qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-13 17:10:21 -07:00
Code Releases Activity

runtime: record proper goroutine state during stack split

Browse Source 
Until now, the goroutine state has been scattered during the
execution of newstack and oldstack. It's all there, and those routines
know how to get back to a working goroutine, but other pieces of
the system, like stack traces, do not. If something does interrupt
the newstack or oldstack execution, the rest of the system can't
understand the goroutine. For example, if newstack decides there
is an overflow and calls throw, the stack tracer wouldn't dump the
goroutine correctly.

For newstack to save a useful state snapshot, it needs to be able
to rewind the PC in the function that triggered the split back to
the beginning of the function. (The PC is a few instructions in, just
after the call to morestack.) To make that possible, we change the
prologues to insert a jmp back to the beginning of the function
after the call to morestack. That is, the prologue used to be roughly:

        TEXT myfunc
                check for split
                jmpcond nosplit
                call morestack
        nosplit:
                sub $xxx, sp

Now an extra instruction is inserted after the call:

        TEXT myfunc
        start:
                check for split
                jmpcond nosplit
                call morestack
                jmp start
        nosplit:
                sub $xxx, sp

The jmp is not executed directly. It is decoded and simulated by
runtime.rewindmorestack to discover the beginning of the function,
and then the call to morestack returns directly to the start label
instead of to the jump instruction. So logically the jmp is still
executed, just not by the cpu.

The prologue thus repeats in the case of a function that needs a
stack split, but against the cost of the split itself, the extra few
instructions are noise. The repeated prologue has the nice effect of
making a stack split double-check that the new stack is big enough:
if morestack happens to return on a too-small stack, we'll now notice
before corruption happens.

The ability for newstack to rewind to the beginning of the function
should help preemption too. If newstack decides that it was called
for preemption instead of a stack split, it now has the goroutine state
correctly paused if rescheduling is needed, and when the goroutine
can run again, it can return to the start label on its original stack
and re-execute the split check.

Here is an example of a split stack overflow showing the full
trace, without any special cases in the stack printer.
(This one was triggered by making the split check incorrect.)

runtime: newstack framesize=0x0 argsize=0x18 sp=0x6aebd0 stack=[0x6b0000, 0x6b0fa0]
        morebuf={pc:0x69f5b sp:0x6aebd8 lr:0x0}
        sched={pc:0x68880 sp:0x6aebd0 lr:0x0 ctxt:0x34e700}
runtime: split stack overflow: 0x6aebd0 < 0x6b0000
fatal error: runtime: split stack overflow

goroutine 1 [stack split]:
runtime.mallocgc(0x290, 0x100000000, 0x1)
        /Users/rsc/g/go/src/pkg/runtime/zmalloc_darwin_amd64.c:21 fp=0x6aebd8
runtime.new()
        /Users/rsc/g/go/src/pkg/runtime/zmalloc_darwin_amd64.c:682 +0x5b fp=0x6aec08
go/build.(*Context).Import(0x5ae340, 0xc210030c71, 0xa, 0xc2100b4380, 0x1b, ...)
        /Users/rsc/g/go/src/pkg/go/build/build.go:424 +0x3a fp=0x6b00a0
main.loadImport(0xc210030c71, 0xa, 0xc2100b4380, 0x1b, 0xc2100b42c0, ...)
        /Users/rsc/g/go/src/cmd/go/pkg.go:249 +0x371 fp=0x6b01a8
main.(*Package).load(0xc21017c800, 0xc2100b42c0, 0xc2101828c0, 0x0, 0x0, ...)
        /Users/rsc/g/go/src/cmd/go/pkg.go:431 +0x2801 fp=0x6b0c98
main.loadPackage(0x369040, 0x7, 0xc2100b42c0, 0x0)
        /Users/rsc/g/go/src/cmd/go/pkg.go:709 +0x857 fp=0x6b0f80
----- stack segment boundary -----
main.(*builder).action(0xc2100902a0, 0x0, 0x0, 0xc2100e6c00, 0xc2100e5750, ...)
        /Users/rsc/g/go/src/cmd/go/build.go:539 +0x437 fp=0x6b14a0
main.(*builder).action(0xc2100902a0, 0x0, 0x0, 0xc21015b400, 0x2, ...)
        /Users/rsc/g/go/src/cmd/go/build.go:528 +0x1d2 fp=0x6b1658
main.(*builder).test(0xc2100902a0, 0xc210092000, 0x0, 0x0, 0xc21008ff60, ...)
        /Users/rsc/g/go/src/cmd/go/test.go:622 +0x1b53 fp=0x6b1f68
----- stack segment boundary -----
main.runTest(0x5a6b20, 0xc21000a020, 0x2, 0x2)
        /Users/rsc/g/go/src/cmd/go/test.go:366 +0xd09 fp=0x6a5cf0
main.main()
        /Users/rsc/g/go/src/cmd/go/main.go:161 +0x4f9 fp=0x6a5f78
runtime.main()
        /Users/rsc/g/go/src/pkg/runtime/proc.c:183 +0x92 fp=0x6a5fa0
runtime.goexit()
        /Users/rsc/g/go/src/pkg/runtime/proc.c:1266 fp=0x6a5fa8

And here is a seg fault during oldstack:

SIGSEGV: segmentation violation
PC=0x1b2a6

runtime.oldstack()
        /Users/rsc/g/go/src/pkg/runtime/stack.c:159 +0x76
runtime.lessstack()
        /Users/rsc/g/go/src/pkg/runtime/asm_amd64.s:270 +0x22

goroutine 1 [stack unsplit]:
fmt.(*pp).printArg(0x2102e64e0, 0xe5c80, 0x2102c9220, 0x73, 0x0, ...)
        /Users/rsc/g/go/src/pkg/fmt/print.go:818 +0x3d3 fp=0x221031e6f8
fmt.(*pp).doPrintf(0x2102e64e0, 0x12fb20, 0x2, 0x221031eb98, 0x1, ...)
        /Users/rsc/g/go/src/pkg/fmt/print.go:1183 +0x15cb fp=0x221031eaf0
fmt.Sprintf(0x12fb20, 0x2, 0x221031eb98, 0x1, 0x1, ...)
        /Users/rsc/g/go/src/pkg/fmt/print.go:234 +0x67 fp=0x221031eb40
flag.(*stringValue).String(0x2102c9210, 0x1, 0x0)
        /Users/rsc/g/go/src/pkg/flag/flag.go:180 +0xb3 fp=0x221031ebb0
flag.(*FlagSet).Var(0x2102f6000, 0x293d38, 0x2102c9210, 0x143490, 0xa, ...)
        /Users/rsc/g/go/src/pkg/flag/flag.go:633 +0x40 fp=0x221031eca0
flag.(*FlagSet).StringVar(0x2102f6000, 0x2102c9210, 0x143490, 0xa, 0x12fa60, ...)
        /Users/rsc/g/go/src/pkg/flag/flag.go:550 +0x91 fp=0x221031ece8
flag.(*FlagSet).String(0x2102f6000, 0x143490, 0xa, 0x12fa60, 0x0, ...)
        /Users/rsc/g/go/src/pkg/flag/flag.go:563 +0x87 fp=0x221031ed38
flag.String(0x143490, 0xa, 0x12fa60, 0x0, 0x161950, ...)
        /Users/rsc/g/go/src/pkg/flag/flag.go:570 +0x6b fp=0x221031ed80
testing.init()
        /Users/rsc/g/go/src/pkg/testing/testing.go:-531 +0xbb fp=0x221031edc0
strings_test.init()
        /Users/rsc/g/go/src/pkg/strings/strings_test.go:1115 +0x62 fp=0x221031ef70
main.init()
        strings/_test/_testmain.go:90 +0x3d fp=0x221031ef78
runtime.main()
        /Users/rsc/g/go/src/pkg/runtime/proc.c:180 +0x8a fp=0x221031efa0
runtime.goexit()
        /Users/rsc/g/go/src/pkg/runtime/proc.c:1269 fp=0x221031efa8

goroutine 2 [runnable]:
runtime.MHeap_Scavenger()
        /Users/rsc/g/go/src/pkg/runtime/mheap.c:438
runtime.goexit()
        /Users/rsc/g/go/src/pkg/runtime/proc.c:1269
created by runtime.main
        /Users/rsc/g/go/src/pkg/runtime/proc.c:166

rax     0x23ccc0
rbx     0x23ccc0
rcx     0x0
rdx     0x38
rdi     0x2102c0170
rsi     0x221032cfe0
rbp     0x221032cfa0
rsp     0x7fff5fbff5b0
r8      0x2102c0120
r9      0x221032cfa0
r10     0x221032c000
r11     0x104ce8
r12     0xe5c80
r13     0x1be82baac718
r14     0x13091135f7d69200
r15     0x0
rip     0x1b2a6
rflags  0x10246
cs      0x2b
fs      0x0
gs      0x0

Fixes #5723.

