grsec needs the FIXED flag to be provided to mmap, which
works now. That said, when the allocation fails to be made
in the specific address, we're still given back a writable
page. This change will unmap that page to avoid using
twice the amount of memory needed.
It'd also be pretty easy to avoid the extra system calls
once we detected that the flag is needed, but I'm not sure
if that edge case is worth the effort.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4634086
All but two packages depend on net:
debug/proc
os/signal
With this change, we can produce
a working build with GOOS=plan9.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/4639053
Correct a few error messages (libcgo -> runtime/cgo)
and delete old nacl_386.c file too.
Fixes#1657.
R=iant
CC=golang-dev
https://golang.org/cl/4603057
5a: add SQRTF and SQRTD
5l: add ASQRTF and ASQRTD
Use ARMv7 VFP VSQRT instruction to speed up math.Sqrt
R=rsc, dave, m
CC=golang-dev
https://golang.org/cl/4551082
This change was adapted from gccgo's libgo/runtime/mem.c at
Ian Taylor's suggestion. It fixes all.bash failing with
"address space conflict: map() =" on amd64 Linux with kernel
version 2.6.32.8-grsec-2.1.14-modsign-xeon-64.
With this change, SysMap will use MAP_FIXED to allocate its desired
address space, after first calling mincore to check that there is
nothing else mapped there.
R=iant, dave, n13m3y3r, rsc
CC=golang-dev
https://golang.org/cl/4438091
breaks Mac build
««« original CL description
runtime: use HOST_CC to compile mkversion
HOST_CC is set in Make.inc, so use that rather
than hardcoding quietgcc
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/4515163
»»»
R=iant
CC=golang-dev
https://golang.org/cl/4515168
Works around bug in kernel implementation on old ARM5 kernels.
Bug was fixed on 26 Nov 2007 (between 2.6.23 and 2.6.24) but
old kernels persist.
Fixes#1750.
R=dfc, golang-dev
CC=golang-dev
https://golang.org/cl/4436072
The g->sched.sp saved stack pointer and the
g->stackbase and g->stackguard stack bounds
can change even while "the world is stopped",
because a goroutine has to call functions (and
therefore might split its stack) when exiting a
system call to check whether the world is stopped
(and if so, wait until the world continues).
That means the garbage collector cannot access
those values safely (without a race) for goroutines
executing system calls. Instead, save a consistent
triple in g->gcsp, g->gcstack, g->gcguard during
entersyscall and have the garbage collector refer
to those.
The old code was occasionally seeing (because of
the race) an sp and stk that did not correspond to
each other, so that stk - sp was not the number of
stack bytes following sp. In that case, if sp < stk
then the call scanblock(sp, stk - sp) scanned too
many bytes (anything between the two pointers,
which pointed into different allocation blocks).
If sp > stk then stk - sp wrapped around.
On 32-bit, stk - sp is a uintptr (uint32) converted
to int64 in the call to scanblock, so a large (~4G)
but positive number. Scanblock would try to scan
that many bytes and eventually fault accessing
unmapped memory. On 64-bit, stk - sp is a uintptr (uint64)
promoted to int64 in the call to scanblock, so a negative
number. Scanblock would not scan anything, possibly
causing in-use blocks to be freed.
In short, 32-bit platforms would have seen either
ineffective garbage collection or crashes during garbage
collection, while 64-bit platforms would have seen
either ineffective or incorrect garbage collection.
You can see the invalid arguments to scanblock in the
stack traces in issue 1620.
Fixes#1620.
Fixes#1746.
R=iant, r
CC=golang-dev
https://golang.org/cl/4437075
runtime: memory allocated by OS not in usable range
runtime: out of memory: cannot allocate 1114112-byte block (2138832896 in use)
throw: out of memory
runtime.throw+0x40 /Users/rsc/g/go/src/pkg/runtime/runtime.c:102
runtime.throw(0x1fffd, 0x101)
runtime.mallocgc+0x2af /Users/rsc/g/go/src/pkg/runtime/malloc.c:60
runtime.mallocgc(0x100004, 0x0, 0x1, 0x1, 0xc093, ...)
runtime.mal+0x40 /Users/rsc/g/go/src/pkg/runtime/malloc.c:289
runtime.mal(0x100004, 0x20bc4)
runtime.new+0x26 /Users/rsc/g/go/src/pkg/runtime/malloc.c:296
runtime.new(0x100004, 0x8fe84000, 0x20bc4)
main.main+0x29 /Users/rsc/x.go:11
main.main()
runtime.mainstart+0xf /Users/rsc/g/go/src/pkg/runtime/386/asm.s:93
runtime.mainstart()
runtime.goexit /Users/rsc/g/go/src/pkg/runtime/proc.c:178
runtime.goexit()
----- goroutine created by -----
_rt0_386+0xbf /Users/rsc/g/go/src/pkg/runtime/386/asm.s:80
R=iant, r
CC=golang-dev
https://golang.org/cl/4444073
In a GOROOT path a backslash is a path separator
not an escape character. For example, `C:\go`.
