qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-10-05 02:21:22 -06:00
Code Releases Activity
141a4a1759
go/src/cmd/5l/noop.c
Russ Cox 141a4a1759 runtime: fix arm reflect.call boundary case 
The fault was lucky: when it wasn't faulting it was silently
copying a word from some other block and later putting
that same word back.  If some other goroutine had changed
that word of memory in the interim, too bad.

The ARM code was inconsistent about whether the
"argument frame" included the saved LR.  Including it made
some things more regular but mostly just caused confusion
in the places where the regularity broke.  Now the rule
reflects reality: argp is always a pointer to arguments,
never a saved link register.

Renamed struct fields to make meaning clearer.

Running ARM in QEMU, package time's gotest:
  * before: 27/58 failed
  * after: 0/50

R=r, r2
CC=golang-dev
https://golang.org/cl/3993041
2011-01-14 14:05:20 -05:00

866 lines
19 KiB
C
Raw Blame History

// Inferno utils/5l/noop.c
// http://code.google.com/p/inferno-os/source/browse/utils/5l/noop.c
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// Code transformations.
#include "l.h"
#include "../ld/lib.h"
// see ../../runtime/proc.c:/StackGuard
enum
{
StackBig = 4096,
StackSmall = 128,
};
static Sym* sym_div;
static Sym* sym_divu;
static Sym* sym_mod;
static Sym* sym_modu;
static void setdiv(int);
static Prog *
movrr(Prog *q, int rs, int rd, Prog *p)
{
if(q == nil)
q = prg();
q->as = AMOVW;
q->line = p->line;
q->from.type = D_REG;
q->from.reg = rs;
q->to.type = D_REG;
q->to.reg = rd;
q->link = p->link;
return q;
}
static Prog *
fnret(Prog *q, int rs, int foreign, Prog *p)
{
q = movrr(q, rs, REGPC, p);
if(foreign){ // BX rs
q->as = ABXRET;
q->from.type = D_NONE;
q->from.reg = NREG;
q->to.reg = rs;
}
return q;
}
static Prog *
aword(int32 w, Prog *p)
{
Prog *q;
q = prg();
q->as = AWORD;
q->line = p->line;
q->from.type = D_NONE;
q->reg = NREG;
q->to.type = D_CONST;
q->to.offset = w;
q->link = p->link;
p->link = q;
return q;
}
static Prog *
adword(int32 w1, int32 w2, Prog *p)
{
Prog *q;
q = prg();
q->as = ADWORD;
q->line = p->line;
q->from.type = D_CONST;
q->from.offset = w1;
q->reg = NREG;
q->to.type = D_CONST;
q->to.offset = w2;
q->link = p->link;
p->link = q;
return q;
}
void
noops(void)
{
Prog *p, *q, *q1, *q2;
int o, foreign;
Prog *pmorestack;
Sym *symmorestack;
/*
* find leaf subroutines
* strip NOPs
* expand RET
* expand BECOME pseudo
*/
if(debug['v'])
Bprint(&bso, "%5.2f noops\n", cputime());
Bflush(&bso);
symmorestack = lookup("runtime.morestack", 0);
if(symmorestack->type != STEXT) {
diag("runtime·morestack not defined");
errorexit();
}
pmorestack = symmorestack->text;
pmorestack->reg |= NOSPLIT;
q = P;
for(cursym = textp; cursym != nil; cursym = cursym->next) {
for(p = cursym->text; p != P; p = p->link) {
setarch(p);
switch(p->as) {
case ATEXT:
p->mark |= LEAF;
break;
case ARET:
break;
case ADIV:
case ADIVU:
case AMOD:
case AMODU:
q = p;
if(prog_div == P)
initdiv();
cursym->text->mark &= ~LEAF;
setdiv(p->as);
continue;
case ANOP:
q1 = p->link;
q->link = q1; /* q is non-nop */
if(q1 != P)
q1->mark |= p->mark;
continue;
case ABL:
case ABX:
cursym->text->mark &= ~LEAF;
case ABCASE:
case AB:
case ABEQ:
case ABNE:
case ABCS:
case ABHS:
case ABCC:
case ABLO:
case ABMI:
case ABPL:
case ABVS:
case ABVC:
case ABHI:
case ABLS:
case ABGE:
case ABLT:
case ABGT:
case ABLE:
q1 = p->cond;
if(q1 != P) {
while(q1->as == ANOP) {
q1 = q1->link;
p->cond = q1;
}
}
break;
}
q = p;
}
}
for(cursym = textp; cursym != nil; cursym = cursym->next) {
for(p = cursym->text; p != P; p = p->link) {
setarch(p);
o = p->as;
switch(o) {
