selftests/vDSO/parse_vdso.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002
0003 #ifndef PARSE_VDSO_H
0004 #define PARSE_VDSO_H
0005
0006 #include <stdint.h>
0007
0008 /*
0009  * To use this vDSO parser, first call one of the vdso_init_* functions.
0010  * If you've already parsed auxv, then pass the value of AT_SYSINFO_EHDR
0011  * to vdso_init_from_sysinfo_ehdr.  Otherwise pass auxv to vdso_init_from_auxv.
0012  * Then call vdso_sym for each symbol you want.  For example, to look up
0013  * gettimeofday on x86_64, use:
0014  *
0015  *     <some pointer> = vdso_sym("LINUX_2.6", "gettimeofday");
0016  * or
0017  *     <some pointer> = vdso_sym("LINUX_2.6", "__vdso_gettimeofday");
0018  *
0019  * vdso_sym will return 0 if the symbol doesn't exist or if the init function
0020  * failed or was not called.  vdso_sym is a little slow, so its return value
0021  * should be cached.
0022  *
0023  * vdso_sym is threadsafe; the init functions are not.
0024  *
0025  * These are the prototypes:
0026  */
0027 void *vdso_sym(const char *version, const char *name);
0028 void vdso_init_from_sysinfo_ehdr(uintptr_t base);
0029 void vdso_init_from_auxv(void *auxv);
0030
0031 #endif