R=r, dvyukov, go.peter.90, dave, iant
CC=golang-dev
https://golang.org/cl/10360048
This commit is contained in:
Russ Cox 2013-06-27 11:32:01 -04:00
parent 2546a54148
commit 6fa3c89b77
27 changed files with 435 additions and 309 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/cmd/5g/gsubr.c
View File

@ -32,8 +32,9 @@
#include <libc.h> #include <libc.h>
#include "gg.h" #include "gg.h"
// TODO(kaib): Can make this bigger if we move // TODO(rsc): Can make this bigger if we move
// the text segment up higher in 5l for all GOOS. // the text segment up higher in 5l for all GOOS.
// At the same time, can raise StackBig in ../../pkg/runtime/stack.h.
long unmappedzero = 4096; long unmappedzero = 4096;
void void

176
src/cmd/5l/noop.c
View File

@ -32,13 +32,7 @@
#include "l.h" #include "l.h"
#include "../ld/lib.h" #include "../ld/lib.h"
#include "../../pkg/runtime/stack.h"
// see ../../runtime/proc.c:/StackGuard
enum
{
StackBig = 4096,
StackSmall = 128,
};
static Sym* sym_div; static Sym* sym_div;
static Sym* sym_divu; static Sym* sym_divu;
@ -180,33 +174,7 @@ noops(void)
break; break;
} }
if(p->reg & NOSPLIT) { if(!(p->reg & NOSPLIT)) {
q1 = prg();
q1->as = AMOVW;
q1->scond |= C_WBIT;
q1->line = p->line;
q1->from.type = D_REG;
q1->from.reg = REGLINK;
q1->to.type = D_OREG;
q1->to.offset = -autosize;
q1->to.reg = REGSP;
q1->spadj = autosize;
q1->link = p->link;
p->link = q1;
} else if (autosize < StackBig) {
// split stack check for small functions
// MOVW g_stackguard(g), R1
// CMP R1, $-autosize(SP)
// MOVW.LO $autosize, R1
// MOVW.LO $args, R2
// MOVW.LO R14, R3
// BL.LO runtime.morestack(SB) // modifies LR
// MOVW.W R14,$-autosize(SP)
// TODO(kaib): add more trampolines
// TODO(kaib): put stackguard in register
// TODO(kaib): add support for -K and underflow detection
// MOVW g_stackguard(g), R1 // MOVW g_stackguard(g), R1
p = appendp(p); p = appendp(p);
p->as = AMOVW; p->as = AMOVW;
@ -215,16 +183,18 @@ noops(void)
p->to.type = D_REG; p->to.type = D_REG;
p->to.reg = 1; p->to.reg = 1;
if(autosize < StackSmall) { if(autosize <= StackSmall) {
// CMP R1, SP // small stack: SP < stackguard
// CMP stackguard, SP
p = appendp(p); p = appendp(p);
p->as = ACMP; p->as = ACMP;
p->from.type = D_REG; p->from.type = D_REG;
p->from.reg = 1; p->from.reg = 1;
p->reg = REGSP; p->reg = REGSP;
} else { } else if(autosize <= StackBig) {
// MOVW $-autosize(SP), R2 // large stack: SP-framesize < stackguard-StackSmall
// CMP R1, R2 // MOVW $-autosize(SP), R2
// CMP stackguard, R2
p = appendp(p); p = appendp(p);
p->as = AMOVW; p->as = AMOVW;
p->from.type = D_CONST; p->from.type = D_CONST;
@ -238,103 +208,97 @@ noops(void)
p->from.type = D_REG; p->from.type = D_REG;
p->from.reg = 1; p->from.reg = 1;
p->reg = 2; p->reg = 2;
} else {
// such a large stack we need to protect against wraparound
// if SP is close to zero.
// SP-stackguard+StackGuard < framesize + (StackGuard-StackSmall)
// The +StackGuard on both sides is required to keep the left side positive:
// SP is allowed to be slightly below stackguard. See stack.h.
// MOVW $StackGuard(SP), R2
// SUB R1, R2
// MOVW $(autosize+(StackGuard-StackSmall)), R3
// CMP R3, R2
p = appendp(p);
p->as = AMOVW;
p->from.type = D_CONST;
p->from.reg = REGSP;
p->from.offset = StackGuard;
p->to.type = D_REG;
p->to.reg = 2;
p = appendp(p);
p->as = ASUB;
p->from.type = D_REG;
p->from.reg = 1;
p->to.type = D_REG;
p->to.reg = 2;
p = appendp(p);
p->as = AMOVW;
p->from.type = D_CONST;
p->from.offset = autosize + (StackGuard - StackSmall);
p->to.type = D_REG;
p->to.reg = 3;
p = appendp(p);
p->as = ACMP;
p->from.type = D_REG;
p->from.reg = 3;
p->reg = 2;
} }
// MOVW.LO $autosize, R1 // MOVW.LS $autosize, R1
p = appendp(p); p = appendp(p);
p->as = AMOVW; p->as = AMOVW;
p->scond = C_SCOND_LO; p->scond = C_SCOND_LS;
p->from.type = D_CONST; p->from.type = D_CONST;
p->from.offset = autosize; p->from.offset = autosize;
p->to.type = D_REG; p->to.type = D_REG;
p->to.reg = 1; p->to.reg = 1;
// MOVW.LO $args, R2 // MOVW.LS $args, R2
p = appendp(p); p = appendp(p);
p->as = AMOVW; p->as = AMOVW;
p->scond = C_SCOND_LO; p->scond = C_SCOND_LS;
p->from.type = D_CONST; p->from.type = D_CONST;
p->from.offset = (cursym->text->to.offset2 + 3) & ~3; p->from.offset = (cursym->text->to.offset2 + 3) & ~3;
p->to.type = D_REG; p->to.type = D_REG;
p->to.reg = 2; p->to.reg = 2;
// MOVW.LO R14, R3 // MOVW.LS R14, R3
p = appendp(p); p = appendp(p);
p->as = AMOVW; p->as = AMOVW;
p->scond = C_SCOND_LO; p->scond = C_SCOND_LS;
p->from.type = D_REG; p->from.type = D_REG;
p->from.reg = REGLINK; p->from.reg = REGLINK;
p->to.type = D_REG; p->to.type = D_REG;
p->to.reg = 3; p->to.reg = 3;
// BL.LO runtime.morestack(SB) // modifies LR // BL.LS runtime.morestack(SB) // modifies LR, returns with LO still asserted
p = appendp(p); p = appendp(p);
p->as = ABL; p->as = ABL;
p->scond = C_SCOND_LO; p->scond = C_SCOND_LS;
p->to.type = D_BRANCH; p->to.type = D_BRANCH;
p->to.sym = symmorestack; p->to.sym = symmorestack;
p->cond = pmorestack; p->cond = pmorestack;
// MOVW.W R14,$-autosize(SP) // BLS start
p = appendp(p); p = appendp(p);
p->as = AMOVW; p->as = ABLS;
p->scond |= C_WBIT;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_OREG;
p->to.offset = -autosize;
p->to.reg = REGSP;
p->spadj = autosize;
} else { // > StackBig
// MOVW $autosize, R1
// MOVW $args, R2
// MOVW R14, R3
// BL runtime.morestack(SB) // modifies LR
// MOVW.W R14,$-autosize(SP)
// MOVW $autosize, R1
p = appendp(p);
p->as = AMOVW;
p->from.type = D_CONST;
p->from.offset = autosize;
p->to.type = D_REG;
p->to.reg = 1;
// MOVW $args, R2
// also need to store the extra 4 bytes.
p = appendp(p);
p->as = AMOVW;
p->from.type = D_CONST;
p->from.offset = (cursym->text->to.offset2 + 3) & ~3;
p->to.type = D_REG;
p->to.reg = 2;
// MOVW R14, R3
p = appendp(p);
p->as = AMOVW;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_REG;
p->to.reg = 3;
// BL runtime.morestack(SB) // modifies LR
p = appendp(p);
p->as = ABL;
p->to.type = D_BRANCH; p->to.type = D_BRANCH;
p->to.sym = symmorestack; p->cond = cursym->text->link;
p->cond = pmorestack;
// MOVW.W R14,$-autosize(SP)
p = appendp(p);
p->as = AMOVW;
p->scond |= C_WBIT;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_OREG;
p->to.offset = -autosize;
p->to.reg = REGSP;
p->spadj = autosize;
} }
// MOVW.W R14,$-autosize(SP)
p = appendp(p);
p->as = AMOVW;
p->scond |= C_WBIT;
p->from.type = D_REG;
p->from.reg = REGLINK;
p->to.type = D_OREG;
p->to.offset = -autosize;
p->to.reg = REGSP;
p->spadj = autosize;
break; break;
case ARET: case ARET:

1
src/cmd/6g/gsubr.c
View File

@ -34,6 +34,7 @@
// TODO(rsc): Can make this bigger if we move // TODO(rsc): Can make this bigger if we move
// the text segment up higher in 6l for all GOOS. // the text segment up higher in 6l for all GOOS.
// At the same time, can raise StackBig in ../../pkg/runtime/stack.h.
vlong unmappedzero = 4096; vlong unmappedzero = 4096;
void void

