555 lines
15 KiB
C
555 lines
15 KiB
C
/* linux/arch/sparc/kernel/signal.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
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* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
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* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
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*/
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/unistd.h>
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#include <linux/mm.h>
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#include <linux/tty.h>
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#include <linux/smp.h>
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#include <linux/binfmts.h> /* do_coredum */
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#include <linux/bitops.h>
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#include <linux/tracehook.h>
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#include <asm/uaccess.h>
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#include <asm/ptrace.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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#include <asm/cacheflush.h> /* flush_sig_insns */
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#include <asm/switch_to.h>
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#include "sigutil.h"
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extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
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void *fpqueue, unsigned long *fpqdepth);
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extern void fpload(unsigned long *fpregs, unsigned long *fsr);
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struct signal_frame {
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struct sparc_stackf ss;
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__siginfo32_t info;
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__siginfo_fpu_t __user *fpu_save;
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unsigned long insns[2] __attribute__ ((aligned (8)));
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unsigned int extramask[_NSIG_WORDS - 1];
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unsigned int extra_size; /* Should be 0 */
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__siginfo_rwin_t __user *rwin_save;
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} __attribute__((aligned(8)));
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struct rt_signal_frame {
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struct sparc_stackf ss;
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siginfo_t info;
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struct pt_regs regs;
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sigset_t mask;
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__siginfo_fpu_t __user *fpu_save;
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unsigned int insns[2];
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stack_t stack;
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unsigned int extra_size; /* Should be 0 */
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__siginfo_rwin_t __user *rwin_save;
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} __attribute__((aligned(8)));
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/* Align macros */
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#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
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#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))
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asmlinkage void do_sigreturn(struct pt_regs *regs)
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{
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struct signal_frame __user *sf;
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unsigned long up_psr, pc, npc;
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sigset_t set;
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__siginfo_fpu_t __user *fpu_save;
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__siginfo_rwin_t __user *rwin_save;
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int err;
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/* Always make any pending restarted system calls return -EINTR */
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current_thread_info()->restart_block.fn = do_no_restart_syscall;
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synchronize_user_stack();
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sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
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/* 1. Make sure we are not getting garbage from the user */
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if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
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goto segv_and_exit;
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if (((unsigned long) sf) & 3)
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goto segv_and_exit;
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err = __get_user(pc, &sf->info.si_regs.pc);
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err |= __get_user(npc, &sf->info.si_regs.npc);
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if ((pc | npc) & 3)
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goto segv_and_exit;
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/* 2. Restore the state */
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up_psr = regs->psr;
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err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
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/* User can only change condition codes and FPU enabling in %psr. */
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regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
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| (regs->psr & (PSR_ICC | PSR_EF));
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/* Prevent syscall restart. */
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pt_regs_clear_syscall(regs);
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err |= __get_user(fpu_save, &sf->fpu_save);
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if (fpu_save)
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err |= restore_fpu_state(regs, fpu_save);
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err |= __get_user(rwin_save, &sf->rwin_save);
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if (rwin_save)
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err |= restore_rwin_state(rwin_save);
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/* This is pretty much atomic, no amount locking would prevent
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* the races which exist anyways.
