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/* Test program for getting symbol table from vdso module.
Copyright (C) 2014 Red Hat, Inc.
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
elfutils is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <inttypes.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include ELFUTILS_HEADER(dwfl)
#ifndef __linux__
int
main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))
{
printf ("Getting the vdso is unsupported.\n");
return 77;
}
#else /* __linux__ */
static int vdso_syms = 0;
static int
module_callback (Dwfl_Module *mod, void **userdata __attribute__((unused)),
const char *name, Dwarf_Addr start __attribute__((unused)),
void *arg __attribute__((unused)))
{
/* We can only recognize the vdso by inspecting the "magic name". */
printf ("module name: %s\n", name);
if (strncmp ("[vdso: ", name, 7) == 0)
{
vdso_syms = dwfl_module_getsymtab (mod);
printf ("vdso syms: %d\n", vdso_syms);
if (vdso_syms < 0)
error (2, 0, "dwfl_module_getsymtab: %s", dwfl_errmsg (-1));
for (int i = 0; i < vdso_syms; i++)
{
GElf_Sym sym;
GElf_Addr addr;
const char *sname = dwfl_module_getsym_info (mod, i, &sym, &addr,
NULL, NULL, NULL);
assert (sname != NULL);
printf ("%d: '%s' %" PRIx64 " (%" PRIx64 ")\n",
i, sname, sym.st_value, addr);
}
}
return DWARF_CB_OK;
}
int
main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))
{
static char *debuginfo_path;
static const Dwfl_Callbacks proc_callbacks =
{
.find_debuginfo = dwfl_standard_find_debuginfo,
.debuginfo_path = &debuginfo_path,
.find_elf = dwfl_linux_proc_find_elf,
};
Dwfl *dwfl = dwfl_begin (&proc_callbacks);
if (dwfl == NULL)
error (2, 0, "dwfl_begin: %s", dwfl_errmsg (-1));
/* Take ourself as "arbitrary" process to inspect. This should work
even with "restricted ptrace". */
pid_t pid = getpid();
int result = dwfl_linux_proc_report (dwfl, pid);
if (result < 0)
error (2, 0, "dwfl_linux_proc_report: %s", dwfl_errmsg (-1));
else if (result > 0)
error (2, result, "dwfl_linux_proc_report");
/* Also explicitly attach for older kernels (cannot read vdso otherwise). */
result = dwfl_linux_proc_attach (dwfl, pid, false);
if (result < 0)
error (2, 0, "dwfl_linux_proc_attach: %s", dwfl_errmsg (-1));
else if (result > 0)
error (2, result, "dwfl_linux_proc_attach");
if (dwfl_report_end (dwfl, NULL, NULL) != 0)
error (2, 0, "dwfl_report_end: %s", dwfl_errmsg (-1));
if (dwfl_getmodules (dwfl, module_callback, NULL, 0) != 0)
error (1, 0, "dwfl_getmodules: %s", dwfl_errmsg (-1));
/* No symbols is ok, then we haven't seen the vdso at all on this arch. */
return vdso_syms >= 0 ? 0 : -1;
}
#endif /* ! __linux__ */
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