case ATEXT:
autosize = p->to.offset + 4;
if(autosize <= 4)
if(cursym->text->mark & LEAF) {
p->to.offset = -4;
autosize = 0;
}
if(!autosize && !(cursym->text->mark & LEAF)) {
if(debug['v'])
Bprint(&bso, "save suppressed in: %s\n",
cursym->name);
Bflush(&bso);
cursym->text->mark |= LEAF;
}
#ifdef CALLEEBX
if(p->from.sym->foreign){
if(thumb)
// don't allow literal pool to seperate these
p = adword(0xe28f7001, 0xe12fff17, p); // arm add 1, pc, r7 and bx r7
// p = aword(0xe12fff17, aword(0xe28f7001, p)); // arm add 1, pc, r7 and bx r7
else
p = aword(0x4778, p); // thumb bx pc and 2 bytes padding
}
#endif
if(cursym->text->mark & LEAF) {
cursym->leaf = 1;
if(!autosize)
break;
}
if(thumb){
if(!(p->reg & NOSPLIT))
diag("stack splitting not supported in thumb");
if(!(cursym->text->mark & LEAF)){
q = movrr(nil, REGLINK, REGTMPT-1, p);
p->link = q;
q1 = prg();
q1->as = AMOVW;
q1->line = p->line;
q1->from.type = D_REG;
q1->from.reg = REGTMPT-1;
q1->to.type = D_OREG;
q1->to.name = D_NONE;
q1->to.reg = REGSP;
q1->to.offset = 0;
q1->link = q->link;
q->link = q1;
}
if(autosize){
q2 = prg();
q2->as = ASUB;
q2->line = p->line;
q2->from.type = D_CONST;
q2->from.offset = autosize;
q2->to.type = D_REG;
q2->to.reg = REGSP;
q2->link = p->link;
p->link = q2;
}
break;
}
if(p->reg & NOSPLIT) {
q1 = prg();
q1->as = AMOVW;
q1->scond |= C_WBIT;
q1->line = p->line;
q1->from.type = D_REG;
q1->from.reg = REGLINK;
q1->to.type = D_OREG;
q1->to.offset = -autosize;
q1->to.reg = REGSP;
q1->link = p->link;
p->link = q1;
} else if (autosize < StackBig) {
// split stack check for small functions
// MOVW g_stackguard(g), R1
// CMP R1, $-autosize(SP)
// MOVW.LO $autosize, R1
// MOVW.LO $args, R2
// MOVW.LO R14, R3
// BL.LO runtime.morestack(SB) // modifies LR
// MOVW.W R14,$-autosize(SP)
// TODO(kaib): add more trampolines
// TODO(kaib): put stackguard in register
// TODO(kaib): add support for -K and underflow detection
// MOVW g_stackguard(g), R1
p = appendp(p);
p->as = AMOVW;
p->from.type = D_OREG;
p->from.reg = REGG;
p->to.type = D_REG;
p->to.reg = 1;
if(autosize < StackSmall) {
// CMP R1, SP
p = appendp(p);
p->as = ACMP;
p->from.type = D_REG;
p->from.reg = 1;
p->reg = REGSP;
} else {
// MOVW $-autosize(SP), R2
// CMP R1, R2
p = appendp(p);
p->as = AMOVW;
p->from.type = D_CONST;
p->from.reg = REGSP;
p->from.offset = -autosize;
p->to.type = D_REG;
p->to.reg = 2;
p = appendp(p);
p->as = ACMP;
p->from.type = D_REG;
p->from.reg = 1;
p->reg = 2;
}
// MOVW.LO $autosize, R1
p = appendp(p);
p->as = AMOVW;
p->scond = C_SCOND_LO;
p->from.type = D_CONST;
p->from.offset = 0;
p->to.type = D_REG;
p->to.reg = 1;
// MOVW.LO $args, R2
p = appendp(p);
p->as = AMOVW;
p->scond = C_SCOND_LO;
p->from.type = D_CONST;
p->from.offset = (cursym->text->to.offset2 + 3) & ~3;
p->to.type = D_REG;
p->to.reg = 2;
// MOVW.LO R14, R3
p = appendp(p);
p->as = AMOVW;
p->scond = C_SCOND_LO;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_REG;
p->to.reg = 3;
// BL.LO runtime.morestack(SB) // modifies LR
p = appendp(p);
p->as = ABL;
p->scond = C_SCOND_LO;
p->to.type = D_BRANCH;
p->to.sym = symmorestack;
p->cond = pmorestack;
// MOVW.W R14,$-autosize(SP)
p = appendp(p);
p->as = AMOVW;
p->scond |= C_WBIT;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_OREG;
p->to.offset = -autosize;
p->to.reg = REGSP;
} else { // > StackBig
// MOVW $autosize, R1
// MOVW $args, R2
// MOVW R14, R3
// BL runtime.morestack(SB) // modifies LR
// MOVW.W R14,$-autosize(SP)
// MOVW $autosize, R1
p = appendp(p);
p->as = AMOVW;
p->from.type = D_CONST;
p->from.offset = autosize;
p->to.type = D_REG;
p->to.reg = 1;
// MOVW $args, R2
// also need to store the extra 4 bytes.
