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