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9f36eaed MJ |
1 | /* SPDX-License-Identifier: MIT |
2 | * | |
07dfc1d0 MD |
3 | * lttng-filter.h |
4 | * | |
5 | * LTTng modules filter header. | |
6 | * | |
bbf3aef5 | 7 | * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
07dfc1d0 MD |
8 | */ |
9 | ||
9f36eaed MJ |
10 | #ifndef _LTTNG_FILTER_H |
11 | #define _LTTNG_FILTER_H | |
12 | ||
07dfc1d0 MD |
13 | #include <linux/kernel.h> |
14 | ||
bbd023d6 MD |
15 | #include <lttng-events.h> |
16 | #include <filter-bytecode.h> | |
07dfc1d0 MD |
17 | |
18 | /* Filter stack length, in number of entries */ | |
19 | #define FILTER_STACK_LEN 10 /* includes 2 dummy */ | |
20 | #define FILTER_STACK_EMPTY 1 | |
21 | ||
3834b99f MD |
22 | #define FILTER_MAX_DATA_LEN 65536 |
23 | ||
07dfc1d0 MD |
24 | #ifdef DEBUG |
25 | #define dbg_printk(fmt, args...) \ | |
26 | printk(KERN_DEBUG "[debug bytecode in %s:%s@%u] " fmt, \ | |
27 | __FILE__, __func__, __LINE__, ## args) | |
28 | #else | |
29 | #define dbg_printk(fmt, args...) \ | |
30 | do { \ | |
31 | /* do nothing but check printf format */ \ | |
32 | if (0) \ | |
33 | printk(KERN_DEBUG "[debug bytecode in %s:%s@%u] " fmt, \ | |
34 | __FILE__, __func__, __LINE__, ## args); \ | |
35 | } while (0) | |
36 | #endif | |
37 | ||
38 | /* Linked bytecode. Child of struct lttng_bytecode_runtime. */ | |
39 | struct bytecode_runtime { | |
40 | struct lttng_bytecode_runtime p; | |
3834b99f MD |
41 | size_t data_len; |
42 | size_t data_alloc_len; | |
43 | char *data; | |
07dfc1d0 | 44 | uint16_t len; |
3834b99f | 45 | char code[0]; |
07dfc1d0 MD |
46 | }; |
47 | ||
48 | enum entry_type { | |
49 | REG_S64, | |
50 | REG_DOUBLE, | |
51 | REG_STRING, | |
02aca193 | 52 | REG_STAR_GLOB_STRING, |
07dfc1d0 | 53 | REG_TYPE_UNKNOWN, |
3834b99f MD |
54 | REG_PTR, |
55 | }; | |
56 | ||
57 | enum load_type { | |
58 | LOAD_ROOT_CONTEXT, | |
59 | LOAD_ROOT_APP_CONTEXT, | |
60 | LOAD_ROOT_PAYLOAD, | |
61 | LOAD_OBJECT, | |
62 | }; | |
63 | ||
64 | enum object_type { | |
65 | OBJECT_TYPE_S8, | |
66 | OBJECT_TYPE_S16, | |
67 | OBJECT_TYPE_S32, | |
68 | OBJECT_TYPE_S64, | |
69 | OBJECT_TYPE_U8, | |
70 | OBJECT_TYPE_U16, | |
71 | OBJECT_TYPE_U32, | |
72 | OBJECT_TYPE_U64, | |
73 | ||
74 | OBJECT_TYPE_DOUBLE, | |
75 | OBJECT_TYPE_STRING, | |
76 | OBJECT_TYPE_STRING_SEQUENCE, | |
77 | ||
78 | OBJECT_TYPE_SEQUENCE, | |
79 | OBJECT_TYPE_ARRAY, | |
80 | OBJECT_TYPE_STRUCT, | |
81 | OBJECT_TYPE_VARIANT, | |
82 | ||
83 | OBJECT_TYPE_DYNAMIC, | |
84 | }; | |
85 | ||
86 | struct filter_get_index_data { | |
87 | uint64_t offset; /* in bytes */ | |
88 | size_t ctx_index; | |
89 | size_t array_len; | |
90 | struct { | |
91 | size_t len; | |
92 | enum object_type type; | |
93 | bool rev_bo; /* reverse byte order */ | |
c89271d4 | 94 | bool user; /* from userspace */ |
3834b99f | 95 | } elem; |
07dfc1d0 MD |
96 | }; |
97 | ||
98 | /* Validation stack */ | |
3834b99f MD |
99 | struct vstack_load { |
100 | enum load_type type; | |
101 | enum object_type object_type; | |
102 | const struct lttng_event_field *field; | |
103 | bool rev_bo; /* reverse byte order */ | |
c89271d4 | 104 | bool user; /* from userspace */ |
3834b99f MD |
105 | }; |
106 | ||
07dfc1d0 MD |
107 | struct vstack_entry { |
108 | enum entry_type type; | |
3834b99f | 109 | struct vstack_load load; |
07dfc1d0 MD |
110 | }; |
111 | ||
112 | struct vstack { | |
113 | int top; /* top of stack */ | |
114 | struct vstack_entry e[FILTER_STACK_LEN]; | |
115 | }; | |
116 | ||
117 | static inline | |
118 | void vstack_init(struct vstack *stack) | |
119 | { | |
120 | stack->top = -1; | |
121 | } | |
122 | ||
123 | static inline | |
124 | struct vstack_entry *vstack_ax(struct vstack *stack) | |
125 | { | |
126 | if (unlikely(stack->top < 0)) | |
127 | return NULL; | |
128 | return &stack->e[stack->top]; | |
129 | } | |
130 | ||
131 | static inline | |
132 | struct vstack_entry *vstack_bx(struct vstack *stack) | |
