1 /* SPDX-License-Identifier: GPL-2.0-only */
2 
3 #ifndef PARSE_VDSO_H
4 #define PARSE_VDSO_H
5 
6 #include <stdint.h>
7 
8 /*
9  * To use this vDSO parser, first call one of the vdso_init_* functions.
10  * If you've already parsed auxv, then pass the value of AT_SYSINFO_EHDR
11  * to vdso_init_from_sysinfo_ehdr.  Otherwise pass auxv to vdso_init_from_auxv.
12  * Then call vdso_sym for each symbol you want.  For example, to look up
13  * gettimeofday on x86_64, use:
14  *
15  *     <some pointer> = vdso_sym("LINUX_2.6", "gettimeofday");
16  * or
17  *     <some pointer> = vdso_sym("LINUX_2.6", "__vdso_gettimeofday");
18  *
19  * vdso_sym will return 0 if the symbol doesn't exist or if the init function
20  * failed or was not called.  vdso_sym is a little slow, so its return value
21  * should be cached.
22  *
23  * vdso_sym is threadsafe; the init functions are not.
24  *
25  * These are the prototypes:
26  */
27 void *vdso_sym(const char *version, const char *name);
28 void vdso_init_from_sysinfo_ehdr(uintptr_t base);
29 void vdso_init_from_auxv(void *auxv);
30 
31 #endif
32