86
src/cmd/6l/pass.c
View File

@ -497,34 +497,61 @@ dostkoff(void)
q1->pcond = p; q1->pcond = p;
} }
if(autoffset < StackBig) { // do we need to call morestack? if(autoffset <= StackSmall) {
if(autoffset <= StackSmall) { // small stack: SP <= stackguard
// small stack // CMPQ SP, stackguard
p = appendp(p);
p->as = ACMPQ;
p->from.type = D_SP;
p->to.type = D_INDIR+D_CX;
} else {
// large stack
p = appendp(p);
p->as = ALEAQ;
p->from.type = D_INDIR+D_SP;
p->from.offset = -(autoffset-StackSmall);
p->to.type = D_AX;
p = appendp(p);
p->as = ACMPQ;
p->from.type = D_AX;
p->to.type = D_INDIR+D_CX;
}
// common
p = appendp(p); p = appendp(p);
p->as = AJHI; p->as = ACMPQ;
p->to.type = D_BRANCH; p->from.type = D_SP;
p->to.offset = 4; p->to.type = D_INDIR+D_CX;
q = p; } else if(autoffset <= StackBig) {
} // large stack: SP-framesize <= stackguard-StackSmall
// LEAQ -xxx(SP), AX
// CMPQ AX, stackguard
p = appendp(p);
p->as = ALEAQ;
p->from.type = D_INDIR+D_SP;
p->from.offset = -(autoffset-StackSmall);
p->to.type = D_AX;
p = appendp(p);
p->as = ACMPQ;
p->from.type = D_AX;
p->to.type = D_INDIR+D_CX;
} else {
// such a large stack we need to protect against wraparound
// if SP is close to zero:
// SP-stackguard+StackGuard <= framesize + (StackGuard-StackSmall)
// The +StackGuard on both sides is required to keep the left side positive:
// SP is allowed to be slightly below stackguard. See stack.h.
// LEAQ StackGuard(SP), AX
// SUBQ stackguard, AX
// CMPQ AX, $(autoffset+(StackGuard-StackSmall))
p = appendp(p);
p->as = ALEAQ;
p->from.type = D_INDIR+D_SP;
p->from.offset = StackGuard;
p->to.type = D_AX;
p = appendp(p);
p->as = ASUBQ;
p->from.type = D_INDIR+D_CX;
p->from.offset = 0;
p->to.type = D_AX;
p = appendp(p);
p->as = ACMPQ;
p->from.type = D_AX;
p->to.type = D_CONST;
p->to.offset = autoffset+(StackGuard-StackSmall);
}
// common
p = appendp(p);
p->as = AJHI;
p->to.type = D_BRANCH;
p->to.offset = 4;
q = p;
// If we ask for more stack, we'll get a minimum of StackMin bytes. // 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, // We need a stack frame large enough to hold the top-of-stack data,
@ -591,6 +618,11 @@ dostkoff(void)
p->pcond = pmorestack[3]; p->pcond = pmorestack[3];
p->to.sym = symmorestack[3]; p->to.sym = symmorestack[3];
} }
p = appendp(p);
p->as = AJMP;
p->to.type = D_BRANCH;
p->pcond = cursym->text->link;
} }
if(q != P) if(q != P)

1
src/cmd/8g/gsubr.c
View File

@ -34,6 +34,7 @@
// TODO(rsc): Can make this bigger if we move // TODO(rsc): Can make this bigger if we move
// the text segment up higher in 8l for all GOOS. // the text segment up higher in 8l for all GOOS.
// At the same time, can raise StackBig in ../../pkg/runtime/stack.h.
uint32 unmappedzero = 4096; uint32 unmappedzero = 4096;
#define CASE(a,b) (((a)<<16)|((b)<<0)) #define CASE(a,b) (((a)<<16)|((b)<<0))

85
src/cmd/8l/pass.c
View File

@ -526,34 +526,61 @@ dostkoff(void)
q1->pcond = p; q1->pcond = p;
} }
if(autoffset < StackBig) { // do we need to call morestack if(autoffset <= StackSmall) {
if(autoffset <= StackSmall) { // small stack: SP <= stackguard
// small stack // CMPL SP, stackguard
p = appendp(p);
p->as = ACMPL;
p->from.type = D_SP;
p->to.type = D_INDIR+D_CX;
} else {
// large stack
p = appendp(p);
p->as = ALEAL;
p->from.type = D_INDIR+D_SP;
p->from.offset = -(autoffset-StackSmall);
p->to.type = D_AX;
p = appendp(p);
p->as = ACMPL;
p->from.type = D_AX;
p->to.type = D_INDIR+D_CX;
}
// common
p = appendp(p); p = appendp(p);
p->as = AJHI; p->as = ACMPL;
p->to.type = D_BRANCH; p->from.type = D_SP;
p->to.offset = 4; p->to.type = D_INDIR+D_CX;
q = p; } else if(autoffset <= StackBig) {
} // large stack: SP-framesize <= stackguard-StackSmall
// LEAL -(autoffset-StackSmall)(SP), AX
// CMPL AX, stackguard
p = appendp(p);
p->as = ALEAL;
p->from.type = D_INDIR+D_SP;
p->from.offset = -(autoffset-StackSmall);
p->to.type = D_AX;
p = appendp(p);
p->as = ACMPL;
p->from.type = D_AX;
p->to.type = D_INDIR+D_CX;
} else {
// such a large stack we need to protect against wraparound
// if SP is close to zero.
// SP-stackguard+StackGuard <= framesize + (StackGuard-StackSmall)
// The +StackGuard on both sides is required to keep the left side positive:
// SP is allowed to be slightly below stackguard. See stack.h.
// LEAL StackGuard(SP), AX
// SUBL stackguard, AX
// CMPL AX, $(autoffset+(StackGuard-StackSmall))
p = appendp(p);
p->as = ALEAL;
p->from.type = D_INDIR+D_SP;
p->from.offset = StackGuard;
p->to.type = D_AX;
p = appendp(p);
p->as = ASUBL;
p->from.type = D_INDIR+D_CX;
p->from.offset = 0;
p->to.type = D_AX;
p = appendp(p);
p->as = ACMPL;
p->from.type = D_AX;
p->to.type = D_CONST;
p->to.offset = autoffset+(StackGuard-StackSmall);
}
// common
p = appendp(p);
p->as = AJHI;
p->to.type = D_BRANCH;
p->to.offset = 4;
q = p;
p = appendp(p); // save frame size in DI p = appendp(p); // save frame size in DI
p->as = AMOVL; p->as = AMOVL;
@ -583,6 +610,10 @@ dostkoff(void)
p->pcond = pmorestack; p->pcond = pmorestack;
p->to.sym = symmorestack; p->to.sym = symmorestack;
p = appendp(p);
p->as = AJMP;
p->to.type = D_BRANCH;
p->pcond = cursym->text->link;
} }
if(q != P) if(q != P)

5
src/libmach/8db.c
View File

@ -202,6 +202,11 @@ i386trace(Map *map, uvlong pc, uvlong sp, uvlong link, Tracer trace)
break; break;
if(s.value == morestack) { if(s.value == morestack) {
// This code is old and won't work anymore.
// But no one uses it anyway.
// Leave it obviously broken until someone needs it.
werrstr("morestack not implemented correctly");
return -1;
// In the middle of morestack. // In the middle of morestack.
// Caller is m->morepc. // Caller is m->morepc.
// Caller's caller is in m->morearg. // Caller's caller is in m->morearg.

14
src/pkg/runtime/asm_386.s
View File

@ -200,8 +200,6 @@ TEXT runtime·morestack(SB),7,$0
CMPL g(CX), SI CMPL g(CX), SI
JNE 2(PC) JNE 2(PC)
INT $3 INT $3
MOVL DX, m_cret(BX)
// frame size in DI // frame size in DI
// arg size in AX // arg size in AX
@ -220,9 +218,13 @@ TEXT runtime·morestack(SB),7,$0
MOVL g(CX), SI MOVL g(CX), SI
MOVL SI, (m_morebuf+gobuf_g)(BX) MOVL SI, (m_morebuf+gobuf_g)(BX)
// Set m->morepc to f's PC. // Set g->sched to context in f.
MOVL 0(SP), AX MOVL 0(SP), AX // f's PC
MOVL AX, m_morepc(BX) MOVL AX, (g_sched+gobuf_pc)(SI)
MOVL SI, (g_sched+gobuf_g)(SI)
LEAL 4(SP), AX // f's SP
MOVL AX, (g_sched+gobuf_sp)(SI)
MOVL DX, (g_sched+gobuf_ctxt)(SI)
// Call newstack on m->g0's stack. // Call newstack on m->g0's stack.
MOVL m_g0(BX), BP MOVL m_g0(BX), BP
@ -262,7 +264,7 @@ TEXT reflect·call(SB), 7, $0
MOVL 8(SP), DX // arg frame MOVL 8(SP), DX // arg frame
MOVL 12(SP), CX // arg size MOVL 12(SP), CX // arg size
MOVL AX, m_morepc(BX) // f's PC MOVL AX, m_cret(BX) // f's PC
MOVL DX, m_moreargp(BX) // f's argument pointer MOVL DX, m_moreargp(BX) // f's argument pointer
MOVL CX, m_moreargsize(BX) // f's argument size MOVL CX, m_moreargsize(BX) // f's argument size
MOVL $1, m_moreframesize(BX) // f's frame size MOVL $1, m_moreframesize(BX) // f's frame size

