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x86/insn: Support big endian cross-compiles

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The x86 instruction decoder code is shared across the kernel source and
the tools. Currently objtool seems to be the only tool from build tools
needed which breaks x86 cross-compilation on big endian systems. Make
the x86 instruction decoder build host endianness agnostic to support
x86 cross-compilation and enable objtool to implement endianness
awareness for big endian architectures support.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Co-developed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
This commit is contained in:
Martin Schwidefsky 2020-11-13 00:03:23 +01:00 committed by Josh Poimboeuf
parent c8d7b7e592
commit 1d509f2a6e
5 changed files with 160 additions and 112 deletions
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33
arch/x86/include/asm/insn.h
View file

@ -7,9 +7,12 @@
* Copyright (C) IBM Corporation, 2009
*/
#include <asm/byteorder.h>
/* insn_attr_t is defined in inat.h */
#include <asm/inat.h>
#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
struct insn_field {
union {
insn_value_t value;
@ -20,6 +23,36 @@ struct insn_field {
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->nbytes = n;
}
#else
struct insn_field {
insn_value_t value;
union {
insn_value_t little;
insn_byte_t bytes[4];
};
/* !0 if we've run insn_get_xxx() for this field */
unsigned char got;
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->little = __cpu_to_le32(v);
p->nbytes = n;
}
#endif
struct insn {
struct insn_field prefixes; /*
* Prefixes

101
arch/x86/lib/insn.c
View file

@ -5,6 +5,7 @@
* Copyright (C) IBM Corporation, 2002, 2004, 2009
*/
#include <linux/kernel.h>
#ifdef __KERNEL__
#include <linux/string.h>
#else
@ -15,15 +16,28 @@
#include <asm/emulate_prefix.h>
#define leXX_to_cpu(t, r) \
({ \
__typeof__(t) v; \
switch (sizeof(t)) { \
case 4: v = le32_to_cpu(r); break; \
case 2: v = le16_to_cpu(r); break; \
case 1: v = r; break; \
default: \
BUILD_BUG(); break; \
} \
v; \
})
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
#define __get_next(t, insn) \
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); leXX_to_cpu(t, r); })
#define __peek_nbyte_next(t, insn, n) \
({ t r = *(t*)((insn)->next_byte + n); r; })
({ t r = *(t*)((insn)->next_byte + n); leXX_to_cpu(t, r); })
#define get_next(t, insn) \
({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); })
@ -157,8 +171,7 @@ void insn_get_prefixes(struct insn *insn)
b = peek_next(insn_byte_t, insn);
attr = inat_get_opcode_attribute(b);
if (inat_is_rex_prefix(attr)) {
insn->rex_prefix.value = b;
insn->rex_prefix.nbytes = 1;
insn_field_set(&insn->rex_prefix, b, 1);
insn->next_byte++;
if (X86_REX_W(b))
/* REX.W overrides opnd_size */
@ -295,8 +308,7 @@ void insn_get_modrm(struct insn *insn)
if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
modrm->value = mod;
modrm->nbytes = 1;
insn_field_set(modrm, mod, 1);
if (inat_is_group(insn->attr)) {
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_group_attribute(mod, pfx_id,
@ -334,7 +346,7 @@ int insn_rip_relative(struct insn *insn)
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
*/
return (modrm->nbytes && (modrm->value & 0xc7) == 0x5);
return (modrm->nbytes && (modrm->bytes[0] & 0xc7) == 0x5);
}
/**
