diff options
Diffstat (limited to 'arch/cris/arch-v10/kernel/signal.c')
-rw-r--r-- | arch/cris/arch-v10/kernel/signal.c | 440 |
1 files changed, 0 insertions, 440 deletions
diff --git a/arch/cris/arch-v10/kernel/signal.c b/arch/cris/arch-v10/kernel/signal.c deleted file mode 100644 index 2beffc37faf8..000000000000 --- a/arch/cris/arch-v10/kernel/signal.c +++ /dev/null @@ -1,440 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * linux/arch/cris/kernel/signal.c - * - * Based on arch/i386/kernel/signal.c by - * Copyright (C) 1991, 1992 Linus Torvalds - * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * - * - * Ideas also taken from arch/arm. - * - * Copyright (C) 2000-2007 Axis Communications AB - * - * Authors: Bjorn Wesen (bjornw@axis.com) - * - */ - -#include <linux/sched.h> -#include <linux/sched/task_stack.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 <asm/processor.h> -#include <asm/ucontext.h> -#include <linux/uaccess.h> -#include <arch/system.h> - -#define DEBUG_SIG 0 - -/* a syscall in Linux/CRIS is a break 13 instruction which is 2 bytes */ -/* manipulate regs so that upon return, it will be re-executed */ - -/* We rely on that pc points to the instruction after "break 13", so the - * library must never do strange things like putting it in a delay slot. - */ -#define RESTART_CRIS_SYS(regs) regs->r10 = regs->orig_r10; regs->irp -= 2; - -void do_signal(int canrestart, struct pt_regs *regs); - -/* - * Do a signal return; undo the signal stack. - */ - -struct sigframe { - struct sigcontext sc; - unsigned long extramask[_NSIG_WORDS-1]; - unsigned char retcode[8]; /* trampoline code */ -}; - -struct rt_sigframe { - struct siginfo *pinfo; - void *puc; - struct siginfo info; - struct ucontext uc; - unsigned char retcode[8]; /* trampoline code */ -}; - - -static int -restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) -{ - unsigned int err = 0; - unsigned long old_usp; - - /* Always make any pending restarted system calls return -EINTR */ - current->restart_block.fn = do_no_restart_syscall; - - /* restore the regs from &sc->regs (same as sc, since regs is first) - * (sc is already checked for VERIFY_READ since the sigframe was - * checked in sys_sigreturn previously) - */ - - if (__copy_from_user(regs, sc, sizeof(struct pt_regs))) - goto badframe; - - /* make sure the U-flag is set so user-mode cannot fool us */ - - regs->dccr |= 1 << 8; - - /* restore the old USP as it was before we stacked the sc etc. - * (we cannot just pop the sigcontext since we aligned the sp and - * stuff after pushing it) - */ - - err |= __get_user(old_usp, &sc->usp); - - wrusp(old_usp); - - /* TODO: the other ports use regs->orig_XX to disable syscall checks - * after this completes, but we don't use that mechanism. maybe we can - * use it now ? - */ - - return err; - -badframe: - return 1; -} - -asmlinkage int sys_sigreturn(void) -{ - struct pt_regs *regs = current_pt_regs(); - struct sigframe __user *frame = (struct sigframe *)rdusp(); - sigset_t set; - - /* - * Since we stacked the signal on a dword boundary, - * then frame should be dword aligned here. If it's - * not, then the user is trying to mess with us. - */ - if (((long)frame) & 3) - goto badframe; - - 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; - - set_current_blocked(&set); - - if (restore_sigcontext(regs, &frame->sc)) - goto badframe; - - /* TODO: SIGTRAP when single-stepping as in arm ? */ - - return regs->r10; - -badframe: - force_sig(SIGSEGV, current); - return 0; -} - -asmlinkage int sys_rt_sigreturn(void) -{ - struct pt_regs *regs = current_pt_regs(); - struct rt_sigframe __user *frame = (struct rt_sigframe *)rdusp(); - sigset_t set; - - /* - * Since we stacked the signal on a dword boundary, - * then frame should be dword aligned here. If it's - * not, then the user is trying to mess with us. - */ - if (((long)frame) & 3) - goto badframe; - - if (!access_ok(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(regs, &frame->uc.uc_mcontext)) - goto badframe; - - if (restore_altstack(&frame->uc.uc_stack)) - goto badframe; - - return regs->r10; - -badframe: - force_sig(SIGSEGV, current); - return 0; -} - -/* - * Set up a signal frame. - */ - -static int setup_sigcontext(struct sigcontext __user *sc, - struct pt_regs *regs, unsigned long mask) -{ - int err = 0; - unsigned long usp = rdusp(); - - /* copy the regs. they are first in sc so we can use sc directly */ - - err |= __copy_to_user(sc, regs, sizeof(struct pt_regs)); - - /* Set the frametype to CRIS_FRAME_NORMAL for the execution of - the signal handler. The frametype will be restored to its previous - value in restore_sigcontext. */ - regs->frametype = CRIS_FRAME_NORMAL; - - /* then some other stuff */ - - err |= __put_user(mask, &sc->oldmask); - - err |= __put_user(usp, &sc->usp); - - return err; -} - -/* Figure out where we want to put the new signal frame - * - usually on the stack. */ - -static inline void __user * -get_sigframe(struct ksignal *ksig, size_t frame_size) -{ - unsigned long sp = sigsp(rdusp(), ksig); - - /* make sure the frame is dword-aligned */ - - sp &= ~3; - - return (void __user*)(sp - frame_size); -} - -/* grab and setup a signal frame. - * - * basically we stack a lot of state info, and arrange for the - * user-mode program to return to the kernel using either a - * trampoline which performs the syscall sigreturn, or a provided - * user-mode trampoline. - */ - -static int setup_frame(struct