diff options
Diffstat (limited to 'arch/cris/arch-v32/kernel/signal.c')
| -rw-r--r-- | arch/cris/arch-v32/kernel/signal.c | 541 |
1 files changed, 0 insertions, 541 deletions
diff --git a/arch/cris/arch-v32/kernel/signal.c b/arch/cris/arch-v32/kernel/signal.c deleted file mode 100644 index 4f2e3ba3bf40..000000000000 --- a/arch/cris/arch-v32/kernel/signal.c +++ /dev/null @@ -1,541 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Copyright (C) 2003, Axis Communications AB. - */ - -#include <linux/sched.h> -#include <linux/sched/task_stack.h> -#include <linux/mm.h> -#include <linux/slab.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/syscalls.h> -#include <linux/vmalloc.h> - -#include <asm/io.h> -#include <asm/processor.h> -#include <asm/ucontext.h> -#include <linux/uaccess.h> -#include <arch/hwregs/cpu_vect.h> - -extern unsigned long cris_signal_return_page; - -/* - * A syscall in CRIS is really a "break 13" instruction, which is 2 - * bytes. The registers is manipulated so upon return the instruction - * will be executed again. - * - * This relies on that PC points to the instruction after the break call. - */ -#define RESTART_CRIS_SYS(regs) regs->r10 = regs->orig_r10; regs->erp -= 2; - -/* Signal frames. */ -struct signal_frame { - struct sigcontext sc; - unsigned long extramask[_NSIG_WORDS - 1]; - unsigned char retcode[8]; /* Trampoline code. */ -}; - -struct rt_signal_frame { - struct siginfo *pinfo; - void *puc; - struct siginfo info; - struct ucontext uc; - unsigned char retcode[8]; /* Trampoline code. */ -}; - -void do_signal(int restart, struct pt_regs *regs); -void keep_debug_flags(unsigned long oldccs, unsigned long oldspc, - struct pt_regs *regs); - -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 registers from &sc->regs. sc is already checked - * for VERIFY_READ since the signal_frame was previously - * checked in sys_sigreturn(). - */ - if (__copy_from_user(regs, sc, sizeof(struct pt_regs))) - goto badframe; - - /* Make that the user-mode flag is set. */ - regs->ccs |= (1 << (U_CCS_BITNR + CCS_SHIFT)); - - /* Don't perform syscall restarting */ - regs->exs = -1; - - /* Restore the old USP. */ - err |= __get_user(old_usp, &sc->usp); - wrusp(old_usp); - - return err; - -badframe: - return 1; -} - -asmlinkage int sys_sigreturn(void) -{ - struct pt_regs *regs = current_pt_regs(); - sigset_t set; - struct signal_frame __user *frame; - unsigned long oldspc = regs->spc; - unsigned long oldccs = regs->ccs; - - frame = (struct signal_frame *) rdusp(); - - /* - * Since the signal is stacked on a dword boundary, the frame - * should be dword aligned here as well. It it's not, then the - * user is trying some funny business. - */ - 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; - - keep_debug_flags(oldccs, oldspc, regs); - - return regs->r10; - -badframe: - force_sig(SIGSEGV, current); - return 0; -} - -asmlinkage int sys_rt_sigreturn(void) -{ - struct pt_regs *regs = current_pt_regs(); - sigset_t set; - struct rt_signal_frame __user *frame; - unsigned long oldspc = regs->spc; - unsigned long oldccs = regs->ccs; - - frame = (struct rt_signal_frame *) rdusp(); - - /* - * Since the signal is stacked on a dword boundary, the frame - * should be dword aligned here as well. It it's not, then the - * user is trying some funny business. - */ - 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; - - keep_debug_flags(oldccs, oldspc, regs); - - return regs->r10; - -badframe: - force_sig(SIGSEGV, current); - return 0; -} - -/* Setup a signal frame. */ -static int -setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, - unsigned long mask) -{ - int err; - unsigned long usp; - - err = 0; - usp = rdusp(); - - /* - * Copy the registers. They are located first in sc, so it's - * possible to use sc directly. - */ - err |= __copy_to_user(sc, regs, sizeof(struct pt_regs)); - - err |= __put_user(mask, &sc->oldmask); - err |= __put_user(usp, &sc->usp); - - return err; -} - -/* Figure out where 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 a lot of state-info is stacked, and arranged for the - * user-mode program to return to the kernel using either a trampiline - * 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) -{ - int err; - unsigned long return_ip; - struct signal_frame __user *frame; - - 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 user-space. If provided, use a stub - * already located in user-space. - */ - if (ksig->ka.sa.sa_flags & SA_RESTORER) { - return_ip = (unsigned long)ksig->ka.sa.sa_restorer; - } else { - /* Trampoline - the desired return ip is in the signal return page. */ - return_ip = cris_signal_return_page; - - /* - * This is movu.w __NR_sigreturn, r9; break 13; - * - * WE DO NOT USE IT ANY MORE! It's only left here for historical - * reasons and because gdb uses it as a signature to notice - * signal handler stack frames. - */ - 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. - * - * Where the code enters now. - * Where the code enter later. - * First argument, signo. - */ - regs->erp = (unsigned long) ksig->ka.sa.sa_handler; - regs->srp = return_ip; - regs->r10 = ksig->sig; - - /* 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) -{ - int err; - unsigned