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*/
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err |= __get_user(set.sig[0], &sf->info.si_mask);
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err |= __copy_from_user(&set.sig[1], &sf->extramask,
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(_NSIG_WORDS-1) * sizeof(unsigned int));
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if (err)
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goto segv_and_exit;
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set_current_blocked(&set);
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return;
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segv_and_exit:
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force_sig(SIGSEGV, current);
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}
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asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
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{
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struct rt_signal_frame __user *sf;
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unsigned int psr, pc, npc;
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__siginfo_fpu_t __user *fpu_save;
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__siginfo_rwin_t __user *rwin_save;
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sigset_t set;
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int err;
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synchronize_user_stack();
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sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
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if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
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(((unsigned long) sf) & 0x03))
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goto segv;
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err = __get_user(pc, &sf->regs.pc);
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err |= __get_user(npc, &sf->regs.npc);
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err |= ((pc | npc) & 0x03);
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err |= __get_user(regs->y, &sf->regs.y);
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err |= __get_user(psr, &sf->regs.psr);
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err |= __copy_from_user(®s->u_regs[UREG_G1],
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&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
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regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
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/* Prevent syscall restart. */
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pt_regs_clear_syscall(regs);
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err |= __get_user(fpu_save, &sf->fpu_save);
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if (!err && fpu_save)
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err |= restore_fpu_state(regs, fpu_save);
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err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
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err |= restore_altstack(&sf->stack);
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if (err)
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goto segv;
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regs->pc = pc;
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regs->npc = npc;
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err |= __get_user(rwin_save, &sf->rwin_save);
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if (!err && rwin_save) {
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if (restore_rwin_state(rwin_save))
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goto segv;
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}
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set_current_blocked(&set);
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return;
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segv:
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force_sig(SIGSEGV, current);
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}
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/* Checks if the fp is valid */
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static inline int invalid_frame_pointer(void __user *fp, int fplen)
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{
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if ((((unsigned long) fp) & 7) || !__access_ok((unsigned long)fp, fplen))
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return 1;
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return 0;
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}
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static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
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{
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unsigned long sp = regs->u_regs[UREG_FP];
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/*
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* If we are on the alternate signal stack and would overflow it, don't.
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* Return an always-bogus address instead so we will die with SIGSEGV.
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*/
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if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
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return (void __user *) -1L;
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/* This is the X/Open sanctioned signal stack switching. */
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sp = sigsp(sp, ksig) - framesize;
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/* Always align the stack frame. This handles two cases. First,
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* sigaltstack need not be mindful of platform specific stack
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* alignment. Second, if we took this signal because the stack
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* is not aligned properly, we'd like to take the signal cleanly
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* and report that.
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*/
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sp &= ~15UL;
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return (void __user *) sp;
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}
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static int setup_frame(struct ksignal *ksig, struct pt_regs *regs,
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sigset_t *oldset)
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{
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struct signal_frame __user *sf;
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int sigframe_size, err, wsaved;
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void __user *tail;
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/* 1. Make sure everything is clean */
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synchronize_user_stack();
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wsaved = current_thread_info()->w_saved;
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sigframe_size = sizeof(*sf);
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if (used_math())
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sigframe_size += sizeof(__siginfo_fpu_t);
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if (wsaved)
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sigframe_size += sizeof(__siginfo_rwin_t);
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sf = (struct signal_frame __user *)
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get_sigframe(ksig, regs, sigframe_size);
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if (invalid_frame_pointer(sf, sigframe_size)) {
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do_exit(SIGILL);
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return -EINVAL;
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}
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tail = sf + 1;
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/* 2. Save the current process state */
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err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
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err |= __put_user(0, &sf->extra_size);
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if (used_math()) {
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__siginfo_fpu_t __user *fp = tail;
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tail += sizeof(*fp);
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err |= save_fpu_state(regs, fp);
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err |= __put_user(fp, &sf->fpu_save);
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} else {
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err |= __put_user(0, &sf->fpu_save);
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}
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if (wsaved) {
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__siginfo_rwin_t __user *rwp = tail;
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tail += sizeof(*rwp);
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err |= save_rwin_state(wsaved, rwp);
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err |= __put_user(rwp, &sf->rwin_save);
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} else {
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err |= __put_user(0, &sf->rwin_save);
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}
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err |= __put_user(oldset->sig[0], &sf->info.si_mask);
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err |= __copy_to_user(sf->extramask, &oldset->sig[1],
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(_NSIG_WORDS - 1) * sizeof(unsigned int));
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if (!wsaved) {
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err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
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sizeof(struct reg_window32));
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} else {
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struct reg_window32 *rp;
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rp = ¤t_thread_info()->reg_window[wsaved - 1];
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err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
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}
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if (err)
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return err;
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/* 3. signal handler back-trampoline and parameters */
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regs->u_regs[UREG_FP] = (unsigned long) sf;
