| /* |
| * linux/arch/unicore32/kernel/signal.c |
| * |
| * Code specific to PKUnity SoC and UniCore ISA |
| * |
| * Copyright (C) 2001-2010 GUAN Xue-tao |
| * |
| * 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/errno.h> |
| #include <linux/signal.h> |
| #include <linux/personality.h> |
| #include <linux/freezer.h> |
| #include <linux/uaccess.h> |
| #include <linux/tracehook.h> |
| #include <linux/elf.h> |
| #include <linux/unistd.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/ucontext.h> |
| |
| #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| |
| /* |
| * For UniCore syscalls, we encode the syscall number into the instruction. |
| */ |
| #define SWI_SYS_SIGRETURN (0xff000000) /* error number for new abi */ |
| #define SWI_SYS_RT_SIGRETURN (0xff000000 | (__NR_rt_sigreturn)) |
| #define SWI_SYS_RESTART (0xff000000 | (__NR_restart_syscall)) |
| |
| #define KERN_SIGRETURN_CODE (KUSER_VECPAGE_BASE + 0x00000500) |
| #define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes)) |
| |
| const unsigned long sigreturn_codes[3] = { |
| SWI_SYS_SIGRETURN, SWI_SYS_RT_SIGRETURN, |
| }; |
| |
| const unsigned long syscall_restart_code[2] = { |
| SWI_SYS_RESTART, /* swi __NR_restart_syscall */ |
| 0x69efc004, /* ldr pc, [sp], #4 */ |
| }; |
| |
| /* |
| * Do a signal return; undo the signal stack. These are aligned to 64-bit. |
| */ |
| struct sigframe { |
| struct ucontext uc; |
| unsigned long retcode[2]; |
| }; |
| |
| struct rt_sigframe { |
| struct siginfo info; |
| struct sigframe sig; |
| }; |
| |
| static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) |
| { |
| sigset_t set; |
| int err; |
| |
| err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); |
| if (err == 0) { |
| sigdelsetmask(&set, ~_BLOCKABLE); |
| set_current_blocked(&set); |
| } |
| |
| err |= __get_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00); |
| err |= __get_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01); |
| err |= __get_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02); |
| err |= __get_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03); |
| err |= __get_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04); |
| err |= __get_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05); |
| err |= __get_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06); |
| err |= __get_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07); |
| err |= __get_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08); |
| err |= __get_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09); |
| err |= __get_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10); |
| err |= __get_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11); |
| err |= __get_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12); |
| err |= __get_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13); |
| err |= __get_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14); |
| err |= __get_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15); |
| err |= __get_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16); |
| err |= __get_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17); |
| err |= __get_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18); |
| err |= __get_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19); |
| err |= __get_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20); |
| err |= __get_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21); |
| err |= __get_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22); |
| err |= __get_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23); |
| err |= __get_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24); |
| err |= __get_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25); |
| err |= __get_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26); |
| err |= __get_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp); |
| err |= __get_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip); |
| err |= __get_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp); |
| err |= __get_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr); |
| err |= __get_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc); |
| err |= __get_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr); |
| |
| err |= !valid_user_regs(regs); |
| |
| return err; |
| } |
| |
| asmlinkage int __sys_rt_sigreturn(struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| |
| /* |
| * 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->UCreg_sp & 7) |
| goto badframe; |
| |
| frame = (struct rt_sigframe __user *)regs->UCreg_sp; |
| |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| |
| if (restore_sigframe(regs, &frame->sig)) |
| goto badframe; |
| |
| if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->UCreg_sp) |
