Austin Clements a8ae93fd26 runtime: fix heap bitmap repeating with large scalar tails ... When heapBitsSetType repeats a source bitmap with a scalar tail (typ.ptrdata < typ.size), it lays out the tail upon reaching the end of the source bitmap by simply increasing the number of bits claimed to be in the incoming bit buffer. This causes later iterations to read the appropriate number of zeros out of the bit buffer before starting on the next repeat of the source bitmap. Currently, however, later iterations of the loop continue to read bits from the source bitmap *regardless of the number of bits currently in the bit buffer*. The bit buffer can only hold 32 or 64 bits, so if the scalar tail is large and the padding bits exceed the size of the bit buffer, the read from the source bitmap on the next iteration will shift the incoming bits into oblivion when it attempts to put them in the bit buffer. When the buffer does eventually shift down to where these bits were supposed to be, it will contain zeros. As a result, words that should be marked as pointers on later repetitions are marked as scalars, so the garbage collector does not trace them. If this is the only reference to an object, it will be incorrectly freed. Fix this by adding logic to drain the bit buffer down if it is large instead of reading more bits from the source bitmap. Fixes #11286. Change-Id: I964432c4b9f1cec334fc8c3da0ff16460203feb6 Reviewed-on: https://go-review.googlesource.com/11360 Reviewed-by: Russ Cox <rsc@golang.org>		2015-06-23 18:37:17 +00:00
..
bench	all: retire architecture letter in file names, public API	2015-05-21 17:32:17 +00:00
bugs	test: migrate remaining tests to run.go	2014-12-22 22:41:34 +00:00
chan	cmd/gc: implement 'for range x {'	2014-07-16 19:27:10 -04:00
ddd2.dir	test: convert tests to run.go whenever possible.	2012-10-10 22:35:27 +02:00
dwarf	test: make rundir match compiledir/errorcheckdir.	2013-01-11 22:00:48 +01:00
fixedbugs	runtime: fix heap bitmap repeating with large scalar tails	2015-06-23 18:37:17 +00:00
import2.dir	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
import4.dir	test: match gccgo import error messages	2013-12-12 19:02:11 -08:00
interface	cmd/internal/gc: improve "type *X has no field or method M" message	2015-05-07 16:21:57 +00:00
ken	go/test/chan1.go: fix typo	2012-02-25 08:47:04 +11:00
method4.dir	cmd/gc: do not omit wrapper for expression (interface{...}).F	2014-01-07 13:26:48 +01:00
safe	test: adapt old-style tests to new flag parsing.	2013-01-11 22:05:46 +01:00
stress	build: adjustments for move from src/pkg to src	2014-09-08 00:06:45 -04:00
syntax	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
64bit.go	cmd/gc: Error out on division by constant zero.	2013-01-30 20:21:08 +01:00
235.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
alias1.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
alias.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
append.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
args.go	test: run some more tests by default	2012-11-08 09:04:27 -08:00
assign1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
assign.go	cmd/gc: prohibit short variable declarations containing duplicate symbols	2014-10-06 17:16:39 -04:00
bigalg.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
bigmap.go	runtime: handle and test large map values	2012-05-24 22:41:07 -04:00
blank1.go	test: match gccgo error messages for blank1.go	2013-09-28 15:19:05 -07:00
blank.go	test: revert changes made for Go SSA interpreter test.	2013-10-08 14:36:20 -04:00
bom.go	gc: initial BOM is legal.	2012-09-10 13:03:07 -07:00
bombad.go	gc: initial BOM is legal.	2012-09-10 13:03:07 -07:00
bounds.go	test: prepare for 64-bit ints	2012-09-24 00:06:41 -04:00
chancap.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
chanlinear.go	runtime: test for linear enqueue/dequeue behavior	2014-12-08 22:18:17 +00:00
char_lit1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
char_lit.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
clearfat.go	[dev.power64] 9g: fix under-zeroing in clearfat	2014-10-31 11:08:27 -04:00
closedchan.go	test: use testlib (first 100)	2012-02-16 23:48:57 -05:00
closure1.go	cmd/gc: capture variables by value	2015-01-29 13:07:30 +00:00
closure2.go	cmd/gc: fix capturing by value for range statements	2015-02-03 15:48:48 +00:00
closure.go	test: enforce 1 proc in the test	2012-07-01 21:59:50 +04:00
cmp6.go	cmd/gc: do not consider length zero arrays as comparable.	2014-01-31 00:30:56 +01:00
cmp.go	cmd/gc: do not nop-convert equivalent but different interface types.	2014-02-27 08:07:50 +01:00
cmplx.go	cmd/gc: reject complex calls with mismatched argument types.	2013-03-11 22:55:14 +01:00
cmplxdivide1.go	test: use testlib in a few more cases	2012-03-22 02:14:44 +08:00
