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
|
// SPDX-License-Identifier: GPL-2.0
/*
* Augment the openat syscall with the contents of the filename pointer argument.
*
* 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 unmodified,
* which will be done as that feature is implemented in the next csets, for now
* it will appear in a dump done by the default tracepoint handler in 'perf trace',
* that uses bpf_output__fprintf() to just dump those contents, as done with
* the bpf-output event associated with the __bpf_output__ map declared in
* tools/perf/include/bpf/stdio.h.
*/
#include <stdio.h>
#include <linux/socket.h>
struct bpf_map SEC("maps") __augmented_syscalls__ = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
.max_entries = __NR_CPUS__,
};
struct augmented_filename {
int size;
int reserved;
char value[256];
};
#define augmented_filename_syscall_enter(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, }; \
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); \
perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
&augmented_args, \
(sizeof(augmented_args) - sizeof(augmented_args.filename.value) + \
augmented_args.filename.size)); \
return 0; \
}
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_enter(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_enter(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_enter(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_enter(newstat);
#ifndef _K_SS_MAXSIZE
#define _K_SS_MAXSIZE 128
#endif
#define augmented_sockaddr_syscall_enter(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); \
perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \
&augmented_args, \
sizeof(augmented_args) - sizeof(augmented_args.addr) + addrlen); \
return 0; \
}
struct sockaddr;
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_enter(connect);
license(GPL);
|