| == -EFAULT) |
| goto badframe; |
| |
| return regs->UCreg_00; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| static int setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, |
| sigset_t *set) |
| { |
| int err = 0; |
| |
| err |= __put_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00); |
| err |= __put_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01); |
| err |= __put_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02); |
| err |= __put_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03); |
| err |= __put_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04); |
| err |= __put_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05); |
| err |= __put_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06); |
| err |= __put_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07); |
| err |= __put_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08); |
| err |= __put_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09); |
| err |= __put_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10); |
| err |= __put_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11); |
| err |= __put_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12); |
| err |= __put_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13); |
| err |= __put_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14); |
| err |= __put_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15); |
| err |= __put_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16); |
| err |= __put_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17); |
| err |= __put_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18); |
| err |= __put_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19); |
| err |= __put_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20); |
| err |= __put_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21); |
| err |= __put_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22); |
| err |= __put_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23); |
| err |= __put_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24); |
| err |= __put_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25); |
| err |= __put_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26); |
| err |= __put_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp); |
| err |= __put_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip); |
| err |= __put_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp); |
| err |= __put_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr); |
| err |= __put_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc); |
| err |= __put_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr); |
| |
| err |= __put_user(current->thread.trap_no, |
| &sf->uc.uc_mcontext.trap_no); |
| err |= __put_user(current->thread.error_code, |
| &sf->uc.uc_mcontext.error_code); |
| err |= __put_user(current->thread.address, |
| &sf->uc.uc_mcontext.fault_address); |
| err |= __put_user(set->sig[0], &sf->uc.uc_mcontext.oldmask); |
| |
| err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); |
| |
| return err; |
| } |
| |
| static inline void __user *get_sigframe(struct k_sigaction *ka, |
| struct pt_regs *regs, int framesize) |
| { |
| unsigned long sp = regs->UCreg_sp; |
| void __user *frame; |
| |
| /* |
| * 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 |
| */ |
| frame = (void __user *)((sp - framesize) & ~7); |
| |
| /* |
| * Check that we can actually write to the signal frame. |
| */ |
| if (!access_ok(VERIFY_WRITE, frame, framesize)) |
| frame = NULL; |
| |
| return frame; |
| } |
| |
| static int setup_return(struct pt_regs *regs, struct k_sigaction *ka, |
| unsigned long __user *rc, void __user *frame, int usig) |
| { |
| unsigned long handler = (unsigned long)ka->sa.sa_handler; |
| unsigned long retcode; |
| unsigned long asr = regs->UCreg_asr & ~PSR_f; |
| |
| unsigned int idx = 0; |
| |
| if (ka->sa.sa_flags & SA_SIGINFO) |
| idx += 1; |
| |
| if (__put_user(sigreturn_codes[idx], rc) || |
| __put_user(sigreturn_codes[idx+1], rc+1)) |
| return 1; |
| |
| retcode = KERN_SIGRETURN_CODE + (idx << 2); |
| |
| regs->UCreg_00 = usig; |
| regs->UCreg_sp = (unsigned long)frame; |
| regs->UCreg_lr = retcode; |
| regs->UCreg_pc = handler; |
| regs->UCreg_asr = asr; |
| |
| return 0; |
| } |
| |
| static int setup_frame(int usig, struct k_sigaction *ka, |
| sigset_t *set, struct pt_regs *regs) |
| { |
| struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); |
| int err = 0; |
| |
| if (!frame) |
| return 1; |
| |
| /* |
| * Set uc.uc_flags to a value which sc.trap_no would never have. |
| */ |
| err |= __put_user(0x5ac3c35a, &frame->uc.uc_flags); |
| |
| err |= setup_sigframe(frame, regs, set); |