14
src/pkg/runtime/asm_amd64.s
View File

@ -186,8 +186,6 @@ TEXT runtime·morestack(SB),7,$0
CMPQ g(CX), SI CMPQ g(CX), SI
JNE 2(PC) JNE 2(PC)
INT $3 INT $3
MOVQ DX, m_cret(BX)
// Called from f. // Called from f.
// Set m->morebuf to f's caller. // Set m->morebuf to f's caller.
@ -200,9 +198,13 @@ TEXT runtime·morestack(SB),7,$0
MOVQ g(CX), SI MOVQ g(CX), SI
MOVQ SI, (m_morebuf+gobuf_g)(BX) MOVQ SI, (m_morebuf+gobuf_g)(BX)
// Set m->morepc to f's PC. // Set g->sched to context in f.
MOVQ 0(SP), AX MOVQ 0(SP), AX // f's PC
MOVQ AX, m_morepc(BX) MOVQ AX, (g_sched+gobuf_pc)(SI)
MOVQ SI, (g_sched+gobuf_g)(SI)
LEAQ 8(SP), AX // f's SP
MOVQ AX, (g_sched+gobuf_sp)(SI)
MOVQ DX, (g_sched+gobuf_ctxt)(SI)
// Call newstack on m->g0's stack. // Call newstack on m->g0's stack.
MOVQ m_g0(BX), BP MOVQ m_g0(BX), BP
@ -240,7 +242,7 @@ TEXT reflect·call(SB), 7, $0
MOVQ 16(SP), DX // arg frame MOVQ 16(SP), DX // arg frame
MOVL 24(SP), CX // arg size MOVL 24(SP), CX // arg size
MOVQ AX, m_morepc(BX) // f's PC MOVQ AX, m_cret(BX) // f's PC
MOVQ DX, m_moreargp(BX) // argument frame pointer MOVQ DX, m_moreargp(BX) // argument frame pointer
MOVL CX, m_moreargsize(BX) // f's argument size MOVL CX, m_moreargsize(BX) // f's argument size
MOVL $1, m_moreframesize(BX) // f's frame size MOVL $1, m_moreframesize(BX) // f's frame size

17
src/pkg/runtime/asm_arm.s
View File

@ -126,6 +126,7 @@ TEXT runtime·gogo(SB), 7, $-4
MOVW R11, gobuf_ret(R1) MOVW R11, gobuf_ret(R1)
MOVW R11, gobuf_lr(R1) MOVW R11, gobuf_lr(R1)
MOVW R11, gobuf_ctxt(R1) MOVW R11, gobuf_ctxt(R1)
CMP R11, R11 // set condition codes for == test, needed by stack split
MOVW gobuf_pc(R1), PC MOVW gobuf_pc(R1), PC
// void mcall(void (*fn)(G*)) // void mcall(void (*fn)(G*))
@ -138,6 +139,8 @@ TEXT runtime·mcall(SB), 7, $-4
// Save caller state in g->sched. // Save caller state in g->sched.
MOVW SP, (g_sched+gobuf_sp)(g) MOVW SP, (g_sched+gobuf_sp)(g)
MOVW LR, (g_sched+gobuf_pc)(g) MOVW LR, (g_sched+gobuf_pc)(g)
MOVW $0, R11
MOVW R11, (g_sched+gobuf_lr)(g)
MOVW g, (g_sched+gobuf_g)(g) MOVW g, (g_sched+gobuf_g)(g)
// Switch to m->g0 & its stack, call fn. // Switch to m->g0 & its stack, call fn.
@ -169,11 +172,16 @@ TEXT runtime·morestack(SB),7,$-4
CMP g, R4 CMP g, R4
BL.EQ runtime·abort(SB) BL.EQ runtime·abort(SB)
// Save in m.
MOVW R7, m_cret(m) // function context
MOVW R1, m_moreframesize(m) MOVW R1, m_moreframesize(m)
MOVW R2, m_moreargsize(m) MOVW R2, m_moreargsize(m)
// Called from f.
// Set g->sched to context in f.
MOVW R7, (g_sched+gobuf_ctxt)(g)
MOVW SP, (g_sched+gobuf_sp)(g)
MOVW LR, (g_sched+gobuf_pc)(g)
MOVW R3, (g_sched+gobuf_lr)(g)
// Called from f. // Called from f.
// Set m->morebuf to f's caller. // Set m->morebuf to f's caller.
MOVW R3, (m_morebuf+gobuf_pc)(m) // f's caller's PC MOVW R3, (m_morebuf+gobuf_pc)(m) // f's caller's PC
@ -182,9 +190,6 @@ TEXT runtime·morestack(SB),7,$-4
MOVW R3, m_moreargp(m) MOVW R3, m_moreargp(m)
MOVW g, (m_morebuf+gobuf_g)(m) MOVW g, (m_morebuf+gobuf_g)(m)
// Set m->morepc to f's PC.
MOVW LR, m_morepc(m)
// Call newstack on m->g0's stack. // Call newstack on m->g0's stack.
MOVW m_g0(m), g MOVW m_g0(m), g
MOVW (g_sched+gobuf_sp)(g), SP MOVW (g_sched+gobuf_sp)(g), SP
@ -212,7 +217,7 @@ TEXT reflect·call(SB), 7, $-4
MOVW 8(SP), R1 // arg frame MOVW 8(SP), R1 // arg frame
MOVW 12(SP), R2 // arg size MOVW 12(SP), R2 // arg size
MOVW R0, m_morepc(m) // f's PC MOVW R0, m_cret(m) // f's PC
MOVW R1, m_moreargp(m) // f's argument pointer MOVW R1, m_moreargp(m) // f's argument pointer
MOVW R2, m_moreargsize(m) // f's argument size MOVW R2, m_moreargsize(m) // f's argument size
MOVW $1, R3 MOVW $1, R3

5
src/pkg/runtime/mgc0.c
View File

@ -1464,7 +1464,7 @@ addstackroots(G *gp)
if(ScanStackByFrames) { if(ScanStackByFrames) {
USED(stk); USED(stk);
USED(guard); USED(guard);
runtime·gentraceback(pc, sp, lr, gp, 0, nil, 0x7fffffff, addframeroots, nil); runtime·gentraceback(pc, sp, lr, gp, 0, nil, 0x7fffffff, addframeroots, nil, false);
} else { } else {
USED(pc); USED(pc);
n = 0; n = 0;
@ -2011,6 +2011,8 @@ runtime·gc(int32 force)
} else { } else {
// switch to g0, call gc(&a), then switch back // switch to g0, call gc(&a), then switch back
g->param = &a; g->param = &a;
g->status = Gwaiting;
g->waitreason = "garbage collection";
runtime·mcall(mgc); runtime·mcall(mgc);
} }
// record a new start time in case we're going around again // record a new start time in case we're going around again
@ -2042,6 +2044,7 @@ mgc(G *gp)
{ {
gc(gp->param); gc(gp->param);
gp->param = nil; gp->param = nil;
gp->status = Grunning;
runtime·gogo(&gp->sched); runtime·gogo(&gp->sched);
} }

2
src/pkg/runtime/mprof.goc
View File

@ -478,7 +478,7 @@ saveg(uintptr pc, uintptr sp, G *gp, TRecord *r)
{ {
int32 n; int32 n;
n = runtime·gentraceback((uintptr)pc, (uintptr)sp, 0, gp, 0, r->stk, nelem(r->stk), nil, nil); n = runtime·gentraceback((uintptr)pc, (uintptr)sp, 0, gp, 0, r->stk, nelem(r->stk), nil, nil, false);
if(n < nelem(r->stk)) if(n < nelem(r->stk))
r->stk[n] = 0; r->stk[n] = 0;
} }

2
src/pkg/runtime/os_plan9_386.c
View File

@ -88,6 +88,8 @@ runtime·sighandler(void *v, int8 *s, G *gp)
return NDFLT; return NDFLT;
Throw: Throw:
m->throwing = 1;
m->caughtsig = gp;
runtime·startpanic(); runtime·startpanic();
runtime·printf("%s\n", s); runtime·printf("%s\n", s);

2
src/pkg/runtime/os_plan9_amd64.c
View File

@ -96,6 +96,8 @@ runtime·sighandler(void *v, int8 *s, G *gp)
return NDFLT; return NDFLT;
Throw: Throw:
m->throwing = 1;
m->caughtsig = gp;
runtime·startpanic(); runtime·startpanic();
runtime·printf("%s\n", s); runtime·printf("%s\n", s);

1
src/pkg/runtime/panic.c
View File

@ -277,6 +277,7 @@ recovery(G *gp)
else else
gp->sched.sp = (uintptr)argp - 2*sizeof(uintptr); gp->sched.sp = (uintptr)argp - 2*sizeof(uintptr);
gp->sched.pc = pc; gp->sched.pc = pc;
gp->sched.lr = 0;
gp->sched.ret = 1; gp->sched.ret = 1;
runtime·gogo(&gp->sched); runtime·gogo(&gp->sched);
} }

