#include <asm/unistd.h> + +#include "ptrace.h" + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +/* + * For ARM syscalls, we encode the syscall number into the instruction. + */ +#define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)) +#define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)) + +static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall); + +/* + * atomically swap in the new signal mask, and wait for a signal. + */ +asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs) +{ + 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); + regs->ARM_r0 = -EINTR; + + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(&saveset, regs, 0)) + return regs->ARM_r0; + } +} + +asmlinkage int +sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, struct pt_regs *regs) +{ + 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); + regs->ARM_r0 = -EINTR; + + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(&saveset, regs, 0)) + return regs->ARM_r0; + } +} + +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; +} + +/* + * Do a signal return; undo the signal stack. + */ +struct sigframe +{ + struct sigcontext sc; + unsigned long extramask[_NSIG_WORDS-1]; + unsigned long retcode; +}; + +struct rt_sigframe +{ + struct siginfo *pinfo; + void *puc; + struct siginfo info; + struct ucontext uc; + unsigned long retcode; +}; + +static int +restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc) +{ + int err = 0; + + __get_user_error(regs->ARM_r0, &sc->arm_r0, err); + __get_user_error(regs->ARM_r1, &sc->arm_r1, err); + __get_user_error(regs->ARM_r2, &sc->arm_r2, err); + __get_user_error(regs->ARM_r3, &sc->arm_r3, err); + __get_user_error(regs->ARM_r4, &sc->arm_r4, err); + __get_user_error(regs->ARM_r5, &sc->arm_r5, err); + __get_user_error(regs->ARM_r6, &sc->arm_r6, err); + __get_user_error(regs->ARM_r7, &sc->arm_r7, err); + __get_user_error(regs->ARM_r8, &sc->arm_r8, err); + __get_user_error(regs->ARM_r9, &sc->arm_r9, err); + __get_user_error(regs->ARM_r10, &sc->arm_r10, err); + __get_user_error(regs->ARM_fp, &sc->arm_fp, err); + __get_user_error(regs->ARM_ip, &sc->arm_ip, err); + __get_user_error(regs->ARM_sp, &sc->arm_sp, err); + __get_user_error(regs->ARM_lr, &sc->arm_lr, err); + __get_user_error(regs->ARM_pc, &sc->arm_pc, err); + + err |= !valid_user_regs(regs); + + return err; +} + +asmlinkage int sys_sigreturn(struct pt_regs *regs) +{ + struct sigframe *frame; + sigset_t set; + + /* + * Since we stacked the signal on a 64-bit boundary, + * then 'sp' should be word aligned here. If it's + * not, then the user is trying to mess with us. + */ + if (regs->ARM_sp & 7) + goto badframe; + + frame = (struct sigframe *)regs->ARM_sp; + + if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) + goto badframe; + if (__get_user(set.sig[0], &frame->sc.oldmask) + || (_NSIG_WORDS > 1 + && __copy_from_user(&set.sig[1], &frame->extramask, + sizeof(frame->extramask)))) + goto badframe; + + sigdelsetmask(&set, ~_BLOCKABLE); + spin_lock_irq(¤t->sighand->siglock); + current->blocked = set; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + if (restore_sigcontext(regs, &frame->sc)) + goto badframe; + + /* Send SIGTRAP if we're single-stepping */ + if (current->ptrace & PT_SINGLESTEP) { + ptrace_cancel_bpt(current); + send_sig(SIGTRAP, current, 1); + } + + return regs->ARM_r0; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) +{ + struct rt_sigframe *frame; + sigset_t set; + + /* + * Since we stacked the signal on a 64-bit boundary, + * then 'sp' should be word aligned here. If it's + * not, then the user is trying to mess with us. + */ + if (regs->ARM_sp & 7) + goto badframe; + + frame = (struct rt_sigframe *)regs->ARM_sp; + + 