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regs->u_regs[UREG_I0] = ksig->sig;
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regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
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regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
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/* 4. signal handler */
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regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
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regs->npc = (regs->pc + 4);
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/* 5. return to kernel instructions */
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if (ksig->ka.ka_restorer)
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regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
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else {
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regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
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/* mov __NR_sigreturn, %g1 */
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err |= __put_user(0x821020d8, &sf->insns[0]);
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/* t 0x10 */
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err |= __put_user(0x91d02010, &sf->insns[1]);
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if (err)
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return err;
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/* Flush instruction space. */
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flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
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}
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return 0;
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}
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static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
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sigset_t *oldset)
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{
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struct rt_signal_frame __user *sf;
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int sigframe_size, wsaved;
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void __user *tail;
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unsigned int psr;
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int err;
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synchronize_user_stack();
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wsaved = current_thread_info()->w_saved;
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sigframe_size = sizeof(*sf);
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if (used_math())
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sigframe_size += sizeof(__siginfo_fpu_t);
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if (wsaved)
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sigframe_size += sizeof(__siginfo_rwin_t);
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sf = (struct rt_signal_frame __user *)
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get_sigframe(ksig, regs, sigframe_size);
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if (invalid_frame_pointer(sf, sigframe_size)) {
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do_exit(SIGILL);
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return -EINVAL;
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}
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tail = sf + 1;
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err = __put_user(regs->pc, &sf->regs.pc);
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err |= __put_user(regs->npc, &sf->regs.npc);
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err |= __put_user(regs->y, &sf->regs.y);
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psr = regs->psr;
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if (used_math())
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psr |= PSR_EF;
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err |= __put_user(psr, &sf->regs.psr);
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err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
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err |= __put_user(0, &sf->extra_size);
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if (psr & PSR_EF) {
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__siginfo_fpu_t *fp = tail;
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tail += sizeof(*fp);
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err |= save_fpu_state(regs, fp);
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err |= __put_user(fp, &sf->fpu_save);
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} else {
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err |= __put_user(0, &sf->fpu_save);
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}
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if (wsaved) {
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__siginfo_rwin_t *rwp = tail;
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tail += sizeof(*rwp);
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err |= save_rwin_state(wsaved, rwp);
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err |= __put_user(rwp, &sf->rwin_save);
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} else {
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err |= __put_user(0, &sf->rwin_save);
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}
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err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
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/* Setup sigaltstack */
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err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
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if (!wsaved) {
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err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
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sizeof(struct reg_window32));
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} else {
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struct reg_window32 *rp;
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rp = ¤t_thread_info()->reg_window[wsaved - 1];
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err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
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}
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err |= copy_siginfo_to_user(&sf->info, &ksig->info);
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if (err)
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return err;
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regs->u_regs[UREG_FP] = (unsigned long) sf;
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regs->u_regs[UREG_I0] = ksig->sig;
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regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
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regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
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regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
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regs->npc = (regs->pc + 4);
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if (ksig->ka.ka_restorer)
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regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
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else {
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regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
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/* mov __NR_sigreturn, %g1 */
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err |= __put_user(0x821020d8, &sf->insns[0]);
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/* t 0x10 */
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err |= __put_user(0x91d02010, &sf->insns[1]);
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if (err)
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return err;
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/* Flush instruction space. */
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flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
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}
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return 0;
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}
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static inline void
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handle_signal(struct ksignal *ksig, struct pt_regs *regs)
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{
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sigset_t *oldset = sigmask_to_save();
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int err;
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if (ksig->ka.sa.sa_flags & SA_SIGINFO)
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err = setup_rt_frame(ksig, regs, oldset);
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else
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err = setup_frame(ksig, regs, oldset);
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signal_setup_done(err, ksig, 0);
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}
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static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
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struct sigaction *sa)
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{
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switch(regs->u_regs[UREG_I0]) {
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case ERESTART_RESTARTBLOCK:
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case ERESTARTNOHAND:
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no_system_call_restart:
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regs->u_regs[UREG_I0] = EINTR;
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regs->psr |= PSR_C;
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break;
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case ERESTARTSYS:
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if (!(sa->sa_flags & SA_RESTART))
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goto no_system_call_restart;
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/* fallthrough */
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case ERESTARTNOINTR:
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regs->u_regs[UREG_I0] = orig_i0;
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regs->pc -= 4;
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regs->npc -= 4;
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}
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}
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/* Note that 'init' is a special process: it doesn't get signals it doesn't
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* want to handle. Thus you cannot kill init even with a SIGKILL even by
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* mistake.
