It turns out that if you write Go pointers to Go memory, the Go compiler
must be involved so that it generates various calls to the GC in the
process. Letting Windows write Go pointers to Go memory violated this.
So, we replace that with just a boring call to runtime.KeepAlive. That's
not a great API, but this is all internal code anyway. We fix it up
more elegantly for external consumption in x/sys/windows with CL 300369.
Fixes#44900.
Change-Id: Id6599a793af9c4815f6c9387b00796923f32cb97
Reviewed-on: https://go-review.googlesource.com/c/go/+/300349
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
It turns out that the proc thread update function doesn't actually
allocate new memory for its arguments and instead just copies the
pointer values into the preallocated memory. Since we were allocating
that memory as []byte, the garbage collector didn't scan it for pointers
to Go allocations and freed them. We _could_ fix this by requiring that
all users of this use runtime.KeepAlive for everything they pass to the
update function, but that seems harder than necessary. Instead, we can
just do the allocation as []unsafe.Pointer, which means the GC can
operate as intended and not free these from beneath our feet. In order
to ensure this remains true, we also add a test for this.
Fixes#44662.
Change-Id: Ib392ba8ceacacec94b11379919c8179841cba29f
Reviewed-on: https://go-review.googlesource.com/c/go/+/297389
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This allows users to specify which process should be used as the parent
process when creating a new process.
Note that this doesn't just trivially pass the handle onward to
PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, because inherited handles must be
valid in the parent process, so if we're changing the destination
process, then we must also change the origin of the parent handles. And,
the StartProcess function must clean up these handles successfully when
exiting, regardless of where the duplication happened. So, we take care
in this commit to use DuplicateHandle for both duplicating and for
closing the inherited handles.
The test was taken originally from CL 288272 and adjusted for use here.
Fixes#44011.
Change-Id: Ib3b132028dcab1aded3dc0e65126c8abebfa35eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/288300
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
This allows users to specify handles that they explicitly want to be
inherited by the new process. These handles must already be marked as
inheritable.
Updates #44011.
Updates #21085.
Change-Id: Ib18322e7dc2909e68c4209e80385492804fa15d3
Reviewed-on: https://go-review.googlesource.com/c/go/+/288298
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Windows does not have CLOEXEC, but rather handles are marked explicitly
for being inherited by new processes. This can cause problems when
different Windows functions create new processes from different threads.
syscall.StartProcess has traditionally used a mutex to prevent races
with itself, but this doesn't handle races with other win32 functions.
Fortunately there's a solution: PROC_THREAD_ATTRIBUTE_HANDLE_LIST allows
us to pass the entire list of handles that we want to be inherited. This
lets us get rid of the mutex and also makes process creation safe across
the Go runtime, no matter the context.
Updates #44011.
Change-Id: Ia3424cd2ec64868849cbd6cbb5b0d765224bf4ab
Reviewed-on: https://go-review.googlesource.com/c/go/+/288297
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Accidentally broken by CL 259978.
For #41825
Change-Id: Id663514e6eefa325faccdb66493d0bb2b3281046
Reviewed-on: https://go-review.googlesource.com/c/go/+/260397
Trust: Ian Lance Taylor <iant@golang.org>
Trust: Alex Brainman <alex.brainman@gmail.com>
Trust: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It's faster to append to a []byte and only convert to string at the
end then it is to build up a string by concatenating characters.
Fixes#41825
Change-Id: I45ddf77dcc62726c919f0533c95d483cee8ba366
Reviewed-on: https://go-review.googlesource.com/c/go/+/259978
Trust: Ian Lance Taylor <iant@golang.org>
Trust: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
This allows creating processes that can only be debugged/accessed by
certain tokens, according to a particular security descriptor. We
already had everything ready for this but just neglected to pass through
the value from the user-accessible SysProcAttr.
Change-Id: I4a3fcc9f5078aa0058b26c103355c984093ae03f
Reviewed-on: https://go-review.googlesource.com/c/go/+/174197
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Each URL was manually verified to ensure it did not serve up incorrect
content.
Change-Id: I4dc846227af95a73ee9a3074d0c379ff0fa955df
Reviewed-on: https://go-review.googlesource.com/115798
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
CL 75253 introduced new SysProcAttr.Token field as Handle.
But we already have exact type for it - Token. Use Token
instead of Handle everywhere - it saves few type conversions
and provides better documentation for new API.
Change-Id: Ibc5407a234a1f49804de15a24b27c8e6a6eba7e0
Reviewed-on: https://go-review.googlesource.com/76314
Reviewed-by: Ian Lance Taylor <iant@golang.org>