ref: d4bc9052beb3305d64a353a16641740380eb87af
dir: /sys/src/cmd/vmx/x86.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <bio.h>
#include <mach.h>
#include "dat.h"
#include "fns.h"
#include "x86.h"
typedef struct VMemReq VMemReq;
struct VMemReq {
QLock;
uintptr va, len;
void *buf;
uintptr rc;
int wr;
};
static uintptr
translateflat(uintptr va, uintptr *pa, int *perm)
{
if(sizeof(uintptr) != 4 && va >> 32 != 0) return 0;
*pa = va;
if(va == 0)
return 0xFFFFFFFFUL;
if(perm != 0) *perm = -1;
return -va;
}
static uintptr
translate32(uintptr va, uintptr *pa, int *perm)
{
void *pd, *pt;
u32int pde, pte;
if(sizeof(uintptr) != 4 && va >> 32 != 0) return -1;
pd = gptr(rget("cr3") & ~0xfff, 4096);
if(pd == nil) return 0;
pde = GET32(pd, (va >> 22) * 4);
if(perm != nil) *perm = pde;
if((pde & 1) == 0) return 0;
if((pde & 0x80) != 0 && (rget("cr4real") & Cr4Pse) != 0){
*pa = pde & 0xffc00000 | (uintptr)(pde & 0x3fe000) << 19 | va & 0x3fffff;
return 0x400000 - (va & 0x3fffff);
}
pt = gptr(pde & ~0xfff, 4096);
if(pt == nil) return 0;
pte = GET32(pt, va >> 10 & 0xffc);
if((pte & 1) == 0) return 0;
if(perm != nil) *perm &= pte;
*pa = pte & ~0xfff | va & 0xfff;
return 0x1000 - (va & 0xfff);
}
static uintptr
translatepae(uintptr, uintptr *, int *)
{
vmerror("PAE translation not implemented");
return 0;
}
static uintptr
translate64(uintptr, uintptr *, int *)
{
vmerror("long mode translation not implemented");
return 0;
}
static uintptr (*
translator(void))(uintptr, uintptr *, int *)
{
uintptr cr0, cr4, efer;
cr0 = rget("cr0real");
if((cr0 & Cr0Pg) == 0)
return translateflat;
efer = rget("efer");
if((efer & EferLme) != 0)
return translate64;
cr4 = rget("cr4real");
if((cr4 & Cr4Pae) != 0)
return translatepae;
return translate32;
}
static void
vmemread0(void *aux)
{
VMemReq *req;
uintptr va, pa, n, ok, pok;
void *v;
uintptr (*trans)(uintptr, uintptr *, int *);
uchar *p;
int wr;
req = aux;
va = req->va;
n = req->len;
p = req->buf;
wr = req->wr;
trans = translator();
while(n > 0){
ok = trans(va, &pa, nil);
if(ok == 0) break;
if(ok > n) ok = n;
v = gptr(pa, 1);
if(v == nil) break;
pok = gavail(v);
if(ok > pok) ok = pok;
if(wr)
memmove(v, p, ok);
else
memmove(p, v, ok);
n -= ok;
p += ok;
va += ok;
}
req->rc = req->len - n;
qunlock(req);
}
uintptr
vmemread(void *buf, uintptr len, uintptr va)
{
VMemReq req;
memset(&req, 0, sizeof(VMemReq));
req.wr = 0;
req.buf = buf;
req.len = len;
req.va = va;
qlock(&req);
sendnotif(vmemread0, &req);
qlock(&req);
return req.rc;
}
uintptr
vmemwrite(void *buf, uintptr len, uintptr va)
{
VMemReq req;
memset(&req, 0, sizeof(VMemReq));
req.wr = 1;
req.buf = buf;
req.len = len;
req.va = va;
qlock(&req);
sendnotif(vmemread0, &req);
qlock(&req);
return req.rc;
}
int
x86access(int seg, uintptr addr0, int asz, uvlong *val, int sz, int acc, TLB *tlb)
{
int cpl;
static char *baser[] = {"csbase", "dsbase", "esbase", "fsbase", "gsbase", "ssbase"};
static char *limitr[] = {"cslimit", "dslimit", "eslimit", "fslimit", "gslimit", "sslimit"};
static char *permr[] = {"csperm", "dsperm", "esperm", "fsperm", "gsperm", "ssperm"};
uvlong tval;
u32int limit, perm;
uintptr addr, base, szmax;
int pperm, wp, i;
uintptr pa[8], pav;
uintptr l;
uchar *ptr;
Region *r;
switch(asz){
case 2: addr0 = (u16int)addr0; break;
case 4: addr0 = (u32int)addr0; break;
case 8: break;
default:
vmerror("invalid asz=%d in x86access", asz);
assert(0);
}
assert(seg < SEGMAX && (u8int)acc <= ACCX);
addr = addr0;
