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runtime, syscall: use the vdso page on linux x86 for faster syscalls instead of int $0x80.

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8l: fix handling CALL $(constant) code generated by 8a.
8a,8l: add indirect call instruction: CALL *data(SB).

R=rsc, iant
CC=golang-dev
https://golang.org/cl/4817054
This commit is contained in:
Yuval Pavel Zholkover 2011-08-29 10:36:06 -04:00 committed by Russ Cox
parent 88e984faa5
commit c20a338c2f
10 changed files with 100 additions and 32 deletions
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7
src/cmd/8a/a.y
View File

@ -210,6 +210,13 @@ spec3: /* JMP/CALL */
$$.from = nullgen;
$$.to = $1;
}
| '*' nam
{
$$.from = nullgen;
$$.to = $2;
$$.to.index = $2.type;
$$.to.type = D_INDIR+D_ADDR;
}
spec4: /* NOP */
nonnon

1
src/cmd/8l/l.h
View File

@ -209,6 +209,7 @@ enum
Zbr,
Zcall,
Zcallcon,
Zcallind,
Zib_,
Zib_rp,
Zibo_m,

3
src/cmd/8l/optab.c
View File

@ -260,6 +260,7 @@ uchar yloop[] =
uchar ycall[] =
{
Ynone, Yml, Zo_m, 2,
Ynone, Ycol, Zcallind, 2,
Ynone, Ybr, Zcall, 0,
Ynone, Yi32, Zcallcon, 1,
0
@ -383,7 +384,7 @@ Optab optab[] =
{ ABTSL, yml_rl, Pm, 0xab },
{ ABTSW, yml_rl, Pq, 0xab },
{ ABYTE, ybyte, Px, 1 },
{ ACALL, ycall, Px, 0xff,(02),0xe8 },
{ ACALL, ycall, Px, 0xff,(02),0xff,(0x15),0xe8 },
{ ACLC, ynone, Px, 0xf8 },
{ ACLD, ynone, Px, 0xfc },
{ ACLI, ynone, Px, 0xfa },

7
src/cmd/8l/pass.c
View File

@ -307,9 +307,12 @@ patch(void)
p->from.offset = 0;
}
}
if(p->as == ACALL || (p->as == AJMP && p->to.type != D_BRANCH)) {
if((p->as == ACALL && p->to.type != D_BRANCH) || (p->as == AJMP && p->to.type != D_BRANCH)) {
s = p->to.sym;
if(s) {
if(p->to.type == D_INDIR+D_ADDR) {
/* skip check if this is an indirect call (CALL *symbol(SB)) */
continue;
} else if(s) {
if(debug['c'])
Bprint(&bso, "%s calls %s\n", TNAME, s->name);
if((s->type&~SSUB) != STEXT) {

14
src/cmd/8l/span.c
View File

@ -285,6 +285,8 @@ oclass(Adr *a)
}
return Yxxx;
}
//if(a->type == D_INDIR+D_ADDR)
// print("*Ycol\n");
return Ycol;
}
return Ym;
@ -1143,6 +1145,18 @@ found:
r->add = p->to.offset;
put4(0);
break;
case Zcallind:
*andptr++ = op;
*andptr++ = o->op[z+1];
r = addrel(cursym);
r->off = p->pc + andptr - and;
r->type = D_ADDR;
r->siz = 4;
r->add = p->to.offset;
r->sym = p->to.sym;
put4(0);
break;
case Zbyte:
v = vaddr(&p->from, &rel);

6
src/cmd/ld/data.c
View File

@ -182,7 +182,11 @@ relocsym(Sym *s)
o = symaddr(r->sym) + r->add;
break;
case D_PCREL:
o = symaddr(r->sym) + r->add - (s->value + r->off + r->siz);
// r->sym can be null when CALL $(constant) is transformed from absoulte PC to relative PC call.
o = 0;
if(r->sym)
o += symaddr(r->sym);
o += r->add - (s->value + r->off + r->siz);
break;
case D_SIZE:
o = r->sym->size + r->add;

