Imported Upstream version 1.4upstream/1.4

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,