We need to distinguish pointers to free spans, which indicate bugs in
our pointer analysis, from pointers to never-in-the-heap spans, which
can legitimately arise from sysAlloc/mmap/etc. This normally isn't a
problem because the heap is contiguous, but in some situations (32
bit, particularly) the heap must grow around an already allocated
region.
The bad pointer test is disabled so this fix doesn't actually do
anything, but it removes one barrier from reenabling it.
Fixes#9872.
Change-Id: I0a92db4d43b642c58d2b40af69c906a8d9777f88
Reviewed-on: https://go-review.googlesource.com/5780
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
The slow path of heapBitsForObjects somewhat subtly assumes that the
pointer will not point to the first word of the object and will round
the pointer wrong if this assumption is violated. This assumption is
safe because the fast path should always take care of this case, but
there's no benefit to making this assumption, it makes the code more
difficult to experiment with than necessary, and it's trivial to
eliminate.
Change-Id: Iedd336f7d529a27d3abeb83e77dfb32a285ea73a
Reviewed-on: https://go-review.googlesource.com/5636
Reviewed-by: Russ Cox <rsc@golang.org>
Move code from malloc1.go, malloc2.go, mem.go, mgc0.go into
appropriate locations.
Factor mgc.go into mgc.go, mgcmark.go, mgcsweep.go, mstats.go.
A lot of this code was in certain files because the right place was in
a C file but it was written in Go, or vice versa. This is one step toward
making things actually well-organized again.
Change-Id: I6741deb88a7cfb1c17ffe0bcca3989e10207968f
Reviewed-on: https://go-review.googlesource.com/5300
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
The code in mfinal.go is moved from malloc*.go and mgc*.go
and substantially unchanged.
The code in mbitmap.go is also moved from those files, but
cleaned up so that it can be called from those files (in most cases
the code being moved was not already a standalone function).
I also renamed the constants and wrote comments describing
the format. The result is a significant cleanup and isolation of
the bitmap code, but, roughly speaking, it should be treated
and reviewed as new code.
The other files changed only as much as necessary to support
this code movement.
This CL does NOT change the semantics of the heap or type
bitmaps at all, although there are now some obvious opportunities
to do so in followup CLs.
Change-Id: I41b8d5de87ad1d3cd322709931ab25e659dbb21d
Reviewed-on: https://go-review.googlesource.com/2991
Reviewed-by: Keith Randall <khr@golang.org>
