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runtime: adjust program counters in race detector
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In most cases we pass return PC to race detector,
and race runtime subtracts one from them.
However, in manual instrumentation in runtime
we pass function start PC to race runtime.
Race runtime can't distinguish these cases
and so it does not subtract one from top PC.
This leads to bogus line numbers in some cases.
Make it consistent and always pass what looks
like a return PC, so that race runtime can
subtract one and still get PC in the same function.

Also delete two unused functions.

Update golang#8053

Change-Id: I4242dec5e055e460c9a8990eaca1d085ae240ed2
Reviewed-on: https://go-review.googlesource.com/4902
Reviewed-by: Ian Lance Taylor <[email protected]>
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dvyukov committed Feb 20, 2015
1 parent 89a091d commit 3fc529e
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Showing 3 changed files with 7 additions and 20 deletions.
3 changes: 3 additions & 0 deletions src/runtime/race.go
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,9 @@ func RaceSemrelease(s *uint32)
// private interface for the runtime
const raceenabled = true

// For all functions accepting callerpc and pc,
// callerpc is a return PC of the function that calls this function,
// pc is start PC of the function that calls this function.
func raceReadObjectPC(t *_type, addr unsafe.Pointer, callerpc, pc uintptr) {
kind := t.kind & kindMask
if kind == kindArray || kind == kindStruct {
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20 changes: 0 additions & 20 deletions src/runtime/race1.go
Original file line number Diff line number Diff line change
Expand Up @@ -226,26 +226,6 @@ func racereadrangepc(addr unsafe.Pointer, sz, callpc, pc uintptr) {
}
}

//go:nosplit
func racewriteobjectpc(addr unsafe.Pointer, t *_type, callpc, pc uintptr) {
kind := t.kind & _KindMask
if kind == _KindArray || kind == _KindStruct {
racewriterangepc(addr, t.size, callpc, pc)
} else {
racewritepc(addr, callpc, pc)
}
}

//go:nosplit
func racereadobjectpc(addr unsafe.Pointer, t *_type, callpc, pc uintptr) {
kind := t.kind & _KindMask
if kind == _KindArray || kind == _KindStruct {
racereadrangepc(addr, t.size, callpc, pc)
} else {
racereadpc(addr, callpc, pc)
}
}

//go:nosplit
func raceacquire(addr unsafe.Pointer) {
raceacquireg(getg(), addr)
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4 changes: 4 additions & 0 deletions src/runtime/race_amd64.s
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,7 @@ TEXT runtime·racereadpc(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ callpc+8(FP), RARG2
MOVQ pc+16(FP), RARG3
ADDQ $1, RARG3 // pc is function start, tsan wants return address
// void __tsan_read_pc(ThreadState *thr, void *addr, void *callpc, void *pc);
MOVQ $__tsan_read_pc(SB), AX
JMP racecalladdr<>(SB)
Expand All @@ -81,6 +82,7 @@ TEXT runtime·racewritepc(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ callpc+8(FP), RARG2
MOVQ pc+16(FP), RARG3
ADDQ $1, RARG3 // pc is function start, tsan wants return address
// void __tsan_write_pc(ThreadState *thr, void *addr, void *callpc, void *pc);
MOVQ $__tsan_write_pc(SB), AX
JMP racecalladdr<>(SB)
Expand All @@ -105,6 +107,7 @@ TEXT runtime·racereadrangepc1(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ size+8(FP), RARG2
MOVQ pc+16(FP), RARG3
ADDQ $1, RARG3 // pc is function start, tsan wants return address
// void __tsan_read_range(ThreadState *thr, void *addr, uintptr size, void *pc);
MOVQ $__tsan_read_range(SB), AX
JMP racecalladdr<>(SB)
Expand All @@ -129,6 +132,7 @@ TEXT runtime·racewriterangepc1(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ size+8(FP), RARG2
MOVQ pc+16(FP), RARG3
ADDQ $1, RARG3 // pc is function start, tsan wants return address
// void __tsan_write_range(ThreadState *thr, void *addr, uintptr size, void *pc);
MOVQ $__tsan_write_range(SB), AX
JMP racecalladdr<>(SB)
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