| 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 __user *frame = |
| get_sigframe(ka, regs, sizeof(*frame)); |
| stack_t stack; |
| int err = 0; |
| |
| if (!frame) |
| return 1; |
| |
| err |= copy_siginfo_to_user(&frame->info, info); |
| |
| err |= __put_user(0, &frame->sig.uc.uc_flags); |
| err |= __put_user(NULL, &frame->sig.uc.uc_link); |
| |
| memset(&stack, 0, sizeof(stack)); |
| stack.ss_sp = (void __user *)current->sas_ss_sp; |
| stack.ss_flags = sas_ss_flags(regs->UCreg_sp); |
| stack.ss_size = current->sas_ss_size; |
| err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack)); |
| |
| err |= setup_sigframe(&frame->sig, regs, set); |
| if (err == 0) |
| err |= setup_return(regs, ka, frame->sig.retcode, frame, usig); |
| |
| if (err == 0) { |
| /* |
| * For realtime signals we must also set the second and third |
| * arguments for the signal handler. |
| */ |
| regs->UCreg_01 = (unsigned long)&frame->info; |
| regs->UCreg_02 = (unsigned long)&frame->sig.uc; |
| } |
| |
| return err; |
| } |
| |
| static inline void setup_syscall_restart(struct pt_regs *regs) |
| { |
| regs->UCreg_00 = regs->UCreg_ORIG_00; |
| regs->UCreg_pc -= 4; |
| } |
| |
| /* |
| * OK, we're invoking a handler |
| */ |
| static int handle_signal(unsigned long sig, struct k_sigaction *ka, |
| siginfo_t *info, sigset_t *oldset, |
| struct pt_regs *regs, int syscall) |
| { |
| struct thread_info *thread = current_thread_info(); |
| struct task_struct *tsk = current; |
| sigset_t blocked; |
| int usig = sig; |
| int ret; |
| |
| /* |
| * If we were from a system call, check for system call restarting... |
| */ |
| if (syscall) { |
| switch (regs->UCreg_00) { |
| case -ERESTART_RESTARTBLOCK: |
| case -ERESTARTNOHAND: |
| regs->UCreg_00 = -EINTR; |
| break; |
| case -ERESTARTSYS: |
| if (!(ka->sa.sa_flags & SA_RESTART)) { |
| regs->UCreg_00 = -EINTR; |
| break; |
| } |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| setup_syscall_restart(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) { |
| force_sigsegv(sig, tsk); |
| return ret; |
| } |
| |
| /* |
| * Block the signal if we were successful. |
| */ |
| sigorsets(&blocked, &tsk->blocked, &ka->sa.sa_mask); |
| if (!(ka->sa.sa_flags & SA_NODEFER)) |
| sigaddset(&blocked, sig); |
| set_current_blocked(&blocked); |
| |
| return 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. |
| * |
| * 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 void do_signal(struct pt_regs *regs, int syscall) |
| { |
| 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; |
| |
| if (try_to_freeze()) |
| goto no_signal; |
| |
| signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| if (signr > 0) { |
| sigset_t *oldset; |
| |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| oldset = ¤t->saved_sigmask; |
| else |
| oldset = ¤t->blocked; |
| if (handle_signal(signr, &ka, &info, oldset, regs, syscall) |
| == 0) { |
| /* |
| * A signal was successfully delivered; the saved |
| * sigmask will have been stored in the signal frame, |
| * and will be restored by sigreturn, so we can simply |
| * clear the TIF_RESTORE_SIGMASK flag. |
| */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| } |
| return; |
| } |
| |
| no_signal: |
| /* |
| * No signal to deliver to the process - restart the syscall. |
| */ |
| if (syscall) { |
| if (regs->UCreg_00 == -ERESTART_RESTARTBLOCK) { |
| u32 __user *usp; |
| |
| regs->UCreg_sp -= 4; |
| usp = (u32 __user *)regs->UCreg_sp; |
| |
| if (put_user(regs->UCreg_pc, usp) == 0) { |
| regs->UCreg_pc = KERN_RESTART_CODE; |
| } else { |
| regs->UCreg_sp += 4; |
| force_sigsegv(0, current); |
| } |
| } |
| if (regs->UCreg_00 == -ERESTARTNOHAND || |
| regs->UCreg_00 == -ERESTARTSYS || |
| regs->UCreg_00 == -ERESTARTNOINTR) { |
| setup_syscall_restart(regs); |
| } |
| |
| /* If there's no signal to deliver, we just put the saved |
| * sigmask back. |
| */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
| } |
| } |
| } |
| |
| asmlinkage void do_notify_resume(struct pt_regs *regs, |
| unsigned int thread_flags, int syscall) |
| { |
| if (thread_flags & _TIF_SIGPENDING) |
| do_signal(regs, syscall); |
| |
| if (thread_flags & _TIF_NOTIFY_RESUME) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(regs); |
| if (current->replacement_session_keyring) |
| key_replace_session_keyring(); |
| } |
| } |
| |
| /* |
| * Copy signal return handlers into the vector page, and |
| * set sigreturn to be a pointer to these. |
| */ |
| void __init early_signal_init(void) |
| { |
| memcpy((void *)kuser_vecpage_to_vectors(KERN_SIGRETURN_CODE), |
| sigreturn_codes, sizeof(sigreturn_codes)); |
| memcpy((void *)kuser_vecpage_to_vectors(KERN_RESTART_CODE), |
| syscall_restart_code, sizeof(syscall_restart_code)); |
| /* Need not to flush icache, since early_trap_init will do it last. */ |
| } |