|  | /* | 
|  | * arch/score/kernel/signal.c | 
|  | * | 
|  | * Score Processor version. | 
|  | * | 
|  | * Copyright (C) 2009 Sunplus Core Technology Co., Ltd. | 
|  | *  Chen Liqin <liqin.chen@sunplusct.com> | 
|  | *  Lennox Wu <lennox.wu@sunplusct.com> | 
|  | * | 
|  | * This program 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. | 
|  | * | 
|  | * This program 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 this program; if not, see the file COPYING, or write | 
|  | * to the Free Software Foundation, Inc., | 
|  | * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA | 
|  | */ | 
|  |  | 
|  | #include <linux/errno.h> | 
|  | #include <linux/signal.h> | 
|  | #include <linux/ptrace.h> | 
|  | #include <linux/unistd.h> | 
|  | #include <linux/uaccess.h> | 
|  | #include <linux/tracehook.h> | 
|  |  | 
|  | #include <asm/cacheflush.h> | 
|  | #include <asm/syscalls.h> | 
|  | #include <asm/ucontext.h> | 
|  |  | 
|  | struct rt_sigframe { | 
|  | u32 rs_ass[4];		/* argument save space */ | 
|  | u32 rs_code[2];		/* signal trampoline */ | 
|  | struct siginfo rs_info; | 
|  | struct ucontext rs_uc; | 
|  | }; | 
|  |  | 
|  | static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) | 
|  | { | 
|  | int err = 0; | 
|  | unsigned long reg; | 
|  |  | 
|  | reg = regs->cp0_epc; err |= __put_user(reg, &sc->sc_pc); | 
|  | err |= __put_user(regs->cp0_psr, &sc->sc_psr); | 
|  | err |= __put_user(regs->cp0_condition, &sc->sc_condition); | 
|  |  | 
|  |  | 
|  | #define save_gp_reg(i) {				\ | 
|  | reg = regs->regs[i];				\ | 
|  | err |= __put_user(reg, &sc->sc_regs[i]);	\ | 
|  | } while (0) | 
|  | save_gp_reg(0); save_gp_reg(1); save_gp_reg(2); | 
|  | save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); | 
|  | save_gp_reg(6);	save_gp_reg(7); save_gp_reg(8); | 
|  | save_gp_reg(9); save_gp_reg(10); save_gp_reg(11); | 
|  | save_gp_reg(12); save_gp_reg(13); save_gp_reg(14); | 
|  | save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); | 
|  | save_gp_reg(18); save_gp_reg(19); save_gp_reg(20); | 
|  | save_gp_reg(21); save_gp_reg(22); save_gp_reg(23); | 
|  | save_gp_reg(24); save_gp_reg(25); save_gp_reg(26); | 
|  | save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); | 
|  | #undef save_gp_reg | 
|  |  | 
|  | reg = regs->ceh; err |= __put_user(reg, &sc->sc_mdceh); | 
|  | reg = regs->cel; err |= __put_user(reg, &sc->sc_mdcel); | 
|  | err |= __put_user(regs->cp0_ecr, &sc->sc_ecr); | 
|  | err |= __put_user(regs->cp0_ema, &sc->sc_ema); | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) | 
|  | { | 
|  | int err = 0; | 
|  | u32 reg; | 
|  |  | 
|  | err |= __get_user(regs->cp0_epc, &sc->sc_pc); | 
|  | err |= __get_user(regs->cp0_condition, &sc->sc_condition); | 
|  |  | 
|  | err |= __get_user(reg, &sc->sc_mdceh); | 
|  | regs->ceh = (int) reg; | 
|  | err |= __get_user(reg, &sc->sc_mdcel); | 
|  | regs->cel = (int) reg; | 
|  |  | 
|  | err |= __get_user(reg, &sc->sc_psr); | 
|  | regs->cp0_psr = (int) reg; | 
|  | err |= __get_user(reg, &sc->sc_ecr); | 
|  | regs->cp0_ecr = (int) reg; | 
|  | err |= __get_user(reg, &sc->sc_ema); | 
|  | regs->cp0_ema = (int) reg; | 
|  |  | 
|  | #define restore_gp_reg(i) do {				\ | 
|  | err |= __get_user(reg, &sc->sc_regs[i]);	\ | 
|  | regs->regs[i] = reg;				\ | 
|  | } while (0) | 
|  | restore_gp_reg(0); restore_gp_reg(1); restore_gp_reg(2); | 
|  | restore_gp_reg(3); restore_gp_reg(4); restore_gp_reg(5); | 