cmplxdivide.c	test: comment the behavior and use of cmplxdivide*	2015-01-15 00:00:06 +00:00
cmplxdivide.go	test: comment the behavior and use of cmplxdivide*	2015-01-15 00:00:06 +00:00
complit1.go	cmd/internal/gc: accept map literals with omitted key type	2015-06-04 02:31:38 +00:00
complit.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
compos.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
const1.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
const2.go	test: match gccgo error messages	2012-09-28 08:30:30 -07:00
const3.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
const4.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
const5.go	cmd/gc: reject builtin function calls in len(fixed array) constants	2014-04-03 19:04:33 -04:00
const6.go	test: match gccgo error strings.	2013-06-26 18:05:02 +02:00
const.go	exp/ssa/interp: (#6 of 5): test interpretation of SSA form of $GOROOT/test/*.go.	2013-02-21 12:48:38 -05:00
convert1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convert3.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convert.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convlit1.go	test: [a-c]: add introductory comments to tests	2012-02-19 13:19:43 +11:00
convlit.go	cmd/internal/gc: unsafe.Pointer constants may only be converted to uintptr	2015-05-07 23:54:28 +00:00
convT2X.go	cmd/gc: cache itab lookup in convT2I.	2012-07-03 09:09:05 +10:00
copy.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
crlf.go	test: use testlib in a few more cases (part 2)	2012-04-20 23:45:43 +08:00
ddd1.go	test: match gccgo error messages	2012-09-28 08:30:30 -07:00
ddd2.go	test: convert tests to run.go whenever possible.	2012-10-10 22:35:27 +02:00
ddd.go	test: enable method expression tests in ddd.go	2012-03-07 11:17:26 -08:00
decl.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
declbad.go	test: correct type in declbad.go	2012-10-07 21:52:57 +02:00
defer.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
deferfin.go	runtime: combine small NoScan allocations	2014-01-24 22:35:11 +04:00
deferprint.go	test: add cmpout to testlib	2012-02-24 13:17:26 +11:00
deferprint.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
divide.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
divmod.go	all: fix a few spelling errors in source comments	2013-12-27 08:59:02 -08:00
empty.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
env.go	os: remove Getenverror	2012-02-18 21:18:13 -08:00
eof1.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
eof.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
errchk	test/errchk: use "#!/usr/bin/env perl" shebang line	2013-05-23 04:41:22 +08:00
escape2.go	cmd/compile: move Node.Curfn into both Node.Func and Node.Name	2015-06-03 20:09:52 +00:00
escape2n.go	cmd/compile: move Node.Curfn into both Node.Func and Node.Name	2015-06-03 20:09:52 +00:00
escape3.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
escape4.go	cmd/internal/gc: transitive inlining	2015-02-26 17:36:00 +00:00
escape5.go	cmd/internal/gc: move check for large-hence-heap-allocated types into escape analysis	2015-05-22 02:13:54 +00:00
escape_array.go	cmd/internal/gc: move check for large-hence-heap-allocated types into escape analysis	2015-05-22 02:13:54 +00:00
escape_calls.go	cmd/internal/gc: make indirect calls properly escape-y	2015-05-22 01:36:11 +00:00
escape_closure.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_field.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_iface.go	test: add tests for escape analysis of interface conversions	2015-03-28 16:15:27 +00:00
escape_indir.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_level.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_map.go	test: add tests for escape analysis of interface conversions	2015-03-28 16:15:27 +00:00
escape_param.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_slice.go	cmd/internal/gc: extend escape analysis to pointers in slices	2015-05-18 15:34:39 +00:00
escape_struct_param1.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_struct_param2.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape_struct_return.go	cmd/internal/gc: improve flow of input params to output params	2015-05-01 13:47:20 +00:00
escape.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
fibo.go	Fix whitespace (use blanks consistently).	2014-12-08 22:22:58 +00:00
float_lit2.go	test: fix two typos in float_lit2.go	2014-05-21 17:19:12 -04:00
float_lit3.go	test/float_lit2.go: rewrite to test values near boundaries	2014-05-21 17:12:06 -04:00
float_lit.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
floatcmp.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
for.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func1.go	cmd/gc: ensure unique parameter and result names in function types	2013-03-15 15:24:13 -04:00