p = appendp(p);
p->as = AMOVW;
p->from.type = D_CONST;
p->from.offset = (cursym->text->to.offset2 + 3) & ~3;
p->to.type = D_REG;
p->to.reg = 2;
// MOVW R14, R3
p = appendp(p);
p->as = AMOVW;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_REG;
p->to.reg = 3;
// BL runtime.morestack(SB) // modifies LR
p = appendp(p);
p->as = ABL;
p->to.type = D_BRANCH;
p->to.sym = symmorestack;
p->cond = pmorestack;
// MOVW.W R14,$-autosize(SP)
p = appendp(p);
p->as = AMOVW;
p->scond |= C_WBIT;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_OREG;
p->to.offset = -autosize;
p->to.reg = REGSP;
}
break;
case ARET:
nocache(p);
foreign = seenthumb && (cursym->foreign || cursym->fnptr);
// print("%s %d %d\n", cursym->name, cursym->foreign, cursym->fnptr);
if(cursym->text->mark & LEAF) {
if(!autosize) {
if(thumb){
p = fnret(p, REGLINK, foreign, p);
break;
}
// if(foreign) print("ABXRET 1 %s\n", cursym->name);
p->as = foreign ? ABXRET : AB;
p->from = zprg.from;
p->to.type = D_OREG;
p->to.offset = 0;
p->to.reg = REGLINK;
break;
}
}
if(thumb){
if(cursym->text->mark & LEAF){
if(autosize){
p->as = AADD;
p->from.type = D_CONST;
p->from.offset = autosize;
p->to.type = D_REG;
p->to.reg = REGSP;
q = nil;
}
else
q = p;
q = fnret(q, REGLINK, foreign, p);
if(q != p)
p->link = q;
}
else{
p->as = AMOVW;
p->from.type = D_OREG;
p->from.name = D_NONE;
p->from.reg = REGSP;
p->from.offset = 0;
p->to.type = D_REG;
p->to.reg = REGTMPT-1;
if(autosize){
q = prg();
q->as = AADD;
q->from.type = D_CONST;
q->from.offset = autosize;
q->to.type = D_REG;
q->to.reg = REGSP;
q->link = p->link;
p->link = q;
}
else
q = p;
q1 = fnret(nil, REGTMPT-1, foreign, p);
q1->link = q->link;
q->link = q1;
}
break;
}
if(foreign) {
// if(foreign) print("ABXRET 3 %s\n", cursym->name);
#define R 1
p->as = AMOVW;
p->from.type = D_OREG;
p->from.name = D_NONE;
p->from.reg = REGSP;
p->from.offset = 0;
p->to.type = D_REG;
p->to.reg = R;
q = prg();
q->as = AADD;
q->scond = p->scond;
q->line = p->line;
q->from.type = D_CONST;
q->from.offset = autosize;
q->to.type = D_REG;
q->to.reg = REGSP;
q->link = p->link;
p->link = q;
q1 = prg();
q1->as = ABXRET;
q1->scond = p->scond;
q1->line = p->line;
q1->to.type = D_OREG;
q1->to.offset = 0;
q1->to.reg = R;
q1->link = q->link;
q->link = q1;
#undef R
}
else {
p->as = AMOVW;
p->scond |= C_PBIT;
p->from.type = D_OREG;
p->from.offset = autosize;
p->from.reg = REGSP;
p->to.type = D_REG;
p->to.reg = REGPC;
}
break;
case ADIV:
case ADIVU:
case AMOD:
case AMODU:
if(debug['M'])
break;
if(p->from.type != D_REG)
break;
if(p->to.type != D_REG)
break;
q1 = p;
/* MOV a,4(SP) */
q = prg();
q->link = p->link;
p->link = q;
p = q;
p->as = AMOVW;
p->line = q1->line;
p->from.type = D_REG;
p->from.reg = q1->from.reg;
p->to.type = D_OREG;
p->to.reg = REGSP;
