1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
4 * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
5 * Copyright (c) 2022 David Vernet <dvernet@meta.com>
6 */
7 #ifndef __SCX_COMMON_BPF_H
8 #define __SCX_COMMON_BPF_H
9
10 /*
11 * The generated kfunc prototypes in vmlinux.h are missing address space
12 * attributes which cause build failures. For now, suppress the generated
13 * prototypes. See https://github.com/sched-ext/scx/issues/1111.
14 */
15 #define BPF_NO_KFUNC_PROTOTYPES
16
17 #ifdef LSP
18 #define __bpf__
19 #include "../vmlinux.h"
20 #else
21 #include "vmlinux.h"
22 #endif
23
24 #include <bpf/bpf_helpers.h>
25 #include <bpf/bpf_tracing.h>
26 #include <asm-generic/errno.h>
27 #include "user_exit_info.h"
28 #include "enum_defs.autogen.h"
29
30 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
31 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
32 #define PF_EXITING 0x00000004
33 #define CLOCK_MONOTONIC 1
34
35 extern int LINUX_KERNEL_VERSION __kconfig;
36 extern const char CONFIG_CC_VERSION_TEXT[64] __kconfig __weak;
37 extern const char CONFIG_LOCALVERSION[64] __kconfig __weak;
38
39 /*
40 * Earlier versions of clang/pahole lost upper 32bits in 64bit enums which can
41 * lead to really confusing misbehaviors. Let's trigger a build failure.
42 */
___vmlinux_h_sanity_check___(void)43 static inline void ___vmlinux_h_sanity_check___(void)
44 {
45 _Static_assert(SCX_DSQ_FLAG_BUILTIN,
46 "bpftool generated vmlinux.h is missing high bits for 64bit enums, upgrade clang and pahole");
47 }
48
49 s32 scx_bpf_create_dsq(u64 dsq_id, s32 node) __ksym;
50 s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool *is_idle) __ksym;
51 void scx_bpf_dsq_insert(struct task_struct *p, u64 dsq_id, u64 slice, u64 enq_flags) __ksym __weak;
52 void scx_bpf_dsq_insert_vtime(struct task_struct *p, u64 dsq_id, u64 slice, u64 vtime, u64 enq_flags) __ksym __weak;
53 u32 scx_bpf_dispatch_nr_slots(void) __ksym;
54 void scx_bpf_dispatch_cancel(void) __ksym;
55 bool scx_bpf_dsq_move_to_local(u64 dsq_id) __ksym __weak;
56 void scx_bpf_dsq_move_set_slice(struct bpf_iter_scx_dsq *it__iter, u64 slice) __ksym __weak;
57 void scx_bpf_dsq_move_set_vtime(struct bpf_iter_scx_dsq *it__iter, u64 vtime) __ksym __weak;
58 bool scx_bpf_dsq_move(struct bpf_iter_scx_dsq *it__iter, struct task_struct *p, u64 dsq_id, u64 enq_flags) __ksym __weak;
59 bool scx_bpf_dsq_move_vtime(struct bpf_iter_scx_dsq *it__iter, struct task_struct *p, u64 dsq_id, u64 enq_flags) __ksym __weak;
60 u32 scx_bpf_reenqueue_local(void) __ksym;
61 void scx_bpf_kick_cpu(s32 cpu, u64 flags) __ksym;
62 s32 scx_bpf_dsq_nr_queued(u64 dsq_id) __ksym;
63 void scx_bpf_destroy_dsq(u64 dsq_id) __ksym;
64 int bpf_iter_scx_dsq_new(struct bpf_iter_scx_dsq *it, u64 dsq_id, u64 flags) __ksym __weak;
65 struct task_struct *bpf_iter_scx_dsq_next(struct bpf_iter_scx_dsq *it) __ksym __weak;
66 void bpf_iter_scx_dsq_destroy(struct bpf_iter_scx_dsq *it) __ksym __weak;
67 void scx_bpf_exit_bstr(s64 exit_code, char *fmt, unsigned long long *data, u32 data__sz) __ksym __weak;
68 void scx_bpf_error_bstr(char *fmt, unsigned long long *data, u32 data_len) __ksym;
69 void scx_bpf_dump_bstr(char *fmt, unsigned long long *data, u32 data_len) __ksym __weak;
70 u32 scx_bpf_cpuperf_cap(s32 cpu) __ksym __weak;
71 u32 scx_bpf_cpuperf_cur(s32 cpu) __ksym __weak;
72 void scx_bpf_cpuperf_set(s32 cpu, u32 perf) __ksym __weak;
