makes stack traces work for segmented stacks
SVN=125371
diff --git a/src/runtime/rt0_amd64.s b/src/runtime/rt0_amd64.s
index 18559eb..21c1aa9 100644
--- a/src/runtime/rt0_amd64.s
+++ b/src/runtime/rt0_amd64.s
@@ -175,7 +175,16 @@
ADDQ $8, SP
RET
+// marker. must be here; used by traceback() to discover calls to _morestack
+TEXT _endmorestack(SB), 7, $-8
+ RET
+
TEXT FLUSH(SB),7,$-8
RET
+TEXT getu(SB),7,$-8
+ MOVQ R15, AX
+ RET
+
+
GLOBL peruser<>(SB),$64
diff --git a/src/runtime/rt1_amd64_darwin.c b/src/runtime/rt1_amd64_darwin.c
index b39c298..9d03ce0 100644
--- a/src/runtime/rt1_amd64_darwin.c
+++ b/src/runtime/rt1_amd64_darwin.c
@@ -145,11 +145,11 @@
_STRUCT_X86_THREAD_STATE64 *ss = get___ss(uc_mcontext);
prints("\nFaulting address: 0x"); sys·printpointer(info->si_addr);
- prints("\npc: 0x"); sys·printpointer((void *)ss->__rip);
- prints("\n\n");
+ prints("\npc: 0x"); sys·printpointer((void *)ss->__rip);
+ prints("\n\n");
- traceback((void *)ss->__rip, (void *)ss->__rsp);
- print_thread_state(ss);
+ traceback((void *)ss->__rip, (void *)ss->__rsp, (void*)ss->__r15);
+ print_thread_state(ss);
sys·exit(2);
}
diff --git a/src/runtime/rt1_amd64_linux.c b/src/runtime/rt1_amd64_linux.c
index e7dfbc7..b31b89a 100644
--- a/src/runtime/rt1_amd64_linux.c
+++ b/src/runtime/rt1_amd64_linux.c
@@ -152,7 +152,7 @@
prints("\npc: 0x"); sys·printpointer((void *)sc->rip);
prints("\n\n");
- traceback((void *)sc->rip, (void *)sc->rsp);
+ traceback((void *)sc->rip, (void *)sc->rsp, (void *)sc->r15);
print_sigcontext(sc);
sys·breakpoint();
diff --git a/src/runtime/rt2_amd64.c b/src/runtime/rt2_amd64.c
index f544ddd..795285d7 100644
--- a/src/runtime/rt2_amd64.c
+++ b/src/runtime/rt2_amd64.c
@@ -8,22 +8,54 @@
static int8 spmark[] = "\xa7\xf1\xd9\x2a\x82\xc8\xd8\xfe";
+typedef struct U U;
+struct U {
+ uint8* stackguard;
+ uint8* stackbase;
+ uint8* istackguard;
+ uint8* istackbase;
+};
+
+typedef struct Stktop Stktop;
+struct Stktop {
+ uint8* oldbase;
+ uint8* oldsp;
+ uint8* magic;
+ uint8* oldguard;
+};
+
+extern void _morestack();
+extern void _endmorestack();
+
void
-traceback(uint8 *pc, uint8 *sp)
+traceback(uint8 *pc, uint8 *sp, void* r15)
{
int32 spoff;
int8* spp;
+ uint8* callpc;
int32 counter;
int32 i;
int8* name;
+ U u;
+ Stktop *stktop;
+ // store local copy of per-process data block that we can write as we unwind
+ mcpy((byte*)&u, (byte*)r15, sizeof(U));
counter = 0;
name = "panic";
for(;;){
- prints("0x");
- sys·printpointer(pc);
- prints("?zi\n");
+ callpc = pc;
+ if((uint8*)_morestack < pc && pc < (uint8*)_endmorestack) {
+ // call site in _morestack(); pop to earlier stack block to get true caller
+ stktop = (Stktop*)u.stackbase;
+ u.stackbase = stktop->oldbase;
+ u.stackguard = stktop->oldguard;
+ sp = stktop->oldsp;
+ pc = ((uint8**)sp)[1];
+ sp += 16; // two irrelevant calls on stack - morestack, plus the call morestack made
+ continue;
+ }
/* find SP offset by stepping back through instructions to SP offset marker */
while(pc > (uint8*)0x1000+sizeof spmark-1) {
for(spp = spmark; *spp != '\0' && *pc++ == (uint8)*spp++; )
@@ -43,7 +75,11 @@
}
if((pc = ((uint8**)sp)[-1]) <= (uint8*)0x1000)
break;
- /* print args for this frame */
+
+ /* print this frame */
+ prints("0x");
+ sys·printpointer(callpc);
+ prints("?zi\n");
prints("\t");
prints(name);
prints("(");
diff --git a/src/runtime/runtime.c b/src/runtime/runtime.c
index f1d7fc3..3f9e8c2 100644
--- a/src/runtime/runtime.c
+++ b/src/runtime/runtime.c
@@ -18,7 +18,7 @@
sys·printpc(&lno);
prints("\n");
sp = (uint8*)&lno;
- traceback(sys·getcallerpc(&lno), sp);
+ traceback(sys·getcallerpc(&lno), sp, getu());
sys·breakpoint();
sys·exit(2);
}
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index bc18381..f64353e 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -93,13 +93,14 @@
* very low level c-called
*/
void FLUSH(void*);
+void* getu(void);
void throw(int8*);
void prints(int8*);
void mcpy(byte*, byte*, uint32);
void* mal(uint32);
uint32 cmpstring(string, string);
void initsig(void);
-void traceback(uint8 *pc, uint8 *sp);
+void traceback(uint8 *pc, uint8 *sp, void* up);
int32 open(byte*, int32);
int32 read(int32, void*, int32);
void close(int32);