10
src/pkg/runtime/linux/386/rt0.s
View File

@ -5,5 +5,13 @@
// Darwin and Linux use the same linkage to main
TEXT _rt0_386_linux(SB),7,$0
JMP _rt0_386(SB)
CALL runtime·linux_setup_vdso(SB)
JMP _rt0_386(SB)
TEXT _fallback_vdso(SB),7,$0
INT $0x80
RET
DATA runtime·_vdso(SB)/4, $_fallback_vdso(SB)
GLOBL runtime·_vdso(SB), $4

24
src/pkg/runtime/linux/386/signal.c
View File

@ -182,3 +182,27 @@ os·sigpipe(void)
sigaction(SIGPIPE, SIG_DFL, false);
runtime·raisesigpipe();
}
#define AT_NULL 0
#define AT_SYSINFO 32
extern uint32 runtime·_vdso;
#pragma textflag 7
void runtime·linux_setup_vdso(int32 argc, void *argv_list)
{
byte **argv = &argv_list;
byte **envp;
uint32 *auxv;
// skip envp to get to ELF auxiliary vector.
for(envp = &argv[argc+1]; *envp != nil; envp++)
;
envp++;
for(auxv=(uint32*)envp; auxv[0] != AT_NULL; auxv += 2) {
if(auxv[0] == AT_SYSINFO) {
runtime·_vdso = auxv[1];
break;
}
}
}

46
src/pkg/runtime/linux/386/sys.s
View File

@ -11,14 +11,14 @@
TEXT runtime·exit(SB),7,$0
MOVL $252, AX // syscall number
MOVL 4(SP), BX
INT $0x80
CALL *runtime·_vdso(SB)
INT $3 // not reached
RET
TEXT runtime·exit1(SB),7,$0
MOVL $1, AX // exit - exit the current os thread
MOVL 4(SP), BX
INT $0x80
CALL *runtime·_vdso(SB)
INT $3 // not reached
RET
@ -27,13 +27,13 @@ TEXT runtime·open(SB),7,$0
MOVL 4(SP), BX
MOVL 8(SP), CX
MOVL 12(SP), DX
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·close(SB),7,$0
MOVL $6, AX // syscall - close
MOVL 4(SP), BX
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·write(SB),7,$0
@ -41,7 +41,7 @@ TEXT runtime·write(SB),7,$0
MOVL 4(SP), BX
MOVL 8(SP), CX
MOVL 12(SP), DX
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·read(SB),7,$0
@ -49,16 +49,16 @@ TEXT runtime·read(SB),7,$0
MOVL 4(SP), BX
MOVL 8(SP), CX
MOVL 12(SP), DX
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·raisesigpipe(SB),7,$12
MOVL $224, AX // syscall - gettid
INT $0x80
CALL *runtime·_vdso(SB)
MOVL AX, 0(SP) // arg 1 tid
MOVL $13, 4(SP) // arg 2 SIGPIPE
MOVL $238, AX // syscall - tkill
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·setitimer(SB),7,$0-24
@ -66,7 +66,7 @@ TEXT runtime·setitimer(SB),7,$0-24
MOVL 4(SP), BX
MOVL 8(SP), CX
MOVL 12(SP), DX
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·mincore(SB),7,$0-24
@ -74,7 +74,7 @@ TEXT runtime·mincore(SB),7,$0-24
MOVL 4(SP), BX
MOVL 8(SP), CX
MOVL 12(SP), DX
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·gettime(SB), 7, $32
@ -82,7 +82,7 @@ TEXT runtime·gettime(SB), 7, $32
LEAL 8(SP), BX
MOVL $0, CX
MOVL $0, DX
INT $0x80
CALL *runtime·_vdso(SB)
MOVL 8(SP), BX // sec
MOVL sec+0(FP), DI
@ -100,7 +100,7 @@ TEXT runtime·rt_sigaction(SB),7,$0
MOVL 8(SP), CX
MOVL 12(SP), DX
MOVL 16(SP), SI
INT $0x80
CALL *runtime·_vdso(SB)
RET
TEXT runtime·sigtramp(SB),7,$44
@ -138,7 +138,9 @@ TEXT runtime·sigignore(SB),7,$0
TEXT runtime·sigreturn(SB),7,$0
MOVL $173, AX // rt_sigreturn
INT $0x80
// Sigreturn expects same SP as signal handler,
// so cannot CALL *runtime._vsdo(SB) here.
INT $0x80
INT $3 // not reached
RET
@ -151,7 +153,7 @@ TEXT runtime·mmap(SB),7,$0
MOVL 20(SP), DI
MOVL 24(SP), BP
SHRL $12, BP
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS 3(PC)
NOTL AX
@ -162,7 +164,7 @@ TEXT runtime·munmap(SB),7,$0
MOVL $91, AX // munmap
MOVL 4(SP), BX
MOVL 8(SP), CX
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS 2(PC)
INT $3
@ -178,7 +180,7 @@ TEXT runtime·futex(SB),7,$0
MOVL 16(SP), SI
MOVL 20(SP), DI
MOVL 24(SP), BP
INT $0x80
CALL *runtime·_vdso(SB)
RET
// int32 clone(int32 flags, void *stack, M *m, G *g, void (*fn)(void));
@ -199,6 +201,10 @@ TEXT runtime·clone(SB),7,$0
MOVL SI, 8(CX)
MOVL $1234, 12(CX)
// cannot use CALL *runtime·_vdso(SB) here, because
// the stack changes during the system call (after
// CALL *runtime·_vdso(SB), the child is still using
// the parent's stack when executing its RET instruction).
INT $0x80
// In parent, return.
@ -214,7 +220,7 @@ TEXT runtime·clone(SB),7,$0
// Initialize AX to Linux tid
MOVL $224, AX
INT $0x80
CALL *runtime·_vdso(SB)
// In child on new stack. Reload registers (paranoia).
MOVL 0(SP), BX // m
@ -262,7 +268,7 @@ TEXT runtime·sigaltstack(SB),7,$-8
MOVL $186, AX // sigaltstack
MOVL new+4(SP), BX
MOVL old+8(SP), CX
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS 2(PC)
INT $3
@ -323,7 +329,7 @@ TEXT runtime·setldt(SB),7,$32
MOVL AX, CX // user_desc
MOVL $16, DX // sizeof(user_desc)
MOVL $123, AX // syscall - modify_ldt
INT $0x80
CALL *runtime·_vdso(SB)
// breakpoint on error
CMPL AX, $0xfffff001
@ -340,5 +346,5 @@ TEXT runtime·setldt(SB),7,$32
TEXT runtime·osyield(SB),7,$0
MOVL $158, AX
INT $0x80
CALL *runtime·_vdso(SB)
RET