73 u32 scx_bpf_nr_node_ids(void) __ksym __weak;
74 u32 scx_bpf_nr_cpu_ids(void) __ksym __weak;
75 int scx_bpf_cpu_node(s32 cpu) __ksym __weak;
76 const struct cpumask *scx_bpf_get_possible_cpumask(void) __ksym __weak;
77 const struct cpumask *scx_bpf_get_online_cpumask(void) __ksym __weak;
78 void scx_bpf_put_cpumask(const struct cpumask *cpumask) __ksym __weak;
79 const struct cpumask *scx_bpf_get_idle_cpumask_node(int node) __ksym __weak;
80 const struct cpumask *scx_bpf_get_idle_cpumask(void) __ksym;
81 const struct cpumask *scx_bpf_get_idle_smtmask_node(int node) __ksym __weak;
82 const struct cpumask *scx_bpf_get_idle_smtmask(void) __ksym;
83 void scx_bpf_put_idle_cpumask(const struct cpumask *cpumask) __ksym;
84 bool scx_bpf_test_and_clear_cpu_idle(s32 cpu) __ksym;
85 s32 scx_bpf_pick_idle_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags) __ksym __weak;
86 s32 scx_bpf_pick_idle_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym;
87 s32 scx_bpf_pick_any_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags) __ksym __weak;
88 s32 scx_bpf_pick_any_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym;
89 bool scx_bpf_task_running(const struct task_struct *p) __ksym;
90 s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym;
91 struct rq *scx_bpf_cpu_rq(s32 cpu) __ksym;
92 struct cgroup *scx_bpf_task_cgroup(struct task_struct *p) __ksym __weak;
93 u64 scx_bpf_now(void) __ksym __weak;
94 void scx_bpf_events(struct scx_event_stats *events, size_t events__sz) __ksym __weak;
95
96 /*
97 * Use the following as @it__iter when calling scx_bpf_dsq_move[_vtime]() from
98 * within bpf_for_each() loops.
99 */
100 #define BPF_FOR_EACH_ITER (&___it)
101
102 #define scx_read_event(e, name) \
103 (bpf_core_field_exists((e)->name) ? (e)->name : 0)
104
105 static inline __attribute__((format(printf, 1, 2)))
___scx_bpf_bstr_format_checker(const char * fmt,...)106 void ___scx_bpf_bstr_format_checker(const char *fmt, ...) {}
107
108 /*
109 * Helper macro for initializing the fmt and variadic argument inputs to both
110 * bstr exit kfuncs. Callers to this function should use ___fmt and ___param to
111 * refer to the initialized list of inputs to the bstr kfunc.
112 */
113 #define scx_bpf_bstr_preamble(fmt, args...) \
114 static char ___fmt[] = fmt; \
115 /* \
116 * Note that __param[] must have at least one \
117 * element to keep the verifier happy. \
118 */ \
119 unsigned long long ___param[___bpf_narg(args) ?: 1] = {}; \
120 \
121 _Pragma("GCC diagnostic push") \
122 _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
123 ___bpf_fill(___param, args); \
124 _Pragma("GCC diagnostic pop")
125
126 /*
127 * scx_bpf_exit() wraps the scx_bpf_exit_bstr() kfunc with variadic arguments
128 * instead of an array of u64. Using this macro will cause the scheduler to
129 * exit cleanly with the specified exit code being passed to user space.
130 */
131 #define scx_bpf_exit(code, fmt, args...) \
132 ({ \
133 scx_bpf_bstr_preamble(fmt, args) \
134 scx_bpf_exit_bstr(code, ___fmt, ___param, sizeof(___param)); \
135 ___scx_bpf_bstr_format_checker(fmt, ##args); \
136 })
137
138 /*
139 * scx_bpf_error() wraps the scx_bpf_error_bstr() kfunc with variadic arguments
140 * instead of an array of u64. Invoking this macro will cause the scheduler to
141 * exit in an erroneous state, with diagnostic information being passed to the
142 * user.
