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-rw-r--r--src/liblink/obj8.c129
1 files changed, 76 insertions, 53 deletions
diff --git a/src/liblink/obj8.c b/src/liblink/obj8.c
index 72934c149..f54153ae9 100644
--- a/src/liblink/obj8.c
+++ b/src/liblink/obj8.c
@@ -33,7 +33,7 @@
#include <bio.h>
#include <link.h>
#include "../cmd/8l/8.out.h"
-#include "../pkg/runtime/stack.h"
+#include "../runtime/stack.h"
static Prog zprg = {
.back = 2,
@@ -261,7 +261,7 @@ static Prog* stacksplit(Link*, Prog*, int32, int, Prog**);
static void
addstacksplit(Link *ctxt, LSym *cursym)
{
- Prog *p, *q;
+ Prog *p, *q, *p1, *p2;
int32 autoffset, deltasp;
int a;
@@ -270,8 +270,8 @@ addstacksplit(Link *ctxt, LSym *cursym)
ctxt->symmorestack[1] = linklookup(ctxt, "runtime.morestack_noctxt", 0);
}
- if(ctxt->headtype == Hplan9 && ctxt->plan9tos == nil)
- ctxt->plan9tos = linklookup(ctxt, "_tos", 0);
+ if(ctxt->headtype == Hplan9 && ctxt->plan9privates == nil)
+ ctxt->plan9privates = linklookup(ctxt, "_privates", 0);
ctxt->cursym = cursym;
@@ -317,13 +317,64 @@ addstacksplit(Link *ctxt, LSym *cursym)
deltasp = autoffset;
if(cursym->text->from.scale & WRAPPER) {
- // g->panicwrap += autoffset + ctxt->arch->ptrsize;
+ // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
+ //
+ // MOVL g_panic(CX), BX
+ // TESTL BX, BX
+ // JEQ end
+ // LEAL (autoffset+4)(SP), DI
+ // CMPL panic_argp(BX), DI
+ // JNE end
+ // MOVL SP, panic_argp(BX)
+ // end:
+ // NOP
+ //
+ // The NOP is needed to give the jumps somewhere to land.
+ // It is a liblink NOP, not an x86 NOP: it encodes to 0 instruction bytes.
+
p = appendp(ctxt, p);
- p->as = AADDL;
- p->from.type = D_CONST;
- p->from.offset = autoffset + ctxt->arch->ptrsize;
- p->to.type = D_INDIR+D_CX;
- p->to.offset = 2*ctxt->arch->ptrsize;
+ p->as = AMOVL;
+ p->from.type = D_INDIR+D_CX;
+ p->from.offset = 4*ctxt->arch->ptrsize; // G.panic
+ p->to.type = D_BX;
+
+ p = appendp(ctxt, p);
+ p->as = ATESTL;
+ p->from.type = D_BX;
+ p->to.type = D_BX;
+
+ p = appendp(ctxt, p);
+ p->as = AJEQ;
+ p->to.type = D_BRANCH;
+ p1 = p;
+
+ p = appendp(ctxt, p);
+ p->as = ALEAL;
+ p->from.type = D_INDIR+D_SP;
+ p->from.offset = autoffset+4;
+ p->to.type = D_DI;
+
+ p = appendp(ctxt, p);
+ p->as = ACMPL;
+ p->from.type = D_INDIR+D_BX;
+ p->from.offset = 0; // Panic.argp
+ p->to.type = D_DI;
+
+ p = appendp(ctxt, p);
+ p->as = AJNE;
+ p->to.type = D_BRANCH;
+ p2 = p;
+
+ p = appendp(ctxt, p);
+ p->as = AMOVL;
+ p->from.type = D_SP;
+ p->to.type = D_INDIR+D_BX;
+ p->to.offset = 0; // Panic.argp
+
+ p = appendp(ctxt, p);
+ p->as = ANOP;
+ p1->pcond = p;
+ p2->pcond = p;
}
if(ctxt->debugzerostack && autoffset && !(cursym->text->from.scale&NOSPLIT)) {
@@ -396,19 +447,6 @@ addstacksplit(Link *ctxt, LSym *cursym)
if(autoffset != deltasp)
ctxt->diag("unbalanced PUSH/POP");
- if(cursym->text->from.scale & WRAPPER) {
- p = load_g_cx(ctxt, p);
- p = appendp(ctxt, p);
- // g->panicwrap -= autoffset + ctxt->arch->ptrsize;
- p->as = ASUBL;
- p->from.type = D_CONST;
- p->from.offset = autoffset + ctxt->arch->ptrsize;
- p->to.type = D_INDIR+D_CX;
- p->to.offset = 2*ctxt->arch->ptrsize;
- p = appendp(ctxt, p);
- p->as = ARET;
- }
-
if(autoffset) {
p->as = AADJSP;