Fixes gotest error:
version.go:3: unknown escape sequence: g
R=rsc
CC=golang-dev
https://golang.org/cl/4437076
Used to fault trying to access l->list->next
when l->list == nil after MCentral_AllocList.
Now prints
runtime: out of memory: no room in arena for 65536-byte allocation (536870912 in use)
throw: out of memory
followed by stack trace.
Fixes#1650.
R=r, dfc
CC=golang-dev
https://golang.org/cl/4446062
Avoid getting out of synch when a function, such as main.init,
has no associated line number information. Without this the
function before main.init can skip the PC all the way to the
next function, which will cause the next function's line table
to be associated with main.init, and leave subsequent
functions with the wrong line numbers.
R=rsc
CC=golang-dev
https://golang.org/cl/4426055
go/types: update for export data format change
reflect: require package qualifiers to match during interface check
runtime: require package qualifiers to match during interface check
test: fixed bug324, adapt to be silent
Fixes#1550.
Issue 1536 remains open.
R=gri, ken2, r
CC=golang-dev
https://golang.org/cl/4442071
* Reduces malloc counts during gob encoder/decoder test from 6/6 to 3/5.
The current reflect uses Set to mean two subtly different things.
(1) If you have a reflect.Value v, it might just represent
itself (as in v = reflect.NewValue(42)), in which case calling
v.Set only changed v, not any other data in the program.
(2) If you have a reflect Value v derived from a pointer
or a slice (as in x := []int{42}; v = reflect.NewValue(x).Index(0)),
v represents the value held there. Changing x[0] affects the
value returned by v.Int(), and calling v.Set affects x[0].
This was not really by design; it just happened that way.
The motivation for the new reflect implementation was
to remove mallocs. The use case (1) has an implicit malloc
inside it. If you can do:
v := reflect.NewValue(0)
v.Set(42)
i := v.Int() // i = 42
then that implies that v is referring to some underlying
chunk of memory in order to remember the 42; that is,
NewValue must have allocated some memory.
Almost all the time you are using reflect the goal is to
inspect or to change other data, not to manipulate data
stored solely inside a reflect.Value.
This CL removes use case (1), so that an assignable
reflect.Value must always refer to some other piece of data
in the program. Put another way, removing this case would
make
v := reflect.NewValue(0)
v.Set(42)
as illegal as
0 = 42.
It would also make this illegal:
x := 0
v := reflect.NewValue(x)
v.Set(42)
for the same reason. (Note that right now, v.Set(42) "succeeds"
but does not change the value of x.)
If you really wanted to make v refer to x, you'd start with &x
and dereference it:
x := 0
v := reflect.NewValue(&x).Elem() // v = *&x
v.Set(42)
It's pretty rare, except in tests, to want to use NewValue and then
call Set to change the Value itself instead of some other piece of
data in the program. I haven't seen it happen once yet while
making the tree build with this change.
For the same reasons, reflect.Zero (formerly reflect.MakeZero)
would also return an unassignable, unaddressable value.
This invalidates the (awkward) idiom:
pv := ... some Ptr Value we have ...
v := reflect.Zero(pv.Type().Elem())
pv.PointTo(v)
which, when the API changed, turned into:
pv := ... some Ptr Value we have ...
v := reflect.Zero(pv.Type().Elem())
pv.Set(v.Addr())
In both, it is far from clear what the code is trying to do. Now that
it is possible, this CL adds reflect.New(Type) Value that does the
obvious thing (same as Go's new), so this code would be replaced by:
pv := ... some Ptr Value we have ...
pv.Set(reflect.New(pv.Type().Elem()))
The changes just described can be confusing to think about,
but I believe it is because the old API was confusing - it was
conflating two different kinds of Values - and that the new API
by itself is pretty simple: you can only Set (or call Addr on)
a Value if it actually addresses some real piece of data; that is,
only if it is the result of dereferencing a Ptr or indexing a Slice.
If you really want the old behavior, you'd get it by translating:
v := reflect.NewValue(x)
into
v := reflect.New(reflect.Typeof(x)).Elem()
v.Set(reflect.NewValue(x))
Gofix will not be able to help with this, because whether
and how to change the code depends on whether the original
code meant use (1) or use (2), so the developer has to read
and think about the code.
You can see the effect on packages in the tree in
https://golang.org/cl/4423043/.
R=r
CC=golang-dev
https://golang.org/cl/4435042
. Missing declaration of runtime.brk_();
. Argument v in runtime.SysReserve() is not used;
(I'd prefer a Plan 9-type solution...)
R=golang-dev, r, r2
CC=golang-dev
https://golang.org/cl/4368076