143 */
144 #define scx_bpf_error(fmt, args...) \
145 ({ \
146 scx_bpf_bstr_preamble(fmt, args) \
147 scx_bpf_error_bstr(___fmt, ___param, sizeof(___param)); \
148 ___scx_bpf_bstr_format_checker(fmt, ##args); \
149 })
150
151 /*
152 * scx_bpf_dump() wraps the scx_bpf_dump_bstr() kfunc with variadic arguments
153 * instead of an array of u64. To be used from ops.dump() and friends.
154 */
155 #define scx_bpf_dump(fmt, args...) \
156 ({ \
157 scx_bpf_bstr_preamble(fmt, args) \
158 scx_bpf_dump_bstr(___fmt, ___param, sizeof(___param)); \
159 ___scx_bpf_bstr_format_checker(fmt, ##args); \
160 })
161
162 /*
163 * scx_bpf_dump_header() is a wrapper around scx_bpf_dump that adds a header
164 * of system information for debugging.
165 */
166 #define scx_bpf_dump_header() \
167 ({ \
168 scx_bpf_dump("kernel: %d.%d.%d %s\ncc: %s\n", \
169 LINUX_KERNEL_VERSION >> 16, \
170 LINUX_KERNEL_VERSION >> 8 & 0xFF, \
171 LINUX_KERNEL_VERSION & 0xFF, \
172 CONFIG_LOCALVERSION, \
173 CONFIG_CC_VERSION_TEXT); \
174 })
175
176 #define BPF_STRUCT_OPS(name, args...) \
177 SEC("struct_ops/"#name) \
178 BPF_PROG(name, ##args)
179
180 #define BPF_STRUCT_OPS_SLEEPABLE(name, args...) \
181 SEC("struct_ops.s/"#name) \
182 BPF_PROG(name, ##args)
183
184 /**
185 * RESIZABLE_ARRAY - Generates annotations for an array that may be resized
186 * @elfsec: the data section of the BPF program in which to place the array
187 * @arr: the name of the array
188 *
189 * libbpf has an API for setting map value sizes. Since data sections (i.e.
190 * bss, data, rodata) themselves are maps, a data section can be resized. If
191 * a data section has an array as its last element, the BTF info for that
192 * array will be adjusted so that length of the array is extended to meet the
193 * new length of the data section. This macro annotates an array to have an
194 * element count of one with the assumption that this array can be resized
195 * within the userspace program. It also annotates the section specifier so
196 * this array exists in a custom sub data section which can be resized
197 * independently.
198 *
199 * See RESIZE_ARRAY() for the userspace convenience macro for resizing an
200 * array declared with RESIZABLE_ARRAY().
201 */
202 #define RESIZABLE_ARRAY(elfsec, arr) arr[1] SEC("."#elfsec"."#arr)
203
204 /**
205 * MEMBER_VPTR - Obtain the verified pointer to a struct or array member
206 * @base: struct or array to index
207 * @member: dereferenced member (e.g. .field, [idx0][idx1], .field[idx0] ...)
208 *
209 * The verifier often gets confused by the instruction sequence the compiler
210 * generates for indexing struct fields or arrays. This macro forces the
211 * compiler to generate a code sequence which first calculates the byte offset,
212 * checks it against the struct or array size and add that byte offset to
213 * generate the pointer to the member to help the verifier.
214 *
215 * Ideally, we want to abort if the calculated offset is out-of-bounds. However,
216 * BPF currently doesn't support abort, so evaluate to %NULL instead. The caller
217 * must check for %NULL and take appropriate action to appease the verifier. To
218 * avoid confusing the verifier, it's best to check for %NULL and dereference
219 * immediately.
220 *
221 * vptr = MEMBER_VPTR(my_array, [i][j]);
222 * if (!vptr)
223 * return error;
224 * *vptr = new_value;
225 *
226 * sizeof(@base) should encompass the memory area to be accessed and thus can't
227 * be a pointer to the area. Use `MEMBER_VPTR(*ptr, .member)` instead of
228 * `MEMBER_VPTR(ptr, ->member)`.