p->to.offset = 4;
/* MOV b,REGTMP */
q = prg();
q->link = p->link;
p->link = q;
p = q;
p->as = AMOVW;
p->line = q1->line;
p->from.type = D_REG;
p->from.reg = q1->reg;
if(q1->reg == NREG)
p->from.reg = q1->to.reg;
p->to.type = D_REG;
p->to.reg = prog_div->from.sym->thumb ? REGTMPT : REGTMP;
p->to.offset = 0;
/* CALL appropriate */
q = prg();
q->link = p->link;
p->link = q;
p = q;
#ifdef CALLEEBX
p->as = ABL;
#else
if(prog_div->from.sym->thumb)
p->as = thumb ? ABL : ABX;
else
p->as = thumb ? ABX : ABL;
#endif
p->line = q1->line;
p->to.type = D_BRANCH;
p->cond = p;
switch(o) {
case ADIV:
p->cond = prog_div;
p->to.sym = sym_div;
break;
case ADIVU:
p->cond = prog_divu;
p->to.sym = sym_divu;
break;
case AMOD:
p->cond = prog_mod;
p->to.sym = sym_mod;
break;
case AMODU:
p->cond = prog_modu;
p->to.sym = sym_modu;
break;
}
/* MOV REGTMP, b */
q = prg();
q->link = p->link;
p->link = q;
p = q;
p->as = AMOVW;
p->line = q1->line;
p->from.type = D_REG;
p->from.reg = prog_div->from.sym->thumb ? REGTMPT : REGTMP;
p->from.offset = 0;
p->to.type = D_REG;
p->to.reg = q1->to.reg;
/* ADD $8,SP */
q = prg();
q->link = p->link;
p->link = q;
p = q;
p->as = AADD;
p->from.type = D_CONST;
p->from.reg = NREG;
p->from.offset = 8;
p->reg = NREG;
p->to.type = D_REG;
p->to.reg = REGSP;
/* SUB $8,SP */
q1->as = ASUB;
q1->from.type = D_CONST;
q1->from.offset = 8;
q1->from.reg = NREG;
q1->reg = NREG;
q1->to.type = D_REG;
q1->to.reg = REGSP;
break;
case AMOVW:
if(thumb){
Adr *a = &p->from;
if(a->type == D_CONST && ((a->name == D_NONE && a->reg == REGSP) || a->name == D_AUTO || a->name == D_PARAM) && (a->offset & 3))
diag("SP offset not multiple of 4");
}
break;
case AMOVB:
case AMOVBU:
case AMOVH:
case AMOVHU:
if(thumb){
if(p->from.type == D_OREG && (p->from.name == D_AUTO || p->from.name == D_PARAM || (p->from.name == D_CONST && p->from.reg == REGSP))){
q = prg();
*q = *p;
if(p->from.name == D_AUTO)
q->from.offset += autosize;
else if(p->from.name == D_PARAM)
q->from.offset += autosize+4;
q->from.name = D_NONE;
q->from.reg = REGTMPT;
p = movrr(p, REGSP, REGTMPT, p);
q->link = p->link;
p->link = q;
}
if(p->to.type == D_OREG && (p->to.name == D_AUTO || p->to.name == D_PARAM || (p->to.name == D_CONST && p->to.reg == REGSP))){
q = prg();
*q = *p;
if(p->to.name == D_AUTO)
q->to.offset += autosize;
else if(p->to.name == D_PARAM)
q->to.offset += autosize+4;
q->to.name = D_NONE;
q->to.reg = REGTMPT;
p = movrr(p, REGSP, REGTMPT, p);
q->link = p->link;
p->link = q;
if(q->to.offset < 0 || q->to.offset > 255){ // complicated
p->to.reg = REGTMPT+1; // mov sp, r8
q1 = prg();
q1->line = p->line;
q1->as = AMOVW;
q1->from.type = D_CONST;
q1->from.offset = q->to.offset;
q1->to.type = D_REG;
q1->to.reg = REGTMPT; // mov $o, r7
p->link = q1;
q1->link = q;
