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Diffstat (limited to 'src/liblink/obj5.c')
-rw-r--r--src/liblink/obj5.c250
1 files changed, 138 insertions, 112 deletions
diff --git a/src/liblink/obj5.c b/src/liblink/obj5.c
index ccd4c81c7..d7f2714ed 100644
--- a/src/liblink/obj5.c
+++ b/src/liblink/obj5.c
@@ -33,7 +33,7 @@
#include <bio.h>
#include <link.h>
#include "../cmd/5l/5.out.h"
-#include "../pkg/runtime/stack.h"
+#include "../runtime/stack.h"
static Prog zprg = {
.as = AGOK,
@@ -92,7 +92,7 @@ progedit(Link *ctxt, Prog *p)
{
char literal[64];
LSym *s;
- LSym *tlsfallback;
+ static LSym *tlsfallback;
p->from.class = 0;
p->to.class = 0;
@@ -111,19 +111,43 @@ progedit(Link *ctxt, Prog *p)
// Replace TLS register fetches on older ARM procesors.
switch(p->as) {
case AMRC:
- // If the instruction matches MRC 15, 0, <reg>, C13, C0, 3, replace it.
- if(ctxt->goarm < 7 && (p->to.offset & 0xffff0fff) == 0xee1d0f70) {
- tlsfallback = linklookup(ctxt, "runtime.read_tls_fallback", 0);
+ // Treat MRC 15, 0, <reg>, C13, C0, 3 specially.
+ if((p->to.offset & 0xffff0fff) == 0xee1d0f70) {
+ // Because the instruction might be rewriten to a BL which returns in R0
+ // the register must be zero.
+ if ((p->to.offset & 0xf000) != 0)
+ ctxt->diag("%L: TLS MRC instruction must write to R0 as it might get translated into a BL instruction", p->lineno);
+
+ if(ctxt->goarm < 7) {
+ // Replace it with BL runtime.read_tls_fallback(SB) for ARM CPUs that lack the tls extension.
+ if(tlsfallback == nil)
+ tlsfallback = linklookup(ctxt, "runtime.read_tls_fallback", 0);
+ // MOVW LR, R11
+ p->as = AMOVW;
+ p->from.type = D_REG;
+ p->from.reg = REGLINK;
+ p->to.type = D_REG;
+ p->to.reg = REGTMP;
- // BL runtime.read_tls_fallback(SB)
- p->as = ABL;
- p->to.type = D_BRANCH;
- p->to.sym = tlsfallback;
- p->to.offset = 0;
- } else {
- // Otherwise, MRC/MCR instructions need no further treatment.
- p->as = AWORD;
+ // BL runtime.read_tls_fallback(SB)
+ p = appendp(ctxt, p);
+ p->as = ABL;
+ p->to.type = D_BRANCH;
+ p->to.sym = tlsfallback;
+ p->to.offset = 0;
+
+ // MOVW R11, LR
+ p = appendp(ctxt, p);
+ p->as = AMOVW;
+ p->from.type = D_REG;
+ p->from.reg = REGTMP;
+ p->to.type = D_REG;
+ p->to.reg = REGLINK;
+ break;
+ }
}
+ // Otherwise, MRC/MCR instructions need no further treatment.
+ p->as = AWORD;
break;
}
@@ -173,15 +197,15 @@ progedit(Link *ctxt, Prog *p)
if(ctxt->flag_shared) {
// Shared libraries use R_ARM_TLS_IE32 instead of
// R_ARM_TLS_LE32, replacing the link time constant TLS offset in
- // runtime.tlsgm with an address to a GOT entry containing the
- // offset. Rewrite $runtime.tlsgm(SB) to runtime.tlsgm(SB) to
+ // runtime.tlsg with an address to a GOT entry containing the
+ // offset. Rewrite $runtime.tlsg(SB) to runtime.tlsg(SB) to
// compensate.