if(tlb != nil && tlb->asz == asz && tlb->seg == seg && tlb->acc == (u8int)acc && addr >= tlb->start && addr + sz >= addr && addr + sz < tlb->end){
ptr = tlb->base + addr;
pa[0] = tlb->pabase + addr;
r = tlb->reg;
goto fast;
}
if(sizeof(uintptr) == 8 && asz == 8){
if(seg == SEGFS || seg == SEGGS)
addr += rget(baser[seg]);
if((u16int)(((u64int)addr >> 48) + 1) > 1){
gpf:
if((acc & ACCSAFE) == 0){
vmdebug("gpf");
postexc("#gp", 0);
}
return -1;
}
if((vlong)addr >= 0)
szmax = (1ULL<<48) - addr;
else
szmax = -addr;
}else{
limit = rget(limitr[seg]);
perm = rget(permr[seg]);
if((perm & 0xc) == 0x4){
if((u32int)(addr + sz - 1) < addr || addr <= limit)
goto limfault;
szmax = (u32int)-addr;
}else{
if((u64int)addr + sz - 1 >= limit){
limfault:
if((acc & ACCSAFE) == 0){
vmdebug("limit fault");
postexc(seg == SEGSS ? "#ss" : "#gp", 0);
}
return -1;
}
szmax = limit - addr + 1;
}
if((perm & 0x10080) != 0x80)
goto gpf;
switch((u8int)acc){
case ACCR: if((perm & 0xa) == 8) goto gpf; break;
case ACCW: if((perm & 0xa) != 2) goto gpf; break;
case ACCX: if((perm & 8) == 0) goto gpf; break;
}
base = rget(baser[seg]);
addr = (u32int)(addr + base);
}
cpl = rget("cs") & 3;
wp = (rget("cr0real") & 1<<16) != 0;
for(i = 0; i < sz; ){
l = translator()(addr+i, &pav, &pperm);
if(l == 0){
pf:
if((acc & ACCSAFE) == 0){
vmdebug("page fault @ %#p", addr+i);
postexc("#pf", pperm & 1 | ((u8int)acc == ACCW) << 1 | (cpl == 3) << 2 | ((u8int)acc == ACCX) << 4);
rset("cr2", addr+i);
}
return -1;
}
if((cpl == 3 || wp) && (u8int)acc == ACCW && (pperm & 2) == 0)
goto pf;
if(cpl == 3 && (pperm & 4) == 0)
goto pf;
if(i == 0 && l < szmax) szmax = l;
while(i < sz && l-- > 0)
pa[i++] = pav++;
}
if(szmax >= sz){
r = regptr(pa[0]);
if(r == nil || pa[0]+sz > r->end) goto slow;
ptr = (uchar*)r->v + (pa[0] - r->start);
if(tlb != nil){
l = gavail(ptr);
if(l < szmax) szmax = l;
tlb->asz = asz;
tlb->seg = seg;
tlb->acc = (u8int)acc;
tlb->start = addr0;
tlb->end = addr0 + szmax;
tlb->reg = r;
tlb->base = ptr - addr0;
tlb->pabase = pa[0] - addr0;
}
fast:
if(r->mmio != nil)
r->mmio(pa[0], val, sz, (u8int)acc == ACCW);
else if(acc == ACCW)
switch(sz){
case 1: PUT8(ptr, 0, *val); break;
case 2: PUT16(ptr, 0, *val); break;
case 4: PUT32(ptr, 0, *val); break;
case 8: PUT64(ptr, 0, *val); break;
default: goto slow;
}
else
switch(sz){
case 1: *val = GET8(ptr, 0); break;
case 2: *val = GET16(ptr, 0); break;
case 4: *val = GET32(ptr, 0); break;
case 8: *val = GET64(ptr, 0); break;
default: goto slow;
}
}else{
slow:
if(acc != ACCW)
*val = 0;
for(i = 0; i < sz; i++){
r = regptr(pa[i]);
if(r == nil)
vmerror("x86access: access to unmapped address %#p", pa[i]);
else if(acc == ACCW){
tval = GET8(val, i);
if(r->mmio != nil)
r->mmio(pa[i], &tval, 1, 1);
else
PUT8(r->v, pa[i] - r->start, tval);
}else{
if(r->mmio != nil)
r->mmio(pa[i], &tval, 1, 0);
else
tval = GET8(r->v, pa[i] - r->start);
PUT8(val, i, tval);
}
}
}
return 0;
}
enum {
ONOPE, OADC, OADD, OAND, OASZ, OCALL, OCMP, OCMPS, ODEC,
OENTER, OEX, OIMUL, OINC, OINS, OLEAVE, OLOCK, OLODS, OMOV, OMOVS,
OOR, OOSZ, OOUTS, OPOP, OPOPA, OPOPF, OPUSH, OPUSHA, OPUSHF,
OREP, OREPNE, ORET, OSBB, OSCAS, OSEG, OSTOS, OSUB,
OTEST, OXCHG, OXLAT, OXOR, OROL, OROR, ORCL, ORCR,
OSHL, OSHR, OSAR, ONOT, ONEG, ODIV, OIDIV, OMUL,
OJMP,
};
static char *onames[] = {
[ONOPE]"ONOPE", [OADC]"OADC", [OADD]"OADD", [OAND]"OAND", [OASZ]"OASZ", [OCALL]"OCALL", [OCMP]"OCMP", [OCMPS]"OCMPS", [ODEC]"ODEC",