q1 = prg();
q1->line = p->line;
q1->as = AADD;
q1->from.type = D_REG;
q1->from.reg = REGTMPT+1;
q1->to.type = D_REG;
q1->to.reg = REGTMPT; // add r8, r7
p->link->link = q1;
q1->link = q;
q->to.offset = 0; // mov* r, 0(r7)
/* phew */
}
}
}
break;
case AMOVM:
if(thumb){
if(p->from.type == D_OREG){
if(p->from.offset == 0)
p->from.type = D_REG;
else
diag("non-zero AMOVM offset");
}
else if(p->to.type == D_OREG){
if(p->to.offset == 0)
p->to.type = D_REG;
else
diag("non-zero AMOVM offset");
}
}
break;
case AB:
if(thumb && p->to.type == D_OREG){
if(p->to.offset == 0){
p->as = AMOVW;
p->from.type = D_REG;
p->from.reg = p->to.reg;
p->to.type = D_REG;
p->to.reg = REGPC;
}
else{
p->as = AADD;
p->from.type = D_CONST;
p->from.offset = p->to.offset;
p->reg = p->to.reg;
p->to.type = D_REG;
p->to.reg = REGTMPT-1;
q = prg();
q->as = AMOVW;
q->line = p->line;
q->from.type = D_REG;
q->from.reg = REGTMPT-1;
q->to.type = D_REG;
q->to.reg = REGPC;
q->link = p->link;
p->link = q;
}
}
if(seenthumb && !thumb && p->to.type == D_OREG && p->to.reg == REGLINK){
// print("warn %s: b (R%d) assuming a return\n", cursym->name, p->to.reg);
p->as = ABXRET;
}
break;
case ABL:
case ABX:
if(thumb && p->to.type == D_OREG){
if(p->to.offset == 0){
p->as = o;
p->from.type = D_NONE;
p->to.type = D_REG;
}
else{
p->as = AADD;
p->from.type = D_CONST;
p->from.offset = p->to.offset;
p->reg = p->to.reg;
p->to.type = D_REG;
p->to.reg = REGTMPT-1;
q = prg();
q->as = o;
q->line = p->line;
q->from.type = D_NONE;
q->to.type = D_REG;
q->to.reg = REGTMPT-1;
q->link = p->link;
p->link = q;
}
}
break;
}
}
}
}
static void
sigdiv(char *n)
{
Sym *s;
s = lookup(n, 0);
if(s->type == STEXT)
if(s->sig == 0)
s->sig = SIGNINTERN;
}
void
divsig(void)
{
sigdiv("_div");
sigdiv("_divu");
sigdiv("_mod");
sigdiv("_modu");
}
void
initdiv(void)
{
Sym *s2, *s3, *s4, *s5;
if(prog_div != P)
return;
sym_div = s2 = lookup("_div", 0);
sym_divu = s3 = lookup("_divu", 0);
sym_mod = s4 = lookup("_mod", 0);
sym_modu = s5 = lookup("_modu", 0);
prog_div = s2->text;
prog_divu = s3->text;
prog_mod = s4->text;
prog_modu = s5->text;
if(prog_div == P) {
diag("undefined: %s", s2->name);
prog_div = cursym->text;
}
if(prog_divu == P) {
diag("undefined: %s", s3->name);
prog_divu = cursym->text;
}
if(prog_mod == P) {
diag("undefined: %s", s4->name);
prog_mod = cursym->text;
}
if(prog_modu == P) {
diag("undefined: %s", s5->name);
prog_modu = cursym->text;
}
}
static void
setdiv(int as)
{
Prog *p = nil;
switch(as){
case ADIV: p = prog_div; break;
case ADIVU: p = prog_divu; break;
case AMOD: p = prog_mod; break;
case AMODU: p = prog_modu; break;
}
if(thumb != p->from.sym->thumb)
p->from.sym->foreign = 1;
}
void
nocache(Prog *p)
{
p->optab = 0;
p->from.class = 0;
p->to.class = 0;
}
View Git Blame Copy Permalink