diff options
Diffstat (limited to 'tools/arch')
| -rw-r--r-- | tools/arch/x86/include/asm/inat.h | 2 | ||||
| -rw-r--r-- | tools/arch/x86/include/asm/insn.h | 46 | ||||
| -rw-r--r-- | tools/arch/x86/include/asm/nops.h | 81 | ||||
| -rw-r--r-- | tools/arch/x86/lib/inat.c | 2 | ||||
| -rw-r--r-- | tools/arch/x86/lib/insn.c | 230 |
5 files changed, 285 insertions, 76 deletions
diff --git a/tools/arch/x86/include/asm/inat.h b/tools/arch/x86/include/asm/inat.h index 877827b7c2c3..a61051400311 100644 --- a/tools/arch/x86/include/asm/inat.h +++ b/tools/arch/x86/include/asm/inat.h @@ -6,7 +6,7 @@ * * Written by Masami Hiramatsu <mhiramat@redhat.com> */ -#include "inat_types.h" +#include "inat_types.h" /* __ignore_sync_check__ */ /* * Internal bits. Don't use bitmasks directly, because these bits are diff --git a/tools/arch/x86/include/asm/insn.h b/tools/arch/x86/include/asm/insn.h index cc777c185212..dc632b41f135 100644 --- a/tools/arch/x86/include/asm/insn.h +++ b/tools/arch/x86/include/asm/insn.h @@ -9,7 +9,7 @@ #include <asm/byteorder.h> /* insn_attr_t is defined in inat.h */ -#include "inat.h" +#include "inat.h" /* __ignore_sync_check__ */ #if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN) @@ -132,13 +132,25 @@ struct insn { #define X86_VEX_M_MAX 0x1f /* VEX3.M Maximum value */ extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64); -extern void insn_get_prefixes(struct insn *insn); -extern void insn_get_opcode(struct insn *insn); -extern void insn_get_modrm(struct insn *insn); -extern void insn_get_sib(struct insn *insn); -extern void insn_get_displacement(struct insn *insn); -extern void insn_get_immediate(struct insn *insn); -extern void insn_get_length(struct insn *insn); +extern int insn_get_prefixes(struct insn *insn); +extern int insn_get_opcode(struct insn *insn); +extern int insn_get_modrm(struct insn *insn); +extern int insn_get_sib(struct insn *insn); +extern int insn_get_displacement(struct insn *insn); +extern int insn_get_immediate(struct insn *insn); +extern int insn_get_length(struct insn *insn); + +enum insn_mode { + INSN_MODE_32, + INSN_MODE_64, + /* Mode is determined by the current kernel build. */ + INSN_MODE_KERN, + INSN_NUM_MODES, +}; + +extern int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m); + +#define insn_decode_kernel(_insn, _ptr) insn_decode((_insn), (_ptr), MAX_INSN_SIZE, INSN_MODE_KERN) /* Attribute will be determined after getting ModRM (for opcode groups) */ static inline void insn_get_attribute(struct insn *insn) @@ -149,17 +161,6 @@ static inline void insn_get_attribute(struct insn *insn) /* Instruction uses RIP-relative addressing */ extern int insn_rip_relative(struct insn *insn); -/* Init insn for kernel text */ -static inline void kernel_insn_init(struct insn *insn, - const void *kaddr, int buf_len) -{ -#ifdef CONFIG_X86_64 - insn_init(insn, kaddr, buf_len, 1); -#else /* CONFIG_X86_32 */ - insn_init(insn, kaddr, buf_len, 0); -#endif -} - static inline int insn_is_avx(struct insn *insn) { if (!insn->prefixes.got) @@ -179,13 +180,6 @@ static inline int insn_has_emulate_prefix(struct insn *insn) return !!insn->emulate_prefix_size; } -/* Ensure this instruction is decoded completely */ -static inline int insn_complete(struct insn *insn) -{ - return insn->opcode.got && insn->modrm.got && insn->sib.got && - insn->displacement.got && insn->immediate.got; -} - static inline insn_byte_t insn_vex_m_bits(struct insn *insn) { if (insn->vex_prefix.nbytes == 2) /* 2 bytes VEX */ diff --git a/tools/arch/x86/include/asm/nops.h b/tools/arch/x86/include/asm/nops.h new file mode 100644 index 000000000000..c1e5e818ba16 --- /dev/null +++ b/tools/arch/x86/include/asm/nops.h @@ -0,0 +1,81 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_NOPS_H +#define _ASM_X86_NOPS_H + +/* + * Define nops for use with alternative() and for tracing. + */ + +#ifndef CONFIG_64BIT + +/* + * Generic 32bit nops from GAS: + * + * 1: nop + * 2: movl %esi,%esi + * 3: leal 0x0(%esi),%esi + * 4: leal 0x0(%esi,%eiz,1),%esi + * 5: leal %ds:0x0(%esi,%eiz,1),%esi + * 6: leal 0x0(%esi),%esi + * 7: leal 0x0(%esi,%eiz,1),%esi + * 8: leal %ds:0x0(%esi,%eiz,1),%esi + * + * Except 5 and 8, which are DS prefixed 4 and 7 resp, where GAS would emit 2 + * nop instructions. + */ +#define BYTES_NOP1 0x90 +#define BYTES_NOP2 0x89,0xf6 +#define BYTES_NOP3 0x8d,0x76,0x00 +#define BYTES_NOP4 0x8d,0x74,0x26,0x00 +#define BYTES_NOP5 0x3e,BYTES_NOP4 +#define BYTES_NOP6 0x8d,0xb6,0x00,0x00,0x00,0x00 +#define BYTES_NOP7 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00 +#define BYTES_NOP8 0x3e,BYTES_NOP7 + +#else + +/* + * Generic 64bit nops from GAS: + * + * 1: nop + * 2: osp nop + * 3: nopl (%eax) + * 4: nopl 0x00(%eax) + * 5: nopl 0x00(%eax,%eax,1) + * 6: osp nopl 0x00(%eax,%eax,1) + * 7: nopl 0x00000000(%eax) + * 8: nopl 0x00000000(%eax,%eax,1) + */ +#define BYTES_NOP1 0x90 +#define BYTES_NOP2 0x66,BYTES_NOP1 +#define BYTES_NOP3 0x0f,0x1f,0x00 +#define BYTES_NOP4 0x0f,0x1f,0x40,0x00 +#define BYTES_NOP5 0x0f,0x1f,0x44,0x00,0x00 +#define BYTES_NOP6 0x66,BYTES_NOP5 +#define BYTES_NOP7 0x0f,0x1f,0x80,0x00,0x00,0x00,0x00 +#define BYTES_NOP8 0x0f,0x1f,0x84,0x00,0x00,0x00,0x00,0x00 + +#endif /* CONFIG_64BIT */ + +#ifdef __ASSEMBLY__ +#define _ASM_MK_NOP(x) .byte x +#else +#define _ASM_MK_NOP(x) ".byte " __stringify(x) "\n" +#endif + +#define ASM_NOP1 _ASM_MK_NOP(BYTES_NOP1) +#define ASM_NOP2 _ASM_MK_NOP(BYTES_NOP2) +#define ASM_NOP3 _ASM_MK_NOP(BYTES_NOP3) +#define ASM_NOP4 _ASM_MK_NOP(BYTES_NOP4) +#define ASM_NOP5 _ASM_MK_NOP(BYTES_NOP5) +#define ASM_NOP6 _ASM_MK_NOP(BYTES_NOP6) +#define ASM_NOP7 _ASM_MK_NOP(BYTES_NOP7) +#define ASM_NOP8 _ASM_MK_NOP(BYTES_NOP8) + +#define ASM_NOP_MAX 8 + +#ifndef __ASSEMBLY__ +extern const unsigned char * const x86_nops[]; +#endif + +#endif /* _ASM_X86_NOPS_H */ diff --git a/tools/arch/x86/lib/inat.c b/tools/arch/x86/lib/inat.c index 4f5ed49e1b4e..dfbcc6405941 100644 --- a/tools/arch/x86/lib/inat.c +++ b/tools/arch/x86/lib/inat.c @@ -4,7 +4,7 @@ * * Written by Masami Hiramatsu <mhiramat@redhat.com> */ -#include "../include/asm/insn.h" +#include "../include/asm/insn.h" /* __ignore_sync_check__ */ /* Attribute tables are generated from opcode map */ #include "inat-tables.c" diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c index 3d9355ed1246..c41f95815480 100644 --- a/tools/arch/x86/lib/insn.c +++ b/tools/arch/x86/lib/insn.c @@ -11,10 +11,13 @@ #else #include <string.h> #endif -#include "../include/asm/inat.h" -#include "../include/asm/insn.h" +#include "../include/asm/inat.h" /* __ignore_sync_check__ */ +#include "../include/asm/insn.h" /* __ignore_sync_check__ */ -#include "../include/asm/emulate_prefix.h" +#include <linux/errno.h> +#include <linux/kconfig.h> + +#include "../include/asm/emulate_prefix.h" /* __ignore_sync_check__ */ #define leXX_to_cpu(t, r) \ ({ \ @@ -51,6 +54,7 @@ * insn_init() - initialize struct insn * @insn: &struct insn to be initialized * @kaddr: address (in kernel memory) of instruction (or copy thereof) + * @buf_len: length of the insn buffer at @kaddr * @x86_64: !0 for 64-bit kernel or 64-bit app */ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64) @@ -111,8 +115,12 @@ static void insn_get_emulate_prefix(struct insn *insn) * Populates the @insn->prefixes bitmap, and updates @insn->next_byte * to point to the (first) opcode. No effect if @insn->prefixes.got * is already set. + * + * * Returns: + * 0: on success + * < 0: on error */ -void insn_get_prefixes(struct insn *insn) +int insn_get_prefixes(struct