author | Enrico Perla <enrico.perla@oracle.com> |
Fri, 04 Nov 2016 05:32:50 -0700 | |
changeset 7245 | 934578b959f0 |
parent 5331 | 9c955076ffe3 |
permissions | -rw-r--r-- |
5331
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
1 |
From e49330911f52bcb2aeb7eae4ca6df4fc8a013abe Mon Sep 17 00:00:00 2001 |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
2 |
From: Austin Clements <[email protected]> |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
3 |
Date: Sun, 15 Nov 2015 23:09:16 -0500 |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
4 |
Subject: [PATCH 44/63] [release-branch.go1.5] runtime: avoid stat underflow |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
5 |
crash |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
6 |
|
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
7 |
If the area returned by sysReserve in mheap.sysAlloc is outside the |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
8 |
usable arena, we sysFree it. We pass a fake stat pointer to sysFree |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
9 |
because we haven't added the allocation to any stat at that point. |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
10 |
However, we pass a 0 stat, so sysFree panics when it decrements the |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
11 |
stat because the fake stat underflows. |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
12 |
|
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
13 |
Fix this by setting the fake stat to the allocation size. |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
14 |
|
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
15 |
Updates #13143 (this is a prerequisite to fixing that bug). |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
16 |
|
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
17 |
Change-Id: I61a6c9be19ac1c95863cf6a8435e19790c8bfc9a |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
18 |
Reviewed-on: https://go-review.googlesource.com/16926 |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
19 |
Reviewed-by: Ian Lance Taylor <[email protected]> |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
20 |
Reviewed-on: https://go-review.googlesource.com/16987 |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
21 |
Run-TryBot: Austin Clements <[email protected]> |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
22 |
Reviewed-by: Russ Cox <[email protected]> |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
23 |
--- |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
24 |
src/runtime/malloc.go | 5 ++++- |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
25 |
1 file changed, 4 insertions(+), 1 deletion(-) |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
26 |
|
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
27 |
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
28 |
index 353f840..a8a5d48 100644 |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
29 |
--- a/src/runtime/malloc.go |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
30 |
+++ b/src/runtime/malloc.go |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
31 |
@@ -411,7 +411,10 @@ func mHeap_SysAlloc(h *mheap, n uintptr) unsafe.Pointer { |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
32 |
h.arena_used = used |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
33 |
h.arena_reserved = reserved |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
34 |
} else { |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
35 |
- var stat uint64 |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
36 |
+ // We haven't added this allocation to |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
37 |
+ // the stats, so subtract it from a |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
38 |
+ // fake stat (but avoid underflow). |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
39 |
+ stat := uint64(p_size) |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
40 |
sysFree((unsafe.Pointer)(p), p_size, &stat) |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
41 |
} |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
42 |
} |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
43 |
-- |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
44 |
2.6.1 |
9c955076ffe3
PSARC/2015/203 Google Go version 1.5
Shawn Walker-Salas <shawn.walker@oracle.com>
parents:
diff
changeset
|
45 |