/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (c) 2022 Meta Platforms, Inc. and affiliates. * Copyright (c) 2022 Tejun Heo <tj@kernel.org> * Copyright (c) 2022 David Vernet <dvernet@meta.com> */ #ifndef __SCX_COMMON_BPF_H #define __SCX_COMMON_BPF_H #ifdef LSP #define __bpf__ #include "../vmlinux/vmlinux.h" #else #include "vmlinux.h" #endif #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <asm-generic/errno.h> #include "user_exit_info.h" #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ #define PF_EXITING 0x00000004 #define CLOCK_MONOTONIC 1 /* * Earlier versions of clang/pahole lost upper 32bits in 64bit enums which can * lead to really confusing misbehaviors. Let's trigger a build failure. */ static inline void ___vmlinux_h_sanity_check___(void) { _Static_assert(SCX_DSQ_FLAG_BUILTIN, "bpftool generated vmlinux.h is missing high bits for 64bit enums, upgrade clang and pahole"); } s32 scx_bpf_create_dsq(u64 dsq_id, s32 node) __ksym; s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool *is_idle) __ksym; void scx_bpf_dispatch(struct task_struct *p, u64 dsq_id, u64 slice, u64 enq_flags) __ksym; void scx_bpf_dispatch_vtime(struct task_struct *p, u64 dsq_id, u64 slice, u64 vtime, u64 enq_flags) __ksym; u32 scx_bpf_dispatch_nr_slots(void) __ksym; void scx_bpf_dispatch_cancel(void) __ksym; bool scx_bpf_consume(u64 dsq_id) __ksym; void scx_bpf_dispatch_from_dsq_set_slice(struct bpf_iter_scx_dsq *it__iter, u64 slice) __ksym; void scx_bpf_dispatch_from_dsq_set_vtime(struct bpf_iter_scx_dsq *it__iter, u64 vtime) __ksym; bool scx_bpf_dispatch_from_dsq(struct bpf_iter_scx_dsq *it__iter, struct task_struct *p, u64 dsq_id, u64 enq_flags) __ksym __weak; bool scx_bpf_dispatch_vtime_from_dsq(struct bpf_iter_scx_dsq *it__iter, struct task_struct *p, u64 dsq_id, u64 enq_flags) __ksym __weak; u32 scx_bpf_reenqueue_local(void) __ksym; void scx_bpf_kick_cpu(s32 cpu, u64 flags) __ksym; s32 scx_bpf_dsq_nr_queued(u64 dsq_id) __ksym; void scx_bpf_destroy_dsq(u64 dsq_id) __ksym; int bpf_iter_scx_dsq_new(struct bpf_iter_scx_dsq *it, u64 dsq_id, u64 flags) __ksym __weak; struct task_struct *bpf_iter_scx_dsq_next(struct bpf_iter_scx_dsq *it) __ksym __weak; void bpf_iter_scx_dsq_destroy(struct bpf_iter_scx_dsq *it) __ksym __weak; void scx_bpf_exit_bstr(s64 exit_code, char *fmt, unsigned long long *data, u32 data__sz) __ksym __weak; void scx_bpf_error_bstr(char *fmt, unsigned long long *data, u32 data_len) __ksym; void scx_bpf_dump_bstr(char *fmt, unsigned long long *data, u32 data_len) __ksym __weak; u32 scx_bpf_cpuperf_cap(s32 cpu) __ksym __weak; u32 scx_bpf_cpuperf_cur(s32 cpu) __ksym __weak; void scx_bpf_cpuperf_set(s32 cpu, u32 perf) __ksym __weak; u32 scx_bpf_nr_cpu_ids(void) __ksym __weak; const struct cpumask *scx_bpf_get_possible_cpumask(void) __ksym __weak; const struct cpumask *scx_bpf_get_online_cpumask(void) __ksym __weak; void scx_bpf_put_cpumask(const struct cpumask *cpumask) __ksym __weak; const struct cpumask *scx_bpf_get_idle_cpumask(void) __ksym; const struct cpumask *scx_bpf_get_idle_smtmask(void) __ksym; void scx_bpf_put_idle_cpumask(const struct cpumask *cpumask) __ksym; bool scx_bpf_test_and_clear_cpu_idle(s32 cpu) __ksym; s32 scx_bpf_pick_idle_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym; s32 scx_bpf_pick_any_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym; bool scx_bpf_task_running(const struct task_struct *p) __ksym; s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym; struct rq *scx_bpf_cpu_rq(s32 cpu) __ksym; struct cgroup *scx_bpf_task_cgroup(struct task_struct *p) __ksym; /* * Use the following as @it__iter when calling * scx_bpf_dispatch[_vtime]_from_dsq() from within bpf_for_each() loops. */ #define BPF_FOR_EACH_ITER (&___it) static inline __attribute__((format(printf, 1, 2))) void ___scx_bpf_bstr_format_checker(const char *fmt, ...) {} /* * Helper macro for initializing the fmt and variadic argument inputs to both * bstr exit kfuncs. Callers to this function should use ___fmt and ___param