long return_ip; - struct rt_signal_frame __user *frame; - - 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 user-space. If provided, use a stub - * already located in user-space. - */ - if (ksig->ka.sa.sa_flags & SA_RESTORER) { - return_ip = (unsigned long) ksig->ka.sa.sa_restorer; - } else { - /* Trampoline - the desired return ip is in the signal return page. */ - return_ip = cris_signal_return_page + 6; - - /* - * This is movu.w __NR_rt_sigreturn, r9; break 13; - * - * WE DO NOT USE IT ANY MORE! It's only left here for historical - * reasons and because gdb uses it as a signature to notice - * signal handler stack frames. - */ - 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. - * - * Where the code enters now. - * Where the code enters later. - * First argument is signo. - * Second argument is (siginfo_t *). - * Third argument is unused. - */ - regs->erp = (unsigned long) ksig->ka.sa.sa_handler; - regs->srp = return_ip; - regs->r10 = ksig->sig; - regs->r11 = (unsigned long) &frame->info; - regs->r12 = 0; - - /* Actually move the usp to reflect the stacked frame. */ - wrusp((unsigned long)frame); - - return 0; -} - -/* Invoke a signal handler to, well, handle the signal. */ -static inline void -handle_signal(int canrestart, struct ksignal *ksig, struct pt_regs *regs) -{ - sigset_t *oldset = sigmask_to_save(); - int ret; - - /* Check if this got called from a system call. */ - if (canrestart) { - /* If so, check system call restarting. */ - switch (regs->r10) { - case -ERESTART_RESTARTBLOCK: - case -ERESTARTNOHAND: - /* - * This means that the syscall should - * only be restarted if there was no - * handler for the signal, and since - * this point isn't reached unless - * there is a handler, there's no need - * to restart. - */ - regs->r10 = -EINTR; - break; - - case -ERESTARTSYS: - /* - * This means 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; - } - - /* Fall through. */ - - case -ERESTARTNOINTR: - /* - * This means that the syscall should - * be called again after the signal - * handler returns. - */ - RESTART_CRIS_SYS(regs); - break; - } - } - - /* 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; - - canrestart = canrestart && ((int)regs->exs >= 0); - - /* - * The common case should go fast, which is why this point is - * reached from kernel-mode. If that's the case, just return - * without doing anything. - */ - if (!user_mode(regs)) - return; - - if (get_signal(&ksig)) { - /* Whee! Actually deliver the signal. */ - handle_signal(canrestart, &ksig, regs); - return; - } - - /* Got here 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->erp -= 2; - } - } - - /* if there's no signal to deliver, we just put the saved sigmask - * back */ - restore_saved_sigmask(); -} - -asmlinkage void -ugdb_trap_user(struct thread_info *ti, int sig) -{ - if (((user_regs(ti)->exs & 0xff00) >> 8) != SINGLE_STEP_INTR_VECT) { - /* Zero single-step PC if the reason we stopped wasn't a single - step exception. This is to avoid relying on it when it isn't - reliable. */ - user_regs(ti)->spc = 0; - } - /* FIXME: Filter out false h/w breakpoint hits (i.e. EDA - not within any configured h/w breakpoint range). Synchronize with - what already exists for kernel debugging. */ - if (((user_regs(ti)->exs & 0xff00) >> 8) == BREAK_8_INTR_VECT) { - /* Break 8: subtract 2 from ERP unless in a delay slot. */ - if (!(user_regs(ti)->erp & 0x1)) - user_regs(ti)->erp -= 2; - } - sys_kill(ti->task->pid, sig); -} - -void -keep_debug_flags(unsigned long oldccs, unsigned long oldspc, - struct pt_regs *regs) -{ - if (oldccs & (1 << Q_CCS_BITNR)) { - /* Pending single step due to single-stepping the break 13 - in the signal trampoline: keep the Q flag. */ - regs->ccs |= (1 << Q_CCS_BITNR); - /* S flag should be set - complain if it's not. */ - if (!(oldccs & (1 << (S_CCS_BITNR + CCS_SHIFT)))) { - printk("Q flag but no S flag?"); - } - regs->ccs |= (1 << (S_CCS_BITNR + CCS_SHIFT)); - /* Assume the SPC is valid and interesting. */ - regs->spc = oldspc; - - } else if (oldccs & (1 << (S_CCS_BITNR + CCS_SHIFT))) { - /* If a h/w bp was set in the signal handler we need - to keep the S flag. */ - regs->ccs |= (1 << (S_CCS_BITNR + CCS_SHIFT)); - /* Don't keep the old SPC though; if we got here due to - a single-step, the Q flag should have been set. */ - } else if (regs->spc) { - /* If we were single-stepping *before* the signal was taken, - we don't want to restore that state now, because GDB will - have forgotten all about it. */ - regs->spc = 0; - regs->ccs &= ~(1 << (S_CCS_BITNR + CCS_SHIFT)); - } -} - -/* Set up the trampolines on the signal return page. */ -int __init -cris_init_signal(void) -{ - u16* data = kmalloc(PAGE_SIZE, GFP_KERNEL); - - /* This is movu.w __NR_sigreturn, r9; break 13; */ - data[0] = 0x9c5f; - data[1] = __NR_sigreturn; - data[2] = 0xe93d; - /* This is movu.w __NR_rt_sigreturn, r9; break 13; */ - data[3] = 0x9c5f; - data[4] = __NR_rt_sigreturn; - data[5] = 0xe93d; - - /* Map to userspace with appropriate permissions (no write access...) */ - cris_signal_return_page = (unsigned long) - __ioremap_prot(virt_to_phys(data), PAGE_SIZE, PAGE_SIGNAL_TRAMPOLINE); - - return 0; -} - -__initcall(cris_init_signal); |