func2.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func3.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func4.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func5.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func6.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
func7.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
func8.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
func.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
funcdup2.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
funcdup.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
gc1.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
gc2.go	test: check for build constraints only upto the first blank line	2015-02-06 05:36:26 +00:00
gc.go	test: explanatory comments [c-g]*	2012-02-19 14:28:53 +11:00
gcstring.go	runtime: fix empty string handling in garbage collector	2014-03-11 23:58:39 -04:00
goprint.go	test: make goprint.go wait longer for go its routine to execute	2013-04-12 16:04:19 -07:00
goprint.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
goto.go	Revert "cmd/internal/gc: ignore declarations of types for goto validation"	2015-05-15 16:35:49 +00:00
helloworld.go	test: add cmpout to testlib	2012-02-24 13:17:26 +11:00
helloworld.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
if.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
import1.go	test: match gccgo import error messages	2013-12-12 19:02:11 -08:00
import2.go	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
import4.go	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
import5.go	gc: disallow absolute import paths	2012-02-29 15:28:36 -05:00
import.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
index0.go	test: run index test by default	2012-11-07 12:33:54 -08:00
index1.go	test: run index test by default	2012-11-07 12:33:54 -08:00
index2.go	test: run index test by default	2012-11-07 12:33:54 -08:00
index.go	test: recognize gccgo error message in index.go	2013-09-27 20:38:52 -07:00
indirect1.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
indirect.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
init1.go	test: deflake init1.go test, tighten its bounds	2015-02-13 22:13:56 +00:00
init.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
initcomma.go	test/initcomma.go: restore what it's supposed to be testing	2012-02-20 07:44:24 +11:00
initialize.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
initializerr.go	test: add "duplicate" struct map key test	2012-12-17 11:05:58 -05:00
inline.go	cmd/internal/gc: transitive inlining	2015-02-26 17:36:00 +00:00
int_lit.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
intcvt.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
iota.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
label1.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
label.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
linkx_run.go	cmd/link: deprecate -X name value in favor of -X name=value	2015-06-05 04:55:41 +00:00
linkx.go	cmd/link: deprecate -X name value in favor of -X name=value	2015-06-05 04:55:41 +00:00
literal.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
live1.go	cmd/gc: correct liveness for fat variables	2014-02-15 10:58:55 -05:00
live2.go	cmd/gc: allocate non-escaping maps on stack	2015-02-12 09:53:52 +00:00
live.go	test: add -update_errors flag to run script	2015-04-10 11:33:42 +00:00
mallocfin.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
map1.go	cmd/gc: fix type checking loop	2012-06-07 03:06:40 -04:00
map.go	test/mapnan.go: add regression test for non-empty interfaces.	2014-08-06 17:02:55 -04:00
maplinear.go	test: make maplinear more robust	2014-10-27 18:59:02 -04:00
method1.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
method2.go	cmd/gc: fix method values whose receiver is an unnamed interface.	2013-08-29 10:00:58 +02:00
method3.go	test: commentary for [h-m]*.go	2012-02-23 18:47:26 +11:00
method4.go	test: convert more tests to rundir/compiledir conventions	2012-10-07 23:22:01 +02:00
method5.go	cmd/gc: implement method values	2013-03-20 17:11:09 -04:00
method.go	test: a number of fixes.	2013-02-11 18:20:52 -05:00
named1.go	cmd/gc: comma-ok assignments produce untyped bool as 2nd result	2014-08-11 16:11:55 -07:00
named.go	gc: return of ideal bool	2012-02-21 22:54:07 -05:00
nil.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
nilcheck.go	cmd/gc: optimize existence-only map lookups	2015-01-07 22:36:06 +00:00
nilptr2.go	test: revert changes made for Go SSA interpreter test.	2013-10-08 14:36:20 -04:00
nilptr3.go	cmd/7g: enable peephole optimizer	2015-04-08 08:16:54 +00:00
nilptr4.go	cmd/gc: fix bad checknil with ints on 32 bit compilers	2014-02-26 12:25:13 -08:00
