xref: /kernel/linux/linux-6.6/tools/testing/selftests/vDSO/parse_vdso.h

/* SPDX-License-Identifier: GPL-2.0-only */

#ifndef PARSE_VDSO_H
#define PARSE_VDSO_H

#include <stdint.h>

/*
 * To use this vDSO parser, first call one of the vdso_init_* functions.
 * If you've already parsed auxv, then pass the value of AT_SYSINFO_EHDR
 * to vdso_init_from_sysinfo_ehdr.  Otherwise pass auxv to vdso_init_from_auxv.
 * Then call vdso_sym for each symbol you want.  For example, to look up
 * gettimeofday on x86_64, use:
 *
 *     <some pointer> = vdso_sym("LINUX_2.6", "gettimeofday");
 * or
 *     <some pointer> = vdso_sym("LINUX_2.6", "__vdso_gettimeofday");
 *
 * vdso_sym will return 0 if the symbol doesn't exist or if the init function
 * failed or was not called.  vdso_sym is a little slow, so its return value
 * should be cached.
 *
 * vdso_sym is threadsafe; the init functions are not.
 *
 * These are the prototypes:
 */
void *vdso_sym(const char *version, const char *name);
void vdso_init_from_sysinfo_ehdr(uintptr_t base);
void vdso_init_from_auxv(void *auxv);

#endif