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_kernel_section {
34 struct alloc_tag *first_tag;
35 unsigned long count;
36 };
37
38 struct alloc_tag_module_section {
39 union {
40 unsigned long start_addr;
41 struct alloc_tag *first_tag;
42 };
43 unsigned long end_addr;
44 /* used size */
45 unsigned long size;
46 };
47
48 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
49
50 #define CODETAG_EMPTY ((void *)1)
51
is_codetag_empty(union codetag_ref * ref)52 static inline bool is_codetag_empty(union codetag_ref *ref)
53 {
54 return ref->ct == CODETAG_EMPTY;
55 }
56
set_codetag_empty(union codetag_ref * ref)57 static inline void set_codetag_empty(union codetag_ref *ref)
58 {
59 if (ref)
60 ref->ct = CODETAG_EMPTY;
61 }
62
63 #else /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
64
is_codetag_empty(union codetag_ref * ref)65 static inline bool is_codetag_empty(union codetag_ref *ref) { return false; }
66
set_codetag_empty(union codetag_ref * ref)67 static inline void set_codetag_empty(union codetag_ref *ref)
68 {
69 if (ref)
70 ref->ct = NULL;
71 }
72
73 #endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
74
75 #ifdef CONFIG_MEM_ALLOC_PROFILING
76
77 #define ALLOC_TAG_SECTION_NAME "alloc_tags"
78
79 struct codetag_bytes {
80 struct codetag *ct;
81 s64 bytes;
82 };
83
84 size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep);
85
ct_to_alloc_tag(struct codetag * ct)86 static inline struct alloc_tag *ct_to_alloc_tag(struct codetag *ct)
87 {
88 return container_of(ct, struct alloc_tag, ct);
89 }
90
91 #if defined(CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU) && defined(MODULE)
92 /*
93 * When percpu variables are required to be defined as weak, static percpu
94 * variables can't be used inside a function (see comments for DECLARE_PER_CPU_SECTION).
95 * Instead we will account all module allocations to a single counter.
96 */
97 DECLARE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
98
99 #define DEFINE_ALLOC_TAG(_alloc_tag) \
100 static struct alloc_tag _alloc_tag __used __aligned(8) \
101 __section(ALLOC_TAG_SECTION_NAME) = { \
102 .ct = CODE_TAG_INIT, \
103 .counters = &_shared_alloc_tag };
104
105 #else /* CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU && MODULE */
106
107 #ifdef MODULE
108
109 #define DEFINE_ALLOC_TAG(_alloc_tag) \
110 static struct alloc_tag _alloc_tag __used __aligned(8) \
111 __section(ALLOC_TAG_SECTION_NAME) = { \
112 .ct = CODE_TAG_INIT, \
113 .counters = NULL };
114
115 #else /* MODULE */
116
117 #define DEFINE_ALLOC_TAG(_alloc_tag) \
118 static DEFINE_PER_CPU(struct alloc_tag_counters, _alloc_tag_cntr); \
119 static struct alloc_tag _alloc_tag __used __aligned(8) \
120 __section(ALLOC_TAG_SECTION_NAME) = { \
121 .ct = CODE_TAG_INIT, \
122 .counters = &_alloc_tag_cntr };
123
124 #endif /* MODULE */
125
126 #endif /* CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU && MODULE */
127
128 DECLARE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
129 mem_alloc_profiling_key);
130
mem_alloc_profiling_enabled(void)131 static inline bool mem_alloc_profiling_enabled(void)
132 {
133 return static_branch_maybe(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
134 &mem_alloc_profiling_key);
135 }
136
137 bool mem_alloc_profiling_permanently_disabled(void);
138
alloc_tag_read(struct alloc_tag * tag)139 static inline struct alloc_tag_counters alloc_tag_read(struct alloc_tag *tag)
140 {
141 struct alloc_tag_counters v = { 0, 0 };
142 struct alloc_tag_counters *counter;
143 int cpu;
144
145 for_each_possible_cpu(cpu) {
146 counter = per_cpu_ptr(tag->counters, cpu);
147 v.bytes += counter->bytes;
148 v.calls += counter->calls;
149 }
150
151 return v;
152 }
153
154 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
alloc_tag_add_check(union codetag_ref * ref,struct alloc_tag * tag)155 static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag)
156 {
157 WARN_ONCE(ref && ref->ct && !is_codetag_empty(ref),
158 "alloc_tag was not cleared (got tag for %s:%u)\n",
159 ref->ct->filename, ref->ct->lineno);
160
161 WARN_ONCE(!tag, "current->alloc_tag not set\n");
162 }
163
alloc_tag_sub_check(union codetag_ref * ref)164 static inline void alloc_tag_sub_check(union codetag_ref *ref)
165 {
166 WARN_ONCE(ref && !ref->ct, "alloc_tag was not set\n");
167 }
168 void alloc_tag_add_early_pfn(unsigned long pfn, unsigned int alloc_flags);
169 #else
alloc_tag_add_check(union codetag_ref * ref,struct alloc_tag * tag)170 static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) {}
alloc_tag_sub_check(union codetag_ref * ref)171 static inline void alloc_tag_sub_check(union codetag_ref *ref) {}
alloc_tag_add_early_pfn(unsigned long pfn,unsigned int alloc_flags)172 static inline void alloc_tag_add_early_pfn(unsigned long pfn, unsigned int alloc_flags) {}
173 #endif
174
175 /* Caller should verify both ref and tag to be valid */
__alloc_tag_ref_set(union codetag_ref * ref,struct alloc_tag * tag)176 static inline bool __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag)
177 {
178 alloc_tag_add_check(ref, tag);
179 if (!ref || !tag)
180 return false;
181
182 ref->ct = &tag->ct;
183 return true;
184 }
185
alloc_tag_ref_set(union codetag_ref * ref,struct alloc_tag * tag)186 static inline bool alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag)
187 {
188 if (unlikely(!__alloc_tag_ref_set(ref, tag)))
189 return false;
190
191 /*
192 * We need in increment the call counter every time we have a new
193 * allocation or when we split a large allocation into smaller ones.
