tools/testing/selftests/vDSO/parse_vdso.h

   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