signal.c

microwindows移植到S3C44B0的源码

			 "   bral " SYMBOL_NAME_STR(ret_from_signal) "\n"
			 "4:\n"
			 ".section __ex_table,\"a\"\n"
			 "   .align 4\n"
			 "   .long 2b,4b\n"
			 "   .long 3b,4b\n"
			 ".previous"
			 : /* no outputs, it doesn't ever return */
			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
			   "n" (frame_offset), "a" (fp)
			 : "a0");
#undef frame_offset
		/*
		 * If we ever get here an exception occurred while
		 * building the above stack-frame.
		 */
		goto badframe;
	}
#endif /* CONFIG_UCLINUX */

	*pd0 = context.sc_d0;
	return err;

badframe:
	return 1;
}

static inline int
rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
		    struct ucontext *uc, int *pd0)
{
#ifndef CONFIG_UCLINUX
	int fsize;
#endif
	int temp;
	greg_t *gregs = uc->uc_mcontext.gregs;
	unsigned long usp;
	int err;

	err = __get_user(temp, &uc->uc_mcontext.version);
	if (temp != MCONTEXT_VERSION)
		goto badframe;
	/* restore passed registers */
	err |= __get_user(regs->d0, &gregs[0]);
	err |= __get_user(regs->d1, &gregs[1]);
	err |= __get_user(regs->d2, &gregs[2]);
	err |= __get_user(regs->d3, &gregs[3]);
	err |= __get_user(regs->d4, &gregs[4]);
	err |= __get_user(regs->d5, &gregs[5]);
	err |= __get_user(sw->d6, &gregs[6]);
	err |= __get_user(sw->d7, &gregs[7]);
	err |= __get_user(regs->a0, &gregs[8]);
	err |= __get_user(regs->a1, &gregs[9]);
	err |= __get_user(regs->a2, &gregs[10]);
	err |= __get_user(sw->a3, &gregs[11]);
	err |= __get_user(sw->a4, &gregs[12]);
	err |= __get_user(sw->a5, &gregs[13]);
	err |= __get_user(sw->a6, &gregs[14]);
	err |= __get_user(usp, &gregs[15]);
	wrusp(usp);
	err |= __get_user(regs->pc, &gregs[16]);
	err |= __get_user(temp, &gregs[17]);
	regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
	regs->orig_d0 = -1;		/* disable syscall checks */
#if DAVIDM /* ifdef uc_formatvec */
	err |= __get_user(temp, &uc->uc_formatvec);
#endif
	regs->format = temp >> 12;
	regs->vector = temp & 0xfff;

#if DAVIDM /* NO_FPU */
	err |= rt_restore_fpu_state(uc);
#endif

	if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
		goto badframe;

#ifndef CONFIG_UCLINUX
	fsize = frame_extra_sizes[regs->format];
	if (fsize < 0) {
		/*
		 * user process trying to return with weird frame format
		 */
#if DEBUG
		printk("user process returning with weird frame format\n");
#endif
		goto badframe;
	}

	/* OK.	Make room on the supervisor stack for the extra junk,
	 * if necessary.
	 */

	if (fsize) {
#define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
		__asm__ __volatile__
			("   movel %0,%/a0\n\t"
			 "   subl %1,%/a0\n\t"     /* make room on stack */
			 "   movel %/a0,%/sp\n\t"  /* set stack pointer */
			 /* move switch_stack and pt_regs */
			 "1: movel %0@+,%/a0@+\n\t"
			 "   dbra %2,1b\n\t"
			 "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
			 "   lsrl  #2,%1\n\t"
			 "   subql #1,%1\n\t"
			 "2: movesl %4@+,%2\n\t"
			 "3: movel %2,%/a0@+\n\t"
			 "   dbra %1,2b\n\t"
			 "   bral " SYMBOL_NAME_STR(ret_from_signal) "\n"
			 "4:\n"
			 ".section __ex_table,\"a\"\n"
			 "   .align 4\n"
			 "   .long 2b,4b\n"
			 "   .long 3b,4b\n"
			 ".previous"
			 : /* no outputs, it doesn't ever return */
			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
			   "n" (frame_offset), "a" (&uc->uc_extra)
			 : "a0");
#undef frame_offset
		/*
		 * If we ever get here an exception occurred while
		 * building the above stack-frame.
		 */
		goto badframe;
	}
#endif /* CONFIG_UCLINUX */

