Commit f8d98f10 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
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x86: Fix to decode grouped AVX with VEX pp bits 



Fix to decode grouped AVX with VEX pp bits which should be
handled as same as last-prefixes. This fixes below warnings
in posttest with CONFIG_CRYPTO_SHA1_SSSE3=y.

 Warning: arch/x86/tools/test_get_len found difference at <sha1_transform_avx>:ffffffff810d5fc0
 Warning: ffffffff810d6069:	c5 f9 73 de 04       	vpsrldq $0x4,%xmm6,%xmm0
 Warning: objdump says 5 bytes, but insn_get_length() says 4
 ...

With this change, test_get_len can decode it correctly.

 $ arch/x86/tools/test_get_len -v -y
 ffffffff810d6069:       c5 f9 73 de 04          vpsrldq $0x4,%xmm6,%xmm0
 Succeed: decoded and checked 1 instructions

Reported-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120210053340.30429.73410.stgit@localhost.localdomain


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 86f5e6a7

arch/x86/include/asm/inat.h

+3 −2
Original line number Diff line number Diff line
@@ -97,11 +97,12 @@ 


/* Attribute search APIs */

extern insn_attr_t inat_get_opcode_attribute(insn_byte_t opcode);

extern int inat_get_last_prefix_id(insn_byte_t last_pfx);

extern insn_attr_t inat_get_escape_attribute(insn_byte_t opcode,

					     insn_byte_t last_pfx,

					     int lpfx_id,

					     insn_attr_t esc_attr);

extern insn_attr_t inat_get_group_attribute(insn_byte_t modrm,

					    insn_byte_t last_pfx,

					    int lpfx_id,

					    insn_attr_t esc_attr);

extern insn_attr_t inat_get_avx_attribute(insn_byte_t opcode,

					  insn_byte_t vex_m,

arch/x86/include/asm/insn.h

+12 −6
Original line number Diff line number Diff line
@@ -96,12 +96,6 @@ struct insn { 
#define X86_VEX_P(vex)	((vex) & 0x03)		/* VEX3 Byte2, VEX2 Byte1 */

#define X86_VEX_M_MAX	0x1f			/* VEX3.M Maximum value */



/* The last prefix is needed for two-byte and three-byte opcodes */

static inline insn_byte_t insn_last_prefix(struct insn *insn)

{

	return insn->prefixes.bytes[3];

}



extern void insn_init(struct insn *insn, const void *kaddr, int x86_64);

extern void insn_get_prefixes(struct insn *insn);

extern void insn_get_opcode(struct insn *insn);
@@ -160,6 +154,18 @@ static inline insn_byte_t insn_vex_p_bits(struct insn *insn) 
		return X86_VEX_P(insn->vex_prefix.bytes[2]);

}



/* Get the last prefix id from last prefix or VEX prefix */

static inline int insn_last_prefix_id(struct insn *insn)

{

	if (insn_is_avx(insn))

		return insn_vex_p_bits(insn);	/* VEX_p is a SIMD prefix id */



	if (insn->prefixes.bytes[3])

		return inat_get_last_prefix_id(insn->prefixes.bytes[3]);



	return 0;

}



/* Offset of each field from kaddr */

static inline int insn_offset_rex_prefix(struct insn *insn)

{

arch/x86/lib/inat.c

+18 −18
Original line number Diff line number Diff line
@@ -29,46 +29,46 @@ insn_attr_t inat_get_opcode_attribute(insn_byte_t opcode) 
	return inat_primary_table[opcode];

}



insn_attr_t inat_get_escape_attribute(insn_byte_t opcode, insn_byte_t last_pfx,

				      insn_attr_t esc_attr)

int inat_get_last_prefix_id(insn_byte_t last_pfx)

{

	const insn_attr_t *table;

	insn_attr_t lpfx_attr;

	int n, m = 0;



	n = inat_escape_id(esc_attr);

	if (last_pfx) {

	lpfx_attr = inat_get_opcode_attribute(last_pfx);

		m = inat_last_prefix_id(lpfx_attr);

	return inat_last_prefix_id(lpfx_attr);

}



insn_attr_t inat_get_escape_attribute(insn_byte_t opcode, int lpfx_id,

				      insn_attr_t esc_attr)

{

	const insn_attr_t *table;

	int n;



	n = inat_escape_id(esc_attr);



	table = inat_escape_tables[n][0];

	if (!table)

		return 0;

	if (inat_has_variant(table[opcode]) && m) {

		table = inat_escape_tables[n][m];

	if (inat_has_variant(table[opcode]) && lpfx_id) {

		table = inat_escape_tables[n][lpfx_id];

		if (!table)

			return 0;

	}

	return table[opcode];

}



insn_attr_t inat_get_group_attribute(insn_byte_t modrm, insn_byte_t last_pfx,

insn_attr_t inat_get_group_attribute(insn_byte_t modrm, int lpfx_id,

				     insn_attr_t grp_attr)

{

	const insn_attr_t *table;

	insn_attr_t lpfx_attr;

	int n, m = 0;

	int n;



	n = inat_group_id(grp_attr);

	if (last_pfx) {

		lpfx_attr = inat_get_opcode_attribute(last_pfx);

		m = inat_last_prefix_id(lpfx_attr);

	}



	table = inat_group_tables[n][0];

	if (!table)

		return inat_group_common_attribute(grp_attr);

	if (inat_has_variant(table[X86_MODRM_REG(modrm)]) && m) {

		table = inat_group_tables[n][m];

	if (inat_has_variant(table[X86_MODRM_REG(modrm)]) && lpfx_id) {

		table = inat_group_tables[n][lpfx_id];

		if (!table)

			return inat_group_common_attribute(grp_attr);

	}

arch/x86/lib/insn.c

+7 −6
Original line number Diff line number Diff line
@@ -185,7 +185,8 @@ err_out: 
void insn_get_opcode(struct insn *insn)

{

	struct insn_field *opcode = &insn->opcode;

	insn_byte_t op, pfx;

	insn_byte_t op;

	int pfx_id;

	if (opcode->got)

		return;

	if (!insn->prefixes.got)
@@ -212,8 +213,8 @@ void insn_get_opcode(struct insn *insn) 
		/* Get escaped opcode */

		op = get_next(insn_byte_t, insn);

		opcode->bytes[opcode->nbytes++] = op;

		pfx = insn_last_prefix(insn);

		insn->attr = inat_get_escape_attribute(op, pfx, insn->attr);

		pfx_id = insn_last_prefix_id(insn);

		insn->attr = inat_get_escape_attribute(op, pfx_id, insn->attr);

	}

	if (inat_must_vex(insn->attr))

		insn->attr = 0;	/* This instruction is bad */
@@ -235,7 +236,7 @@ err_out: 
void insn_get_modrm(struct insn *insn)

{

	struct insn_field *modrm = &insn->modrm;

	insn_byte_t pfx, mod;

	insn_byte_t pfx_id, mod;

	if (modrm->got)

		return;

	if (!insn->opcode.got)
@@ -246,8 +247,8 @@ void insn_get_modrm(struct insn *insn) 
		modrm->value = mod;

		modrm->nbytes = 1;

		if (inat_is_group(insn->attr)) {

			pfx = insn_last_prefix(insn);

			insn->attr = inat_get_group_attribute(mod, pfx,

			pfx_id = insn_last_prefix_id(insn);

			insn->attr = inat_get_group_attribute(mod, pfx_id,

							      insn->attr);

			if (insn_is_avx(insn) && !inat_accept_vex(insn->attr))

				insn->attr = 0;	/* This is bad */

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