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