| /* MN10300 Signal handling |
| * |
| * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public Licence |
| * as published by the Free Software Foundation; either version |
| * 2 of the Licence, or (at your option) any later version. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/kernel.h> |
| #include <linux/signal.h> |
| #include <linux/errno.h> |
| #include <linux/wait.h> |
| #include <linux/ptrace.h> |
| #include <linux/unistd.h> |
| #include <linux/stddef.h> |
| #include <linux/tty.h> |
| #include <linux/personality.h> |
| #include <linux/suspend.h> |
| #include <linux/tracehook.h> |
| #include <asm/cacheflush.h> |
| #include <asm/ucontext.h> |
| #include <asm/uaccess.h> |
| #include <asm/fpu.h> |
| #include "sigframe.h" |
| |
| #define DEBUG_SIG 0 |
| |
| /* |
| * do a signal return; undo the signal stack. |
| */ |
| static int restore_sigcontext(struct pt_regs *regs, |
| struct sigcontext __user *sc, long *_d0) |
| { |
| unsigned int err = 0; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| |
| if (is_using_fpu(current)) |
| fpu_kill_state(current); |
| |
| #define COPY(x) err |= __get_user(regs->x, &sc->x) |
| COPY(d1); COPY(d2); COPY(d3); |
| COPY(a0); COPY(a1); COPY(a2); COPY(a3); |
| COPY(e0); COPY(e1); COPY(e2); COPY(e3); |
| COPY(e4); COPY(e5); COPY(e6); COPY(e7); |
| COPY(lar); COPY(lir); |
| COPY(mdr); COPY(mdrq); |
| COPY(mcvf); COPY(mcrl); COPY(mcrh); |
| COPY(sp); COPY(pc); |
| #undef COPY |
| |
| { |
| unsigned int tmpflags; |
| #ifndef CONFIG_MN10300_USING_JTAG |
| #define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \ |
| EPSW_T | EPSW_nAR) |
| #else |
| #define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \ |
| EPSW_nAR) |
| #endif |
| err |= __get_user(tmpflags, &sc->epsw); |
| regs->epsw = (regs->epsw & ~USER_EPSW) | |
| (tmpflags & USER_EPSW); |
| regs->orig_d0 = -1; /* disable syscall checks */ |
| } |
| |
| { |
| struct fpucontext *buf; |
| err |= __get_user(buf, &sc->fpucontext); |
| if (buf) { |
| if (verify_area(VERIFY_READ, buf, sizeof(*buf))) |
| goto badframe; |
| err |= fpu_restore_sigcontext(buf); |
| } |
| } |
| |
| err |= __get_user(*_d0, &sc->d0); |
| return err; |
| |
| badframe: |
| return 1; |
| } |
| |
| /* |
| * standard signal return syscall |
| */ |
| asmlinkage long sys_sigreturn(void) |
| { |
| struct sigframe __user *frame; |
| sigset_t set; |
| long d0; |
| |
| frame = (struct sigframe __user *) current_frame()->sp; |
| if (verify_area(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| if (__get_user(set.sig[0], &frame->sc.oldmask)) |
| goto badframe; |
| |
| if (_NSIG_WORDS > 1 && |
| __copy_from_user(&set.sig[1], &frame->extramask, |
| sizeof(frame->extramask))) |
| goto badframe; |
| |
| set_current_blocked(&set); |
| |
| if (restore_sigcontext(current_frame(), &frame->sc, &d0)) |
| goto badframe; |
| |
| return d0; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| /* |
| * realtime signal return syscall |
| */ |
| asmlinkage long sys_rt_sigreturn(void) |
| { |
| struct rt_sigframe __user *frame; |
| sigset_t set; |
| long d0; |
| |
| frame = (struct rt_sigframe __user *) current_frame()->sp; |
| if (verify_area(VERIFY_READ, 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(current_frame(), &frame->uc.uc_mcontext, &d0)) |
| goto badframe; |
| |
| if (restore_altstack(&frame->uc.uc_stack)) |
| goto badframe; |
| |
| return d0; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| /* |
| * store the userspace context into a signal frame |
| */ |
| static int setup_sigcontext(struct sigcontext __user *sc, |
| struct fpucontext *fpuctx, |
| struct pt_regs *regs, |
| unsigned long mask) |
| { |
| int tmp, err = 0; |
| |
| #define COPY(x) err |= __put_user(regs->x, &sc->x) |
| COPY(d0); COPY(d1); COPY(d2); COPY(d3); |