to * refer to the initialized list of inputs to the bstr kfunc. */ #define scx_bpf_bstr_preamble(fmt, args...) \ static char ___fmt[] = fmt; \ /* \ * Note that __param[] must have at least one \ * element to keep the verifier happy. \ */ \ unsigned long long ___param[___bpf_narg(args) ?: 1] = {}; \ \ _Pragma("GCC diagnostic push") \ _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \ ___bpf_fill(___param, args); \ _Pragma("GCC diagnostic pop") \ /* * scx_bpf_exit() wraps the scx_bpf_exit_bstr() kfunc with variadic arguments * instead of an array of u64. Using this macro will cause the scheduler to * exit cleanly with the specified exit code being passed to user space. */ #define scx_bpf_exit(code, fmt, args...) \ ({ \ scx_bpf_bstr_preamble(fmt, args) \ scx_bpf_exit_bstr(code, ___fmt, ___param, sizeof(___param)); \ ___scx_bpf_bstr_format_checker(fmt, ##args); \ }) /* * scx_bpf_error() wraps the scx_bpf_error_bstr() kfunc with variadic arguments * instead of an array of u64. Invoking this macro will cause the scheduler to * exit in an erroneous state, with diagnostic information being passed to the * user. */ #define scx_bpf_error(fmt, args...) \ ({ \ scx_bpf_bstr_preamble(fmt, args) \ scx_bpf_error_bstr(___fmt, ___param, sizeof(___param)); \ ___scx_bpf_bstr_format_checker(fmt, ##args); \ }) /* * scx_bpf_dump() wraps the scx_bpf_dump_bstr() kfunc with variadic arguments * instead of an array of u64. To be used from ops.dump() and friends. */ #define scx_bpf_dump(fmt, args...) \ ({ \ scx_bpf_bstr_preamble(fmt, args) \ scx_bpf_dump_bstr(___fmt, ___param, sizeof(___param)); \ ___scx_bpf_bstr_format_checker(fmt, ##args); \ }) #define BPF_STRUCT_OPS(name, args...) \ SEC("struct_ops/"#name) \ BPF_PROG(name, ##args) #define BPF_STRUCT_OPS_SLEEPABLE(name, args...) \ SEC("struct_ops.s/"#name) \ BPF_PROG(name, ##args) /** * RESIZABLE_ARRAY - Generates annotations for an array that may be resized * @elfsec: the data section of the BPF program in which to place the array * @arr: the name of the array * * libbpf has an API for setting map value sizes. Since data sections (i.e. * bss, data, rodata) themselves are maps, a data section can be resized. If * a data section has an array as its last element, the BTF info for that * array will be adjusted so that length of the array is extended to meet the * new length of the data section. This macro annotates an array to have an * element count of one with the assumption that this array can be resized * within the userspace program. It also annotates the section specifier so * this array exists in a custom sub data section which can be resized * independently. * * See RESIZE_ARRAY() for the userspace convenience macro for resizing an * array declared with RESIZABLE_ARRAY(). */ #define RESIZABLE_ARRAY(elfsec, arr) arr[1] SEC("."#elfsec"."#arr) /** * MEMBER_VPTR - Obtain the verified pointer to a struct or array member * @base: struct or array to index * @member: dereferenced member (e.g. .field, [idx0][idx1], .field[idx0] ...) * * The verifier often gets confused by the instruction sequence the compiler * generates for indexing struct fields or arrays. This macro forces the * compiler to generate a code sequence which first calculates the byte offset, * checks it against the struct or array size and add that byte offset to * generate the pointer to the member to help the verifier. * * Ideally, we want to abort if the calculated offset is out-of-bounds. However, * BPF currently doesn't support abort, so evaluate to %NULL instead. The caller * must check for %NULL and take appropriate action to appease the verifier. To * avoid confusing the verifier, it's best to check for %NULL and dereference * immediately. * * vptr = MEMBER_VPTR(my_array, [i][j]); * if (!vptr) * return error; * *vptr = new_value; * * sizeof(@base) should encompass the memory area to be accessed and thus can't * be a pointer to the area. Use `MEMBER_VPTR(*ptr, .member)` instead of * `MEMBER_VPTR(ptr, ->member)`. */ #define