22
src/pkg/runtime/proc.c
View File

@ -234,14 +234,25 @@ runtime·tracebackothers(G *me)
int32 traceback; int32 traceback;
traceback = runtime·gotraceback(nil); traceback = runtime·gotraceback(nil);
// Show the current goroutine first, if we haven't already.
if((gp = m->curg) != nil && gp != me) {
runtime·printf("\n");
runtime·goroutineheader(gp);
runtime·traceback(gp->sched.pc, gp->sched.sp, gp->sched.lr, gp);
}
for(gp = runtime·allg; gp != nil; gp = gp->alllink) { for(gp = runtime·allg; gp != nil; gp = gp->alllink) {
if(gp == me || gp->status == Gdead) if(gp == me || gp == m->curg || gp->status == Gdead)
continue; continue;
if(gp->issystem && traceback < 2) if(gp->issystem && traceback < 2)
continue; continue;
runtime·printf("\n"); runtime·printf("\n");
runtime·goroutineheader(gp); runtime·goroutineheader(gp);
runtime·traceback(gp->sched.pc, gp->sched.sp, 0, gp); if(gp->status == Grunning)
runtime·printf("\tgoroutine running on other thread; stack unavailable\n");
else
runtime·traceback(gp->sched.pc, gp->sched.sp, gp->sched.lr, gp);
} }
} }
@ -656,6 +667,7 @@ runtime·newextram(void)
gp = runtime·malg(4096); gp = runtime·malg(4096);
gp->sched.pc = (uintptr)runtime·goexit; gp->sched.pc = (uintptr)runtime·goexit;
gp->sched.sp = gp->stackbase; gp->sched.sp = gp->stackbase;
gp->sched.lr = 0;
gp->sched.g = gp; gp->sched.g = gp;
gp->status = Gsyscall; gp->status = Gsyscall;
mp->curg = gp; mp->curg = gp;
@ -1830,7 +1842,7 @@ runtime·sigprof(uint8 *pc, uint8 *sp, uint8 *lr, G *gp)
runtime·unlock(&prof); runtime·unlock(&prof);
return; return;
} }
n = runtime·gentraceback((uintptr)pc, (uintptr)sp, (uintptr)lr, gp, 0, prof.pcbuf, nelem(prof.pcbuf), nil, nil); n = runtime·gentraceback((uintptr)pc, (uintptr)sp, (uintptr)lr, gp, 0, prof.pcbuf, nelem(prof.pcbuf), nil, nil, false);
if(n > 0) if(n > 0)
prof.fn(prof.pcbuf, n); prof.fn(prof.pcbuf, n);
runtime·unlock(&prof); runtime·unlock(&prof);
@ -2446,12 +2458,16 @@ runtime·testSchedLocalQueueSteal(void)
} }
} }
extern void runtime·morestack(void);
bool bool
runtime·haszeroargs(uintptr pc) runtime·haszeroargs(uintptr pc)
{ {
return pc == (uintptr)runtime·goexit || return pc == (uintptr)runtime·goexit ||
pc == (uintptr)runtime·mcall || pc == (uintptr)runtime·mcall ||
pc == (uintptr)runtime·mstart || pc == (uintptr)runtime·mstart ||
pc == (uintptr)runtime·lessstack ||
pc == (uintptr)runtime·morestack ||
pc == (uintptr)_rt0_go; pc == (uintptr)_rt0_go;
} }

8
src/pkg/runtime/runtime.h
View File

@ -269,9 +269,7 @@ struct G
}; };
struct M struct M
{ {
// The offsets of these fields are known to (hard-coded in) libmach.
G* g0; // goroutine with scheduling stack G* g0; // goroutine with scheduling stack
void (*morepc)(void);
void* moreargp; // argument pointer for more stack void* moreargp; // argument pointer for more stack
Gobuf morebuf; // gobuf arg to morestack Gobuf morebuf; // gobuf arg to morestack
@ -284,6 +282,7 @@ struct M
uintptr tls[4]; // thread-local storage (for x86 extern register) uintptr tls[4]; // thread-local storage (for x86 extern register)
void (*mstartfn)(void); void (*mstartfn)(void);
G* curg; // current running goroutine G* curg; // current running goroutine
G* caughtsig; // goroutine running during fatal signal
P* p; // attached P for executing Go code (nil if not executing Go code) P* p; // attached P for executing Go code (nil if not executing Go code)
P* nextp; P* nextp;
int32 id; int32 id;
@ -676,7 +675,7 @@ struct Stkframe
uintptr varlen; // number of bytes at varp uintptr varlen; // number of bytes at varp
}; };
int32 runtime·gentraceback(uintptr, uintptr, uintptr, G*, int32, uintptr*, int32, void(*)(Stkframe*, void*), void*); int32 runtime·gentraceback(uintptr, uintptr, uintptr, G*, int32, uintptr*, int32, void(*)(Stkframe*, void*), void*, bool);
void runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G* gp); void runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G* gp);
void runtime·tracebackothers(G*); void runtime·tracebackothers(G*);
bool runtime·haszeroargs(uintptr pc); bool runtime·haszeroargs(uintptr pc);
@ -803,6 +802,7 @@ int32 runtime·mcount(void);
int32 runtime·gcount(void); int32 runtime·gcount(void);
void runtime·mcall(void(*)(G*)); void runtime·mcall(void(*)(G*));
uint32 runtime·fastrand1(void); uint32 runtime·fastrand1(void);
void runtime·rewindmorestack(Gobuf*);
void runtime·setmg(M*, G*); void runtime·setmg(M*, G*);
void runtime·newextram(void); void runtime·newextram(void);
@ -1015,7 +1015,7 @@ Hmap* runtime·makemap_c(MapType*, int64);
Hchan* runtime·makechan_c(ChanType*, int64); Hchan* runtime·makechan_c(ChanType*, int64);
void runtime·chansend(ChanType*, Hchan*, byte*, bool*, void*); void runtime·chansend(ChanType*, Hchan*, byte*, bool*, void*);
void runtime·chanrecv(ChanType*, Hchan*, byte*, bool*, bool*); void runtime·chanrecv(ChanType*, Hchan*, byte*, bool*, bool*);
bool runtime·showframe(Func*, bool); bool runtime·showframe(Func*, G*);
void runtime·ifaceE2I(InterfaceType*, Eface, Iface*); void runtime·ifaceE2I(InterfaceType*, Eface, Iface*);

3
src/pkg/runtime/signal_386.c
View File

@ -96,6 +96,8 @@ runtime·sighandler(int32 sig, Siginfo *info, void *ctxt, G *gp)
return; return;
Throw: Throw:
m->throwing = 1;
m->caughtsig = gp;
runtime·startpanic(); runtime·startpanic();
if(sig < 0 || sig >= NSIG) if(sig < 0 || sig >= NSIG)
@ -113,6 +115,7 @@ Throw:
if(runtime·gotraceback(&crash)){ if(runtime·gotraceback(&crash)){
runtime·traceback(SIG_EIP(info, ctxt), SIG_ESP(info, ctxt), 0, gp); runtime·traceback(SIG_EIP(info, ctxt), SIG_ESP(info, ctxt), 0, gp);
runtime·tracebackothers(gp); runtime·tracebackothers(gp);
runtime·printf("\n");
runtime·dumpregs(info, ctxt); runtime·dumpregs(info, ctxt);
} }

3
src/pkg/runtime/signal_amd64.c
View File

@ -106,6 +106,8 @@ runtime·sighandler(int32 sig, Siginfo *info, void *ctxt, G *gp)
return; return;
Throw: Throw:
m->throwing = 1;
m->caughtsig = gp;
runtime·startpanic(); runtime·startpanic();
if(sig < 0 || sig >= NSIG) if(sig < 0 || sig >= NSIG)
@ -123,6 +125,7 @@ Throw:
if(runtime·gotraceback(&crash)){ if(runtime·gotraceback(&crash)){
runtime·traceback(SIG_RIP(info, ctxt), SIG_RSP(info, ctxt), 0, gp); runtime·traceback(SIG_RIP(info, ctxt), SIG_RSP(info, ctxt), 0, gp);
runtime·tracebackothers(gp); runtime·tracebackothers(gp);
runtime·printf("\n");
runtime·dumpregs(info, ctxt); runtime·dumpregs(info, ctxt);
} }

2
src/pkg/runtime/signal_arm.c
View File

@ -94,6 +94,8 @@ runtime·sighandler(int32 sig, Siginfo *info, void *ctxt, G *gp)
return; return;
Throw: Throw:
m->throwing = 1;
m->caughtsig = gp;
if(runtime·panicking) // traceback already printed if(runtime·panicking) // traceback already printed
runtime·exit(2); runtime·exit(2);
runtime·panicking = 1; runtime·panicking = 1;

