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Commit 6d615c78 authored by David Howells's avatar David Howells Committed by Linus Torvalds
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MN10300: Handle misaligned postinc-with-imm addressing mode correctly 



Correctly handle misalignment in MOV instructions with postinc-with-immediate
addressing mode operands.  In these, the immediate value is the increment to
be applied the address register, not the displacement to the address.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ddb6d05c

arch/mn10300/mm/misalignment.c

+56 −51
Original line number Diff line number Diff line
@@ -44,7 +44,8 @@ 


static int misalignment_addr(unsigned long *registers, unsigned params,

			     unsigned opcode, unsigned long disp,

			     void **_address, unsigned long **_postinc);

			     void **_address, unsigned long **_postinc,

			     unsigned long *_inc);



static int misalignment_reg(unsigned long *registers, unsigned params,

			    unsigned opcode, unsigned long disp,
@@ -150,7 +151,7 @@ enum value_id { 
};



struct mn10300_opcode {

	const char	*name;

	const char	name[8];

	u_int32_t	opcode;

	u_int32_t	opmask;

	unsigned	exclusion;
@@ -310,7 +311,7 @@ static const struct mn10300_opcode mn10300_opcodes[] = { 
{ "mov_lne",	0xf7e00009,  0xffff000f,  0x22, FMT_D10, AM33,	 {MEMINC2 (RN4,SIMM4_2), RM6}},

{ "mov_lra",	0xf7e0000a,  0xffff000f,  0x22, FMT_D10, AM33,	 {MEMINC2 (RN4,SIMM4_2), RM6}},



{ 0, 0, 0, 0, 0, 0, {0}},

{ "", 0, 0, 0, 0, 0, {0}},

};



/*
@@ -321,11 +322,11 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code) 
	const struct exception_table_entry *fixup;

	const struct mn10300_opcode *pop;

	unsigned long *registers = (unsigned long *) regs;

	unsigned long data, *store, *postinc, disp;

	unsigned long data, *store, *postinc, disp, inc;

	mm_segment_t seg;

	siginfo_t info;

	uint32_t opcode, noc, xo, xm;

	uint8_t *pc, byte;

	uint8_t *pc, byte, datasz;

	void *address;

	unsigned tmp, npop, dispsz, loop;
@@ -347,7 +348,7 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code) 
	opcode = byte;

	noc = 8;



	for (pop = mn10300_opcodes; pop->name; pop++) {

	for (pop = mn10300_opcodes; pop->name[0]; pop++) {

		npop = ilog2(pop->opcode | pop->opmask);

		if (npop <= 0 || npop > 31)

			continue;
@@ -484,32 +485,31 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code) 
		goto failed;

	}



	/* determine the data transfer size of the move */

	if (pop->name[3] == 0 || /* "mov" */

	    pop->name[4] == 'l') /* mov_lcc */

		inc = datasz = 4;

	else if (pop->name[3] == 'h') /* movhu */

		inc = datasz = 2;

	else

		goto unsupported_instruction;



	if (pop->params[0] & 0x80000000) {

		/* move memory to register */

		if (!misalignment_addr(registers, pop->params[0], opcode, disp,

				       &address, &postinc))

				       &address, &postinc, &inc))

			goto bad_addr_mode;



		if (!misalignment_reg(registers, pop->params[1], opcode, disp,

				      &store))

			goto bad_reg_mode;



		if (strcmp(pop->name, "mov") == 0 ||

		    memcmp(pop->name, "mov_l", 5) == 0) {

			kdebug("mov (%p),DARn", address);

			if (copy_from_user(&data, (void *) address, 4) != 0)

				goto transfer_failed;

			if (pop->params[0] & 0x1000000)

				*postinc += 4;

		} else if (strcmp(pop->name, "movhu") == 0) {

			kdebug("movhu (%p),DARn", address);

			data = 0;

			if (copy_from_user(&data, (void *) address, 2) != 0)

		kdebug("mov%u (%p),DARn", datasz, address);

		if (copy_from_user(&data, (void *) address, datasz) != 0)

			goto transfer_failed;

			if (pop->params[0] & 0x1000000)

				*postinc += 2;

		} else {

			goto unsupported_instruction;

		if (pop->params[0] & 0x1000000) {

			kdebug("inc=%lx", inc);

			*postinc += inc;

		}



		*store = data;
@@ -521,26 +521,16 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code) 
			goto bad_reg_mode;



		if (!misalignment_addr(registers, pop->params[1], opcode, disp,

				       &address, &postinc))

				       &address, &postinc, &inc))

			goto bad_addr_mode;



		data = *store;



		if (strcmp(pop->name, "mov") == 0) {

			kdebug("mov %lx,(%p)", data, address);

			if (copy_to_user((void *) address, &data, 4) != 0)

		kdebug("mov%u %lx,(%p)", datasz, data, address);

		if (copy_to_user((void *) address, &data, datasz) != 0)

			goto transfer_failed;

		if (pop->params[1] & 0x1000000)

				*postinc += 4;

		} else if (strcmp(pop->name, "movhu") == 0) {

			kdebug("movhu %hx,(%p)", (uint16_t) data, address);

			if (copy_to_user((void *) address, &data, 2) != 0)

				goto transfer_failed;

			if (pop->params[1] & 0x1000000)

				*postinc += 2;

		} else {

			goto unsupported_instruction;

		}

			*postinc += inc;

	}



	tmp = format_tbl[pop->format].opsz + format_tbl[pop->format].dispsz;
@@ -560,10 +550,17 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code) 
 */

static int misalignment_addr(unsigned long *registers, unsigned params,

			     unsigned opcode, unsigned long disp,

			     void **_address, unsigned long **_postinc)

			     void **_address, unsigned long **_postinc,

			     unsigned long *_inc)

{

	unsigned long *postinc = NULL, address = 0, tmp;



	if (!(params & 0x1000000)) {

		kdebug("noinc");

		*_inc = 0;

		_inc = NULL;

	}



	params &= 0x00ffffff;



	do {
@@ -624,32 +621,40 @@ static int misalignment_addr(unsigned long *registers, unsigned params, 
			address += registers[REG_SP >> 2];

			break;



			/* displacements are either to be added to the address

			 * before use, or, in the case of post-inc addressing,

			 * to be added into the base register after use */

		case SD8:

		case SIMM8:

			address += (int32_t) (int8_t) (disp & 0xff);

			break;

			disp = (long) (int8_t) (disp & 0xff);

			goto displace_or_inc;

		case SD16:

			address += (int32_t) (int16_t) (disp & 0xffff);

			break;

			disp = (long) (int16_t) (disp & 0xffff);

			goto displace_or_inc;

		case SD24:

			tmp = disp << 8;

			asm("asr 8,%0" : "=r"(tmp) : "0"(tmp));

			address += tmp;

			break;

			disp = (long) tmp;

			goto displace_or_inc;

		case SIMM4_2:

			tmp = opcode >> 4 & 0x0f;

			tmp <<= 28;

			asm("asr 28,%0" : "=r"(tmp) : "0"(tmp));

			address += tmp;

			break;

			disp = (long) tmp;

			goto displace_or_inc;

		case IMM24:

			address += disp & 0x00ffffff;

			break;

			disp &= 0x00ffffff;

			goto displace_or_inc;

		case IMM32:

		case IMM32_MEM:

		case IMM32_HIGH8:

		case IMM32_HIGH8_MEM:

		displace_or_inc:

			kdebug("%s %lx", _inc ? "incr" : "disp", disp);

			if (!_inc)

				address += disp;

			else

				*_inc = disp;

			break;

		default:

			BUG();