[OENTER]"OENTER", [OIMUL]"OIMUL", [OINC]"OINC", [OINS]"OINS", [OLEAVE]"OLEAVE", [OLOCK]"OLOCK", [OLODS]"OLODS", [OMOV]"OMOV", [OMOVS]"OMOVS",
[OOR]"OOR", [OOSZ]"OOSZ", [OOUTS]"OOUTS", [OPOP]"OPOP", [OPOPA]"OPOPA", [OPOPF]"OPOPF", [OPUSH]"OPUSH", [OPUSHA]"OPUSHA", [OPUSHF]"OPUSHF",
[OREP]"OREP", [OREPNE]"OREPNE", [ORET]"ORET", [OSBB]"OSBB", [OSCAS]"OSCAS", [OSEG]"OSEG", [OSTOS]"OSTOS", [OSUB]"OSUB",
[OTEST]"OTEST", [OXCHG]"OXCHG", [OXLAT]"OXLAT", [OXOR]"OXOR", [OEX]"OEX", [OROL]"OROL", [OROR]"OROR", [ORCL]"ORCL", [ORCR]"ORCR",
[OSHL]"OSHL", [OSHR]"OSHR", [OSAR]"OSAR", [ONOT]"ONOT", [ONEG]"ONEG", [ODIV]"ODIV", [OIDIV]"OIDIV", [OMUL]"OMUL", [OJMP]"OJMP"
};
#define enumconv(x,buf,tab) ((x)<nelem(tab)?(tab)[x]:(sprint(buf,"%d",(x)),buf))
/*
size fields:
0 b byte
1 v short/long/vlong (16-bit,32-bit,64-bit mode)
2 z short/long/long
3 w short
*/
enum {
ANOPE,
A1 = 1, /* constant 1 */
/* general purpose registers with size+1 in high nibble */
AGPRb = 0x10,
AGPRv = 0x20,
AGPRz = 0x30,
AAXb = 0x10, ACXb = 0x11, ADXb = 0x12, ABXb = 0x13, ASPb = 0x14, ABPb = 0x15, ASIb = 0x16, ADIb = 0x17,
AAXv = 0x20, ACXv = 0x21, ADXv = 0x22, ABXv = 0x23, ASPv = 0x24, ABPv = 0x25, ASIv = 0x26, ADIv = 0x27,
AAXz = 0x30, ACXz = 0x31, ADXz = 0x32, ABXz = 0x33, ASPz = 0x34, ABPz = 0x35, ASIz = 0x36, ADIz = 0x37,
ASEG = 0x40, ACS = 0x40, ADS = 0x41, AES = 0x42, AFS = 0x43, AGS = 0x44, ASS = 0x45,
/* below has valid size in lower nibble */
AGOTSZ = 0x50,
AOb = 0x50, AOv = 0x51,
AIMM = 0x70,
AIb = 0x70, AIz = 0x72,
/* below involves modrm */
AMODRM = 0x80,
AEb = 0x80, AEv = 0x81,
AGb = 0x90, AGv = 0x91,
ASw = 0xA3,
};
static char *anames[] = {
[ANOPE]"ANOPE", [AEb]"AEb", [AEv]"AEv", [AGb]"AGb", [AGv]"AGv", [AIb]"AIb", [AIz]"AIz",
[ASw]"ASw", [AOb]"AOb", [AOv]"AOv",
[ACS]"ACS", [ADS]"ADS", [AES]"AES", [AFS]"AFS", [AGS]"AGS", [ASS]"ASS",
[AAXb]"AAXb", [ABXb]"ABXb", [ACXb]"ACXb", [ADXb]"ADXb", [ABPb]"ABPb", [ASPb]"ASPb", [ASIb]"ASIb", [ADIb]"ADIb",
[AAXv]"AAXv", [ABXv]"ABXv", [ACXv]"ACXv", [ADXv]"ADXv", [ABPv]"ABPv", [ASPv]"ASPv", [ASIv]"ASIv", [ADIv]"ADIv",
[AAXz]"AAXz", [ABXz]"ABXz", [ACXz]"ACXz", [ADXz]"ADXz", [ABPz]"ABPz", [ASPz]"ASPz", [ASIz]"ASIz", [ADIz]"ADIz",
};
/* typically b is dst and c is src */
#define O(a,b,c) ((a)|(b)<<8|(c)<<16)
/* we only care about operations that can go to memory */
static u32int optab[256] = {
/*0*/ O(OADD,AEb,AGb), O(OADD,AEv,AGv), O(OADD,AGb,AEb), O(OADD,AGv,AEv), O(OADD,AAXb,AIb), O(OADD,AAXz,AIz), O(OPUSH,AES,0), O(OPOP,AES,0),
O(OOR,AEb,AGb), O(OOR,AEv,AGv), O(OOR,AGb,AEb), O(OOR,AGv,AEv), O(OOR,AAXb,AIb), O(OOR,AAXz,AIz), O(OPUSH,ACS,0), 0,
/*1*/ O(OADC,AEb,AGb), O(OADC,AEv,AGv), O(OADC,AGb,AEb), O(OADC,AGv,AEv), O(OADC,AAXb,AIb), O(OADC,AAXz,AIz), O(OPUSH,ASS,0), O(OPOP,ASS,0),
O(OSBB,AEb,AGb), O(OSBB,AEv,AGv), O(OSBB,AGb,AEb), O(OSBB,AGv,AEv), O(OSBB,AAXb,AIb), O(OSBB,AAXz,AIz), O(OPUSH,ADS,0), O(OPOP,ADS,0),
/*2*/ O(OAND,AEb,AGb), O(OAND,AEv,AGv), O(OAND,AGb,AEb), O(OAND,AGv,AEv), O(OAND,AAXb,AIb), O(OAND,AAXz,AIz), O(OSEG,AES,0), 0/*DAA*/,
O(OSUB,AEb,AGb), O(OSUB,AEv,AGv), O(OSUB,AGb,AEb), O(OSUB,AGv,AEv), O(OSUB,AAXb,AIb), O(OSUB,AAXz,AIz), O(OSEG,ACS,0), 0/*DAS*/,
/*3*/ O(OXOR,AEb,AGb), O(OXOR,AEv,AGv), O(OXOR,AGb,AEb), O(OXOR,AGv,AEv), O(OXOR,AAXb,AIb), O(OXOR,AAXz,AIz), O(OSEG,ASS,0), 0/*AAA*/,
O(OCMP,AEb,AGb), O(OCMP,AEv,AGv), O(OCMP,AGb,AEb), O(OCMP,AGv,AEv), O(OCMP,AAXb,AIb), O(OCMP,AAXz,AIz), O(OSEG,ADS,0), 0/*AAS*/,
/*4*/ 0, 0, 0, 0, 0, 0, 0, 0, /* rex prefixes */
0, 0, 0, 0, 0, 0, 0, 0,
