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 18 struct 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 */ 28 struct alloc_tag { 29 struct codetag ct; 30 struct alloc_tag_counters __percpu *counters; 31 } __aligned(8); 32 33 struct alloc_tag_module_section { 34 unsigned long start_addr; 35 unsigned long end_addr; 36 /* used size */ 37 unsigned long size; 38 }; 39 40 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 41 42 #define CODETAG_EMPTY ((void *)1) 43 44 static inline bool is_codetag_empty(union codetag_ref *ref) 45 { 46 return ref->ct == CODETAG_EMPTY; 47 } 48 49 static inline void set_codetag_empty(union codetag_ref *ref) 50 { 51 if (ref) 52 ref->ct = CODETAG_EMPTY; 53 } 54 55 #else /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */ 56 57 static inline bool is_codetag_empty(union codetag_ref *ref) { return false; } 58 static inline void set_codetag_empty(union codetag_ref *ref) {} 59 60 #endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */ 61 62 #ifdef CONFIG_MEM_ALLOC_PROFILING 63 64 #define ALLOC_TAG_SECTION_NAME "alloc_tags" 65 66 struct codetag_bytes { 67 struct codetag *ct; 68 s64 bytes; 69 }; 70 71 size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep); 72 73 static inline struct alloc_tag *ct_to_alloc_tag(struct codetag *ct) 74 { 75 return container_of(ct, struct alloc_tag, ct); 76 } 77 78 #ifdef ARCH_NEEDS_WEAK_PER_CPU 79 /* 80 * When percpu variables are required to be defined as weak, static percpu 81 * variables can't be used inside a function (see comments for DECLARE_PER_CPU_SECTION). 82 * Instead we will account all module allocations to a single counter. 83 */ 84 DECLARE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag); 85 86 #define DEFINE_ALLOC_TAG(_alloc_tag) \ 87 static struct alloc_tag _alloc_tag __used __aligned(8) \ 88 __section(ALLOC_TAG_SECTION_NAME) = { \ 89 .ct = CODE_TAG_INIT, \ 90 .counters = &_shared_alloc_tag }; 91 92 #else /* ARCH_NEEDS_WEAK_PER_CPU */ 93 94 #define DEFINE_ALLOC_TAG(_alloc_tag) \ 95 static DEFINE_PER_CPU(struct alloc_tag_counters, _alloc_tag_cntr); \ 96 static struct alloc_tag _alloc_tag __used __aligned(8) \ 97 __section(ALLOC_TAG_SECTION_NAME) = { \ 98 .ct = CODE_TAG_INIT, \ 99 .counters = &_alloc_tag_cntr }; 100 101 #endif /* ARCH_NEEDS_WEAK_PER_CPU */ 102 103 DECLARE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT, 104 mem_alloc_profiling_key); 105 106 static inline bool mem_alloc_profiling_enabled(void) 107 { 108 return static_branch_maybe(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT, 109 &mem_alloc_profiling_key); 110 } 111 112 static inline struct alloc_tag_counters alloc_tag_read(struct alloc_tag *tag) 113 { 114 struct alloc_tag_counters v = { 0, 0 }; 115 struct alloc_tag_counters *counter; 116 int cpu; 117 118 for_each_possible_cpu(cpu) { 119 counter = per_cpu_ptr(tag->counters, cpu); 120 v.bytes += counter->bytes; 121 v.calls += counter->calls; 122 } 123 124 return v; 125 } 126 127 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 128 static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) 129 { 130 WARN_ONCE(ref && ref->ct, 131 "alloc_tag was not cleared (got tag for %s:%u)\n", 132 ref->ct->filename, ref->ct->lineno); 133 134 WARN_ONCE(!tag, "current->alloc_tag not set\n"); 135 } 136 137 static inline void alloc_tag_sub_check(union codetag_ref *ref) 138 { 139 WARN_ONCE(ref && !ref->ct, "alloc_tag was not set\n"); 140 } 141 #else 142 static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) {} 143 static inline void alloc_tag_sub_check(union codetag_ref *ref) {} 144 #endif 145 146 /* Caller should verify both ref and tag to be valid */ 147 static inline bool __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) 148 { 149 alloc_tag_add_check(ref, tag); 150 if (!ref || !tag) 151 return false; 152 153 ref->ct = &tag->ct; 154 return true; 155 } 156 157 static inline bool alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) 158 { 159 if (unlikely(!__alloc_tag_ref_set(ref, tag))) 160 return false; 161 162 /* 163 * We need in increment the call counter every time we have a new 164 * allocation or when we split a large allocation into smaller ones. 165 * Each new reference for every sub-allocation needs to increment call 166 * counter because when we free each part the counter will be decremented. 167 */ 168 this_cpu_inc(tag->counters->calls); 169 return true; 170 } 171 172 static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, size_t bytes) 173 { 174 if (likely(alloc_tag_ref_set(ref, tag))) 175 this_cpu_add(tag->counters->bytes, bytes); 176 } 177 178 static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes) 179 { 180 struct alloc_tag *tag; 181 182 alloc_tag_sub_check(ref); 183 if (!ref || !ref->ct) 184 return; 185 186 if (is_codetag_empty(ref)) { 187 ref->ct = NULL; 188 return; 189 } 190 191 tag = ct_to_alloc_tag(ref->ct); 192 193 this_cpu_sub(tag->counters->bytes, bytes); 194 this_cpu_dec(tag->counters->calls); 195 196 ref->ct = NULL; 197 } 198 199 #define alloc_tag_record(p) ((p) = current->alloc_tag) 200 201 #else /* CONFIG_MEM_ALLOC_PROFILING */ 202 203 #define DEFINE_ALLOC_TAG(_alloc_tag) 204 static inline bool mem_alloc_profiling_enabled(void) { return false; } 205 static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, 206 size_t bytes) {} 207 static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes) {} 208 #define alloc_tag_record(p) do {} while (0) 209 210 #endif /* CONFIG_MEM_ALLOC_PROFILING */ 211 212 #define alloc_hooks_tag(_tag, _do_alloc) \ 213 ({ \ 214 struct alloc_tag * __maybe_unused _old = alloc_tag_save(_tag); \ 215 typeof(_do_alloc) _res = _do_alloc; \ 216 alloc_tag_restore(_tag, _old); \ 217 _res; \ 218 }) 219 220 #define alloc_hooks(_do_alloc) \ 221 ({ \ 222 DEFINE_ALLOC_TAG(_alloc_tag); \ 223 alloc_hooks_tag(&_alloc_tag, _do_alloc); \ 224 }) 225 226 #endif /* _LINUX_ALLOC_TAG_H */ 227