14
src/pkg/syscall/asm_linux_386.s
View File

@ -17,7 +17,7 @@ TEXT ·Syscall(SB),7,$0
MOVL 16(SP), DX
MOVL $0, SI
MOVL $0, DI
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS ok
MOVL $-1, 20(SP) // r1
@ -43,7 +43,7 @@ TEXT ·Syscall6(SB),7,$0
MOVL 20(SP), SI
MOVL 24(SP), DI
MOVL 28(SP), BP
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS ok6
MOVL $-1, 32(SP) // r1
@ -67,7 +67,7 @@ TEXT ·RawSyscall(SB),7,$0
MOVL 16(SP), DX
MOVL $0, SI
MOVL $0, DI
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS ok1
MOVL $-1, 20(SP) // r1
@ -90,7 +90,7 @@ TEXT ·RawSyscall6(SB),7,$0
MOVL 20(SP), SI
MOVL 24(SP), DI
MOVL 28(SP), BP
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS ok2
MOVL $-1, 32(SP) // r1
@ -116,7 +116,7 @@ TEXT ·socketcall(SB),7,$0
MOVL $0, DX
MOVL $0, SI
MOVL $0, DI
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS oksock
MOVL $-1, 32(SP) // n
@ -139,7 +139,7 @@ TEXT ·rawsocketcall(SB),7,$0
MOVL $0, DX
MOVL $0, SI
MOVL $0, DI
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS oksock1
MOVL $-1, 32(SP) // n
@ -165,7 +165,7 @@ TEXT ·Seek(SB),7,$0
MOVL 8(SP), DX // offset-low
LEAL 20(SP), SI // result pointer
MOVL 16(SP), DI // whence
INT $0x80
CALL *runtime·_vdso(SB)
CMPL AX, $0xfffff001
JLS okseek
MOVL $-1, 20(SP) // newoffset low