	*pd0 = regs->d0;
	return err;

badframe:
	return 1;
}

asmlinkage int do_sigreturn(unsigned long __unused)
{
	struct switch_stack *sw = (struct switch_stack *) &__unused;
	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
	unsigned long usp = rdusp();
	struct sigframe *frame = (struct sigframe *)(usp - 4);
	sigset_t set;
	int d0;

	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
	    (_NSIG_WORDS > 1 &&
	     __copy_from_user(&set.sig[1], &frame->extramask,
			      sizeof(frame->extramask))))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	current->blocked = set;
	recalc_sigpending(current);
	
	if (restore_sigcontext(regs, &frame->sc, frame + 1, &d0))
		goto badframe;
	return d0;

badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

asmlinkage int do_rt_sigreturn(unsigned long __unused)
{
	struct switch_stack *sw = (struct switch_stack *) &__unused;
	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
	unsigned long usp = rdusp();
	struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
	sigset_t set;
	int d0;

	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	current->blocked = set;
	recalc_sigpending(current);
	
	if (rt_restore_ucontext(regs, sw, &frame->uc, &d0))
		goto badframe;
	return d0;

badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

#ifndef NO_FPU
/*
 * Set up a signal frame.
 */

static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
{
	if (FPU_IS_EMU) {
		/* save registers */
		memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
		memcpy(sc->sc_fpregs, current->thread.fp, 24);
		return;
	}

	__asm__ volatile (".chip 68k/68881\n\t"
			  "fsave %0\n\t"
			  ".chip 68k"
			  : : "m" (*sc->sc_fpstate) : "memory");

	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
		fpu_version = sc->sc_fpstate[0];
		if (CPU_IS_020_OR_030 &&
		    regs->vector >= (VEC_FPBRUC * 4) &&
		    regs->vector <= (VEC_FPNAN * 4)) {
			/* Clear pending exception in 68882 idle frame */
			if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
				sc->sc_fpstate[0x38] |= 1 << 3;
		}
		__asm__ volatile (".chip 68k/68881\n\t"
				  "fmovemx %/fp0-%/fp1,%0\n\t"
				  "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t"
				  ".chip 68k"
				  : /* no outputs */
				  : "m" (*sc->sc_fpregs),
				    "m" (*sc->sc_fpcntl)
				  : "memory");
	}
}

static inline int rt_save_fpu_state(struct ucontext *uc, struct pt_regs *regs)
{
	unsigned char fpstate[FPCONTEXT_SIZE];
	int context_size = CPU_IS_060 ? 8 : 0;
	int err = 0;

	if (FPU_IS_EMU) {
		/* save fpu control register */
		err |= copy_to_user(&uc->uc_mcontext.fpregs.f_pcr,
				current->thread.fpcntl, 12);
		/* save all other fpu register */
		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
				current->thread.fp, 96);
		return err;
	}

	__asm__ volatile (".chip 68k/68881\n\t"
			  "fsave %0\n\t"
			  ".chip 68k"
			  : : "m" (*fpstate) : "memory");

	err |= __put_user(*(long *)fpstate, (long *)&uc->uc_fpstate);
	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
		fpregset_t fpregs;
		if (!CPU_IS_060)
			context_size = fpstate[1];
		fpu_version = fpstate[0];
		if (CPU_IS_020_OR_030 &&
		    regs->vector >= (VEC_FPBRUC * 4) &&
		    regs->vector <= (VEC_FPNAN * 4)) {
			/* Clear pending exception in 68882 idle frame */
			if (*(unsigned short *) fpstate == 0x1f38)
				fpstate[0x38] |= 1 << 3;
		}
		__asm__ volatile (".chip 68k/68881\n\t"
				  "fmovemx %/fp0-%/fp7,%0\n\t"
				  "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t"
				  ".chip 68k"
				  : /* no outputs */
				  : "m" (*fpregs.f_fpregs),
				    "m" (fpregs.f_pcr)
				  : "memory");
		err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
				    sizeof(fpregs));
	}
	if (context_size)
		err |= copy_to_user((long *)&uc->uc_fpstate + 1, fpstate + 4,
				    context_size);
	return err;
}