65
src/pkg/runtime/stack.c
View File

@ -7,6 +7,11 @@
#include "malloc.h" #include "malloc.h"
#include "stack.h" #include "stack.h"
enum
{
StackDebug = 0,
};
typedef struct StackCacheNode StackCacheNode; typedef struct StackCacheNode StackCacheNode;
struct StackCacheNode struct StackCacheNode
{ {
@ -128,20 +133,29 @@ void
runtime·oldstack(void) runtime·oldstack(void)
{ {
Stktop *top; Stktop *top;
Gobuf label;
uint32 argsize; uint32 argsize;
byte *sp, *old; byte *sp, *old;
uintptr *src, *dst, *dstend; uintptr *src, *dst, *dstend;
G *gp; G *gp;
int64 goid; int64 goid;
//printf("oldstack m->cret=%p\n", m->cret);
gp = m->curg; gp = m->curg;
top = (Stktop*)gp->stackbase; top = (Stktop*)gp->stackbase;
old = (byte*)gp->stackguard - StackGuard; old = (byte*)gp->stackguard - StackGuard;
sp = (byte*)top; sp = (byte*)top;
argsize = top->argsize; argsize = top->argsize;
if(StackDebug) {
runtime·printf("runtime: oldstack gobuf={pc:%p sp:%p lr:%p} cret=%p argsize=%p\n",
top->gobuf.pc, top->gobuf.sp, top->gobuf.lr, m->cret, (uintptr)argsize);
}
gp->sched = top->gobuf;
gp->sched.ret = m->cret;
m->cret = 0; // drop reference
gp->status = Gwaiting;
gp->waitreason = "stack unsplit";
if(argsize > 0) { if(argsize > 0) {
sp -= argsize; sp -= argsize;
dst = (uintptr*)top->argp; dst = (uintptr*)top->argp;
@ -153,16 +167,15 @@ runtime·oldstack(void)
goid = top->gobuf.g->goid; // fault if g is bad, before gogo goid = top->gobuf.g->goid; // fault if g is bad, before gogo
USED(goid); USED(goid);
label = top->gobuf;
gp->stackbase = top->stackbase; gp->stackbase = top->stackbase;
gp->stackguard = top->stackguard; gp->stackguard = top->stackguard;
gp->stackguard0 = gp->stackguard; gp->stackguard0 = gp->stackguard;
if(top->free != 0) if(top->free != 0)
runtime·stackfree(old, top->free); runtime·stackfree(old, top->free);
label.ret = m->cret; gp->status = Grunning;
m->cret = 0; // drop reference runtime·gogo(&gp->sched);
runtime·gogo(&label);
} }
// Called from reflect·call or from runtime·morestack when a new // Called from reflect·call or from runtime·morestack when a new
@ -186,11 +199,31 @@ runtime·newstack(void)
framesize = m->moreframesize; framesize = m->moreframesize;
argsize = m->moreargsize; argsize = m->moreargsize;
gp = m->curg; gp = m->curg;
gp->status = Gwaiting;
gp->waitreason = "stack split";
reflectcall = framesize==1;
if(m->morebuf.sp < gp->stackguard - StackGuard) { if(!reflectcall)
runtime·printf("runtime: split stack overflow: %p < %p\n", m->morebuf.sp, gp->stackguard - StackGuard); runtime·rewindmorestack(&gp->sched);
sp = m->morebuf.sp;
if(thechar == '6' || thechar == '8') {
// The call to morestack cost a word.
sp -= sizeof(uintptr);
}
if(StackDebug || sp < gp->stackguard - StackGuard) {
runtime·printf("runtime: newstack framesize=%p argsize=%p sp=%p stack=[%p, %p]\n"
"\tmorebuf={pc:%p sp:%p lr:%p}\n"
"\tsched={pc:%p sp:%p lr:%p ctxt:%p}\n",
(uintptr)framesize, (uintptr)argsize, sp, gp->stackguard - StackGuard, gp->stackbase,
m->morebuf.pc, m->morebuf.sp, m->morebuf.lr,
gp->sched.pc, gp->sched.sp, gp->sched.lr, gp->sched.ctxt);
}
if(sp < gp->stackguard - StackGuard) {
runtime·printf("runtime: split stack overflow: %p < %p\n", sp, gp->stackguard - StackGuard);
runtime·throw("runtime: split stack overflow"); runtime·throw("runtime: split stack overflow");
} }
if(argsize % sizeof(uintptr) != 0) { if(argsize % sizeof(uintptr) != 0) {
runtime·printf("runtime: stack split with misaligned argsize %d\n", argsize); runtime·printf("runtime: stack split with misaligned argsize %d\n", argsize);
runtime·throw("runtime: stack split argsize"); runtime·throw("runtime: stack split argsize");
@ -221,9 +254,8 @@ runtime·newstack(void)
free = framesize; free = framesize;
} }
if(0) { if(StackDebug) {
runtime·printf("newstack framesize=%d argsize=%d morepc=%p moreargp=%p gobuf=%p, %p top=%p old=%p\n", runtime·printf("\t-> new stack [%p, %p]\n", stk, top);
framesize, argsize, m->morepc, m->moreargp, m->morebuf.pc, m->morebuf.sp, top, gp->stackbase);
} }
top->stackbase = gp->stackbase; top->stackbase = gp->stackbase;
@ -234,6 +266,7 @@ runtime·newstack(void)
top->free = free; top->free = free;
m->moreargp = nil; m->moreargp = nil;
m->morebuf.pc = (uintptr)nil; m->morebuf.pc = (uintptr)nil;
m->morebuf.lr = (uintptr)nil;
m->morebuf.sp = (uintptr)nil; m->morebuf.sp = (uintptr)nil;
// copy flag from panic // copy flag from panic
@ -266,12 +299,12 @@ runtime·newstack(void)
label.pc = (uintptr)runtime·lessstack; label.pc = (uintptr)runtime·lessstack;
label.g = m->curg; label.g = m->curg;
if(reflectcall) if(reflectcall)
runtime·gostartcallfn(&label, (FuncVal*)m->morepc); runtime·gostartcallfn(&label, (FuncVal*)m->cret);
else { else {
// The stack growth code saves ctxt (not ret) in m->cret. runtime·gostartcall(&label, (void(*)(void))gp->sched.pc, gp->sched.ctxt);
runtime·gostartcall(&label, m->morepc, (void*)m->cret); gp->sched.ctxt = nil;
m->cret = 0;
} }
gp->status = Grunning;
runtime·gogo(&label); runtime·gogo(&label);
*(int32*)345 = 123; // never return *(int32*)345 = 123; // never return

12
src/pkg/runtime/stack.h
View File

@ -79,13 +79,11 @@ enum {
StackMin = 4096, StackMin = 4096,
FixedStack = StackMin + StackSystem, FixedStack = StackMin + StackSystem,
// Functions that need frames bigger than this call morestack // Functions that need frames bigger than this use an extra
// unconditionally. That is, on entry to a function it is assumed // instruction to do the stack split check, to avoid overflow
// that the amount of space available in the current stack segment // in case SP - framesize wraps below zero.
// couldn't possibly be bigger than StackBig. If stack segments // This value can be no bigger than the size of the unmapped
// do run with more space than StackBig, the space may not be // space at zero.
// used efficiently. As a result, StackBig should not be significantly
// smaller than StackMin or StackExtra.
StackBig = 4096, StackBig = 4096,
// The stack guard is a pointer this many bytes above the // The stack guard is a pointer this many bytes above the

4
src/pkg/runtime/symtab.c
View File

@ -646,11 +646,11 @@ contains(String s, int8 *p)
} }
bool bool
runtime·showframe(Func *f, bool current) runtime·showframe(Func *f, G *gp)
{ {
static int32 traceback = -1; static int32 traceback = -1;
if(current && m->throwing > 0) if(m->throwing && gp != nil && (gp == m->curg || gp == m->caughtsig))
return 1; return 1;
if(traceback < 0) if(traceback < 0)
traceback = runtime·gotraceback(nil); traceback = runtime·gotraceback(nil);

18
src/pkg/runtime/sys_arm.c
View File

@ -15,3 +15,21 @@ runtime·gostartcall(Gobuf *gobuf, void (*fn)(void), void *ctxt)
gobuf->pc = (uintptr)fn; gobuf->pc = (uintptr)fn;
gobuf->ctxt = ctxt; gobuf->ctxt = ctxt;
} }
// Called to rewind context saved during morestack back to beginning of function.
// To help us, the linker emits a jmp back to the beginning right after the
// call to morestack. We just have to decode and apply that jump.
void
runtime·rewindmorestack(Gobuf *gobuf)
{
uint32 inst;
inst = *(uint32*)gobuf->pc;
if((gobuf->pc&3) == 0 && (inst>>24) == 0x9a) {
//runtime·printf("runtime: rewind pc=%p to pc=%p\n", gobuf->pc, gobuf->pc + ((int32)(inst<<8)>>6) + 8);
gobuf->pc += ((int32)(inst<<8)>>6) + 8;
return;
}
runtime·printf("runtime: pc=%p %x\n", gobuf->pc, inst);
runtime·throw("runtime: misuse of rewindmorestack");
}