229 */
230 #define MEMBER_VPTR(base, member) (typeof((base) member) *) \
231 ({ \
232 u64 __base = (u64)&(base); \
233 u64 __addr = (u64)&((base) member) - __base; \
234 _Static_assert(sizeof(base) >= sizeof((base) member), \
235 "@base is smaller than @member, is @base a pointer?"); \
236 asm volatile ( \
237 "if %0 <= %[max] goto +2\n" \
238 "%0 = 0\n" \
239 "goto +1\n" \
240 "%0 += %1\n" \
241 : "+r"(__addr) \
242 : "r"(__base), \
243 [max]"i"(sizeof(base) - sizeof((base) member))); \
244 __addr; \
245 })
246
247 /**
248 * ARRAY_ELEM_PTR - Obtain the verified pointer to an array element
249 * @arr: array to index into
250 * @i: array index
251 * @n: number of elements in array
252 *
253 * Similar to MEMBER_VPTR() but is intended for use with arrays where the
254 * element count needs to be explicit.
255 * It can be used in cases where a global array is defined with an initial
256 * size but is intended to be be resized before loading the BPF program.
257 * Without this version of the macro, MEMBER_VPTR() will use the compile time
258 * size of the array to compute the max, which will result in rejection by
259 * the verifier.
260 */
261 #define ARRAY_ELEM_PTR(arr, i, n) (typeof(arr[i]) *) \
262 ({ \
263 u64 __base = (u64)arr; \
264 u64 __addr = (u64)&(arr[i]) - __base; \
265 asm volatile ( \
266 "if %0 <= %[max] goto +2\n" \
267 "%0 = 0\n" \
268 "goto +1\n" \
269 "%0 += %1\n" \
270 : "+r"(__addr) \
271 : "r"(__base), \
272 [max]"r"(sizeof(arr[0]) * ((n) - 1))); \
273 __addr; \
274 })
275
276
277 /*
278 * BPF declarations and helpers
279 */
280
281 /* list and rbtree */
282 #define __contains(name, node) __attribute__((btf_decl_tag("contains:" #name ":" #node)))
283 #define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
284
285 void *bpf_obj_new_impl(__u64 local_type_id, void *meta) __ksym;
286 void bpf_obj_drop_impl(void *kptr, void *meta) __ksym;
287
288 #define bpf_obj_new(type) ((type *)bpf_obj_new_impl(bpf_core_type_id_local(type), NULL))
289 #define bpf_obj_drop(kptr) bpf_obj_drop_impl(kptr, NULL)
290
291 int bpf_list_push_front_impl(struct bpf_list_head *head,
292 struct bpf_list_node *node,
293 void *meta, __u64 off) __ksym;
294 #define bpf_list_push_front(head, node) bpf_list_push_front_impl(head, node, NULL, 0)
295
296 int bpf_list_push_back_impl(struct bpf_list_head *head,
297 struct bpf_list_node *node,
298 void *meta, __u64 off) __ksym;
299 #define bpf_list_push_back(head, node) bpf_list_push_back_impl(head, node, NULL, 0)
300
301 struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head) __ksym;
302 struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) __ksym;
303 struct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root,
304 struct bpf_rb_node *node) __ksym;
305 int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node,
306 bool (less)(struct bpf_rb_node *a, const struct bpf_rb_node *b),
307 void *meta, __u64 off) __ksym;
308 #define bpf_rbtree_add(head, node, less) bpf_rbtree_add_impl(head, node, less, NULL, 0)
309
310 struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root) __ksym;
311
312 void *bpf_refcount_acquire_impl(void *kptr, void *meta) __ksym;
313 #define bpf_refcount_acquire(kptr) bpf_refcount_acquire_impl(kptr, NULL)
314
315 /* task */
316 struct task_struct *bpf_task_from_pid(s32 pid) __ksym;
317 struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym;
318 void bpf_task_release(struct task_struct *p) __ksym;
319
320 /* cgroup */
321 struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym;
322 void bpf_cgroup_release(struct cgroup *cgrp) __ksym;
323 struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym;
324
325 /* css iteration */
326 struct bpf_iter_css;
327 struct cgroup_subsys_state;
328 extern int bpf_iter_css_new(struct bpf_iter_css *it,
329 struct cgroup_subsys_state *start,
330 unsigned int flags) __weak __ksym;
331 extern struct cgroup_subsys_state *
332 bpf_iter_css_next(struct bpf_iter_css *it) __weak __ksym;