MEMBER_VPTR(base, member) (typeof((base) member) *) \ ({ \ u64 __base = (u64)&(base); \ u64 __addr = (u64)&((base) member) - __base; \ _Static_assert(sizeof(base) >= sizeof((base) member), \ "@base is smaller than @member, is @base a pointer?"); \ asm volatile ( \ "if %0 <= %[max] goto +2\n" \ "%0 = 0\n" \ "goto +1\n" \ "%0 += %1\n" \ : "+r"(__addr) \ : "r"(__base), \ [max]"i"(sizeof(base) - sizeof((base) member))); \ __addr; \ }) /** * ARRAY_ELEM_PTR - Obtain the verified pointer to an array element * @arr: array to index into * @i: array index * @n: number of elements in array * * Similar to MEMBER_VPTR() but is intended for use with arrays where the * element count needs to be explicit. * It can be used in cases where a global array is defined with an initial * size but is intended to be be resized before loading the BPF program. * Without this version of the macro, MEMBER_VPTR() will use the compile time * size of the array to compute the max, which will result in rejection by * the verifier. */ #define ARRAY_ELEM_PTR(arr, i, n) (typeof(arr[i]) *) \ ({ \ u64 __base = (u64)arr; \ u64 __addr = (u64)&(arr[i]) - __base; \ asm volatile ( \ "if %0 <= %[max] goto +2\n" \ "%0 = 0\n" \ "goto +1\n" \ "%0 += %1\n" \ : "+r"(__addr) \ : "r"(__base), \ [max]"r"(sizeof(arr[0]) * ((n) - 1))); \ __addr; \ }) /* * BPF declarations and helpers */ /* list and rbtree */ #define __contains(name, node) __attribute__((btf_decl_tag("contains:" #name ":" #node))) #define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8))) void *bpf_obj_new_impl(__u64 local_type_id, void *meta) __ksym; void bpf_obj_drop_impl(void *kptr, void *meta) __ksym; #define bpf_obj_new(type) ((type *)bpf_obj_new_impl(bpf_core_type_id_local(type), NULL)) #define bpf_obj_drop(kptr) bpf_obj_drop_impl(kptr, NULL) void bpf_list_push_front(struct bpf_list_head *head, struct bpf_list_node *node) __ksym; void bpf_list_push_back(struct bpf_list_head *head, struct bpf_list_node *node) __ksym; struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head) __ksym; struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) __ksym; struct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root, struct bpf_rb_node *node) __ksym; int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node, bool (less)(struct bpf_rb_node *a, const struct bpf_rb_node *b), void *meta, __u64 off) __ksym; #define bpf_rbtree_add(head, node, less) bpf_rbtree_add_impl(head, node, less, NULL, 0) struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root) __ksym; void *bpf_refcount_acquire_impl(void *kptr, void *meta) __ksym; #define bpf_refcount_acquire(kptr) bpf_refcount_acquire_impl(kptr, NULL) /* task */ struct task_struct *bpf_task_from_pid(s32 pid) __ksym; struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym; void bpf_task_release(struct task_struct *p) __ksym; /* cgroup */ struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym; void bpf_cgroup_release(struct cgroup *cgrp) __ksym; struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; /* css iteration */ struct bpf_iter_css; struct cgroup_subsys_state; extern int bpf_iter_css_new(struct bpf_iter_css *it, struct cgroup_subsys_state *start, unsigned int flags) __weak __ksym; extern struct cgroup_subsys_state * bpf_iter_css_next(struct bpf_iter_css *it) __weak __ksym; extern void bpf_iter_css_destroy(struct bpf_iter_css *it) __weak __ksym; /* cpumask */ struct bpf_cpumask *bpf_cpumask_create(void) __ksym; struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym; void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym; u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym; u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym; void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym; void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym; bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym; bool bpf_cpumask_test_and_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym; bool bpf_cpumask_test_and_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym; void