- if(ctxt->gmsym == nil)
- ctxt->gmsym = linklookup(ctxt, "runtime.tlsgm", 0);
+ if(ctxt->tlsg == nil)
+ ctxt->tlsg = linklookup(ctxt, "runtime.tlsg", 0);
- if(p->from.type == D_CONST && p->from.name == D_EXTERN && p->from.sym == ctxt->gmsym)
+ if(p->from.type == D_CONST && p->from.name == D_EXTERN && p->from.sym == ctxt->tlsg)
p->from.type = D_OREG;
- if(p->to.type == D_CONST && p->to.name == D_EXTERN && p->to.sym == ctxt->gmsym)
+ if(p->to.type == D_CONST && p->to.name == D_EXTERN && p->to.sym == ctxt->tlsg)
p->to.type = D_OREG;
}
}
@@ -233,7 +257,7 @@ nocache(Prog *p)
static void
addstacksplit(Link *ctxt, LSym *cursym)
{
- Prog *p, *pl, *q, *q1, *q2;
+ Prog *p, *pl, *p1, *p2, *q, *q1, *q2;
int o;
int32 autosize, autoffset;
@@ -429,32 +453,89 @@ addstacksplit(Link *ctxt, LSym *cursym)
p->spadj = autosize;
if(cursym->text->reg & WRAPPER) {
- // g->panicwrap += autosize;
- // MOVW panicwrap_offset(g), R3
- // ADD $autosize, R3
- // MOVW R3 panicwrap_offset(g)
+ // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
+ //
+ // MOVW g_panic(g), R1
+ // CMP $0, R1
+ // B.EQ end
+ // MOVW panic_argp(R1), R2
+ // ADD $(autosize+4), R13, R3
+ // CMP R2, R3
+ // B.NE end
+ // ADD $4, R13, R4
+ // MOVW R4, panic_argp(R1)
+ // end:
+ // NOP
+ //
+ // The NOP is needed to give the jumps somewhere to land.
+ // It is a liblink NOP, not an ARM NOP: it encodes to 0 instruction bytes.
+
p = appendp(ctxt, p);
p->as = AMOVW;
p->from.type = D_OREG;
p->from.reg = REGG;
- p->from.offset = 2*ctxt->arch->ptrsize;
+ p->from.offset = 4*ctxt->arch->ptrsize; // G.panic
p->to.type = D_REG;
- p->to.reg = 3;
+ p->to.reg = 1;
+
+ p = appendp(ctxt, p);
+ p->as = ACMP;
+ p->from.type = D_CONST;
+ p->from.offset = 0;
+ p->reg = 1;
+
+ p = appendp(ctxt, p);
+ p->as = ABEQ;
+ p->to.type = D_BRANCH;
+ p1 = p;
+
+ p = appendp(ctxt, p);
+ p->as = AMOVW;
+ p->from.type = D_OREG;
+ p->from.reg = 1;
+ p->from.offset = 0; // Panic.argp
+ p->to.type = D_REG;
+ p->to.reg = 2;
p = appendp(ctxt, p);
p->as = AADD;
p->from.type = D_CONST;
- p->from.offset = autosize;
+ p->from.offset = autosize+4;
+ p->reg = 13;
p->to.type = D_REG;
p->to.reg = 3;
-
+
+ p = appendp(ctxt, p);
+ p->as = ACMP;
+ p->from.type = D_REG;
+ p->from.reg = 2;
+ p->reg = 3;
+
+ p = appendp(ctxt, p);
+ p->as = ABNE;
+ p->to.type = D_BRANCH;
+ p2 = p;
+
+ p = appendp(ctxt, p);
+ p->as = AADD;
+ p->from.type = D_CONST;
+ p->from.offset = 4;
+ p->reg = 13;
+ p->to.type = D_REG;
+ p->to.reg = 4;
+
p = appendp(ctxt, p);
p->as = AMOVW;
p->from.type = D_REG;
- p->from.reg = 3;
+ p->from.reg = 4;
p->to.type = D_OREG;
- p->to.reg = REGG;
- p->to.offset = 2*ctxt->arch->ptrsize;
+ p->to.reg = 1;
+ p->to.offset = 0; // Panic.argp
+
+ p = appendp(ctxt, p);
+ p->as = ANOP;
+ p1->pcond = p;
+ p2->pcond = p;
}
break;
@@ -475,44 +556,6 @@ addstacksplit(Link *ctxt, LSym *cursym)
}
}
- if(cursym->text->reg & WRAPPER) {
- int scond;
-
- // Preserve original RET's cond, to allow RET.EQ
- // in the implementation of reflect.call.