333 extern void bpf_iter_css_destroy(struct bpf_iter_css *it) __weak __ksym;
334
335 /* cpumask */
336 struct bpf_cpumask *bpf_cpumask_create(void) __ksym;
337 struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym;
338 void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym;
339 u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym;
340 u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym;
341 void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
342 void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
343 bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym;
344 bool bpf_cpumask_test_and_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
345 bool bpf_cpumask_test_and_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
346 void bpf_cpumask_setall(struct bpf_cpumask *cpumask) __ksym;
347 void bpf_cpumask_clear(struct bpf_cpumask *cpumask) __ksym;
348 bool bpf_cpumask_and(struct bpf_cpumask *dst, const struct cpumask *src1,
349 const struct cpumask *src2) __ksym;
350 void bpf_cpumask_or(struct bpf_cpumask *dst, const struct cpumask *src1,
351 const struct cpumask *src2) __ksym;
352 void bpf_cpumask_xor(struct bpf_cpumask *dst, const struct cpumask *src1,
353 const struct cpumask *src2) __ksym;
354 bool bpf_cpumask_equal(const struct cpumask *src1, const struct cpumask *src2) __ksym;
355 bool bpf_cpumask_intersects(const struct cpumask *src1, const struct cpumask *src2) __ksym;
356 bool bpf_cpumask_subset(const struct cpumask *src1, const struct cpumask *src2) __ksym;
357 bool bpf_cpumask_empty(const struct cpumask *cpumask) __ksym;
358 bool bpf_cpumask_full(const struct cpumask *cpumask) __ksym;
359 void bpf_cpumask_copy(struct bpf_cpumask *dst, const struct cpumask *src) __ksym;
360 u32 bpf_cpumask_any_distribute(const struct cpumask *cpumask) __ksym;
361 u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1,
362 const struct cpumask *src2) __ksym;
363 u32 bpf_cpumask_weight(const struct cpumask *cpumask) __ksym;
364
365 int bpf_iter_bits_new(struct bpf_iter_bits *it, const u64 *unsafe_ptr__ign, u32 nr_words) __ksym;
366 int *bpf_iter_bits_next(struct bpf_iter_bits *it) __ksym;
367 void bpf_iter_bits_destroy(struct bpf_iter_bits *it) __ksym;
368
369 #define def_iter_struct(name) \
370 struct bpf_iter_##name { \
371 struct bpf_iter_bits it; \
372 const struct cpumask *bitmap; \
373 };
374
375 #define def_iter_new(name) \
376 static inline int bpf_iter_##name##_new( \
377 struct bpf_iter_##name *it, const u64 *unsafe_ptr__ign, u32 nr_words) \
378 { \
379 it->bitmap = scx_bpf_get_##name##_cpumask(); \
380 return bpf_iter_bits_new(&it->it, (const u64 *)it->bitmap, \
381 sizeof(struct cpumask) / 8); \
382 }
383
384 #define def_iter_next(name) \
385 static inline int *bpf_iter_##name##_next(struct bpf_iter_##name *it) { \
386 return bpf_iter_bits_next(&it->it); \
387 }
388
389 #define def_iter_destroy(name) \
390 static inline void bpf_iter_##name##_destroy(struct bpf_iter_##name *it) { \
391 scx_bpf_put_cpumask(it->bitmap); \
392 bpf_iter_bits_destroy(&it->it); \
393 }
394 #define def_for_each_cpu(cpu, name) for_each_##name##_cpu(cpu)
395
396 /// Provides iterator for possible and online cpus.
397 ///
398 /// # Example
399 ///
400 /// ```
401 /// static inline void example_use() {
402 /// int *cpu;
403 ///
404 /// for_each_possible_cpu(cpu){
405 /// bpf_printk("CPU %d is possible", *cpu);
406 /// }
407 ///
408 /// for_each_online_cpu(cpu){
409 /// bpf_printk("CPU %d is online", *cpu);
410 /// }
411 /// }
412 /// ```
413 def_iter_struct(possible);
414 def_iter_new(possible);
415 def_iter_next(possible);
416 def_iter_destroy(possible);
417 #define for_each_possible_cpu(cpu) bpf_for_each(possible, cpu, NULL, 0)
418
419 def_iter_struct(online);
420 def_iter_new(online);
421 def_iter_next(online);
422 def_iter_destroy(online);
423 #define for_each_online_cpu(cpu) bpf_for_each(online, cpu, NULL, 0)
424
425 /*
426 * Access a cpumask in read-only mode (typically to check bits).