194 * Each new reference for every sub-allocation needs to increment call
195 * counter because when we free each part the counter will be decremented.
196 */
197 this_cpu_inc(tag->counters->calls);
198 return true;
199 }
200
alloc_tag_add(union codetag_ref * ref,struct alloc_tag * tag,size_t bytes)201 static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, size_t bytes)
202 {
203 if (likely(alloc_tag_ref_set(ref, tag)))
204 this_cpu_add(tag->counters->bytes, bytes);
205 }
206
alloc_tag_sub(union codetag_ref * ref,size_t bytes)207 static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes)
208 {
209 struct alloc_tag *tag;
210
211 alloc_tag_sub_check(ref);
212 if (!ref || !ref->ct)
213 return;
214
215 if (is_codetag_empty(ref)) {
216 ref->ct = NULL;
217 return;
218 }
219
220 tag = ct_to_alloc_tag(ref->ct);
221
222 this_cpu_sub(tag->counters->bytes, bytes);
223 this_cpu_dec(tag->counters->calls);
224
225 ref->ct = NULL;
226 }
227
alloc_tag_set_inaccurate(struct alloc_tag * tag)228 static inline void alloc_tag_set_inaccurate(struct alloc_tag *tag)
229 {
230 tag->ct.flags |= CODETAG_FLAG_INACCURATE;
231 }
232
alloc_tag_is_inaccurate(struct alloc_tag * tag)233 static inline bool alloc_tag_is_inaccurate(struct alloc_tag *tag)
234 {
235 return !!(tag->ct.flags & CODETAG_FLAG_INACCURATE);
236 }
237
238 #define alloc_tag_record(p) ((p) = current->alloc_tag)
239
240 #else /* CONFIG_MEM_ALLOC_PROFILING */
241
242 #define DEFINE_ALLOC_TAG(_alloc_tag)
mem_alloc_profiling_enabled(void)243 static inline bool mem_alloc_profiling_enabled(void) { return false; }
mem_alloc_profiling_permanently_disabled(void)244 static inline bool mem_alloc_profiling_permanently_disabled(void) { return true; }
alloc_tag_add(union codetag_ref * ref,struct alloc_tag * tag,size_t bytes)245 static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag,
246 size_t bytes) {}
alloc_tag_sub(union codetag_ref * ref,size_t bytes)247 static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes) {}
alloc_tag_set_inaccurate(struct alloc_tag * tag)248 static inline void alloc_tag_set_inaccurate(struct alloc_tag *tag) {}
alloc_tag_is_inaccurate(struct alloc_tag * tag)249 static inline bool alloc_tag_is_inaccurate(struct alloc_tag *tag) { return false; }
250 #define alloc_tag_record(p) do {} while (0)
251
252 #endif /* CONFIG_MEM_ALLOC_PROFILING */
253
254 #define alloc_hooks_tag(_tag, _do_alloc) \
255 ({ \
256 typeof(_do_alloc) _res; \
257 if (mem_alloc_profiling_enabled()) { \
258 struct alloc_tag * __maybe_unused _old; \
259 _old = alloc_tag_save(_tag); \
260 _res = _do_alloc; \
261 alloc_tag_restore(_tag, _old); \
262 } else \
263 _res = _do_alloc; \
264 _res; \
265 })
266
267 #define alloc_hooks(_do_alloc) \
268 ({ \
269 DEFINE_ALLOC_TAG(_alloc_tag); \
270 alloc_hooks_tag(&_alloc_tag, _do_alloc); \
271 })
272
273 #endif /* _LINUX_ALLOC_TAG_H */
274