- scond = p->scond;
- p->scond = C_SCOND_NONE;
-
- // g->panicwrap -= autosize;
- // MOVW panicwrap_offset(g), R3
- // SUB $autosize, R3
- // MOVW R3 panicwrap_offset(g)
- p->as = AMOVW;
- p->from.type = D_OREG;
- p->from.reg = REGG;
- p->from.offset = 2*ctxt->arch->ptrsize;
- p->to.type = D_REG;
- p->to.reg = 3;
- p = appendp(ctxt, p);
-
- p->as = ASUB;
- p->from.type = D_CONST;
- p->from.offset = autosize;
- p->to.type = D_REG;
- p->to.reg = 3;
- p = appendp(ctxt, p);
-
- p->as = AMOVW;
- p->from.type = D_REG;
- p->from.reg = 3;
- p->to.type = D_OREG;
- p->to.reg = REGG;
- p->to.offset = 2*ctxt->arch->ptrsize;
- p = appendp(ctxt, p);
-
- p->scond = scond;
- }
-
p->as = AMOVW;
p->scond |= C_PBIT;
p->from.type = D_OREG;
@@ -707,41 +750,42 @@ softfloat(Link *ctxt, LSym *cursym)
default:
goto notsoft;
+ }
- soft:
- if (!wasfloat || (p->mark&LABEL)) {
- next = ctxt->arch->prg();
- *next = *p;
+ soft:
+ if (!wasfloat || (p->mark&LABEL)) {
+ next = ctxt->arch->prg();
+ *next = *p;
- // BL _sfloat(SB)
- *p = zprg;
- p->link = next;
- p->as = ABL;
+ // BL _sfloat(SB)
+ *p = zprg;
+ p->link = next;
+ p->as = ABL;
p->to.type = D_BRANCH;
- p->to.sym = symsfloat;
- p->lineno = next->lineno;
-
- p = next;
- wasfloat = 1;
- }
- break;
+ p->to.sym = symsfloat;
+ p->lineno = next->lineno;
- notsoft:
- wasfloat = 0;
+ p = next;
+ wasfloat = 1;
}
+ continue;
+
+ notsoft:
+ wasfloat = 0;
}
}
static Prog*
stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt)
{
- int32 arg;
-
// MOVW g_stackguard(g), R1
p = appendp(ctxt, p);
p->as = AMOVW;
p->from.type = D_OREG;
p->from.reg = REGG;
+ 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_REG;
p->to.reg = 1;
@@ -820,29 +864,6 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt)
p->scond = C_SCOND_NE;
}
- // MOVW.LS $framesize, R1
- p = appendp(ctxt, p);
- p->as = AMOVW;
- p->scond = C_SCOND_LS;
- p->from.type = D_CONST;
- p->from.offset = framesize;
- p->to.type = D_REG;
- p->to.reg = 1;
-
- // MOVW.LS $args, R2
- p = appendp(ctxt, p);
- p->as = AMOVW;
- p->scond = C_SCOND_LS;
- p->from.type = D_CONST;
- 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->from.offset = arg;
- p->to.type = D_REG;
- p->to.reg = 2;
-
// MOVW.LS R14, R3
p = appendp(ctxt, p);
p->as = AMOVW;
@@ -857,7 +878,10 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt)
p->as = ABL;
p->scond = C_SCOND_LS;
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];
// BLS start
p = appendp(ctxt, p);
@@ -1025,6 +1049,7 @@ loop:
LinkArch linkarm = {
.name = "arm",
.thechar = '5',
+ .endian = LittleEndian,
.addstacksplit = addstacksplit,
.assemble = span5,
@@ -1052,6 +1077,7 @@ LinkArch linkarm = {
.D_PARAM = D_PARAM,
.D_SCONST = D_SCONST,
.D_STATIC = D_STATIC,
+ .D_OREG = D_OREG,
.ACALL = ABL,
.ADATA = ADATA,
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-28 15:33:03 +0000