@ -353,11 +365,11 @@ void insn_get_sib(struct insn *insn)
if (!insn->modrm.got)
insn_get_modrm(insn);
if (insn->modrm.nbytes) {
modrm = (insn_byte_t)insn->modrm.value;
modrm = insn->modrm.bytes[0];
if (insn->addr_bytes != 2 &&
X86_MODRM_MOD(modrm) != 3 && X86_MODRM_RM(modrm) == 4) {
insn->sib.value = get_next(insn_byte_t, insn);
insn->sib.nbytes = 1;
insn_field_set(&insn->sib,
get_next(insn_byte_t, insn), 1);
}
}
insn->sib.got = 1;
@ -407,19 +419,18 @@ void insn_get_displacement(struct insn *insn)
if (mod == 3)
goto out;
if (mod == 1) {
insn->displacement.value = get_next(signed char, insn);
insn->displacement.nbytes = 1;
insn_field_set(&insn->displacement,
get_next(signed char, insn), 1);
} else if (insn->addr_bytes == 2) {
if ((mod == 0 && rm == 6) || mod == 2) {
insn->displacement.value =
get_next(short, insn);
insn->displacement.nbytes = 2;
insn_field_set(&insn->displacement,
get_next(short, insn), 2);
}
} else {
if ((mod == 0 && rm == 5) || mod == 2 ||
(mod == 0 && base == 5)) {
insn->displacement.value = get_next(int, insn);
insn->displacement.nbytes = 4;
insn_field_set(&insn->displacement,
get_next(int, insn), 4);
}
}
}
@ -435,18 +446,14 @@ static int __get_moffset(struct insn *insn)
{
switch (insn->addr_bytes) {
case 2:
insn->moffset1.value = get_next(short, insn);
insn->moffset1.nbytes = 2;
insn_field_set(&insn->moffset1, get_next(short, insn), 2);
break;
case 4:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
break;
case 8:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn->moffset2.value = get_next(int, insn);
insn->moffset2.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
insn_field_set(&insn->moffset2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -464,13 +471,11 @@ static int __get_immv32(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case 4:
case 8:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -487,18 +492,15 @@ static int __get_immv(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn->immediate1.nbytes = 4;
break;
case 8:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -515,12 +517,10 @@ static int __get_immptr(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
break;
case 8:
/* ptr16:64 is not exist (no segment) */
@ -528,8 +528,7 @@ static int __get_immptr(struct insn *insn)
default: /* opnd_bytes must be modified manually */
goto err_out;
}
insn->immediate2.value = get_next(unsigned short, insn);
insn->immediate2.nbytes = 2;
insn_field_set(&insn->immediate2, get_next(unsigned short, insn), 2);
insn->immediate1.got = insn->immediate2.got = 1;
return 1;
@ -565,22 +564,17 @@ void insn_get_immediate(struct insn *insn)
switch (inat_immediate_size(insn->attr)) {
case INAT_IMM_BYTE:
insn->immediate.value = get_next(signed char, insn);
insn->immediate.nbytes = 1;
insn_field_set(&insn->immediate, get_next(signed char, insn), 1);
break;
case INAT_IMM_WORD:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case INAT_IMM_DWORD:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
case INAT_IMM_QWORD:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
case INAT_IMM_PTR:
if (!__get_immptr(insn))
@ -599,8 +593,7 @@ void insn_get_immediate(struct insn *insn)
goto err_out;
}
if (inat_has_second_immediate(insn->attr)) {
insn->immediate2.value = get_next(signed char, insn);
insn->immediate2.nbytes = 1;
insn_field_set(&insn->immediate2, get_next(signed char, insn), 1);
}
done:
insn->immediate.got = 1;

