diff options
| author | Austin Clements <austin@google.com> | 2015-11-15 23:09:16 -0500 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2015-11-16 17:32:29 +0000 |
| commit | 97dc591534e580ede4c6145456dadf1e009f1bea (patch) | |
| tree | 84f38b17a74e0a11adc1f25d0ec26b7399cbbfa5 /src/runtime/malloc.go | |
| parent | 9b299c1efd902842b788d7dc103512b6b2568ea9 (diff) | |
| download | go-97dc591534e580ede4c6145456dadf1e009f1bea.tar.xz | |
runtime: avoid stat underflow crash
If the area returned by sysReserve in mheap.sysAlloc is outside the
usable arena, we sysFree it. We pass a fake stat pointer to sysFree
because we haven't added the allocation to any stat at that point.
However, we pass a 0 stat, so sysFree panics when it decrements the
stat because the fake stat underflows.
Fix this by setting the fake stat to the allocation size.
Updates #13143 (this is a prerequisite to fixing that bug).
Change-Id: I61a6c9be19ac1c95863cf6a8435e19790c8bfc9a
Reviewed-on: https://go-review.googlesource.com/16926
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/runtime/malloc.go')
| -rw-r--r-- | src/runtime/malloc.go | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go index 6430511d7d..8ce420a653 100644 --- a/src/runtime/malloc.go +++ b/src/runtime/malloc.go @@ -414,7 +414,10 @@ func (h *mheap) sysAlloc(n uintptr) unsafe.Pointer { h.arena_used = used h.arena_reserved = reserved } else { - var stat uint64 + // We haven't added this allocation to + // the stats, so subtract it from a + // fake stat (but avoid underflow). + stat := uint64(p_size) sysFree(unsafe.Pointer(p), p_size, &stat) } } |