/*5*/ O(OPUSH,AAXv,0), O(OPUSH,ACXv,0), O(OPUSH,ADXv,0), O(OPUSH,ABXv,0), O(OPUSH,ASPv,0), O(OPUSH,ABPv,0), O(OPUSH,ASIv,0), O(OPUSH,ADIv,0),
O(OPOP,AAXv,0), O(OPOP,ACXv,0), O(OPOP,ADXv,0), O(OPOP,ABXv,0), O(OPOP,ASPv,0), O(OPOP,ABPv,0), O(OPOP,ASIv,0), O(OPOP,ADIv,0),
/*6*/ OPUSHA, OPOPA, 0/*BOUND*/, 0/*ARPL*/, O(OSEG,AFS,0), O(OSEG,AGS,0), OOSZ, OASZ,
O(OPUSH,AIz,0), O(OIMUL,AGv,AIz), O(OPUSH,AIb,0), O(OIMUL,AGv,AIb), OINS, OINS, OOUTS, OOUTS,
/*7*/ 0, 0, 0, 0, 0, 0, 0, 0, /* jumps */
0, 0, 0, 0, 0, 0, 0, 0,
/*8*/ OEX, OEX, OEX, OEX, O(OTEST,AEb,AGb), O(OTEST,AEv,AGv), O(OXCHG,AEb,AGb), O(OXCHG,AEv,AGv),
O(OMOV,AEb,AGb), O(OMOV,AEv,AGv), O(OMOV,AGb,AEb), O(OMOV,AGv,AEv), O(OMOV,AEv,ASw), 0/*LEA*/, O(OMOV,ASw,AEv), OEX,
/*9*/ 0, 0, 0, 0, 0, 0, 0, 0, /* register exchange */
0/*CBW*/, 0/*CWD*/, OCALL, 0/*FWAIT*/, OPUSHF, OPOPF, 0/*OSAHF*/, 0/*OLAHF*/,
/*A*/ O(OMOV,AAXb,AOb), O(OMOV,AAXv,AOv), O(OMOV,AOb,AAXb), O(OMOV,AOv,AAXv), OMOVS, OMOVS, OCMPS, OCMPS,
0, 0/*TEST Reg,Imm*/, OSTOS, OSTOS, OLODS, OLODS, OSCAS, OSCAS,
/*B*/ 0, 0, 0, 0, 0, 0, 0, 0, /* move immediate to register */
0, 0, 0, 0, 0, 0, 0, 0,
/*C*/ OEX, OEX, ORET, ORET, 0/*LES*/, 0/*LDS*/, OEX, OEX,
OENTER, OLEAVE, ORET, ORET, 0/*INT3*/, 0/*INTn*/, 0/*INTO*/, 0/*IRET*/,
/*D*/ OEX, OEX, OEX, OEX, 0/*AAM*/, 0/*AAD*/, 0, OXLAT,
0, 0, 0, 0, 0, 0, 0, 0, /* fpu */
/*E*/ 0, 0, 0/*LOOPx*/, 0/*JrCXZ*/, 0, 0/*IN*/, 0, 0/*OUT*/,
OCALL, OCALL, 0, 0/*JMP*/, 0, 0/*IN*/, 0, 0/*OUT*/,
/*F*/ OLOCK, 0, OREPNE, OREP, 0/*HALT*/, 0/*CMC*/, OEX, OEX,
0/*CLC*/, 0/*STC*/, 0/*CLI*/, 0/*STI*/, 0/*CLD*/, 0/*STD*/, OEX, OEX,
};
/* OEX tables (operations determined by modrm byte) */
static u32int optab80[8] = {O(OADD,AEb,AIb), O(OOR,AEb,AIb), O(OADC,AEb,AIb), O(OSBB,AEb,AIb), O(OAND,AEb,AIb), O(OSUB,AEb,AIb), O(OXOR,AEb,AIb), O(OCMP,AEb,AIb)};
static u32int optab81[8] = {O(OADD,AEv,AIz), O(OOR,AEv,AIz), O(OADC,AEv,AIz), O(OSBB,AEv,AIz), O(OAND,AEv,AIz), O(OSUB,AEv,AIz), O(OXOR,AEv,AIz), O(OCMP,AEv,AIz)};
/* 0x82 is identical to 0x80 */
static u32int optab83[8] = {O(OADD,AEv,AIb), O(OOR,AEv,AIb), O(OADC,AEv,AIb), O(OSBB,AEv,AIb), O(OAND,AEv,AIb), O(OSUB,AEv,AIb), O(OXOR,AEv,AIb), O(OCMP,AEv,AIb)};
static u32int optab8F[8] = {O(OPOP,AEv,0)};
static u32int optabC0[8] = {O(OROL,AEb,AIb), O(OROR,AEb,AIb), O(ORCL,AEb,AIb), O(ORCR,AEb,AIb), O(OSHL,AEb,AIb), O(OSHR,AEb,AIb), 0, O(OSAR,AEb,AIb)};
static u32int optabC1[8] = {O(OROL,AEv,AIb), O(OROR,AEv,AIb), O(ORCL,AEv,AIb), O(ORCR,AEv,AIb), O(OSHL,AEv,AIb), O(OSHR,AEv,AIb), 0, O(OSAR,AEv,AIb)};
static u32int optabD0[8] = {O(OROL,AEb,A1), O(OROR,AEb,A1), O(ORCL,AEb,A1), O(ORCR,AEb,A1), O(OSHL,AEb,A1), O(OSHR,AEb,A1), 0, O(OSAR,AEb,A1)};
static u32int optabD1[8] = {O(OROL,AEv,A1), O(OROR,AEv,A1), O(ORCL,AEv,A1), O(ORCR,AEv,A1), O(OSHL,AEv,A1), O(OSHR,AEv,A1), 0, O(OSAR,AEv,A1)};
static u32int optabD2[8] = {O(OROL,AEb,ACXb), O(OROR,AEb,ACXb), O(ORCL,AEb,ACXb), O(ORCR,AEb,ACXb), O(OSHL,AEb,ACXb), O(OSHR,AEb,ACXb), 0, O(OSAR,AEb,ACXb)};
static u32int optabD3[8] = {O(OROL,AEv,ACXb), O(OROR,AEv,ACXb), O(ORCL,AEv,ACXb), O(ORCR,AEv,ACXb), O(OSHL,AEv,ACXb), O(OSHR,AEv,ACXb), 0, O(OSAR,AEv,ACXb)};
static u32int optabC6[8] = {O(OMOV,AEb,AIb)};
static u32int optabC7[8] = {O(OMOV,AEv,AIz)};
static u32int optabF6[8] = {O(OTEST,AEb,AIb), 0, O(ONOT,AEb,0), O(ONEG,AEb,0), O(OMUL,AAXb,AEb), O(OIMUL,AAXb,0), O(ODIV,AAXb,0), O(OIDIV,AAXb,0)};
static u32int optabF7[8] = {O(OTEST,AEv,AIz), 0, O(ONOT,AEv,0), O(ONEG,AEv,0), O(OMUL,AAXv,AEv), O(OIMUL,AAXv,0), O(ODIV,AAXv,0), O(OIDIV,AAXv,0)};