nilptr.go	test/nilptr: add more tests	2013-09-05 23:06:34 -04:00
nosplit.go	test: fix build on GOARCH=ppc64/ppc64le	2015-06-06 20:22:57 +00:00
nul1.go	test: run some more tests by default	2012-11-08 09:04:27 -08:00
parentype.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
peano.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
print.go	runtime: move built-in print routines to go.	2014-07-31 13:48:48 -07:00
print.out	runtime: move built-in print routines to go.	2014-07-31 13:48:48 -07:00
printbig.go	test: add cmpout to testlib	2012-02-24 13:17:26 +11:00
printbig.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
range.go	cmd/gc: implement 'for range x {'	2014-07-16 19:27:10 -04:00
recover1.go	test: use testlib (final 61)	2012-02-16 23:51:04 -05:00
recover2.go	test: use testlib (final 61)	2012-02-16 23:51:04 -05:00
recover3.go	tests: remove two misuses of nil pointers	2013-08-15 11:51:04 -04:00
recover4.go	test: fix recover4 test on 64kb systems	2015-03-17 05:25:01 +00:00
recover.go	test: add more cases to recover.go	2014-10-22 08:06:15 -07:00
rename1.go	test: fix the fix of the rename tests.	2012-02-24 15:06:32 +11:00
rename.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00
reorder2.go	cmd/gc: shorten temporary lifetimes when possible	2014-04-01 13:31:38 -04:00
reorder.go	test: a number of fixes.	2013-02-11 18:20:52 -05:00
return.go	test: add cases to return.go that gccgo got wrong	2013-08-07 11:31:01 -07:00
rotate0.go	test: re-enable rotate tests	2015-05-28 19:40:58 +00:00
rotate1.go	test: re-enable rotate tests	2015-05-28 19:40:58 +00:00
rotate2.go	test: re-enable rotate tests	2015-05-28 19:40:58 +00:00
rotate3.go	test: re-enable rotate tests	2015-05-28 19:40:58 +00:00
rotate.go	test: add rotate.go and fixedbugs/bug313	2013-01-11 22:42:55 +01:00
run.go	cmd/compile: run escape analysis after method wrapper generation	2015-06-17 02:36:45 +00:00
rune.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
runtime.go	test/[n-r]*.go: add documentation	2012-02-24 10:30:39 +11:00
shift1.go	test: avoid "declared but not used" errors in shift1.go	2014-07-20 12:25:24 -07:00
shift2.go	test: add shift expression incorrectly rejected by gccgo.	2013-06-25 08:06:34 +02:00
sieve.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
sigchld.go	test: skip SIGCHLD test on Plan 9	2014-01-29 09:28:23 +01:00
sigchld.out	test: split golden.out into expected output per test	2012-01-18 16:12:24 -08:00
simassign.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
sinit_run.go	all: retire architecture letter in file names, public API	2015-05-21 17:32:17 +00:00
sinit.go	test: move linkx and sinit to run.go	2014-11-06 15:14:08 -05:00
sizeof.go	test: correct sizeof.go.	2013-06-02 19:10:11 +02:00
slice3.go	cmd/gc, runtime: treat slices and strings like pointers in garbage collection	2014-08-25 14:38:19 -04:00
slice3err.go	test: match gccgo error messages	2013-12-12 17:18:12 -08:00
slicecap.go	cmd/gc, runtime: treat slices and strings like pointers in garbage collection	2014-08-25 14:38:19 -04:00
sliceopt.go	cmd/internal/gc: optimize slice + write barrier	2015-05-13 19:20:39 +00:00
solitaire.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
stack.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
string_lit.go	test: add []rune case to string_lit.go	2013-12-12 17:17:02 -08:00
stringrange.go	all: make Unicode surrogate halves illegal as UTF-8	2012-08-08 14:01:23 -07:00
struct0.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
switch3.go	cmd/gc: accept switches on comparable arrays.	2012-08-03 21:47:26 +02:00
switch4.go	cmd/gc: disallow fallthrough in final case of switch	2013-03-15 00:35:09 -04:00
switch.go	cmd/gc: disallow fallthrough in final case of switch	2013-03-15 00:35:09 -04:00
tinyfin.go	runtime: combine small NoScan allocations	2014-01-24 22:35:11 +04:00
torture.go	cmd/8g: don't allocate a register early for cap(CHAN).	2014-07-01 09:20:51 +02:00
turing.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
typecheck.go	cmd/gc: silence assignment errors to undefined symbols	2014-01-03 21:03:20 +01:00
typeswitch1.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
typeswitch2.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
typeswitch3.go	test: match gccgo error messages	2012-09-28 08:30:30 -07:00
typeswitch.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
undef.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
utf.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
varerr.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
varinit.go	test/[n-z]*.go: add documentation	2012-02-24 11:48:19 +11:00
writebarrier.go	cmd/internal/gc: add missing write barrier in append(x, BigStructWithPointers)	2015-05-19 15:28:29 +00:00
zerodivide.go	test: ensure all failing tests exit nonzero.	2013-02-12 13:17:49 -05:00