#endif

static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
			     unsigned long mask)
{
	sc->sc_mask = mask;
	sc->sc_usp = rdusp();
	sc->sc_d0 = regs->d0;
	sc->sc_d1 = regs->d1;
	sc->sc_a0 = regs->a0;
	sc->sc_a1 = regs->a1;
	sc->sc_sr = regs->sr;
	sc->sc_pc = regs->pc;
	sc->sc_formatvec = regs->format << 12 | regs->vector;
#ifndef NO_FPU
	save_fpu_state(sc, regs);
#endif
}

static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs)
{
	struct switch_stack *sw = (struct switch_stack *)regs - 1;
	greg_t *gregs = uc->uc_mcontext.gregs;
	int err = 0;

	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
	err |= __put_user(regs->d0, &gregs[0]);
	err |= __put_user(regs->d1, &gregs[1]);
	err |= __put_user(regs->d2, &gregs[2]);
	err |= __put_user(regs->d3, &gregs[3]);
	err |= __put_user(regs->d4, &gregs[4]);
	err |= __put_user(regs->d5, &gregs[5]);
	err |= __put_user(sw->d6, &gregs[6]);
	err |= __put_user(sw->d7, &gregs[7]);
	err |= __put_user(regs->a0, &gregs[8]);
	err |= __put_user(regs->a1, &gregs[9]);
	err |= __put_user(regs->a2, &gregs[10]);
	err |= __put_user(sw->a3, &gregs[11]);
	err |= __put_user(sw->a4, &gregs[12]);
	err |= __put_user(sw->a5, &gregs[13]);
	err |= __put_user(sw->a6, &gregs[14]);
	err |= __put_user(rdusp(), &gregs[15]);
	err |= __put_user(regs->pc, &gregs[16]);
	err |= __put_user(regs->sr, &gregs[17]);
#if DAVIDM /* ifdef uc_formatvec */
	err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
#endif
#ifndef NO_FPU
	err |= rt_save_fpu_state(uc, regs);
#endif
	return err;
}

static inline void push_cache (unsigned long vaddr)
{
#if 0 /* DAVIDM - implement this for 5407, maybe */
	/*
	 * Using the old cache_push_v() was really a big waste.
	 *
	 * What we are trying to do is to flush 8 bytes to ram.
	 * Flushing 2 cache lines of 16 bytes is much cheaper than
	 * flushing 1 or 2 pages, as previously done in
	 * cache_push_v().
	 *                                                     Jes
	 */
	if (CPU_IS_040) {
		unsigned long temp;

		__asm__ __volatile__ (".chip 68040\n\t"
				      "nop\n\t"
				      "ptestr (%1)\n\t"
				      "movec %%mmusr,%0\n\t"
				      ".chip 68k"
				      : "=r" (temp)
				      : "a" (vaddr));

		temp &= PAGE_MASK;
		temp |= vaddr & ~PAGE_MASK;

		__asm__ __volatile__ (".chip 68040\n\t"
				      "nop\n\t"
				      "cpushl %%bc,(%0)\n\t"
				      ".chip 68k"
				      : : "a" (temp));
	}
	else if (CPU_IS_060) {
		unsigned long temp;
		__asm__ __volatile__ (".chip 68060\n\t"
				      "plpar (%0)\n\t"
				      ".chip 68k"
				      : "=a" (temp)
				      : "0" (vaddr));
		__asm__ __volatile__ (".chip 68060\n\t"
				      "cpushl %%bc,(%0)\n\t"
				      ".chip 68k"
				      : : "a" (temp));
	}
	else {
		/*
		 * 68030/68020 have no writeback cache;
		 * still need to clear icache.
		 * Note that vaddr is guaranteed to be long word aligned.
		 */
		unsigned long temp;
		asm volatile ("movec %%cacr,%0" : "=r" (temp));
		temp += 4;
		asm volatile ("movec %0,%%caar\n\t"
			      "movec %1,%%cacr"
			      : : "r" (vaddr), "r" (temp));
		asm volatile ("movec %0,%%caar\n\t"
			      "movec %1,%%cacr"
			      : : "r" (vaddr + 4), "r" (temp));
	}
#endif
}

static inline void *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
{
	unsigned long usp;

	/* Default to using normal stack.  */
	usp = rdusp();

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (!on_sig_stack(usp))
			usp = current->sas_ss_sp + current->sas_ss_size;
	}
	return (void *)((usp - frame_size) & -8UL);
}

static void setup_frame (int sig, struct k_sigaction *ka,
			 sigset_t *set, struct pt_regs *regs)
{
	struct sigframe *frame;
	unsigned long a5;
#ifndef CONFIG_UCLINUX
	int fsize = frame_extra_sizes[regs->format];
#endif
	struct sigcontext context;
	int err = 0;