static u32int optabFE[8] = {O(OINC,AEb,0),O(ODEC,AEb,0)};
static u32int optabFF[8] = {O(OINC,AEv,0),O(ODEC,AEv,0),OCALL,OCALL,OJMP,OJMP,O(OPUSH,AEv,0),0};
typedef struct Instr Instr;
typedef struct Oper Oper;
/* for registers we put the number in addr and add +0x10 for "high bytes" (AH etc) */
struct Oper {
enum { OPNONE, OPREG, OPSEG, OPIMM, OPMEM } type;
uintptr addr;
int sz;
uvlong val;
};
struct Instr {
u8int bytes[16];
int nbytes;
u8int opcode; /* first byte after the prefixes */
u32int inf;
u8int modrm, sib;
vlong disp;
uvlong imm;
enum {
INSLOCK = 0x1,
INSREP = 0x2,
INSREPNE = 0x4,
INSOSZ = 0x8,
INSASZ = 0x10,
INSMODRM = 0x20,
INSSIB = 0x40,
INSDISP8 = 0x80,
INSDISP16 = 0x100,
INSDISP32 = 0x200,
INSDISP64 = 0x400,
INSIMM8 = 0x800,
INSIMM16 = 0x1000,
INSIMM32 = 0x2000,
/* INSIMM64 = 0x4000, not yet */
} flags;
int seg;
u8int osz, asz;
Oper op[2];
};
struct Step {
uintptr pc, npc;
u8int mode;
TLB tlb;
Instr;
} step;
static int
fetch8(int acc)
{
uvlong v;
if(step.nbytes >= sizeof(step.bytes)){
if((acc & ACCSAFE) == 0){
vmerror("x86step: instruction too long (pc=%#p)", step.pc);
postexc("#ud", NOERRC);
}
return -1;
}
if(x86access(SEGCS, step.npc, step.mode, &v, 1, ACCX|acc, &step.tlb) < 0){
vmerror("x86step: fault while trying to load %#p, shouldn't happen", step.pc);
return -1;
}
step.npc++;
step.bytes[step.nbytes++] = v;
return (u8int)v;
}
static int
fetch16(int acc)
{
int r0, r1;
if(r0 = fetch8(acc), r0 < 0) return -1;
if(r1 = fetch8(acc), r1 < 0) return -1;
return r0 | r1 << 8;
}
static vlong
fetch32(int acc)
{
int r0, r1, r2, r3;
if(r0 = fetch8(acc), r0 < 0) return -1;
if(r1 = fetch8(acc), r1 < 0) return -1;
if(r2 = fetch8(acc), r2 < 0) return -1;
if(r3 = fetch8(acc), r3 < 0) return -1;
return r0 | r1 << 8 | r2 << 16 | r3 << 24;
}
static int
fetch64(int acc, uvlong *p)
{
vlong r0, r1;
if(r0 = fetch32(acc), r0 < 0) return -1;
if(r1 = fetch32(acc), r1 < 0) return -1;
*p = r0 | r1 << 32;
return 0;
}
static long
machread(int, void *vb, long n, vlong soff)
{
uvlong o;
o = soff;
if(o < step.pc) return 0;
if(o >= step.pc+step.nbytes) return 0;
if(n > step.pc+step.nbytes-o)
n = step.pc+step.nbytes-o;
memmove(vb, step.bytes+(o-step.pc), n);
return n;
}
static void
giveup(void)
{
static Map *m;
char buf[128];
char *p, *e;
extern Machdata i386mach;
int i, rc;
if(m == nil){
m = newmap(nil, 1);
setmap(m, -1, 0, -1, 0, "text");
m->seg[0].read = machread;
}
p = buf;
e = buf + sizeof(buf);
while(fetch8(ACCSAFE) >= 0)
;
if(rc = i386mach.das(m, step.pc, 0, buf, sizeof(buf)), rc >= 0){
p += strlen(buf);
p = seprint(p, e, " # ");
}else
rc = step.nbytes;
for(i = 0; i < rc; i++)
p = seprint(p, e, "%.2x ", step.bytes[i]);
vmerror("x86step: unimplemented instruction %s", buf);
}
static int
grab(void)
{
int op;
int rc;
vlong vrc;
u32int inf;
u32int *tab;
again:
op = fetch8(0);
if(op < 0) return -1;
inf = optab[op];
if(inf == 0){ giveup(); return -1; }
switch((u8int)inf){
case OLOCK: step.flags |= INSLOCK; goto again;
case OREP: step.flags |= INSREP; goto again;
case OREPNE: step.flags |= INSREPNE; goto again;
case OOSZ: step.flags |= INSOSZ; step.osz = step.osz == 2 ? 4 : 2; goto again;
case OASZ: step.flags |= INSASZ; step.asz = step.asz == 2 ? 4 : 2; goto again;
case OSEG: step.seg = inf >> 8; goto again;
}
step.opcode = op;
if((u8int)(inf >> 8) >= AMODRM || (u8int)(inf >> 16) >= AMODRM || inf == OEX){
rc = fetch8(0);
if(rc < 0) return -1;