p->from.type = D_CONST;
@@ -463,7 +501,6 @@ static Prog*
stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt, Prog **jmpok)
{
Prog *q, *q1;
- int arg;
if(ctxt->debugstack) {
// 8l -K means check not only for stack
@@ -501,6 +538,9 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt, Prog **jmpok)
p->as = ACMPL;
p->from.type = D_SP;
p->to.type = D_INDIR+D_CX;
+ p->to.offset = 2*ctxt->arch->ptrsize; // G.stackguard0
+ if(ctxt->cursym->cfunc)
+ p->to.offset = 3*ctxt->arch->ptrsize; // G.stackguard1
} else if(framesize <= StackBig) {
// large stack: SP-framesize <= stackguard-StackSmall
// LEAL -(framesize-StackSmall)(SP), AX
@@ -515,6 +555,9 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt, Prog **jmpok)
p->as = ACMPL;
p->from.type = D_AX;
p->to.type = D_INDIR+D_CX;
+ p->to.offset = 2*ctxt->arch->ptrsize; // G.stackguard0
+ if(ctxt->cursym->cfunc)
+ p->to.offset = 3*ctxt->arch->ptrsize; // G.stackguard1
} else {
// Such a large stack we need to protect against wraparound
// if SP is close to zero.
@@ -534,6 +577,9 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt, Prog **jmpok)
p->as = AMOVL;
p->from.type = D_INDIR+D_CX;
p->from.offset = 0;
+ p->from.offset = 2*ctxt->arch->ptrsize; // G.stackguard0
+ if(ctxt->cursym->cfunc)
+ p->from.offset = 3*ctxt->arch->ptrsize; // G.stackguard1
p->to.type = D_SI;
p = appendp(ctxt, p);
@@ -573,37 +619,13 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt, Prog **jmpok)
p->to.offset = 4;
q = p;
- p = appendp(ctxt, p); // save frame size in DI
- p->as = AMOVL;
- p->to.type = D_DI;
- p->from.type = D_CONST;
-
- // If we ask for more stack, we'll get a minimum of StackMin bytes.
- // We need a stack frame large enough to hold the top-of-stack data,
- // the function arguments+results, our caller's PC, our frame,
- // a word for the return PC of the next call, and then the StackLimit bytes
- // that must be available on entry to any function called from a function
- // that did a stack check. If StackMin is enough, don't ask for a specific
- // amount: then we can use the custom functions and save a few
- // instructions.
- if(StackTop + ctxt->cursym->text->to.offset2 + ctxt->arch->ptrsize + framesize + ctxt->arch->ptrsize + StackLimit >= StackMin)
- p->from.offset = (framesize+7) & ~7LL;
-
- arg = ctxt->cursym->text->to.offset2;
- if(arg == 1) // special marker for known 0
- arg = 0;
- if(arg&3)
- ctxt->diag("misaligned argument size in stack split");
- p = appendp(ctxt, p); // save arg size in AX
- p->as = AMOVL;
- p->to.type = D_AX;
- p->from.type = D_CONST;
- p->from.offset = arg;
-
p = appendp(ctxt, p);
p->as = ACALL;
p->to.type = D_BRANCH;
- p->to.sym = ctxt->symmorestack[noctxt];
+ if(ctxt->cursym->cfunc)
+ p->to.sym = linklookup(ctxt, "runtime.morestackc", 0);
+ else
+ p->to.sym = ctxt->symmorestack[noctxt];
p = appendp(ctxt, p);
p->as = AJMP;
@@ -697,7 +719,7 @@ xfol(Link *ctxt, Prog *p, Prog **last)
{
Prog *q;
int i;
- enum as a;
+ int a;
loop:
if(p == nil)
@@ -816,6 +838,7 @@ loop:
LinkArch link386 = {
.name = "386",
.thechar = '8',
+ .endian = LittleEndian,
.addstacksplit = addstacksplit,
.assemble = span8,
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-28 18:07:44 +0000