bpf_cpumask_setall(struct bpf_cpumask *cpumask) __ksym; void bpf_cpumask_clear(struct bpf_cpumask *cpumask) __ksym; bool bpf_cpumask_and(struct bpf_cpumask *dst, const struct cpumask *src1, const struct cpumask *src2) __ksym; void bpf_cpumask_or(struct bpf_cpumask *dst, const struct cpumask *src1, const struct cpumask *src2) __ksym; void bpf_cpumask_xor(struct bpf_cpumask *dst, const struct cpumask *src1, const struct cpumask *src2) __ksym; bool bpf_cpumask_equal(const struct cpumask *src1, const struct cpumask *src2) __ksym; bool bpf_cpumask_intersects(const struct cpumask *src1, const struct cpumask *src2) __ksym; bool bpf_cpumask_subset(const struct cpumask *src1, const struct cpumask *src2) __ksym; bool bpf_cpumask_empty(const struct cpumask *cpumask) __ksym; bool bpf_cpumask_full(const struct cpumask *cpumask) __ksym; void bpf_cpumask_copy(struct bpf_cpumask *dst, const struct cpumask *src) __ksym; u32 bpf_cpumask_any_distribute(const struct cpumask *cpumask) __ksym; u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1, const struct cpumask *src2) __ksym; u32 bpf_cpumask_weight(const struct cpumask *cpumask) __ksym; /* * Access a cpumask in read-only mode (typically to check bits). */ const struct cpumask *cast_mask(struct bpf_cpumask *mask) { return (const struct cpumask *)mask; } /* rcu */ void bpf_rcu_read_lock(void) __ksym; void bpf_rcu_read_unlock(void) __ksym; /* * Other helpers */ /* useful compiler attributes */ #define likely(x) __builtin_expect(!!(x), 1) #define unlikely(x) __builtin_expect(!!(x), 0) #define __maybe_unused __attribute__((__unused__)) /* * READ/WRITE_ONCE() are from kernel (include/asm-generic/rwonce.h). They * prevent compiler from caching, redoing or reordering reads or writes. */ typedef __u8 __attribute__((__may_alias__)) __u8_alias_t; typedef __u16 __attribute__((__may_alias__)) __u16_alias_t; typedef __u32 __attribute__((__may_alias__)) __u32_alias_t; typedef __u64 __attribute__((__may_alias__)) __u64_alias_t; static __always_inline void __read_once_size(const volatile void *p, void *res, int size) { switch (size) { case 1: *(__u8_alias_t *) res = *(volatile __u8_alias_t *) p; break; case 2: *(__u16_alias_t *) res = *(volatile __u16_alias_t *) p; break; case 4: *(__u32_alias_t *) res = *(volatile __u32_alias_t *) p; break; case 8: *(__u64_alias_t *) res = *(volatile __u64_alias_t *) p; break; default: barrier(); __builtin_memcpy((void *)res, (const void *)p, size); barrier(); } } static __always_inline void __write_once_size(volatile void *p, void *res, int size) { switch (size) { case 1: *(volatile __u8_alias_t *) p = *(__u8_alias_t *) res; break; case 2: *(volatile __u16_alias_t *) p = *(__u16_alias_t *) res; break; case 4: *(volatile __u32_alias_t *) p = *(__u32_alias_t *) res; break; case 8: *(volatile __u64_alias_t *) p = *(__u64_alias_t *) res; break; default: barrier(); __builtin_memcpy((void *)p, (const void *)res, size); barrier(); } } #define READ_ONCE(x) \ ({ \ union { typeof(x) __val; char __c[1]; } __u = \ { .__c = { 0 } }; \ __read_once_size(&(x), __u.__c, sizeof(x)); \ __u.__val; \ }) #define WRITE_ONCE(x, val) \ ({ \ union { typeof(x) __val; char __c[1]; } __u = \ { .__val = (val) }; \ __write_once_size(&(x), __u.__c, sizeof(x)); \ __u.__val; \ }) /* * log2_u32 - Compute the base 2 logarithm of a 32-bit exponential value. * @v: The value for which we're computing the base 2 logarithm. */ static inline u32 log2_u32(u32 v) { u32 r; u32 shift; r = (v > 0xFFFF) << 4; v >>= r; shift = (v > 0xFF) << 3; v >>= shift; r |= shift; shift = (v > 0xF) << 2; v >>= shift; r |= shift; shift = (v > 0x3) << 1; v >>= shift; r |= shift; r |= (v >> 1); return r; } /* * log2_u64 - Compute the base 2 logarithm of a 64-bit exponential value. * @v: The value for which we're computing the base 2 logarithm. */ static inline u32 log2_u64(u64 v) { u32 hi = v >> 32; if (hi) return log2_u32(hi) + 32 + 1; else return log2_u32(v) + 1; } #include "compat.bpf.h" #endif /* __SCX_COMMON_BPF_H */