step.modrm = rc;
step.flags |= INSMODRM;
if(step.asz != 2 && (step.modrm & 0x07) == 0x04 && step.modrm < 0xc0){
rc = fetch8(0); if(rc < 0) return -1;
step.sib = rc;
step.flags |= INSSIB;
}
switch(step.modrm >> 6){
case 1:
rc = fetch8(0); if(rc < 0) return -1;
step.disp = (s8int)rc;
step.flags |= INSDISP8;
break;
case 0:
if((step.modrm & 7) != (step.asz == 2) + 5 && (step.sib & 7) != 5)
break;
/* wet floor */
case 2:
if(step.asz == 2){
rc = fetch16(0); if(rc < 0) return -1;
step.disp = (s16int)rc;
step.flags |= INSDISP16;
}else{
vrc = fetch32(0); if(vrc < 0) return -1;
step.disp = (s32int)vrc;
step.flags |= INSDISP32;
}
break;
}
}
if(inf == OEX){
switch(op){
case 0x80: case 0x82: tab = optab80; break;
case 0x81: tab = optab81; break;
case 0x83: tab = optab83; break;
case 0x8f: tab = optab8F; break;
case 0xc0: tab = optabC0; break;
case 0xc1: tab = optabC1; break;
case 0xd0: tab = optabD0; break;
case 0xd1: tab = optabD1; break;
case 0xd2: tab = optabD2; break;
case 0xd3: tab = optabD3; break;
case 0xc6: tab = optabC6; break;
case 0xc7: tab = optabC7; break;
case 0xf6: tab = optabF6; break;
case 0xf7: tab = optabF7; break;
case 0xfe: tab = optabFE; break;
case 0xff: tab = optabFF; break;
default: tab = nil;
}
if(tab == nil || (inf = tab[step.modrm >> 3 & 7]) == 0){
giveup();
return -1;
}
}
if(((u8int)(inf >> 8) & 0xf0) == AIMM){
rc = inf >> 8 & 0xf;
imm:
switch(rc){
case 0:
rc = fetch8(0); if(rc < 0) return -1;
step.imm = rc;
step.flags |= INSIMM8;
break;
case 2:
switch(step.osz){
case 2:
rc = fetch16(0); if(rc < 0) return -1;
step.imm = rc;
step.flags |= INSIMM16;
break;
case 4:
case 8:
vrc = fetch32(0); if(vrc < 0) return -1;
step.imm = vrc;
step.flags |= INSIMM32;
break;
}
break;
default:
vmerror("x86step: grab: immediate size=%d, shouldn't happen", rc);
giveup();
return -1;
}
}else if((u8int)(inf >> 16 & 0xf0) == AIMM){
rc = inf >> 16 & 0xf;
goto imm;
}
if(((u8int)(inf >> 8) & 0xf0) == AOb || (u8int)(inf >> 16 & 0xf0) == AOb)
switch(step.asz){
case 2:
rc = fetch16(0); if(rc < 0) return -1;
step.disp = rc;
step.flags |= INSDISP16;
break;
case 4:
vrc = fetch32(0); if(vrc < 0) return -1;
step.disp = vrc;
step.flags |= INSDISP32;
break;
case 8:
if(fetch64(0, (uvlong *) &step.disp) < 0) return -1;
step.flags |= INSDISP64;
break;
}
step.inf = inf;
return 0;
}
static void
decreg(Oper *o, int n, int sz)
{
o->type = OPREG;
o->sz = sz;
if(sz == 1 && n >= 4){
o->addr = n ^ 0x14;
o->val = (u8int)(rget(x86reg[n&3]) >> 8);
}else{
o->addr = n;
o->val = rgetsz(x86reg[n], sz);
}
}
static void
decmodrm(Oper *o, int sz)
{
u8int mod, m;
mod = step.modrm >> 6;
m = step.modrm & 7;
if(mod == 3){
decreg(o, m, sz);
return;
}
o->type = OPMEM;
o->sz = sz;
if(step.asz == 2){
switch(m){
case 0: o->addr = rget(RBX) + rget(RSI); break;
case 1: o->addr = rget(RBX) + rget(RDI); break;
case 2: o->addr = rget(RBP) + rget(RSI); break;
case 3: o->addr = rget(RBX) + rget(RDI); break;
case 4: o->addr = rget(RSI); break;
case 5: o->addr = rget(RDI); break;
case 6: o->addr = mod == 0 ? 0 : rget(RBP); break;
case 7: o->addr = rget(RBX); break;
}
o->addr = (u16int)(o->addr + step.disp);
if(step.seg < 0)
if(m == 6 && mod != 0)
step.seg = SEGSS;
else
step.seg = SEGDS;
return;
}
if(m != 4){
if((step.modrm & 0xc7) == 5)
o->addr = 0;
else
o->addr = rget(x86reg[m]);
o->addr = (u32int)(o->addr + step.disp);
if(step.seg < 0)
if(m == 5 && mod != 0)
step.seg = SEGSS;
else
step.seg = SEGDS;
return;
}
if((step.sib >> 3 & 7) != 4)
