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
|
# Copyright 2022-2024 Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# This file is part of the gdb testsuite.
#
# Test that GDB for AArch64/Linux can properly handle pointers with
# the upper 16 bits (PAC) or 8 bits (Tag) set, as well as the
# VA_RANGE_SELECT bit (55).
require is_aarch64_target
standard_testfile
if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
return -1
}
if ![runto_main] {
return -1
}
# We need to iterate over two distinct ranges, separated by a single bit.
# This bit is 55 (VA_RANGE_SELECT) which tells us if we have a kernel-space
# address or a user-space address.
# The tag field has 8 bits.
set tag_bits_count 8
# The pac field has 7 bits.
set pac_bits_count 7
# A couple patterns that we reuse for the tests later. One is for a successful
# memory read and the other is for a memory read failure.
set memory_read_ok_pattern "$::hex\( <l>\)?:\[ \t\]+$::hex"
set memory_read_fail_pattern "$::hex:\[ \t\]+Cannot access memory at address $::hex"
set pac_enabled 0
# Check if PAC is enabled.
gdb_test_multiple "ptype \$pauth_cmask" "fetch PAC cmask" {
-re -wrap "type = long" {
set pac_enabled 1
}
-re -wrap "type = void" {
}
-re ".*$gdb_prompt $" {
fail $gdb_test_name
return 1
}
}
# Value of the cmask register.
set cmask 0
# If there are PAC registers, GDB uses those to unmask the PAC bits.
if {$pac_enabled} {
set cmask [get_valueof "" "\$pauth_cmask >> 48" "0" "fetch PAC cmask"]
}
# Cycle through the tag and pac bit ranges and check how GDB
# behaves when trying to access these addresses.
foreach_with_prefix upper_bits {"0x0" "0x1" "0x2" "0x4" "0x8" "0x10" "0x20" "0x40" "0x80"} {
foreach_with_prefix lower_bits {"0x0" "0x1" "0x2" "0x4" "0x8" "0x10" "0x20" "0x40"} {
# A successful memory read pattern
set pattern $memory_read_ok_pattern
if {!$pac_enabled} {
# If PAC is not supported, memory reads will fail if
# lower_bits != 0x0
if {$lower_bits != "0x0"} {
set pattern $memory_read_fail_pattern
}
} else {
# Otherwise, figure out if the memory read will succeed or not by
# checking cmask.
gdb_test_multiple "p/x (~${cmask}ULL & (${lower_bits}ULL))" "" {
-re -wrap "= 0x0" {
# Either cmask is 0x7F or lower_bits is 0x0.
# Either way, the memory read should succeed.
}
-re -wrap "= $::hex" {
if {$lower_bits != "0x0"} {
# cmask doesn't mask off all the PAC bits, which
# results in a memory read failure, with the actual
# address being accessed differing from the one we
# passed.
set pattern $memory_read_fail_pattern
}
}
}
}
# Test without the VA_RANGE_SELECT bit set.
gdb_test "x/gx ((unsigned long) l_ptr | ((${upper_bits}ULL << 56) | (${lower_bits}ULL << 48)))" \
$pattern \
"user-space memory access"
# Now test with the VA_RANGE_SELECT bit set.
gdb_test "x/gx ((unsigned long) l_ptr | ((${upper_bits}ULL << 56) | (${lower_bits}ULL << 48) | (1ULL << 55))) " \
$memory_read_fail_pattern \
"kernel-space memory access"
}
}
|