| COPY(a0); COPY(a1); COPY(a2); COPY(a3); |
| COPY(e0); COPY(e1); COPY(e2); COPY(e3); |
| COPY(e4); COPY(e5); COPY(e6); COPY(e7); |
| COPY(lar); COPY(lir); |
| COPY(mdr); COPY(mdrq); |
| COPY(mcvf); COPY(mcrl); COPY(mcrh); |
| COPY(sp); COPY(epsw); COPY(pc); |
| #undef COPY |
| |
| tmp = fpu_setup_sigcontext(fpuctx); |
| if (tmp < 0) |
| err = 1; |
| else |
| err |= __put_user(tmp ? fpuctx : NULL, &sc->fpucontext); |
| |
| /* non-iBCS2 extensions.. */ |
| err |= __put_user(mask, &sc->oldmask); |
| |
| return err; |
| } |
| |
| /* |
| * determine which stack to use.. |
| */ |
| static inline void __user *get_sigframe(struct ksignal *ksig, |
| struct pt_regs *regs, |
| size_t frame_size) |
| { |
| unsigned long sp = sigsp(regs->sp, ksig); |
| |
| return (void __user *) ((sp - frame_size) & ~7UL); |
| } |
| |
| /* |
| * set up a normal signal frame |
| */ |
| static int setup_frame(struct ksignal *ksig, sigset_t *set, |
| struct pt_regs *regs) |
| { |
| struct sigframe __user *frame; |
| int rsig, sig = ksig->sig; |
| |
| frame = get_sigframe(ksig, regs, sizeof(*frame)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| return -EFAULT; |
| |
| rsig = sig; |
| if (sig < 32 && |
| current_thread_info()->exec_domain && |
| current_thread_info()->exec_domain->signal_invmap) |
| rsig = current_thread_info()->exec_domain->signal_invmap[sig]; |
| |
| if (__put_user(rsig, &frame->sig) < 0 || |
| __put_user(&frame->sc, &frame->psc) < 0) |
| return -EFAULT; |
| |
| if (setup_sigcontext(&frame->sc, &frame->fpuctx, regs, set->sig[0])) |
| return -EFAULT; |
| |
| if (_NSIG_WORDS > 1) { |
| if (__copy_to_user(frame->extramask, &set->sig[1], |
| sizeof(frame->extramask))) |
| return -EFAULT; |
| } |
| |
| /* set up to return from userspace. If provided, use a stub already in |
| * userspace */ |
| if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
| if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode)) |
| return -EFAULT; |
| } else { |
| if (__put_user((void (*)(void))frame->retcode, |
| &frame->pretcode)) |
| return -EFAULT; |
| /* this is mov $,d0; syscall 0 */ |
| if (__put_user(0x2c, (char *)(frame->retcode + 0)) || |
| __put_user(__NR_sigreturn, (char *)(frame->retcode + 1)) || |
| __put_user(0x00, (char *)(frame->retcode + 2)) || |
| __put_user(0xf0, (char *)(frame->retcode + 3)) || |
| __put_user(0xe0, (char *)(frame->retcode + 4))) |
| return -EFAULT; |
| flush_icache_range((unsigned long) frame->retcode, |
| (unsigned long) frame->retcode + 5); |
| } |
| |
| /* set up registers for signal handler */ |
| regs->sp = (unsigned long) frame; |
| regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
| regs->d0 = sig; |
| regs->d1 = (unsigned long) &frame->sc; |
| |
| #if DEBUG_SIG |
| printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", |
| sig, current->comm, current->pid, frame, regs->pc, |
| frame->pretcode); |
| #endif |
| |
| return 0; |
| } |
| |
| /* |
| * set up a realtime signal frame |
| */ |
| static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
| struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| int rsig, sig = ksig->sig; |
| |
| frame = get_sigframe(ksig, regs, sizeof(*frame)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| return -EFAULT; |
| |
| rsig = sig; |
| if (sig < 32 && |
| current_thread_info()->exec_domain && |
| current_thread_info()->exec_domain->signal_invmap) |
| rsig = current_thread_info()->exec_domain->signal_invmap[sig]; |
| |
| if (__put_user(rsig, &frame->sig) || |
| __put_user(&frame->info, &frame->pinfo) || |
| __put_user(&frame->uc, &frame->puc) || |
| copy_siginfo_to_user(&frame->info, &ksig->info)) |
| return -EFAULT; |
| |
| /* create the ucontext. */ |
| if (__put_user(0, &frame->uc.uc_flags) || |
| __put_user(0, &frame->uc.uc_link) || |