o->addr = rget(x86reg[step.sib >> 3 & 7]);
else
o->addr = 0;
o->addr <<= step.sib >> 6;
if((step.sib & 7) != 5 || mod != 0)
o->addr += rget(x86reg[step.sib & 7]);
o->addr = (u32int)(o->addr + step.disp);
if(step.seg < 0)
if((step.sib & 7) == 4 || (step.sib & 7) == 5 && mod != 0)
step.seg = SEGSS;
else
step.seg = SEGDS;
}
static int
parseoper(void)
{
int i;
u8int f;
Oper *o;
u8int sizes[4] = {1, step.osz, step.osz == 8 ? 4 : step.osz, 2};
for(i = 0; i < 2; i++){
f = step.inf >> 8 * (i + 1);
o = &step.op[i];
switch(f & 0xf0){
case AGPRb:
case AGPRv:
case AGPRz:
o->type = OPREG;
o->addr = f & 0xf;
o->val = rget(x86reg[f & 0xf]);
o->sz = sizes[(f >> 4) - 1];
break;
case ASEG:
o->type = OPSEG;
o->addr = f & 0xf;
o->val = rget(x86segreg[f & 0xf]);
o->sz = 2;
break;
case AOb:
o->type = OPMEM;
o->addr = step.disp;
o->sz = sizes[f & 0xf];
if(step.seg < 0)
step.seg = SEGDS;
break;
case AIMM:
o->type = OPIMM;
o->val = step.imm;
o->sz = sizes[f & 0xf];
break;
case AEb:
decmodrm(o, sizes[f & 0xf]);
break;
case A1:
o->type = OPIMM;
o->val = 1;
o->sz = 1;
break;
case AGb:
decreg(o, step.modrm >> 3 & 7, sizes[f & 0xf]);
break;
}
}
return 0;
}
static int
opwrite(Oper *o, uvlong v)
{
char *n;
switch(o->type){
case OPREG:
n = x86reg[o->addr & 0xf];
if((o->addr & 0x10) != 0)
rset(n, rget(n) & ~0xff00ULL | (u8int)v << 8);
else
rsetsz(n, v, o->sz);
return 0;
case OPMEM:
if(x86access(step.seg, o->addr, step.asz, &v, o->sz, ACCW, &step.tlb) < 0)
return -1;
return 0;
case OPSEG:
giveup();
return -1;
default:
vmerror("x86step: opwrite: unhandled o->type==%d, shouldn't happen", o->type);
giveup();
return -1;
}
}
static int
opread(Oper *o, uvlong *v)
{
switch(o->type){
case OPREG:
case OPSEG:
case OPIMM:
*v = o->val;
return 0;
case OPMEM:
if(x86access(step.seg, o->addr, step.asz, v, o->sz, ACCR, &step.tlb) < 0)
return -1;
return 0;
default:
vmerror("x86step: opread: unhandled o->type==%d, shouldn't happen", o->type);
giveup();
return -1;
}
}
static vlong
alu(int op, vlong a, int asz, vlong b, int bsz, uvlong *flags)
{
vlong c;
vlong amsk, sbit;
u32int flout;
u8int p;
flout = 0;
amsk = (-1ULL)>>64-8*asz;
sbit = 1<<8*asz-1;
b = b << 64 - 8*bsz >> 64 - 8*bsz;
switch(op){
case OADD:
case OADC:
c = (a & amsk) + (b & amsk);
if(op == OADC) c += *flags & 1;
if((~(a ^ b) & (a ^ c) & 1<<sbit) != 0) flout |= OF;
if((a & 0xf) + (b & 0xf) >= 0x10) flout |= AF;
goto addsub;
case OSUB:
case OSBB:
case OCMP:
c = (a & amsk) - (b & amsk);
if(op == OSBB) c -= *flags & 1;
if(((a ^ b) & (a ^ c) & 1<<sbit) != 0) flout |= OF;
if((a & 0xf) < (b & 0xf)) flout |= AF;
addsub:
if((c & ~amsk) != 0) flout |= CF;
logic:
if((c & 1<<sbit) != 0) flout |= SF;
if((c & amsk) == 0) flout |= ZF;
p = c;
if(0x69966996 << (p ^ p >> 4) < 0) flout |= PF;
break;
case OAND: c = a & b; goto logic;
case OOR: c = a | b; goto logic;
case OXOR: c = a ^ b; goto logic;
default:
vmerror("x86step: alu: unhandled case op==%d, shouldn't happen", op);
return 0;
}
*flags ^= (*flags ^ flout) & (CF|SF|ZF|OF|AF|PF);
return c & amsk;
}
static int
opcstring(void)
{
int sz, srcseg, rc, inc;
uvlong srcaddr, dstaddr;
uvlong v;
uvlong cx;
char buf[16];
if((step.opcode & 1) != 0)
sz = step.osz;
else
sz = 1;
srcseg = step.seg >= 0 ? step.seg : SEGDS;
srcaddr = rget(RSI);
dstaddr = rget(RDI);
if((step.flags & INSREP) != 0)
cx = rgetsz(RCX, step.asz);
else
cx = 1;
if((rget(RFLAGS) & 0x400) != 0)
inc = -sz;
else
inc = sz;
rc = 1;
switch((u8int)step.inf){
case OLODS:
