1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * allocation tagging 4 */ 5#ifndef _LINUX_ALLOC_TAG_H 6#define _LINUX_ALLOC_TAG_H 7 8#include <linux/bug.h> 9#include <linux/codetag.h> 10#include <linux/container_of.h> 11#include <linux/preempt.h> 12#include <asm/percpu.h> 13#include <linux/cpumask.h> 14#include <linux/smp.h> 15#include <linux/static_key.h> 16#include <linux/irqflags.h> 17 18struct alloc_tag_counters { 19 u64 bytes; 20 u64 calls; 21}; 22 23/* 24 * An instance of this structure is created in a special ELF section at every 25 * allocation callsite. At runtime, the special section is treated as 26 * an array of these. Embedded codetag utilizes codetag framework. 27 */ 28struct alloc_tag { 29 struct codetag ct; 30 struct alloc_tag_counters __percpu *counters; 31} __aligned(8); 32 33#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 34 35#define CODETAG_EMPTY ((void *)1) 36 37static inline bool is_codetag_empty(union codetag_ref *ref) 38{ 39 return ref->ct == CODETAG_EMPTY; 40} 41 42static inline void set_codetag_empty(union codetag_ref *ref) 43{ 44 if (ref) 45 ref->ct = CODETAG_EMPTY; 46} 47 48#else /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */ 49 50static inline bool is_codetag_empty(union codetag_ref *ref) { return false; } 51static inline void set_codetag_empty(union codetag_ref *ref) {} 52 53#endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */ 54 55#ifdef CONFIG_MEM_ALLOC_PROFILING 56 57struct codetag_bytes { 58 struct codetag *ct; 59 s64 bytes; 60}; 61 62size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep); 63 64static inline struct alloc_tag *ct_to_alloc_tag(struct codetag *ct) 65{ 66 return container_of(ct, struct alloc_tag, ct); 67} 68 69#ifdef ARCH_NEEDS_WEAK_PER_CPU 70/* 71 * When percpu variables are required to be defined as weak, static percpu 72 * variables can't be used inside a function (see comments for DECLARE_PER_CPU_SECTION). 73 * Instead we will accound all module allocations to a single counter. 74 */ 75DECLARE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag); 76 77#define DEFINE_ALLOC_TAG(_alloc_tag) \ 78 static struct alloc_tag _alloc_tag __used __aligned(8) \ 79 __section("alloc_tags") = { \ 80 .ct = CODE_TAG_INIT, \ 81 .counters = &_shared_alloc_tag }; 82 83#else /* ARCH_NEEDS_WEAK_PER_CPU */ 84 85#define DEFINE_ALLOC_TAG(_alloc_tag) \ 86 static DEFINE_PER_CPU(struct alloc_tag_counters, _alloc_tag_cntr); \ 87 static struct alloc_tag _alloc_tag __used __aligned(8) \ 88 __section("alloc_tags") = { \ 89 .ct = CODE_TAG_INIT, \ 90 .counters = &_alloc_tag_cntr }; 91 92#endif /* ARCH_NEEDS_WEAK_PER_CPU */ 93 94DECLARE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT, 95 mem_alloc_profiling_key); 96 97static inline bool mem_alloc_profiling_enabled(void) 98{ 99 return static_branch_maybe(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT, 100 &mem_alloc_profiling_key); 101} 102 103static inline struct alloc_tag_counters alloc_tag_read(struct alloc_tag *tag) 104{ 105 struct alloc_tag_counters v = { 0, 0 }; 106 struct alloc_tag_counters *counter; 107 int cpu; 108 109 for_each_possible_cpu(cpu) { 110 counter = per_cpu_ptr(tag->counters, cpu); 111 v.bytes += counter->bytes; 112 v.calls += counter->calls; 113 } 114 115 return v; 116} 117 118#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 119static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) 120{ 121 WARN_ONCE(ref && ref->ct, 122 "alloc_tag was not cleared (got tag for %s:%u)\n", 123 ref->ct->filename, ref->ct->lineno); 124 125 WARN_ONCE(!tag, "current->alloc_tag not set"); 126} 127 128static inline void alloc_tag_sub_check(union codetag_ref *ref) 129{ 130 WARN_ONCE(ref && !ref->ct, "alloc_tag was not set\n"); 131} 132#else 133static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) {} 134static inline void alloc_tag_sub_check(union codetag_ref *ref) {} 135#endif 136 137/* Caller should verify both ref and tag to be valid */ 138static inline void __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) 139{ 140 ref->ct = &tag->ct; 141 /* 142 * We need in increment the call counter every time we have a new 143 * allocation or when we split a large allocation into smaller ones. 144 * Each new reference for every sub-allocation needs to increment call 145 * counter because when we free each part the counter will be decremented. 146 */ 147 this_cpu_inc(tag->counters->calls); 148} 149 150static inline void alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) 151{ 152 alloc_tag_add_check(ref, tag); 153 if (!ref || !tag) 154 return; 155 156 __alloc_tag_ref_set(ref, tag); 157} 158 159static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, size_t bytes) 160{ 161 alloc_tag_add_check(ref, tag); 162 if (!ref || !tag) 163 return; 164 165 __alloc_tag_ref_set(ref, tag); 166 this_cpu_add(tag->counters->bytes, bytes); 167} 168 169static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes) 170{ 171 struct alloc_tag *tag; 172 173 alloc_tag_sub_check(ref); 174 if (!ref || !ref->ct) 175 return; 176 177 if (is_codetag_empty(ref)) { 178 ref->ct = NULL; 179 return; 180 } 181 182 tag = ct_to_alloc_tag(ref->ct); 183 184 this_cpu_sub(tag->counters->bytes, bytes); 185 this_cpu_dec(tag->counters->calls); 186 187 ref->ct = NULL; 188} 189 190#define alloc_tag_record(p) ((p) = current->alloc_tag) 191 192#else /* CONFIG_MEM_ALLOC_PROFILING */ 193 194#define DEFINE_ALLOC_TAG(_alloc_tag) 195static inline bool mem_alloc_profiling_enabled(void) { return false; } 196static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, 197 size_t bytes) {} 198static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes) {} 199#define alloc_tag_record(p) do {} while (0) 200 201#endif /* CONFIG_MEM_ALLOC_PROFILING */ 202 203#define alloc_hooks_tag(_tag, _do_alloc) \ 204({ \ 205 struct alloc_tag * __maybe_unused _old = alloc_tag_save(_tag); \ 206 typeof(_do_alloc) _res = _do_alloc; \ 207 alloc_tag_restore(_tag, _old); \ 208 _res; \ 209}) 210 211#define alloc_hooks(_do_alloc) \ 212({ \ 213 DEFINE_ALLOC_TAG(_alloc_tag); \ 214 alloc_hooks_tag(&_alloc_tag, _do_alloc); \ 215}) 216 217#endif /* _LINUX_ALLOC_TAG_H */ 218