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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
// SPDX-License-Identifier: GPL-2.0
/*
* Augment syscalls with the contents of the pointer arguments.
*
* Test it with:
*
* perf trace -e tools/perf/examples/bpf/augmented_syscalls.c cat /etc/passwd > /dev/null
*
* It'll catch some openat syscalls related to the dynamic linked and
* the last one should be the one for '/etc/passwd'.
*
* This matches what is marshalled into the raw_syscall:sys_enter payload
* expected by the 'perf trace' beautifiers, and can be used by them, that will
* check if perf_sample->raw_data is more than what is expected for each
* syscalls:sys_{enter,exit}_SYSCALL tracepoint, uing the extra data as the
* contents of pointer arguments.
*/
#include <stdio.h>
#include <linux/socket.h>
/* bpf-output associated map */
bpf_map(__augmented_syscalls__, PERF_EVENT_ARRAY, int, u32, __NR_CPUS__);
struct syscall_exit_args {
unsigned long long common_tp_fields;
long syscall_nr;
long ret;
};
struct augmented_filename {
unsigned int size;
int reserved;
char value[256];
};
#define augmented_filename_syscall(syscall) \
struct augmented_enter_##syscall##_args { \
struct syscall_enter_##syscall##_args args; \
struct augmented_filename filename; \
}; \
int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \
{ \
struct augmented_enter_##syscall##_args augmented_args = { .filename.reserved = 0, }; \
unsigned int len = sizeof(augmented_args); \
probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \
augmented_args.filename.size = probe_read_str(&augmented_args.filename.value, \
sizeof(augmented_args.filename.value), \
args->filename_ptr); \
if (augmented_args.filename.size < sizeof(augmented_args.filename.value)) { \
len -= sizeof(augmented_args.filename.value) - augmented_args.filename.size; \
len &= sizeof(augmented_args.filename.value) - 1; \
} \
/* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \
return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
&augmented_args, len); \
} \
int syscall_exit(syscall)(struct syscall_exit_args *args) \
{ \
return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \
}
struct syscall_enter_openat_args {
unsigned long long common_tp_fields;
long syscall_nr;
long dfd;
char *filename_ptr;
long flags;
long mode;
};
augmented_filename_syscall(openat);
struct syscall_enter_open_args {
unsigned long long common_tp_fields;
long syscall_nr;
char *filename_ptr;
long flags;
long mode;
};
augmented_filename_syscall(open);
struct syscall_enter_inotify_add_watch_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
char *filename_ptr;
long mask;
};
augmented_filename_syscall(inotify_add_watch);
struct statbuf;
struct syscall_enter_newstat_args {
unsigned long long common_tp_fields;
long syscall_nr;
char *filename_ptr;
struct stat *statbuf;
};
augmented_filename_syscall(newstat);
#ifndef _K_SS_MAXSIZE
#define _K_SS_MAXSIZE 128
#endif
#define augmented_sockaddr_syscall(syscall) \
struct augmented_enter_##syscall##_args { \
struct syscall_enter_##syscall##_args args; \
struct sockaddr_storage addr; \
}; \
int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \
{ \
struct augmented_enter_##syscall##_args augmented_args; \
unsigned long addrlen = sizeof(augmented_args.addr); \
probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \
/* FIXME_CLANG_OPTIMIZATION_THAT_ACCESSES_USER_CONTROLLED_ADDRLEN_DESPITE_THIS_CHECK */ \
/* if (addrlen > augmented_args.args.addrlen) */ \
/* addrlen = augmented_args.args.addrlen; */ \
/* */ \
probe_read(&augmented_args.addr, addrlen, args->addr_ptr); \
/* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \
return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
&augmented_args, \
sizeof(augmented_args) - sizeof(augmented_args.addr) + addrlen);\
} \
int syscall_exit(syscall)(struct syscall_exit_args *args) \
{ \
return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \
}
struct sockaddr;
struct syscall_enter_bind_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
struct sockaddr *addr_ptr;
unsigned long addrlen;
};
augmented_sockaddr_syscall(bind);
struct syscall_enter_connect_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
struct sockaddr *addr_ptr;
unsigned long addrlen;
};
augmented_sockaddr_syscall(connect);
struct syscall_enter_sendto_args {
unsigned long long common_tp_fields;
long syscall_nr;
long fd;
void *buff;
long len;
unsigned long flags;
struct sockaddr *addr_ptr;
long addr_len;
};
augmented_sockaddr_syscall(sendto);
license(GPL);
|
