diff options
Diffstat (limited to 'arch/unicore32/kernel/signal.c')
| -rw-r--r-- | arch/unicore32/kernel/signal.c | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/signal.c b/arch/unicore32/kernel/signal.c new file mode 100644 index 00000000000..6905f0ebdc7 --- /dev/null +++ b/arch/unicore32/kernel/signal.c @@ -0,0 +1,441 @@ +/* + * 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/uaccess.h> +#include <linux/tracehook.h> +#include <linux/elf.h> +#include <linux/unistd.h> + +#include <asm/cacheflush.h> +#include <asm/ucontext.h> + +/* + * 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) + 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 (restore_altstack(&frame->sig.uc.uc_stack)) + 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)); + 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); + err |= __save_altstack(&frame->sig.uc.uc_stack, regs->UCreg_sp); + 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 void handle_signal(unsigned long sig, struct k_sigaction *ka, + siginfo_t *info, struct pt_regs *regs, int syscall) +{ + struct thread_info *thread = current_thread_info(); + struct task_struct *tsk = current; + sigset_t *oldset = sigmask_to_save(); + 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; + } + + signal_delivered(sig, info, ka, regs, 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; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + handle_signal(signr, &ka, &info, regs, syscall); + return; + } + + /* + * 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. + */ + restore_saved_sigmask(); +} + +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); + } +} + +/* + * 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. */ +} |