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 (restore_sigcontext(regs, &frame->uc.uc_mcontext)) + goto badframe; + + /* Send SIGTRAP if we're single-stepping */ + if (current->ptrace & PT_SINGLESTEP) { + ptrace_cancel_bpt(current); + send_sig(SIGTRAP, current, 1); + } + + return regs->ARM_r0; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +static int +setup_sigcontext(struct sigcontext *sc, /*struct _fpstate *fpstate,*/ + struct pt_regs *regs, unsigned long mask) +{ + int err = 0; + + __put_user_error(regs->ARM_r0, &sc->arm_r0, err); + __put_user_error(regs->ARM_r1, &sc->arm_r1, err); + __put_user_error(regs->ARM_r2, &sc->arm_r2, err); + __put_user_error(regs->ARM_r3, &sc->arm_r3, err); + __put_user_error(regs->ARM_r4, &sc->arm_r4, err); + __put_user_error(regs->ARM_r5, &sc->arm_r5, err); + __put_user_error(regs->ARM_r6, &sc->arm_r6, err); + __put_user_error(regs->ARM_r7, &sc->arm_r7, err); + __put_user_error(regs->ARM_r8, &sc->arm_r8, err); + __put_user_error(regs->ARM_r9, &sc->arm_r9, err); + __put_user_error(regs->ARM_r10, &sc->arm_r10, err); + __put_user_error(regs->ARM_fp, &sc->arm_fp, err); + __put_user_error(regs->ARM_ip, &sc->arm_ip, err); + __put_user_error(regs->ARM_sp, &sc->arm_sp, err); + __put_user_error(regs->ARM_lr, &sc->arm_lr, err); + __put_user_error(regs->ARM_pc, &sc->arm_pc, err); + + __put_user_error(current->thread.trap_no, &sc->trap_no, err); + __put_user_error(current->thread.error_code, &sc->error_code, err); + __put_user_error(current->thread.address, &sc->fault_address, err); + __put_user_error(mask, &sc->oldmask, err); + + return err; +} + +static inline void * +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) +{ + unsigned long sp = regs->ARM_sp; + + /* + * This is the X/Open sanctioned signal stack switching. + */ + if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) + sp = current->sas_ss_sp + current->sas_ss_size; + + /* + * ATPCS B01 mandates 8-byte alignment + */ + return (void *)((sp - framesize) & ~7); +} + +static int +setup_return(struct pt_regs *regs, struct k_sigaction *ka, + unsigned long *rc, void *frame, int usig) +{ + unsigned long handler = (unsigned long)ka->sa.sa_handler; + unsigned long retcode; + + if (ka->sa.sa_flags & SA_RESTORER) { + retcode = (unsigned long)ka->sa.sa_restorer; + } else { + + if (__put_user((ka->sa.sa_flags & SA_SIGINFO)?SWI_SYS_RT_SIGRETURN:SWI_SYS_SIGRETURN, rc)) + return 1; + + retcode = ((unsigned long)rc); + } + + regs->ARM_r0 = usig; + regs->ARM_sp = (unsigned long)frame; + regs->ARM_lr = retcode; + regs->ARM_pc = handler & ~3; + + return 0; +} + +static int +setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) +{ + struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame)); + int err = 0; + + if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) + return 1; + + err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]); + + if (_NSIG_WORDS > 1) { + err |= __copy_to_user(frame->extramask, &set->sig[1], + sizeof(frame->extramask)); + } + + if (err == 0) + err = setup_return(regs, ka, &frame->retcode, frame, usig); + + return err; +} + +static int +setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, + sigset_t *set, struct pt_regs *regs) +{ + struct rt_sigframe *frame = get_sigframe(ka, regs, sizeof(*frame)); + int err = 0; + + if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) + return 1; + + __put_user_error(&frame->info, &frame->pinfo, err); + __put_user_error(&frame->uc, &frame->puc, err); + err |= copy_siginfo_to_user(&frame->info, info); + + /* Clear all the bits of the ucontext we don't use. */ + err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext)); + + err |= setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/ + regs, set->sig[0]); + err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + + if (err == 0) + err = setup_return(regs, ka, &frame->retcode, frame, usig); + + if (err == 0) { + /* + * For realtime signals we must also set the second and third + * arguments for the signal handler. + * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06 + */ + regs->ARM_r1 = (unsigned long)frame->pinfo; + regs->ARM_r2 = (unsigned long)frame->puc; + } + + return err; +} + +static inline void restart_syscall(struct pt_regs *regs) +{ + regs->ARM_r0 = regs->ARM_ORIG_r0; + regs->ARM_pc -= 4; +} + +/* + * OK, we're invoking a handler + */ +static void +handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset, + struct pt_regs * regs, int syscall) +{ + struct thread_info *thread = current_thread_info(); + struct task_struct *tsk = current; + struct k_sigaction *ka = &tsk->sighand->action[sig-1]; + int usig = sig; + int ret; + + /* + * If we were from a system call, check for system call restarting... + */ + if (syscall) { + switch (regs->ARM_r0) { + case -ERESTART_RESTARTBLOCK: + current_thread_info()->restart_block.fn = + do_no_restart_syscall; + case -ERESTARTNOHAND: + regs->ARM_r0 = -EINTR; + break; + case -ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->ARM_r0 = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + restart_syscall(regs); + } + } + + /* + * translate the signal + */ + if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) + usig = thread->exec_domain->signal_invmap[usig]; + + /* + * Set up the stack frame + */ + if (ka->sa.sa_flags & SA_SIGINFO) + ret = setup_rt_frame(usig, ka, info, oldset, regs); + else + ret = setup_frame(usig, ka, oldset, regs); + + /* + * Check that the resulting registers are actually sane. + */ + ret |= !valid_user_regs(regs); + + if (ret == 0) { + if (ka->sa.sa_flags & SA_ONESHOT) + ka->sa.sa_handler = SIG_DFL; + + if (!(ka->sa.sa_flags & SA_NODEFER)) { + spin_lock_irq(&tsk->sighand->siglock); + sigorsets(&tsk->blocked, &tsk->blocked, + &ka->sa.sa_mask); + sigaddset(&tsk->blocked, sig); + recalc_sigpending(); + spin_unlock_irq(&tsk->sighand->siglock); + } + return; + } + + force_sigsegv(sig, tsk); +} + +/* + * 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. + * + * Note that we go through the signals twice: once to check the signals that + * the kernel can handle, and then we build all the user-level signal handling + * stack-frames in one go after that. + */ +static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall) +{ + 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 0; + + if (current->ptrace & PT_SINGLESTEP) + ptrace_cancel_bpt(current); + + signr = get_signal_to_deliver(&info, regs, NULL); + if (signr > 0) { + handle_signal(signr, &info, oldset, regs, syscall); + if (current->ptrace & PT_SINGLESTEP) + ptrace_set_bpt(current); + return 1; + } + + /* + * No signal to deliver to the process - restart the syscall. + */ + if (syscall) { + if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) { + u32 *usp; + + regs->ARM_sp -= 12; + usp = (u32 *)regs->ARM_sp; + + put_user(regs->ARM_pc, &usp[0]); + /* swi __NR_restart_syscall */ + put_user(0xef000000 | __NR_restart_syscall, &usp[1]); + /* ldr pc, [sp], #12 */ +// FIXME!!! is #12 correct there? + put_user(0xe49df00c, &usp[2]); + + regs->ARM_pc = regs->ARM_sp + 4; + } + if (regs->ARM_r0 == -ERESTARTNOHAND || + regs->ARM_r0 == -ERESTARTSYS || + regs->ARM_r0 == -ERESTARTNOINTR) { + restart_syscall(regs); + } + } + if (current->ptrace & PT_SINGLESTEP) + ptrace_set_bpt(current); + return 0; +} + +asmlinkage void +do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) +{ + if (thread_flags & _TIF_SIGPENDING) + do_signal(¤t->blocked, regs, syscall); +} |