133 | { | |
134 | if (unlikely(stack->top < 1)) | |
135 | return NULL; | |
136 | return &stack->e[stack->top - 1]; | |
137 | } | |
138 | ||
139 | static inline | |
140 | int vstack_push(struct vstack *stack) | |
141 | { | |
142 | if (stack->top >= FILTER_STACK_LEN - 1) { | |
143 | printk(KERN_WARNING "Stack full\n"); | |
144 | return -EINVAL; | |
145 | } | |
146 | ++stack->top; | |
147 | return 0; | |
148 | } | |
149 | ||
150 | static inline | |
151 | int vstack_pop(struct vstack *stack) | |
152 | { | |
153 | if (unlikely(stack->top < 0)) { | |
154 | printk(KERN_WARNING "Stack empty\n"); | |
155 | return -EINVAL; | |
156 | } | |
157 | stack->top--; | |
158 | return 0; | |
159 | } | |
160 | ||
161 | /* Execution stack */ | |
02aca193 PP |
162 | enum estack_string_literal_type { |
163 | ESTACK_STRING_LITERAL_TYPE_NONE, | |
164 | ESTACK_STRING_LITERAL_TYPE_PLAIN, | |
165 | ESTACK_STRING_LITERAL_TYPE_STAR_GLOB, | |
166 | }; | |
167 | ||
3834b99f MD |
168 | struct load_ptr { |
169 | enum load_type type; | |
170 | enum object_type object_type; | |
171 | const void *ptr; | |
172 | bool rev_bo; | |
c89271d4 | 173 | bool user; /* from userspace */ |
3834b99f MD |
174 | /* Temporary place-holders for contexts. */ |
175 | union { | |
176 | int64_t s64; | |
177 | uint64_t u64; | |
178 | double d; | |
179 | } u; | |
180 | /* | |
181 | * "field" is only needed when nested under a variant, in which | |
182 | * case we cannot specialize the nested operations. | |
183 | */ | |
184 | const struct lttng_event_field *field; | |
185 | }; | |
186 | ||
07dfc1d0 MD |
187 | struct estack_entry { |
188 | union { | |
189 | int64_t v; | |
190 | ||
191 | struct { | |
192 | const char *str; | |
f127e61e | 193 | const char __user *user_str; |
07dfc1d0 | 194 | size_t seq_len; |
02aca193 | 195 | enum estack_string_literal_type literal_type; |
c89271d4 | 196 | bool user; /* is string from userspace ? */ |
07dfc1d0 | 197 | } s; |
3834b99f | 198 | struct load_ptr ptr; |
07dfc1d0 MD |
199 | } u; |
200 | }; | |
201 | ||
202 | struct estack { | |
203 | int top; /* top of stack */ | |
204 | struct estack_entry e[FILTER_STACK_LEN]; | |
205 | }; | |
206 | ||
207 | #define estack_ax_v ax | |
208 | #define estack_bx_v bx | |
209 | ||
210 | #define estack_ax(stack, top) \ | |
211 | ({ \ | |
5f12cb8d | 212 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
213 | &(stack)->e[top]; \ |
214 | }) | |
215 | ||
216 | #define estack_bx(stack, top) \ | |
217 | ({ \ | |
5f12cb8d | 218 | BUG_ON((top) <= FILTER_STACK_EMPTY + 1); \ |
07dfc1d0 MD |
219 | &(stack)->e[(top) - 1]; \ |
220 | }) | |
221 | ||
222 | #define estack_push(stack, top, ax, bx) \ | |
223 | do { \ | |
5f12cb8d | 224 | BUG_ON((top) >= FILTER_STACK_LEN - 1); \ |
07dfc1d0 MD |
225 | (stack)->e[(top) - 1].u.v = (bx); \ |
226 | (bx) = (ax); \ | |
227 | ++(top); \ | |
228 | } while (0) | |
229 | ||
230 | #define estack_pop(stack, top, ax, bx) \ | |
231 | do { \ | |
5f12cb8d | 232 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
233 | (ax) = (bx); \ |
234 | (bx) = (stack)->e[(top) - 2].u.v; \ | |
235 | (top)--; \ | |
236 | } while (0) | |
237 | ||
238 | const char *lttng_filter_print_op(enum filter_op op); | |
239 | ||
240 | int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode); | |
ce5579a7 | 241 | int lttng_filter_validate_bytecode_load(struct bytecode_runtime *bytecode); |
3834b99f MD |
242 | int lttng_filter_specialize_bytecode(struct lttng_event *event, |
243 | struct bytecode_runtime *bytecode); | |
07dfc1d0 MD |
244 | |
245 | uint64_t lttng_filter_false(void *filter_data, | |
79150a49 | 246 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
247 | const char *filter_stack_data); |
248 | uint64_t lttng_filter_interpret_bytecode(void *filter_data, | |
79150a49 | 249 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
250 | const char *filter_stack_data); |
251 | ||
252 | #endif /* _LTTNG_FILTER_H */ |