| __save_altstack(&frame->uc.uc_stack, regs->sp) || |
| setup_sigcontext(&frame->uc.uc_mcontext, |
| &frame->fpuctx, regs, set->sig[0]) || |
| __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set))) |
| return -EFAULT; |
| |
| /* set up to return from userspace. If provided, use a stub already in |
| * userspace */ |
| if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
| if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode)) |
| return -EFAULT; |
| |
| } else { |
| if (__put_user((void(*)(void))frame->retcode, |
| &frame->pretcode) || |
| /* This is mov $,d0; syscall 0 */ |
| __put_user(0x2c, (char *)(frame->retcode + 0)) || |
| __put_user(__NR_rt_sigreturn, |
| (char *)(frame->retcode + 1)) || |
| __put_user(0x00, (char *)(frame->retcode + 2)) || |
| __put_user(0xf0, (char *)(frame->retcode + 3)) || |
| __put_user(0xe0, (char *)(frame->retcode + 4))) |
| return -EFAULT; |
| |
| flush_icache_range((u_long) frame->retcode, |
| (u_long) frame->retcode + 5); |
| } |
| |
| /* Set up registers for signal handler */ |
| regs->sp = (unsigned long) frame; |
| regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
| regs->d0 = sig; |
| regs->d1 = (long) &frame->info; |
| |
| #if DEBUG_SIG |
| printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", |
| sig, current->comm, current->pid, frame, regs->pc, |
| frame->pretcode); |
| #endif |
| |
| return 0; |
| } |
| |
| static inline void stepback(struct pt_regs *regs) |
| { |
| regs->pc -= 2; |
| regs->orig_d0 = -1; |
| } |
| |
| /* |
| * handle the actual delivery of a signal to userspace |
| */ |
| static int 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_d0 >= 0) { |
| /* If so, check system call restarting.. */ |
| switch (regs->d0) { |
| case -ERESTART_RESTARTBLOCK: |
| case -ERESTARTNOHAND: |
| regs->d0 = -EINTR; |
| break; |
| |
| case -ERESTARTSYS: |
| if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
| regs->d0 = -EINTR; |
| break; |
| } |
| |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| regs->d0 = regs->orig_d0; |
| stepback(regs); |
| } |
| } |
| |
| /* Set up the stack frame */ |
| if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
| ret = setup_rt_frame(ksig, oldset, regs); |
| else |
| ret = setup_frame(ksig, oldset, regs); |
| |
| signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); |
| return 0; |
| } |
| |
| /* |
| * handle a potential signal |
| */ |
| static void do_signal(struct pt_regs *regs) |
| { |
| struct ksignal ksig; |
| |
| if (get_signal(&ksig)) { |
| handle_signal(&ksig, regs); |
| return; |
| } |
| |
| /* did we come from a system call? */ |
| if (regs->orig_d0 >= 0) { |
| /* restart the system call - no handlers present */ |
| switch (regs->d0) { |
| case -ERESTARTNOHAND: |
| case -ERESTARTSYS: |
| case -ERESTARTNOINTR: |
| regs->d0 = regs->orig_d0; |
| stepback(regs); |
| break; |
| |
| case -ERESTART_RESTARTBLOCK: |
| regs->d0 = __NR_restart_syscall; |
| stepback(regs); |
| break; |
| } |
| } |
| |
| /* if there's no signal to deliver, we just put the saved sigmask |
| * back */ |
| restore_saved_sigmask(); |
| } |
| |
| /* |
| * notification of userspace execution resumption |
| * - triggered by current->work.notify_resume |
| */ |
| asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) |
| { |
| /* Pending single-step? */ |
| if (thread_info_flags & _TIF_SINGLESTEP) { |
| #ifndef CONFIG_MN10300_USING_JTAG |
| regs->epsw |= EPSW_T; |
| clear_thread_flag(TIF_SINGLESTEP); |
| #else |
| BUG(); /* no h/w single-step if using JTAG unit */ |
| #endif |
| } |
| |
| /* deal with pending signal delivery */ |
| if (thread_info_flags & _TIF_SIGPENDING) |
| do_signal(regs); |
| |
| if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(current_frame()); |
| } |
| } |