4
arch/x86/tools/insn_sanity.c
View file

@ -14,10 +14,6 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define unlikely(cond) (cond)
#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
#include <asm/insn.h>
#include <inat.c>
#include <insn.c>

33
tools/arch/x86/include/asm/insn.h
View file

@ -7,9 +7,12 @@
* Copyright (C) IBM Corporation, 2009
*/
#include <asm/byteorder.h>
/* insn_attr_t is defined in inat.h */
#include "inat.h"
#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
struct insn_field {
union {
insn_value_t value;
@ -20,6 +23,36 @@ struct insn_field {
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->nbytes = n;
}
#else
struct insn_field {
insn_value_t value;
union {
insn_value_t little;
insn_byte_t bytes[4];
};
/* !0 if we've run insn_get_xxx() for this field */
unsigned char got;
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->little = __cpu_to_le32(v);
p->nbytes = n;
}
#endif
struct insn {
struct insn_field prefixes; /*
* Prefixes

101
tools/arch/x86/lib/insn.c
View file

@ -5,6 +5,7 @@
* Copyright (C) IBM Corporation, 2002, 2004, 2009
*/
#include <linux/kernel.h>
#ifdef __KERNEL__
#include <linux/string.h>
#else
@ -15,15 +16,28 @@
#include "../include/asm/emulate_prefix.h"
#define leXX_to_cpu(t, r) \
({ \
__typeof__(t) v; \
switch (sizeof(t)) { \
case 4: v = le32_to_cpu(r); break; \
case 2: v = le16_to_cpu(r); break; \
case 1: v = r; break; \
default: \
BUILD_BUG(); break; \
} \
v; \
})
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
#define __get_next(t, insn) \
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); leXX_to_cpu(t, r); })
#define __peek_nbyte_next(t, insn, n) \
({ t r = *(t*)((insn)->next_byte + n); r; })
({ t r = *(t*)((insn)->next_byte + n); leXX_to_cpu(t, r); })
#define get_next(t, insn) \
({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); })
@ -157,8 +171,7 @@ void insn_get_prefixes(struct insn *insn)
b = peek_next(insn_byte_t, insn);
attr = inat_get_opcode_attribute(b);
if (inat_is_rex_prefix(attr)) {
insn->rex_prefix.value = b;
insn->rex_prefix.nbytes = 1;
insn_field_set(&insn->rex_prefix, b, 1);
insn->next_byte++;
if (X86_REX_W(b))
/* REX.W overrides opnd_size */
@ -295,8 +308,7 @@ void insn_get_modrm(struct insn *insn)
if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
modrm->value = mod;
modrm->nbytes = 1;
insn_field_set(modrm, mod, 1);
if (inat_is_group(insn->attr)) {
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_group_attribute(mod, pfx_id,
@ -334,7 +346,7 @@ int insn_rip_relative(struct insn *insn)
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
*/
return (modrm->nbytes && (modrm->value & 0xc7) == 0x5);
return (modrm->nbytes && (modrm->bytes[0] & 0xc7) == 0x5);
}
/**
@ -353,11 +365,11 @@ void insn_get_sib(struct insn *insn)
if (!insn->modrm.got)
insn_get_modrm(insn);
if (insn->modrm.nbytes) {
modrm = (insn_byte_t)insn->modrm.value;
modrm = insn->modrm.bytes[0];
if (insn->addr_bytes != 2 &&
X86_MODRM_MOD(modrm) != 3 && X86_MODRM_RM(modrm) == 4) {
insn->sib.value = get_next(insn_byte_t, insn);
insn->sib.nbytes = 1;
insn_field_set(&insn->sib,
get_next(insn_byte_t, insn), 1);
}
}
insn->sib.got = 1;
@ -407,19 +419,18 @@ void insn_get_displacement(struct insn *insn)
if (mod == 3)
goto out;
if (mod == 1) {
insn->displacement.value = get_next(signed char, insn);
insn->displacement.nbytes = 1;
insn_field_set(&insn->displacement,
get_next(signed char, insn), 1);
} else if (insn->addr_bytes == 2) {
if ((mod == 0 && rm == 6) || mod == 2) {
insn->displacement.value =
get_next(short, insn);
insn->displacement.nbytes = 2;
insn_field_set(&insn->displacement,
get_next(short, insn), 2);
}
} else {
if ((mod == 0 && rm == 5) || mod == 2 ||
(mod == 0 && base == 5)) {
insn->displacement.value = get_next(int, insn);
insn->displacement.nbytes = 4;
insn_field_set(&insn->displacement,
get_next(int, insn), 4);
}
}
}
@ -435,18 +446,14 @@ static int __get_moffset(struct insn *insn)
{
switch (insn->addr_bytes) {
case 2:
insn->moffset1.value = get_next(short, insn);
insn->moffset1.nbytes = 2;
insn_field_set(&insn->moffset1, get_next(short, insn), 2);
break;
case 4:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
break;
case 8:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn->moffset2.value = get_next(int, insn);
insn->moffset2.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
insn_field_set(&insn->moffset2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -464,13 +471,11 @@ static int __get_immv32(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case 4:
case 8:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -487,18 +492,15 @@ static int __get_immv(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn->immediate1.nbytes = 4;
break;
case 8:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -515,12 +517,10 @@ static int __get_immptr(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
break;
case 8:
/* ptr16:64 is not exist (no segment) */
@ -528,8 +528,7 @@ static int __get_immptr(struct insn *insn)
default: /* opnd_bytes must be modified manually */
goto err_out;
}
insn->immediate2.value = get_next(unsigned short, insn);
insn->immediate2.nbytes = 2;
insn_field_set(&insn->immediate2, get_next(unsigned short, insn), 2);
insn->immediate1.got = insn->immediate2.got = 1;
return 1;
@ -565,22 +564,17 @@ void insn_get_immediate(struct insn *insn)
switch (inat_immediate_size(insn->attr)) {
case INAT_IMM_BYTE:
insn->immediate.value = get_next(signed char, insn);
insn->immediate.nbytes = 1;
insn_field_set(&insn->immediate, get_next(signed char, insn), 1);
break;
case INAT_IMM_WORD:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case INAT_IMM_DWORD:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
case INAT_IMM_QWORD:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
case INAT_IMM_PTR:
if (!__get_immptr(insn))
@ -599,8 +593,7 @@ void insn_get_immediate(struct insn *insn)
goto err_out;
}
if (inat_has_second_immediate(insn->attr)) {
insn->immediate2.value = get_next(signed char, insn);
insn->immediate2.nbytes = 1;
insn_field_set(&insn->immediate2, get_next(signed char, insn), 1);
}
done:
insn->immediate.got = 1;