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*/
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static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
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{
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struct ksignal ksig;
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int restart_syscall;
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bool has_handler;
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/* It's a lot of work and synchronization to add a new ptrace
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* register for GDB to save and restore in order to get
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* orig_i0 correct for syscall restarts when debugging.
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*
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* Although it should be the case that most of the global
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* registers are volatile across a system call, glibc already
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* depends upon that fact that we preserve them. So we can't
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* just use any global register to save away the orig_i0 value.
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*
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* In particular %g2, %g3, %g4, and %g5 are all assumed to be
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* preserved across a system call trap by various pieces of
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* code in glibc.
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*
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* %g7 is used as the "thread register". %g6 is not used in
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* any fixed manner. %g6 is used as a scratch register and
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* a compiler temporary, but it's value is never used across
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* a system call. Therefore %g6 is usable for orig_i0 storage.
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*/
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if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
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regs->u_regs[UREG_G6] = orig_i0;
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has_handler = get_signal(&ksig);
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/* If the debugger messes with the program counter, it clears
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* the software "in syscall" bit, directing us to not perform
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* a syscall restart.
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*/
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restart_syscall = 0;
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if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
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restart_syscall = 1;
|
|
orig_i0 = regs->u_regs[UREG_G6];
|
|
}
|
|
|
|
if (has_handler) {
|
|
if (restart_syscall)
|
|
syscall_restart(orig_i0, regs, &ksig.ka.sa);
|
|
handle_signal(&ksig, regs);
|
|
} else {
|
|
if (restart_syscall) {
|
|
switch (regs->u_regs[UREG_I0]) {
|
|
case ERESTARTNOHAND:
|
|
case ERESTARTSYS:
|
|
case ERESTARTNOINTR:
|
|
/* replay the system call when we are done */
|
|
regs->u_regs[UREG_I0] = orig_i0;
|
|
regs->pc -= 4;
|
|
regs->npc -= 4;
|
|
pt_regs_clear_syscall(regs);
|
|
case ERESTART_RESTARTBLOCK:
|
|
regs->u_regs[UREG_G1] = __NR_restart_syscall;
|
|
regs->pc -= 4;
|
|
regs->npc -= 4;
|
|
pt_regs_clear_syscall(regs);
|
|
}
|
|
}
|
|
restore_saved_sigmask();
|
|
}
|
|
}
|
|
|
|
void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
|
|
unsigned long thread_info_flags)
|
|
{
|
|
if (thread_info_flags & _TIF_SIGPENDING)
|
|
do_signal(regs, orig_i0);
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
}
|
|
}
|
|
|
|
asmlinkage int
|
|
do_sys_sigstack(struct sigstack __user *ssptr, struct sigstack __user *ossptr,
|
|
unsigned long sp)
|
|
{
|
|
int ret = -EFAULT;
|
|
|
|
/* First see if old state is wanted. */
|
|
if (ossptr) {
|
|
if (put_user(current->sas_ss_sp + current->sas_ss_size,
|
|
&ossptr->the_stack) ||
|
|
__put_user(on_sig_stack(sp), &ossptr->cur_status))
|
|
goto out;
|
|
}
|
|
|
|
/* Now see if we want to update the new state. */
|
|
if (ssptr) {
|
|
char *ss_sp;
|
|
|
|
if (get_user(ss_sp, &ssptr->the_stack))
|
|
goto out;
|
|
/* If the current stack was set with sigaltstack, don't
|
|
swap stacks while we are on it. */
|
|
ret = -EPERM;
|
|
if (current->sas_ss_sp && on_sig_stack(sp))
|
|
goto out;
|
|
|
|
/* Since we don't know the extent of the stack, and we don't
|
|
track onstack-ness, but rather calculate it, we must
|
|
presume a size. Ho hum this interface is lossy. */
|
|
current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
|
|
current->sas_ss_size = SIGSTKSZ;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
return ret;
|
|
}
|