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Commit cf87c3f6 authored by Paul Mackerras's avatar Paul Mackerras Committed by Michael Ellerman
Browse files

powerpc: Emulate icbi, mcrf and conditional-trap instructions 



This extends the instruction emulation done by analyse_instr() and
emulate_step() to handle a few more instructions that are found in
the kernel.

Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent be96f633

arch/powerpc/include/asm/sstep.h

+1 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ enum instruction_type { 
#define DCBF		0x100

#define DCBTST		0x200

#define DCBT		0x300

#define ICBI		0x400



/* Size field in type word */

#define SIZE(n)		((n) << 8)

arch/powerpc/lib/sstep.c

+60 −0
Original line number Diff line number Diff line
@@ -600,6 +600,23 @@ static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1, 
	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);

}



static int __kprobes trap_compare(long v1, long v2)

{

	int ret = 0;



	if (v1 < v2)

		ret |= 0x10;

	else if (v1 > v2)

		ret |= 0x08;

	else

		ret |= 0x04;

	if ((unsigned long)v1 < (unsigned long)v2)

		ret |= 0x02;

	else if ((unsigned long)v1 > (unsigned long)v2)

		ret |= 0x01;

	return ret;

}



/*

 * Elements of 32-bit rotate and mask instructions.

 */
@@ -669,6 +686,13 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs, 
		return 1;

	case 19:

		switch ((instr >> 1) & 0x3ff) {

		case 0:		/* mcrf */

			rd = (instr >> 21) & 0x1c;

			ra = (instr >> 16) & 0x1c;

			val = (regs->ccr >> ra) & 0xf;

			regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd);

			goto instr_done;



		case 16:	/* bclr */

		case 528:	/* bcctr */

			op->type = BRANCH;
@@ -745,6 +769,17 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs, 
	rb = (instr >> 11) & 0x1f;



	switch (opcode) {

#ifdef __powerpc64__

	case 2:		/* tdi */

		if (rd & trap_compare(regs->gpr[ra], (short) instr))

			goto trap;

		goto instr_done;

#endif

	case 3:		/* twi */

		if (rd & trap_compare((int)regs->gpr[ra], (short) instr))

			goto trap;

		goto instr_done;



	case 7:		/* mulli */

		regs->gpr[rd] = regs->gpr[ra] * (short) instr;

		goto instr_done;
@@ -893,6 +928,18 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs, 


	case 31:

		switch ((instr >> 1) & 0x3ff) {

		case 4:		/* tw */

			if (rd == 0x1f ||

			    (rd & trap_compare((int)regs->gpr[ra],

					       (int)regs->gpr[rb])))

				goto trap;

			goto instr_done;

#ifdef __powerpc64__

		case 68:	/* td */

			if (rd & trap_compare(regs->gpr[ra], regs->gpr[rb]))

				goto trap;

			goto instr_done;

#endif

		case 83:	/* mfmsr */

			if (regs->msr & MSR_PR)

				goto priv;
@@ -1269,6 +1316,11 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs, 
			op->ea = xform_ea(instr, regs);

			op->reg = rd;

			return 0;



		case 982:	/* icbi */

			op->type = MKOP(CACHEOP, ICBI, 0);

			op->ea = xform_ea(instr, regs);

			return 0;

		}

		break;

	}
@@ -1597,6 +1649,11 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs, 
	op->val = SRR1_PROGPRIV;

	return 0;



 trap:

	op->type = INTERRUPT | 0x700;

	op->val = SRR1_PROGTRAP;

	return 0;



#ifdef CONFIG_PPC_FPU

 fpunavail:

	op->type = INTERRUPT | 0x800;
@@ -1714,6 +1771,9 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) 
			if (op.reg == 0)

				prefetch((void *) op.ea);

			break;

		case ICBI:

			__cacheop_user_asmx(op.ea, err, "icbi");

			break;

		}

		if (err)

			return 0;