ksignal *ksig, sigset_t *set, - struct pt_regs *regs) -{ - struct sigframe __user *frame; - unsigned long return_ip; - int err = 0; - - frame = get_sigframe(ksig, sizeof(*frame)); - - if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) - return -EFAULT; - - err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); - if (err) - return -EFAULT; - - if (_NSIG_WORDS > 1) { - err |= __copy_to_user(frame->extramask, &set->sig[1], - sizeof(frame->extramask)); - } - if (err) - return -EFAULT; - - /* Set up to return from userspace. If provided, use a stub - already in userspace. */ - if (ksig->ka.sa.sa_flags & SA_RESTORER) { - return_ip = (unsigned long)ksig->ka.sa.sa_restorer; - } else { - /* trampoline - the desired return ip is the retcode itself */ - return_ip = (unsigned long)&frame->retcode; - /* This is movu.w __NR_sigreturn, r9; break 13; */ - err |= __put_user(0x9c5f, (short __user*)(frame->retcode+0)); - err |= __put_user(__NR_sigreturn, (short __user*)(frame->retcode+2)); - err |= __put_user(0xe93d, (short __user*)(frame->retcode+4)); - } - - if (err) - return -EFAULT; - - /* Set up registers for signal handler */ - - regs->irp = (unsigned long) ksig->ka.sa.sa_handler; /* what we enter NOW */ - regs->srp = return_ip; /* what we enter LATER */ - regs->r10 = ksig->sig; /* first argument is signo */ - - /* actually move the usp to reflect the stacked frame */ - - wrusp((unsigned long)frame); - - return 0; -} - -static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, - struct pt_regs *regs) -{ - struct rt_sigframe __user *frame; - unsigned long return_ip; - int err = 0; - - frame = get_sigframe(ksig, sizeof(*frame)); - - if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) - return -EFAULT; - - err |= __put_user(&frame->info, &frame->pinfo); - err |= __put_user(&frame->uc, &frame->puc); - err |= copy_siginfo_to_user(&frame->info, &ksig->info); - if (err) - return -EFAULT; - - /* 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, regs, set->sig[0]); - - err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); - - err |= __save_altstack(&frame->uc.uc_stack, rdusp()); - - if (err) - return -EFAULT; - - /* Set up to return from userspace. If provided, use a stub - already in userspace. */ - if (ksig->ka.sa.sa_flags & SA_RESTORER) { - return_ip = (unsigned long)ksig->ka.sa.sa_restorer; - } else { - /* trampoline - the desired return ip is the retcode itself */ - return_ip = (unsigned long)&frame->retcode; - /* This is movu.w __NR_rt_sigreturn, r9; break 13; */ - err |= __put_user(0x9c5f, (short __user *)(frame->retcode+0)); - err |= __put_user(__NR_rt_sigreturn, - (short __user *)(frame->retcode+2)); - err |= __put_user(0xe93d, (short __user *)(frame->retcode+4)); - } - - if (err) - return -EFAULT; - - /* Set up registers for signal handler */ - - /* What we enter NOW */ - regs->irp = (unsigned long) ksig->ka.sa.sa_handler; - /* What we enter LATER */ - regs->srp = return_ip; - /* First argument is signo */ - regs->r10 = ksig->sig; - /* Second argument is (siginfo_t *) */ - regs->r11 = (unsigned long)&frame->info; - /* Third argument is unused */ - regs->r12 = 0; - - /* Actually move the usp to reflect the stacked frame */ - wrusp((unsigned long)frame); - - return 0; -} - -/* - * OK, we're invoking a handler - */ - -static inline void handle_signal(int canrestart, struct ksignal *ksig, - struct pt_regs *regs) -{ - sigset_t *oldset = sigmask_to_save(); - int ret; - - /* Are we from a system call? */ - if (canrestart) { - /* If so, check system call restarting.. */ - switch (regs->r10) { - case -ERESTART_RESTARTBLOCK: - case -ERESTARTNOHAND: - /* ERESTARTNOHAND means that the syscall should - * only be restarted if there was no handler for - * the signal, and since we only get here if there - * is a handler, we don't restart */ - regs->r10 = -EINTR; - break; - case -ERESTARTSYS: - /* ERESTARTSYS means to restart the syscall if - * there is no handler or the handler was - * registered with SA_RESTART */ - if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { - regs->r10 = -EINTR; - break; - } - /* fallthrough */ - case -ERESTARTNOINTR: - /* ERESTARTNOINTR means that the syscall should - * be called again after the signal handler returns. */ - RESTART_CRIS_SYS(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, 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. - * - * Also note that the regs structure given here as an argument, is the latest - * pushed pt_regs. It may or may not be the same as the first pushed registers - * when the initial usermode->kernelmode transition took place. Therefore - * we can use user_mode(regs) to see if we came directly from kernel or user - * mode below. - */ - -void do_signal(int canrestart, struct pt_regs *regs) -{ - struct ksignal ksig; - - /* - * 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 (get_signal(&ksig)) { - /* Whee! Actually deliver the signal. */ - handle_signal(canrestart, &ksig, regs); - return; - } - - /* Did we come from a system call? */ - if (canrestart) { - /* Restart the system call - no handlers present */ - if (regs->r10 == -ERESTARTNOHAND || - regs->r10 == -ERESTARTSYS || - regs->r10 == -ERESTARTNOINTR) { - RESTART_CRIS_SYS(regs); - } - if (regs->r10 == -ERESTART_RESTARTBLOCK) { - regs->r9 = __NR_restart_syscall; - regs->irp -= 2; - } - } - - /* if there's no signal to deliver, we just put the saved sigmask - * back */ - restore_saved_sigmask(); -} |