21
src/pkg/runtime/sys_x86.c
View File

@ -19,3 +19,24 @@ runtime·gostartcall(Gobuf *gobuf, void (*fn)(void), void *ctxt)
gobuf->pc = (uintptr)fn; gobuf->pc = (uintptr)fn;
gobuf->ctxt = ctxt; gobuf->ctxt = ctxt;
} }
// Called to rewind context saved during morestack back to beginning of function.
// To help us, the linker emits a jmp back to the beginning right after the
// call to morestack. We just have to decode and apply that jump.
void
runtime·rewindmorestack(Gobuf *gobuf)
{
byte *pc;
pc = (byte*)gobuf->pc;
if(pc[0] == 0xe9) { // jmp 4-byte offset
gobuf->pc = gobuf->pc + 5 + *(int32*)(pc+1);
return;
}
if(pc[0] == 0xeb) { // jmp 1-byte offset
gobuf->pc = gobuf->pc + 2 + *(int8*)(pc+1);
return;
}
runtime·printf("runtime: pc=%p %x %x %x %x %x\n", pc, pc[0], pc[1], pc[2], pc[3], pc[4]);
runtime·throw("runtime: misuse of rewindmorestack");
}

81
src/pkg/runtime/traceback_arm.c
View File

@ -8,7 +8,6 @@
void runtime·deferproc(void); void runtime·deferproc(void);
void runtime·newproc(void); void runtime·newproc(void);
void runtime·newstack(void);
void runtime·morestack(void); void runtime·morestack(void);
void runtime·sigpanic(void); void runtime·sigpanic(void);
void _div(void); void _div(void);
@ -17,9 +16,9 @@ void _divu(void);
void _modu(void); void _modu(void);
int32 int32
runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip, uintptr *pcbuf, int32 max, void (*callback)(Stkframe*, void*), void *v) runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip, uintptr *pcbuf, int32 max, void (*callback)(Stkframe*, void*), void *v, bool printall)
{ {
int32 i, n, skip0; int32 i, n, nprint, skip0;
uintptr x, tracepc; uintptr x, tracepc;
bool waspanic, printing; bool waspanic, printing;
Func *f, *f2; Func *f, *f2;
@ -28,6 +27,7 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
skip0 = skip; skip0 = skip;
nprint = 0;
runtime·memclr((byte*)&frame, sizeof frame); runtime·memclr((byte*)&frame, sizeof frame);
frame.pc = pc0; frame.pc = pc0;
frame.lr = lr0; frame.lr = lr0;
@ -58,7 +58,7 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
frame.sp = stk->gobuf.sp; frame.sp = stk->gobuf.sp;
frame.lr = 0; frame.lr = 0;
frame.fp = 0; frame.fp = 0;
if(printing && runtime·showframe(nil, gp == m->curg)) if(printing && runtime·showframe(nil, gp))
runtime·printf("----- stack segment boundary -----\n"); runtime·printf("----- stack segment boundary -----\n");
stk = (Stktop*)stk->stackbase; stk = (Stktop*)stk->stackbase;
continue; continue;
@ -97,7 +97,8 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
frame.arglen = f2->frame; // conservative overestimate frame.arglen = f2->frame; // conservative overestimate
else { else {
runtime·printf("runtime: unknown argument frame size for %S\n", f->name); runtime·printf("runtime: unknown argument frame size for %S\n", f->name);
runtime·throw("invalid stack"); if(!printing)
runtime·throw("invalid stack");
} }
// Derive location and size of local variables. // Derive location and size of local variables.
@ -130,15 +131,13 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
if(callback != nil) if(callback != nil)
callback(&frame, v); callback(&frame, v);
if(printing) { if(printing) {
if(runtime·showframe(f, gp == m->curg)) { if(printall || runtime·showframe(f, gp)) {
// Print during crash. // Print during crash.
// main(0x1, 0x2, 0x3) // main(0x1, 0x2, 0x3)
// /home/rsc/go/src/runtime/x.go:23 +0xf // /home/rsc/go/src/runtime/x.go:23 +0xf
tracepc = frame.pc; // back up to CALL instruction for funcline. tracepc = frame.pc; // back up to CALL instruction for funcline.
if(n > 0 && frame.pc > f->entry && !waspanic) if(n > 0 && frame.pc > f->entry && !waspanic)
tracepc -= sizeof(uintptr); tracepc -= sizeof(uintptr);
if(m->throwing && gp == m->curg)
runtime·printf("[fp=%p] ", frame.fp);
runtime·printf("%S(", f->name); runtime·printf("%S(", f->name);
for(i = 0; i < f->args/sizeof(uintptr); i++) { for(i = 0; i < f->args/sizeof(uintptr); i++) {
if(i != 0) if(i != 0)
@ -153,7 +152,10 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc)); runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(frame.pc > f->entry) if(frame.pc > f->entry)
runtime·printf(" +%p", (uintptr)(frame.pc - f->entry)); runtime·printf(" +%p", (uintptr)(frame.pc - f->entry));
if(m->throwing && gp == m->curg)
runtime·printf(" fp=%p", frame.fp);
runtime·printf("\n"); runtime·printf("\n");
nprint++;
} }
} }
n++; n++;
@ -161,28 +163,6 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
skipped: skipped:
waspanic = f->entry == (uintptr)runtime·sigpanic; waspanic = f->entry == (uintptr)runtime·sigpanic;
if(printing && f->entry == (uintptr)runtime·newstack && gp == m->g0) {
runtime·printf("----- newstack called from goroutine %D -----\n", m->curg->goid);
frame.pc = (uintptr)m->morepc;
frame.sp = (uintptr)m->moreargp - sizeof(void*);
frame.lr = m->morebuf.pc;
frame.fp = m->morebuf.sp;
gp = m->curg;
stk = (Stktop*)gp->stackbase;
continue;
}
if(printing && f->entry == (uintptr)runtime·lessstack && gp == m->g0) {
runtime·printf("----- lessstack called from goroutine %D -----\n", m->curg->goid);
gp = m->curg;
stk = (Stktop*)gp->stackbase;
frame.sp = stk->gobuf.sp;
frame.pc = stk->gobuf.pc;
frame.fp = 0;
frame.lr = 0;
continue;
}
// Do not unwind past the bottom of the stack. // Do not unwind past the bottom of the stack.
if(frame.pc == (uintptr)runtime·goexit || f->entry == (uintptr)runtime·mstart || f->entry == (uintptr)_rt0_go) if(frame.pc == (uintptr)runtime·goexit || f->entry == (uintptr)runtime·mstart || f->entry == (uintptr)_rt0_go)
break; break;
@ -214,21 +194,31 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
} }
} }
if(printing && (frame.pc = gp->gopc) != 0 && (f = runtime·findfunc(frame.pc)) != nil if(pcbuf == nil && callback == nil)
&& runtime·showframe(f, gp == m->curg) && gp->goid != 1) { n = nprint;
runtime·printf("created by %S\n", f->name);
tracepc = frame.pc; // back up to CALL instruction for funcline.
if(n > 0 && frame.pc > f->entry)
tracepc -= sizeof(uintptr);
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(frame.pc > f->entry)
runtime·printf(" +%p", (uintptr)(frame.pc - f->entry));
runtime·printf("\n");
}
return n; return n;
} }
static void
printcreatedby(G *gp)
{
uintptr pc, tracepc;
Func *f;
if((pc = gp->gopc) != 0 && (f = runtime·findfunc(pc)) != nil
&& runtime·showframe(f, gp) && gp->goid != 1) {
runtime·printf("created by %S\n", f->name);
tracepc = pc; // back up to CALL instruction for funcline.
if(pc > f->entry)
tracepc -= sizeof(uintptr);
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(pc > f->entry)
runtime·printf(" +%p", (uintptr)(pc - f->entry));
runtime·printf("\n");
}
}
void void
runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G *gp) runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G *gp)
{ {
@ -238,7 +228,12 @@ runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G *gp)
sp = gp->sched.sp; sp = gp->sched.sp;
lr = 0; lr = 0;
} }
runtime·gentraceback(pc, sp, lr, gp, 0, nil, 100, nil, nil);
// Print traceback. By default, omits runtime frames.
// If that means we print nothing at all, repeat forcing all frames printed.
if(runtime·gentraceback(pc, sp, lr, gp, 0, nil, 100, nil, nil, false) == 0)
runtime·gentraceback(pc, sp, lr, gp, 0, nil, 100, nil, nil, true);
printcreatedby(gp);
} }
// func caller(n int) (pc uintptr, file string, line int, ok bool) // func caller(n int) (pc uintptr, file string, line int, ok bool)
@ -250,5 +245,5 @@ runtime·callers(int32 skip, uintptr *pcbuf, int32 m)
sp = runtime·getcallersp(&skip); sp = runtime·getcallersp(&skip);
pc = (uintptr)runtime·getcallerpc(&skip); pc = (uintptr)runtime·getcallerpc(&skip);
return runtime·gentraceback(pc, sp, 0, g, skip, pcbuf, m, nil, nil); return runtime·gentraceback(pc, sp, 0, g, skip, pcbuf, m, nil, nil, false);
} }