for(; cx > 0; cx--){
if(x86access(srcseg, srcaddr, step.asz, &v, sz, ACCR, &step.tlb) < 0){
rc = 0;
break;
}
rsetsz(RAX, v, sz);
srcaddr += inc;
}
break;
case OSTOS:
v = rget(RAX);
for(; cx > 0; cx--){
if(x86access(SEGES, dstaddr, step.asz, &v, sz, ACCW, &step.tlb) < 0){
rc = 0;
break;
}
dstaddr += inc;
}
break;
case OMOVS:
for(; cx > 0; cx--){
if(x86access(srcseg, srcaddr, step.asz, &v, sz, ACCR, &step.tlb) < 0 ||
x86access(SEGES, dstaddr, step.asz, &v, sz, ACCW, &step.tlb) < 0){
rc = 0;
break;
}
srcaddr += inc;
dstaddr += inc;
}
break;
default:
vmerror("x86step: opcstring: unhandled case %s", enumconv((u8int)step.inf, buf, onames));
giveup();
return 0;
}
rsetsz(RSI, srcaddr, step.asz);
rsetsz(RDI, dstaddr, step.asz);
if((step.flags & (INSREP|INSREPNE)) != 0)
rsetsz(RCX, cx, step.asz);
return rc;
}
static int
opcstack(void)
{
uvlong val, sp;
int spsz;
/* todo: get stack pointer size from stack segment */
spsz = step.mode;
sp = rgetsz(RSP, spsz);
switch((u8int)step.inf){
case OPUSH:
if(opread(&step.op[0], &val) < 0) return 0;
if(step.op[0].sz < step.osz && step.op[0].type != OPSEG)
val = (vlong)val << 64 - 8 * step.op[0].sz >> 64 - 8 * step.op[0].sz;
sp -= step.osz;
if(x86access(SEGSS, sp, spsz, &val, step.osz, ACCW, &step.tlb) < 0) return 0;
break;
case OPOP:
if(x86access(SEGSS, sp, spsz, &val, step.osz, ACCR, &step.tlb) < 0) return 0;
if(opwrite(&step.op[0], val) < 0) return 0;
sp += step.osz;
break;
default:
vmerror("x86step: stack: unhandled case op==%d, shouldn't happen", (u8int)step.inf);
return 0;
}
rsetsz(RSP, sp, spsz);
return 1;
}
int
x86step(void)
{
uvlong val, valb;
uvlong rflags;
char buf[16];
memset(&step, 0, sizeof(step));
step.seg = -1;
step.pc = rget(RPC);
step.npc = step.pc;
step.mode = 4;
step.asz = step.osz = step.mode;
if(grab() < 0 || parseoper() < 0)
return 0;
// print("flags=%#ux modrm=%#ux sib=%#ux disp=%#ullx imm=%#ullx\n", step.flags, step.modrm, step.sib, step.disp, step.imm);
// print("op0: type=%#ux addr=%#ullx val=%#ullx sz=%d\n", , );
// print("op1: type=%#ux addr=%#ullx val=%#ullx sz=%d\n", step.op[1].type, step.op[1].addr, step.op[1].val, step.op[1].sz);
print("%#.*p %s (%#ux,%d,%#ullx,%#ullx) (%#ux,%d,%#ullx,%#ullx) si %#llux di %#llux\n", 2*step.mode, step.pc, enumconv((u8int)step.inf,buf,onames), step.op[0].type, step.op[0].sz, (uvlong)step.op[0].addr, step.op[0].val, step.op[1].type, step.op[1].sz, (uvlong)step.op[1].addr, step.op[1].val, rget(RSI), rget(RDI));
switch((u8int)step.inf){
case OMOV:
if((step.flags & (INSREP|INSREPNE|INSLOCK)) != 0) {giveup(); return 0;}
if(opread(&step.op[1], &val) < 0) return 0;
if(opwrite(&step.op[0], val) < 0) return 0;
return 1;
case OSTOS: case OLODS: case OMOVS:
if((step.flags & (INSREPNE|INSLOCK)) != 0) {giveup(); return 0;}
return opcstring();
case OADD: case OADC: case OSUB: case OSBB: case OCMP: case OAND: case OOR: case OXOR:
if((step.flags & (INSREP|INSREPNE)) != 0) {giveup(); return 0;}
if(opread(&step.op[0], &val) < 0) return 0;
if(opread(&step.op[1], &valb) < 0) return 0;
rflags = rget(RFLAGS);
val = alu((u8int)step.inf, val, step.op[0].sz, valb, step.op[1].sz, &rflags);
if((u8int)step.inf != OCMP && opwrite(&step.op[0], val) < 0) return 0;
rset(RFLAGS, rflags);
return 1;
case OPUSH: case OPOP:
if((step.flags & (INSLOCK|INSREPNE|INSLOCK)) != 0) {giveup(); return 0;}
return opcstack();
default:
vmerror("x86step: unhandled case %s", enumconv((u8int)step.inf, buf, onames));
giveup();
return 0;
}
}