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9f36eaed MJ |
1 | /* SPDX-License-Identifier: MIT |
2 | * | |
2df37e95 | 3 | * lttng/filter.h |
07dfc1d0 MD |
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 | ||
2df37e95 MD |
15 | #include <lttng/events.h> |
16 | #include <lttng/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...) \ | |
5a15f70c | 26 | printk(KERN_DEBUG "LTTng: [debug bytecode in %s:%s@%u] " fmt, \ |
07dfc1d0 MD |
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) \ | |
5a15f70c | 33 | printk(KERN_DEBUG "LTTng: [debug bytecode in %s:%s@%u] " fmt, \ |
07dfc1d0 MD |
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 */ | |
94 | } elem; | |
07dfc1d0 MD |
95 | }; |
96 | ||
97 | /* Validation stack */ | |
3834b99f MD |
98 | struct vstack_load { |
99 | enum load_type type; | |
100 | enum object_type object_type; | |
101 | const struct lttng_event_field *field; | |
102 | bool rev_bo; /* reverse byte order */ | |
103 | }; | |
104 | ||
07dfc1d0 MD |
105 | struct vstack_entry { |
106 | enum entry_type type; | |
3834b99f | 107 | struct vstack_load load; |
07dfc1d0 MD |
108 | }; |
109 | ||
110 | struct vstack { | |
111 | int top; /* top of stack */ | |
112 | struct vstack_entry e[FILTER_STACK_LEN]; | |
113 | }; | |
114 | ||
115 | static inline | |
116 | void vstack_init(struct vstack *stack) | |
117 | { | |
118 | stack->top = -1; | |
119 | } | |
120 | ||
121 | static inline | |
122 | struct vstack_entry *vstack_ax(struct vstack *stack) | |
123 | { | |
124 | if (unlikely(stack->top < 0)) | |
125 | return NULL; | |
126 | return &stack->e[stack->top]; | |
127 | } | |
128 | ||
129 | static inline | |
130 | struct vstack_entry *vstack_bx(struct vstack *stack) | |
131 | { | |
132 | if (unlikely(stack->top < 1)) | |
133 | return NULL; | |
134 | return &stack->e[stack->top - 1]; | |
135 | } | |
136 | ||
137 | static inline | |
138 | int vstack_push(struct vstack *stack) | |
139 | { | |
140 | if (stack->top >= FILTER_STACK_LEN - 1) { | |
5a15f70c | 141 | printk(KERN_WARNING "LTTng: filter: Stack full\n"); |
07dfc1d0 MD |
142 | return -EINVAL; |
143 | } | |
144 | ++stack->top; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | static inline | |
149 | int vstack_pop(struct vstack *stack) | |
150 | { | |
151 | if (unlikely(stack->top < 0)) { | |
5a15f70c | 152 | printk(KERN_WARNING "LTTng: filter: Stack empty\n"); |
07dfc1d0 MD |
153 | return -EINVAL; |
154 | } | |
155 | stack->top--; | |
156 | return 0; | |
157 | } | |
158 | ||
159 | /* Execution stack */ | |
02aca193 PP |
160 | enum estack_string_literal_type { |
161 | ESTACK_STRING_LITERAL_TYPE_NONE, | |
162 | ESTACK_STRING_LITERAL_TYPE_PLAIN, | |
163 | ESTACK_STRING_LITERAL_TYPE_STAR_GLOB, | |
164 | }; | |
165 | ||
3834b99f MD |
166 | struct load_ptr { |
167 | enum load_type type; | |
168 | enum object_type object_type; | |
169 | const void *ptr; | |
170 | bool rev_bo; | |
171 | /* Temporary place-holders for contexts. */ | |
172 | union { | |
173 | int64_t s64; | |
174 | uint64_t u64; | |
175 | double d; | |
176 | } u; | |
177 | /* | |
178 | * "field" is only needed when nested under a variant, in which | |
179 | * case we cannot specialize the nested operations. | |
180 | */ | |
181 | const struct lttng_event_field *field; | |
182 | }; | |
183 | ||
07dfc1d0 MD |
184 | struct estack_entry { |
185 | union { | |
186 | int64_t v; | |
187 | ||
188 | struct { | |
189 | const char *str; | |
f127e61e | 190 | const char __user *user_str; |
07dfc1d0 | 191 | size_t seq_len; |
02aca193 | 192 | enum estack_string_literal_type literal_type; |
f127e61e | 193 | int user; /* is string from userspace ? */ |
07dfc1d0 | 194 | } s; |
3834b99f | 195 | struct load_ptr ptr; |
07dfc1d0 MD |
196 | } u; |
197 | }; | |
198 | ||
199 | struct estack { | |
200 | int top; /* top of stack */ | |
201 | struct estack_entry e[FILTER_STACK_LEN]; | |
202 | }; | |
203 | ||
204 | #define estack_ax_v ax | |
205 | #define estack_bx_v bx | |
206 | ||
207 | #define estack_ax(stack, top) \ | |
208 | ({ \ | |
5f12cb8d | 209 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
210 | &(stack)->e[top]; \ |
211 | }) | |
212 | ||
213 | #define estack_bx(stack, top) \ | |
214 | ({ \ | |
5f12cb8d | 215 | BUG_ON((top) <= FILTER_STACK_EMPTY + 1); \ |
07dfc1d0 MD |
216 | &(stack)->e[(top) - 1]; \ |
217 | }) | |
218 | ||
219 | #define estack_push(stack, top, ax, bx) \ | |
220 | do { \ | |
5f12cb8d | 221 | BUG_ON((top) >= FILTER_STACK_LEN - 1); \ |
07dfc1d0 MD |
222 | (stack)->e[(top) - 1].u.v = (bx); \ |
223 | (bx) = (ax); \ | |
224 | ++(top); \ | |
225 | } while (0) | |
226 | ||
227 | #define estack_pop(stack, top, ax, bx) \ | |
228 | do { \ | |
5f12cb8d | 229 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
230 | (ax) = (bx); \ |
231 | (bx) = (stack)->e[(top) - 2].u.v; \ | |
232 | (top)--; \ | |
233 | } while (0) | |
234 | ||
235 | const char *lttng_filter_print_op(enum filter_op op); | |
236 | ||
237 | int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode); | |
3834b99f MD |
238 | int lttng_filter_specialize_bytecode(struct lttng_event *event, |
239 | struct bytecode_runtime *bytecode); | |
07dfc1d0 MD |
240 | |
241 | uint64_t lttng_filter_false(void *filter_data, | |
79150a49 | 242 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
243 | const char *filter_stack_data); |
244 | uint64_t lttng_filter_interpret_bytecode(void *filter_data, | |
79150a49 | 245 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
246 | const char *filter_stack_data); |
247 | ||
248 | #endif /* _LTTNG_FILTER_H */ |