91
src/pkg/runtime/traceback_x86.c
View File

@ -10,7 +10,6 @@
void runtime·deferproc(void); void runtime·deferproc(void);
void runtime·newproc(void); void runtime·newproc(void);
void runtime·newstack(void);
void runtime·morestack(void); void runtime·morestack(void);
void runtime·sigpanic(void); void runtime·sigpanic(void);
@ -22,9 +21,9 @@ void runtime·sigpanic(void);
// collector (callback != nil). A little clunky to merge these, but avoids // collector (callback != nil). A little clunky to merge these, but avoids
// duplicating the code and all its subtlety. // duplicating the code and all its subtlety.
int32 int32
runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip, uintptr *pcbuf, int32 max, void (*callback)(Stkframe*, void*), void *v) runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip, uintptr *pcbuf, int32 max, void (*callback)(Stkframe*, void*), void *v, bool printall)
{ {
int32 i, n, sawnewstack; int32 i, n, nprint;
uintptr tracepc; uintptr tracepc;
bool waspanic, printing; bool waspanic, printing;
Func *f, *f2; Func *f, *f2;
@ -33,6 +32,7 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
USED(lr0); USED(lr0);
nprint = 0;
runtime·memclr((byte*)&frame, sizeof frame); runtime·memclr((byte*)&frame, sizeof frame);
frame.pc = pc0; frame.pc = pc0;
frame.sp = sp0; frame.sp = sp0;
@ -47,7 +47,6 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
} }
n = 0; n = 0;
sawnewstack = 0;
stk = (Stktop*)gp->stackbase; stk = (Stktop*)gp->stackbase;
while(n < max) { while(n < max) {
// Typically: // Typically:
@ -63,7 +62,7 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
frame.sp = stk->gobuf.sp; frame.sp = stk->gobuf.sp;
frame.lr = 0; frame.lr = 0;
frame.fp = 0; frame.fp = 0;
if(printing && runtime·showframe(nil, gp == m->curg)) if(printing && runtime·showframe(nil, gp))
runtime·printf("----- stack segment boundary -----\n"); runtime·printf("----- stack segment boundary -----\n");
stk = (Stktop*)stk->stackbase; stk = (Stktop*)stk->stackbase;
continue; continue;
@ -101,7 +100,8 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
frame.arglen = f2->frame; // conservative overestimate frame.arglen = f2->frame; // conservative overestimate
else { else {
runtime·printf("runtime: unknown argument frame size for %S\n", f->name); runtime·printf("runtime: unknown argument frame size for %S\n", f->name);
runtime·throw("invalid stack"); if(!printing)
runtime·throw("invalid stack");
} }
// Derive location and size of local variables. // Derive location and size of local variables.
@ -133,7 +133,7 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
if(callback != nil) if(callback != nil)
callback(&frame, v); callback(&frame, v);
if(printing) { if(printing) {
if(runtime·showframe(f, gp == m->curg)) { if(printall || runtime·showframe(f, gp)) {
// Print during crash. // Print during crash.
// main(0x1, 0x2, 0x3) // main(0x1, 0x2, 0x3)
// /home/rsc/go/src/runtime/x.go:23 +0xf // /home/rsc/go/src/runtime/x.go:23 +0xf
@ -141,8 +141,6 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
tracepc = frame.pc; // back up to CALL instruction for funcline. tracepc = frame.pc; // back up to CALL instruction for funcline.
if(n > 0 && frame.pc > f->entry && !waspanic) if(n > 0 && frame.pc > f->entry && !waspanic)
tracepc--; tracepc--;
if(m->throwing && gp == m->curg)
runtime·printf("[fp=%p] ", frame.fp);
runtime·printf("%S(", f->name); runtime·printf("%S(", f->name);
for(i = 0; i < f->args/sizeof(uintptr); i++) { for(i = 0; i < f->args/sizeof(uintptr); i++) {
if(i != 0) if(i != 0)
@ -157,7 +155,10 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc)); runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(frame.pc > f->entry) if(frame.pc > f->entry)
runtime·printf(" +%p", (uintptr)(frame.pc - f->entry)); runtime·printf(" +%p", (uintptr)(frame.pc - f->entry));
if(m->throwing && gp == m->curg)
runtime·printf(" fp=%p", frame.fp);
runtime·printf("\n"); runtime·printf("\n");
nprint++;
} }
} }
n++; n++;
@ -168,36 +169,6 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
if(f->entry == (uintptr)runtime·deferproc || f->entry == (uintptr)runtime·newproc) if(f->entry == (uintptr)runtime·deferproc || f->entry == (uintptr)runtime·newproc)
frame.fp += 2*sizeof(uintptr); frame.fp += 2*sizeof(uintptr);
if(f->entry == (uintptr)runtime·newstack)
sawnewstack = 1;
if(printing && f->entry == (uintptr)runtime·morestack && gp == m->g0 && sawnewstack) {
// The fact that we saw newstack means that morestack
// has managed to record its information in m, so we can
// use it to keep unwinding the stack.
runtime·printf("----- morestack called from goroutine %D -----\n", m->curg->goid);
frame.pc = (uintptr)m->morepc;
frame.sp = m->morebuf.sp - sizeof(void*);
frame.lr = m->morebuf.pc;
frame.fp = m->morebuf.sp;
sawnewstack = 0;
gp = m->curg;
stk = (Stktop*)gp->stackbase;
continue;
}
if(printing && f->entry == (uintptr)runtime·lessstack && gp == m->g0) {
// Lessstack is running on scheduler stack. Switch to original goroutine.
runtime·printf("----- lessstack called from goroutine %D -----\n", m->curg->goid);
gp = m->curg;
stk = (Stktop*)gp->stackbase;
frame.sp = stk->gobuf.sp;
frame.pc = stk->gobuf.pc;
frame.fp = 0;
frame.lr = 0;
continue;
}
// Do not unwind past the bottom of the stack. // Do not unwind past the bottom of the stack.
if(frame.pc == (uintptr)runtime·goexit || f->entry == (uintptr)runtime·mstart || f->entry == (uintptr)_rt0_go) if(frame.pc == (uintptr)runtime·goexit || f->entry == (uintptr)runtime·mstart || f->entry == (uintptr)_rt0_go)
break; break;
@ -209,22 +180,31 @@ runtime·gentraceback(uintptr pc0, uintptr sp0, uintptr lr0, G *gp, int32 skip,
frame.fp = 0; frame.fp = 0;
} }
// Show what created goroutine, except main goroutine (goid 1). if(pcbuf == nil && callback == nil)
if(printing && (frame.pc = gp->gopc) != 0 && (f = runtime·findfunc(frame.pc)) != nil n = nprint;
&& runtime·showframe(f, gp == m->curg) && gp->goid != 1) {
runtime·printf("created by %S\n", f->name);
tracepc = frame.pc; // back up to CALL instruction for funcline.
if(n > 0 && frame.pc > f->entry)
tracepc--;
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(frame.pc > f->entry)
runtime·printf(" +%p", (uintptr)(frame.pc - f->entry));
runtime·printf("\n");
}
return n; return n;
} }
static void
printcreatedby(G *gp)
{
uintptr pc, tracepc;
Func *f;
// Show what created goroutine, except main goroutine (goid 1).
if((pc = gp->gopc) != 0 && (f = runtime·findfunc(pc)) != nil && gp->goid != 1) {
runtime·printf("created by %S\n", f->name);
tracepc = pc; // back up to CALL instruction for funcline.
if(pc > f->entry)
tracepc--;
runtime·printf("\t%S:%d", f->src, runtime·funcline(f, tracepc));
if(pc > f->entry)
runtime·printf(" +%p", (uintptr)(pc - f->entry));
runtime·printf("\n");
}
}
void void
runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G *gp) runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G *gp)
{ {
@ -235,7 +215,12 @@ runtime·traceback(uintptr pc, uintptr sp, uintptr lr, G *gp)
pc = gp->sched.pc; pc = gp->sched.pc;
sp = gp->sched.sp; sp = gp->sched.sp;
} }
runtime·gentraceback(pc, sp, 0, gp, 0, nil, 100, nil, nil);
// Print traceback. By default, omits runtime frames.
// If that means we print nothing at all, repeat forcing all frames printed.
if(runtime·gentraceback(pc, sp, 0, gp, 0, nil, 100, nil, nil, false) == 0)
runtime·gentraceback(pc, sp, 0, gp, 0, nil, 100, nil, nil, true);
printcreatedby(gp);
} }
int32 int32
@ -246,5 +231,5 @@ runtime·callers(int32 skip, uintptr *pcbuf, int32 m)
sp = runtime·getcallersp(&skip); sp = runtime·getcallersp(&skip);
pc = (uintptr)runtime·getcallerpc(&skip); pc = (uintptr)runtime·getcallerpc(&skip);
return runtime·gentraceback(pc, sp, 0, g, skip, pcbuf, m, nil, nil); return runtime·gentraceback(pc, sp, 0, g, skip, pcbuf, m, nil, nil, false);
} }