xref: /aosp_15_r20/external/musl/src/malloc/mallocng/glue.h (revision c9945492fdd68bbe62686c5b452b4dc1be3f8453)
1 #ifndef MALLOC_GLUE_H
2 #define MALLOC_GLUE_H
3 
4 #include <stdint.h>
5 #include <sys/mman.h>
6 #include <pthread.h>
7 #include <unistd.h>
8 #include <elf.h>
9 #include <string.h>
10 #include "atomic.h"
11 #include "syscall.h"
12 #include "libc.h"
13 #include "lock.h"
14 #include "dynlink.h"
15 
16 // use macros to appropriately namespace these.
17 #define size_classes __malloc_size_classes
18 #define ctx __malloc_context
19 #define alloc_meta __malloc_alloc_meta
20 #define is_allzero __malloc_allzerop
21 #define dump_heap __dump_heap
22 
23 #define malloc __libc_malloc_impl
24 #define realloc __libc_realloc
25 #define free __libc_free
26 
27 #define USE_MADV_FREE 0
28 
29 #if USE_REAL_ASSERT
30 #include <assert.h>
31 #else
32 #undef assert
33 #define assert(x) do { if (!(x)) a_crash(); } while(0)
34 #endif
35 
36 #define brk(p) ((uintptr_t)__syscall(SYS_brk, p))
37 
38 #define mmap __mmap
39 #define madvise __madvise
40 #define mremap __mremap
41 
42 #define DISABLE_ALIGNED_ALLOC (__malloc_replaced && !__aligned_alloc_replaced)
43 
get_random_secret()44 static inline uint64_t get_random_secret()
45 {
46 	uint64_t secret = (uintptr_t)&secret * 1103515245;
47 	for (size_t i=0; libc.auxv[i]; i+=2)
48 		if (libc.auxv[i]==AT_RANDOM)
49 			memcpy(&secret, (char *)libc.auxv[i+1]+8, sizeof secret);
50 	return secret;
51 }
52 
53 #ifndef PAGESIZE
54 #define PAGESIZE PAGE_SIZE
55 #endif
56 
57 #define MT (libc.need_locks)
58 
59 #define RDLOCK_IS_EXCLUSIVE 1
60 
61 __attribute__((__visibility__("hidden")))
62 extern int __malloc_lock[1];
63 
64 #define LOCK_OBJ_DEF \
65 int __malloc_lock[1]; \
66 void __malloc_atfork(int who) { malloc_atfork(who); }
67 
rdlock()68 static inline void rdlock()
69 {
70 	if (MT) LOCK(__malloc_lock);
71 }
wrlock()72 static inline void wrlock()
73 {
74 	if (MT) LOCK(__malloc_lock);
75 }
unlock()76 static inline void unlock()
77 {
78 	UNLOCK(__malloc_lock);
79 }
upgradelock()80 static inline void upgradelock()
81 {
82 }
resetlock()83 static inline void resetlock()
84 {
85 	__malloc_lock[0] = 0;
86 }
87 
malloc_atfork(int who)88 static inline void malloc_atfork(int who)
89 {
90 	if (who<0) rdlock();
91 	else if (who>0) resetlock();
92 	else unlock();
93 }
94 
95 #endif
96