427 */
cast_mask(struct bpf_cpumask * mask)428 static __always_inline const struct cpumask *cast_mask(struct bpf_cpumask *mask)
429 {
430 return (const struct cpumask *)mask;
431 }
432
433 /*
434 * Return true if task @p cannot migrate to a different CPU, false
435 * otherwise.
436 */
is_migration_disabled(const struct task_struct * p)437 static inline bool is_migration_disabled(const struct task_struct *p)
438 {
439 if (bpf_core_field_exists(p->migration_disabled))
440 return p->migration_disabled;
441 return false;
442 }
443
444 /* rcu */
445 void bpf_rcu_read_lock(void) __ksym;
446 void bpf_rcu_read_unlock(void) __ksym;
447
448 /*
449 * Time helpers, most of which are from jiffies.h.
450 */
451
452 /**
453 * time_delta - Calculate the delta between new and old time stamp
454 * @after: first comparable as u64
455 * @before: second comparable as u64
456 *
457 * Return: the time difference, which is >= 0
458 */
time_delta(u64 after,u64 before)459 static inline s64 time_delta(u64 after, u64 before)
460 {
461 return (s64)(after - before) > 0 ? (s64)(after - before) : 0;
462 }
463
464 /**
465 * time_after - returns true if the time a is after time b.
466 * @a: first comparable as u64
467 * @b: second comparable as u64
468 *
469 * Do this with "<0" and ">=0" to only test the sign of the result. A
470 * good compiler would generate better code (and a really good compiler
471 * wouldn't care). Gcc is currently neither.
472 *
473 * Return: %true is time a is after time b, otherwise %false.
474 */
time_after(u64 a,u64 b)475 static inline bool time_after(u64 a, u64 b)
476 {
477 return (s64)(b - a) < 0;
478 }
479
480 /**
481 * time_before - returns true if the time a is before time b.
482 * @a: first comparable as u64
483 * @b: second comparable as u64
484 *
485 * Return: %true is time a is before time b, otherwise %false.
486 */
time_before(u64 a,u64 b)487 static inline bool time_before(u64 a, u64 b)
488 {
489 return time_after(b, a);
490 }
491
492 /**
493 * time_after_eq - returns true if the time a is after or the same as time b.
494 * @a: first comparable as u64
495 * @b: second comparable as u64
496 *
497 * Return: %true is time a is after or the same as time b, otherwise %false.
498 */
time_after_eq(u64 a,u64 b)499 static inline bool time_after_eq(u64 a, u64 b)
500 {
501 return (s64)(a - b) >= 0;
502 }
503
504 /**
505 * time_before_eq - returns true if the time a is before or the same as time b.
506 * @a: first comparable as u64
507 * @b: second comparable as u64
508 *
509 * Return: %true is time a is before or the same as time b, otherwise %false.
510 */
time_before_eq(u64 a,u64 b)511 static inline bool time_before_eq(u64 a, u64 b)
512 {
513 return time_after_eq(b, a);
514 }
515
516 /**
517 * time_in_range - Calculate whether a is in the range of [b, c].
518 * @a: time to test
519 * @b: beginning of the range
520 * @c: end of the range
521 *
522 * Return: %true is time a is in the range [b, c], otherwise %false.
523 */
time_in_range(u64 a,u64 b,u64 c)524 static inline bool time_in_range(u64 a, u64 b, u64 c)
525 {
526 return time_after_eq(a, b) && time_before_eq(a, c);
527 }
528
529 /**
530 * time_in_range_open - Calculate whether a is in the range of [b, c).
531 * @a: time to test
532 * @b: beginning of the range
533 * @c: end of the range
534 *
535 * Return: %true is time a is in the range [b, c), otherwise %false.
536 */
time_in_range_open(u64 a,u64 b,u64 c)537 static inline bool time_in_range_open(u64 a, u64 b, u64 c)
538 {
539 return time_after_eq(a, b) && time_before(a, c);
540 }
541
542
543 /*
544 * Other helpers
545 */
546
547 /* useful compiler attributes */
548 #define likely(x) __builtin_expect(!!(x), 1)
549 #define unlikely(x) __builtin_expect(!!(x), 0)
550 #define __maybe_unused __attribute__((__unused__))
551
552 /*
553 * READ/WRITE_ONCE() are from kernel (include/asm-generic/rwonce.h). They
554 * prevent compiler from caching, redoing or reordering reads or writes.
