1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
//===-- msan_chained_origin_depot.cc -----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// A storage for chained origins.
//===----------------------------------------------------------------------===//
#include "msan_chained_origin_depot.h"
#include "sanitizer_common/sanitizer_stackdepotbase.h"
namespace __msan {
struct ChainedOriginDepotDesc {
u32 here_id;
u32 prev_id;
/* This is murmur2 hash for the 64->32 bit case.
It does not behave all that well because the keys have a very biased
distribution (I've seen 7-element buckets with the table only 14% full).
here_id is built of
* (1 bits) Reserved, zero.
* (8 bits) Part id = bits 13..20 of the hash value of here_id's key.
* (23 bits) Sequential number (each part has each own sequence).
prev_id has either the same distribution as here_id (but with 3:8:21)
split, or one of two reserved values (-1) or (-2). Either case can
dominate depending on the workload.
*/
u32 hash() const {
const u32 m = 0x5bd1e995;
const u32 seed = 0x9747b28c;
const u32 r = 24;
u32 h = seed;
u32 k = here_id;
k *= m;
k ^= k >> r;
k *= m;
h *= m;
h ^= k;
k = prev_id;
k *= m;
k ^= k >> r;
k *= m;
h *= m;
h ^= k;
h ^= h >> 13;
h *= m;
h ^= h >> 15;
return h;
}
bool is_valid() { return true; }
};
struct ChainedOriginDepotNode {
ChainedOriginDepotNode *link;
u32 id;
u32 here_id;
u32 prev_id;
typedef ChainedOriginDepotDesc args_type;
bool eq(u32 hash, const args_type &args) const {
return here_id == args.here_id && prev_id == args.prev_id;
}
static uptr storage_size(const args_type &args) {
return sizeof(ChainedOriginDepotNode);
}
void store(const args_type &args, u32 other_hash) {
here_id = args.here_id;
prev_id = args.prev_id;
}
args_type load() const {
args_type ret = {here_id, prev_id};
return ret;
}
struct Handle {
ChainedOriginDepotNode *node_;
Handle() : node_(0) {}
explicit Handle(ChainedOriginDepotNode *node) : node_(node) {}
bool valid() { return node_; }
u32 id() { return node_->id; }
int here_id() { return node_->here_id; }
int prev_id() { return node_->prev_id; }
};
Handle get_handle() { return Handle(this); }
typedef Handle handle_type;
};
// kTabSizeLog = 22 => 32Mb static storage for bucket pointers.
static StackDepotBase<ChainedOriginDepotNode, 3, 20> chainedOriginDepot;
StackDepotStats *ChainedOriginDepotGetStats() {
return chainedOriginDepot.GetStats();
}
bool ChainedOriginDepotPut(u32 here_id, u32 prev_id, u32 *new_id) {
ChainedOriginDepotDesc desc = {here_id, prev_id};
bool inserted;
ChainedOriginDepotNode::Handle h = chainedOriginDepot.Put(desc, &inserted);
*new_id = h.valid() ? h.id() : 0;
return inserted;
}
// Retrieves a stored stack trace by the id.
u32 ChainedOriginDepotGet(u32 id, u32 *other) {
ChainedOriginDepotDesc desc = chainedOriginDepot.Get(id);
*other = desc.prev_id;
return desc.here_id;
}
} // namespace __msan
|