insn *insn) { struct insn_field *prefixes = &insn->prefixes; insn_attr_t attr; @@ -120,7 +128,7 @@ void insn_get_prefixes(struct insn *insn) int i, nb; if (prefixes->got) - return; + return 0; insn_get_emulate_prefix(insn); @@ -230,8 +238,10 @@ vex_end: prefixes->got = 1; + return 0; + err_out: - return; + return -ENODATA; } /** @@ -243,16 +253,25 @@ err_out: * If necessary, first collects any preceding (prefix) bytes. * Sets @insn->opcode.value = opcode1. No effect if @insn->opcode.got * is already 1. + * + * Returns: + * 0: on success + * < 0: on error */ -void insn_get_opcode(struct insn *insn) +int insn_get_opcode(struct insn *insn) { struct insn_field *opcode = &insn->opcode; + int pfx_id, ret; insn_byte_t op; - int pfx_id; + if (opcode->got) - return; - if (!insn->prefixes.got) - insn_get_prefixes(insn); + return 0; + + if (!insn->prefixes.got) { + ret = insn_get_prefixes(insn); + if (ret) + return ret; + } /* Get first opcode */ op = get_next(insn_byte_t, insn); @@ -267,9 +286,13 @@ void insn_get_opcode(struct insn *insn) insn->attr = inat_get_avx_attribute(op, m, p); if ((inat_must_evex(insn->attr) && !insn_is_evex(insn)) || (!inat_accept_vex(insn->attr) && - !inat_is_group(insn->attr))) - insn->attr = 0; /* This instruction is bad */ - goto end; /* VEX has only 1 byte for opcode */ + !inat_is_group(insn->attr))) { + /* This instruction is bad */ + insn->attr = 0; + return -EINVAL; + } + /* VEX has only 1 byte for opcode */ + goto end; } insn->attr = inat_get_opcode_attribute(op); @@ -280,13 +303,18 @@ void insn_get_opcode(struct insn *insn) 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 */ + + if (inat_must_vex(insn->attr)) { + /* This instruction is bad */ + insn->attr = 0; + return -EINVAL; + } end: opcode->got = 1; + return 0; err_out: - return; + return -ENODATA; } /** @@ -296,15 +324,25 @@ err_out: * Populates @insn->modrm and updates @insn->next_byte to point past the * ModRM byte, if any. If necessary, first collects the preceding bytes * (prefixes and opcode(s)). No effect if @insn->modrm.got is already 1. + * + * Returns: + * 0: on success + * < 0: on error */ -void insn_get_modrm(struct insn *insn) +int insn_get_modrm(struct insn *insn) { struct insn_field *modrm = &insn->modrm; insn_byte_t pfx_id, mod; + int ret; + if (modrm->got) - return; - if (!insn->opcode.got) - insn_get_opcode(insn); + return 0; + + if (!insn->opcode.got) { + ret = insn_get_opcode(insn); + if (ret) + return ret; + } if (inat_has_modrm(insn->attr)) { mod = get_next(insn_byte_t, insn); @@ -313,17 +351,22 @@ void insn_get_modrm(struct insn *insn) 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 */ + if (insn_is_avx(insn) && !inat_accept_vex(insn->attr)) { + /* Bad insn */ + insn->attr = 0; + return -EINVAL; + } } } if (insn->x86_64 && inat_is_force64(insn->attr)) insn->opnd_bytes = 8; + modrm->got = 1; + return 0; err_out: - return; + return -ENODATA; } @@ -337,11 +380,16 @@ err_out: int insn_rip_relative(struct insn *insn) { struct insn_field *modrm = &insn->modrm; + int ret; if (!insn->x86_64) return 0; - if (!modrm->got) - insn_get_modrm(insn); + + if (!modrm->got) { + ret = insn_get_modrm(insn); + if (ret) + return 0; + } /* * For rip-relative instructions, the mod field (top 2 bits) * is zero and the r/m field (bottom 3 bits) is 0x5. @@ -355,15 +403,25 @@ int insn_rip_relative(struct insn *insn) * * If necessary, first collects the instruction up to and including the * ModRM byte. + * + * Returns: + * 0: if decoding succeeded + * < 0: otherwise. */ -void insn_get_sib(struct insn *insn) +int insn_get_sib(struct insn *insn) { insn_byte_t modrm; + int ret; if (insn->sib.got) - return; - if (!insn->modrm.got) - insn_get_modrm(insn); + return 0; + + if (!insn->modrm.got) { + ret = insn_get_modrm(insn); + if (ret) + return ret; + } + if (insn->modrm.nbytes) { modrm = insn->modrm.bytes[0]; if (insn->addr_bytes != 2 && @@ -374,8 +432,10 @@ void insn_get_sib(struct insn *insn) } insn->sib.got = 1; + return 0; + err_out: - return; + return -ENODATA; } @@ -386,15 +446,25 @@ err_out: * If necessary, first collects the instruction up to and including the * SIB byte. * Displacement value is sign-expanded. + * + * * Returns: + * 0: if decoding succeeded + * < 0: otherwise. */ -void insn_get_displacement(struct insn *insn) +int insn_get_displacement(struct insn *insn) { insn_byte_t mod, rm, base; + int ret; if (insn->displacement.got) - return; - if (!insn->sib.got) - insn_get_sib(insn); + return 0; + + if (!insn->sib.got) { + ret = insn_get_sib(insn); + if (ret) + return ret; + } + if (insn->modrm.nbytes) { /* * Interpreting the modrm byte: @@ -436,9 +506,10 @@ void insn_get_displacement(struct insn *insn) } out: insn->displacement.got = 1; + return 0; err_out: - return; + return -ENODATA; } /* Decode moffset16/32/64. Return 0 if failed */ @@ -537,20 +608,30 @@ err_out: } /** - * insn_get_immediate() - Get the immediates of instruction + * insn_get_immediate() - Get the immediate in an instruction * @insn: &struct insn containing instruction * * If necessary, first collects the instruction up to and including the * displacement bytes. * Basically, most of immediates are sign-expanded. Unsigned-value can be - * get by bit masking with ((1 << (nbytes * 8)) - 1) + * computed by bit masking with ((1 << (nbytes * 8)) - 1) + * + * Returns: + * 0: on success + * < 0: on error */ -void insn_get_immediate(struct insn *insn) +int insn_get_immediate(struct insn *insn) { + int ret; + if (insn->immediate.got) - return; - if (!insn->displacement.got) - insn_get_displacement(insn); + return 0; + + if (!insn->displacement.got) { + ret = insn_get_displacement(insn); + if (ret) + return ret; + } if (inat_has_moffset(insn->attr)) { if (!__get_moffset(insn)) @@ -597,9 +678,10 @@ void insn_get_immediate(struct insn *insn) } done: insn->immediate.got = 1; + return 0; err_out: - return; + return -ENODATA; } /** @@ -608,13 +690,65 @@ err_out: * * If necessary, first collects the instruction up to and including the * immediates bytes. - */ -void insn_get_length(struct insn *insn) + * + * Returns: + * - 0 on success + * - < 0 on error +*/ +int insn_get_length(struct insn *insn) { + int ret; + if (insn->length) - return; - if (!insn->immediate.got) - insn_get_immediate(insn); + return 0; + + if (!insn->immediate.got) { + ret = insn_get_immediate(insn); + if (ret) + return ret; + } + insn->length = (unsigned char)((unsigned long)insn->next_byte - (unsigned long)insn->kaddr); + + return 0; +} + +/* Ensure this instruction is decoded completely */ +static inline int insn_complete(struct insn *insn) +{ + return insn->opcode.got && insn->modrm.got && insn->sib.got && + insn->displacement.got && insn->immediate.got; +} + +/** + * insn_decode() - Decode an x86 instruction + * @insn: &struct insn to be initialized + * @kaddr: address (in kernel memory) of instruction (or copy thereof) + * @buf_len: length of the insn buffer at @kaddr + * @m: insn mode, see enum insn_mode + * + * Returns: + * 0: if decoding succeeded + * < 0: otherwise. + */ +int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m) +{ + int ret; + +#define INSN_MODE_KERN (enum insn_mode)-1 /* __ignore_sync_check__ mode is only valid in the kernel */ + + if (m == INSN_MODE_KERN) + insn_init(insn, kaddr, buf_len, IS_ENABLED(CONFIG_X86_64)); + else + insn_init(insn, kaddr, buf_len, m == INSN_MODE_64); + + ret = insn_get_length(insn); + if (ret) + return ret; + + if (insn_complete(insn)) + return 0; + + return -EINVAL; } |