|  | restore_gp_reg(6); restore_gp_reg(7); restore_gp_reg(8); | 
|  | restore_gp_reg(9); restore_gp_reg(10); restore_gp_reg(11); | 
|  | restore_gp_reg(12); restore_gp_reg(13); restore_gp_reg(14); | 
|  | restore_gp_reg(15); restore_gp_reg(16); restore_gp_reg(17); | 
|  | restore_gp_reg(18); restore_gp_reg(19);	restore_gp_reg(20); | 
|  | restore_gp_reg(21); restore_gp_reg(22); restore_gp_reg(23); | 
|  | restore_gp_reg(24); restore_gp_reg(25); restore_gp_reg(26); | 
|  | restore_gp_reg(27); restore_gp_reg(28); restore_gp_reg(29); | 
|  | #undef restore_gp_reg | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Determine which stack to use.. | 
|  | */ | 
|  | static void __user *get_sigframe(struct k_sigaction *ka, | 
|  | struct pt_regs *regs, size_t frame_size) | 
|  | { | 
|  | unsigned long sp; | 
|  |  | 
|  | /* Default to using normal stack */ | 
|  | sp = regs->regs[0]; | 
|  | sp -= 32; | 
|  |  | 
|  | /* This is the X/Open sanctioned signal stack switching.  */ | 
|  | if ((ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp))) | 
|  | sp = current->sas_ss_sp + current->sas_ss_size; | 
|  |  | 
|  | return (void __user*)((sp - frame_size) & ~7); | 
|  | } | 
|  |  | 
|  | asmlinkage long | 
|  | score_sigaltstack(struct pt_regs *regs) | 
|  | { | 
|  | const stack_t __user *uss = (const stack_t __user *) regs->regs[4]; | 
|  | stack_t __user *uoss = (stack_t __user *) regs->regs[5]; | 
|  | unsigned long usp = regs->regs[0]; | 
|  |  | 
|  | return do_sigaltstack(uss, uoss, usp); | 
|  | } | 
|  |  | 
|  | asmlinkage long | 
|  | score_rt_sigreturn(struct pt_regs *regs) | 
|  | { | 
|  | struct rt_sigframe __user *frame; | 
|  | sigset_t set; | 
|  | stack_t st; | 
|  | int sig; | 
|  |  | 
|  | /* Always make any pending restarted system calls return -EINTR */ | 
|  | current_thread_info()->restart_block.fn = do_no_restart_syscall; | 
|  |  | 
|  | frame = (struct rt_sigframe __user *) regs->regs[0]; | 
|  | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | 
|  | goto badframe; | 
|  | if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set))) | 
|  | goto badframe; | 
|  |  | 
|  | set_current_blocked(&set); | 
|  |  | 
|  | sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext); | 
|  | if (sig < 0) | 
|  | goto badframe; | 
|  | else if (sig) | 
|  | force_sig(sig, current); | 
|  |  | 
|  | if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st))) | 
|  | goto badframe; | 
|  |  | 
|  | /* It is more difficult to avoid calling this function than to | 
|  | call it and ignore errors.  */ | 
|  | do_sigaltstack((stack_t __user *)&st, NULL, regs->regs[0]); | 
|  |  | 
|  | __asm__ __volatile__( | 
|  | "mv\tr0, %0\n\t" | 
|  | "la\tr8, syscall_exit\n\t" | 
|  | "br\tr8\n\t" | 
|  | : : "r" (regs) : "r8"); | 
|  |  | 
|  | badframe: | 
|  | force_sig(SIGSEGV, current); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs, | 
|  | int signr, sigset_t *set, siginfo_t *info) | 
|  | { | 
|  | struct rt_sigframe __user *frame; | 
|  | int err = 0; | 
|  |  | 
|  | frame = get_sigframe(ka, regs, sizeof(*frame)); | 
|  | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | /* | 
|  | * Set up the return code ... | 
|  | * | 
|  | *         li      v0, __NR_rt_sigreturn | 
|  | *         syscall | 
|  | */ | 
|  | err |= __put_user(0x87788000 + __NR_rt_sigreturn*2, | 
|  | frame->rs_code + 0); | 
|  | err |= __put_user(0x80008002, frame->rs_code + 1); | 
|  | flush_cache_sigtramp((unsigned long) frame->rs_code); | 