555 */
556 typedef __u8 __attribute__((__may_alias__)) __u8_alias_t;
557 typedef __u16 __attribute__((__may_alias__)) __u16_alias_t;
558 typedef __u32 __attribute__((__may_alias__)) __u32_alias_t;
559 typedef __u64 __attribute__((__may_alias__)) __u64_alias_t;
560
__read_once_size(const volatile void * p,void * res,int size)561 static __always_inline void __read_once_size(const volatile void *p, void *res, int size)
562 {
563 switch (size) {
564 case 1: *(__u8_alias_t *) res = *(volatile __u8_alias_t *) p; break;
565 case 2: *(__u16_alias_t *) res = *(volatile __u16_alias_t *) p; break;
566 case 4: *(__u32_alias_t *) res = *(volatile __u32_alias_t *) p; break;
567 case 8: *(__u64_alias_t *) res = *(volatile __u64_alias_t *) p; break;
568 default:
569 barrier();
570 __builtin_memcpy((void *)res, (const void *)p, size);
571 barrier();
572 }
573 }
574
__write_once_size(volatile void * p,void * res,int size)575 static __always_inline void __write_once_size(volatile void *p, void *res, int size)
576 {
577 switch (size) {
578 case 1: *(volatile __u8_alias_t *) p = *(__u8_alias_t *) res; break;
579 case 2: *(volatile __u16_alias_t *) p = *(__u16_alias_t *) res; break;
580 case 4: *(volatile __u32_alias_t *) p = *(__u32_alias_t *) res; break;
581 case 8: *(volatile __u64_alias_t *) p = *(__u64_alias_t *) res; break;
582 default:
583 barrier();
584 __builtin_memcpy((void *)p, (const void *)res, size);
585 barrier();
586 }
587 }
588
589 #define READ_ONCE(x) \
590 ({ \
591 union { typeof(x) __val; char __c[1]; } __u = \
592 { .__c = { 0 } }; \
593 __read_once_size(&(x), __u.__c, sizeof(x)); \
594 __u.__val; \
595 })
596
597 #define WRITE_ONCE(x, val) \
598 ({ \
599 union { typeof(x) __val; char __c[1]; } __u = \
600 { .__val = (val) }; \
601 __write_once_size(&(x), __u.__c, sizeof(x)); \
602 __u.__val; \
603 })
604
605 #define READ_ONCE_ARENA(type, x) \
606 ({ \
607 union { type __val; char __c[1]; } __u = \
608 { .__c = { 0 } }; \
609 __read_once_size((void *)&(x), __u.__c, sizeof(x)); \
610 __u.__val; \
611 })
612
613 #define WRITE_ONCE_ARENA(type, x, val) \
614 ({ \
615 union { type __val; char __c[1]; } __u = \
616 { .__val = (val) }; \
617 __write_once_size((void *)&(x), __u.__c, sizeof(x)); \
618 __u.__val; \
619 })
620
621 /*
622 * log2_u32 - Compute the base 2 logarithm of a 32-bit exponential value.
623 * @v: The value for which we're computing the base 2 logarithm.
624 */
log2_u32(u32 v)625 static inline u32 log2_u32(u32 v)
626 {
627 u32 r;
628 u32 shift;
629
630 r = (v > 0xFFFF) << 4; v >>= r;
631 shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
632 shift = (v > 0xF) << 2; v >>= shift; r |= shift;
633 shift = (v > 0x3) << 1; v >>= shift; r |= shift;
634 r |= (v >> 1);
635 return r;
636 }
637
638 /*
639 * log2_u64 - Compute the base 2 logarithm of a 64-bit exponential value.
640 * @v: The value for which we're computing the base 2 logarithm.
641 */
log2_u64(u64 v)642 static inline u32 log2_u64(u64 v)
643 {
644 u32 hi = v >> 32;
645 if (hi)
646 return log2_u32(hi) + 32 + 1;
647 else
648 return log2_u32(v) + 1;
649 }
650
651 #include "compat.bpf.h"
652 #include "enums.bpf.h"
653
654 #endif /* __SCX_COMMON_BPF_H */
655