|  |  | 
|  | err |= copy_siginfo_to_user(&frame->rs_info, info); | 
|  | err |= __put_user(0, &frame->rs_uc.uc_flags); | 
|  | err |= __put_user(NULL, &frame->rs_uc.uc_link); | 
|  | err |= __put_user((void __user *)current->sas_ss_sp, | 
|  | &frame->rs_uc.uc_stack.ss_sp); | 
|  | err |= __put_user(sas_ss_flags(regs->regs[0]), | 
|  | &frame->rs_uc.uc_stack.ss_flags); | 
|  | err |= __put_user(current->sas_ss_size, | 
|  | &frame->rs_uc.uc_stack.ss_size); | 
|  | err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); | 
|  | err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set)); | 
|  |  | 
|  | if (err) | 
|  | goto give_sigsegv; | 
|  |  | 
|  | regs->regs[0] = (unsigned long) frame; | 
|  | regs->regs[3] = (unsigned long) frame->rs_code; | 
|  | regs->regs[4] = signr; | 
|  | regs->regs[5] = (unsigned long) &frame->rs_info; | 
|  | regs->regs[6] = (unsigned long) &frame->rs_uc; | 
|  | regs->regs[29] = (unsigned long) ka->sa.sa_handler; | 
|  | regs->cp0_epc = (unsigned long) ka->sa.sa_handler; | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | give_sigsegv: | 
|  | force_sigsegv(signr, current); | 
|  | return -EFAULT; | 
|  | } | 
|  |  | 
|  | static void handle_signal(unsigned long sig, siginfo_t *info, | 
|  | struct k_sigaction *ka, struct pt_regs *regs) | 
|  | { | 
|  | if (regs->is_syscall) { | 
|  | switch (regs->regs[4]) { | 
|  | case ERESTART_RESTARTBLOCK: | 
|  | case ERESTARTNOHAND: | 
|  | regs->regs[4] = EINTR; | 
|  | break; | 
|  | case ERESTARTSYS: | 
|  | if (!(ka->sa.sa_flags & SA_RESTART)) { | 
|  | regs->regs[4] = EINTR; | 
|  | break; | 
|  | } | 
|  | case ERESTARTNOINTR: | 
|  | regs->regs[4] = regs->orig_r4; | 
|  | regs->regs[7] = regs->orig_r7; | 
|  | regs->cp0_epc -= 8; | 
|  | } | 
|  |  | 
|  | regs->is_syscall = 0; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Set up the stack frame | 
|  | */ | 
|  | if (setup_rt_frame(ka, regs, sig, sigmask_to_save(), info) < 0) | 
|  | return; | 
|  |  | 
|  | signal_delivered(sig, info, ka, regs, 0); | 
|  | } | 
|  |  | 
|  | static void do_signal(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; | 
|  |  | 
|  | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | 
|  | if (signr > 0) { | 
|  | /* Actually deliver the signal.  */ | 
|  | handle_signal(signr, &info, &ka, regs); | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (regs->is_syscall) { | 
|  | if (regs->regs[4] == ERESTARTNOHAND || | 
|  | regs->regs[4] == ERESTARTSYS || | 
|  | regs->regs[4] == ERESTARTNOINTR) { | 
|  | regs->regs[4] = regs->orig_r4; | 
|  | regs->regs[7] = regs->orig_r7; | 
|  | regs->cp0_epc -= 8; | 
|  | } | 
|  |  | 
|  | if (regs->regs[4] == ERESTART_RESTARTBLOCK) { | 
|  | regs->regs[27] = __NR_restart_syscall; | 
|  | regs->regs[4] = regs->orig_r4; | 
|  | regs->regs[7] = regs->orig_r7; | 
|  | regs->cp0_epc -= 8; | 
|  | } | 
|  |  | 
|  | regs->is_syscall = 0;	/* Don't deal with this again.  */ | 
|  | } | 
|  |  | 
|  | /* | 
|  | * If there's no signal to deliver, we just put the saved sigmask | 
|  | * back | 
|  | */ | 
|  | restore_saved_sigmask(); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * notification of userspace execution resumption | 
|  | * - triggered by the TIF_WORK_MASK flags | 
|  | */ | 
|  | asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, | 
|  | __u32 thread_info_flags) | 
|  | { | 
|  | /* 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(regs); | 
|  | } | 
|  | } |