glibc/elf/ifuncmod1.c

/* Test STT_GNU_IFUNC symbols:

   1. Direct function call.
   2. Function pointer.
   3. Visibility.
 */
#include "ifunc-sel.h"

int global = -1;
/* Can't use __attribute__((visibility("protected"))) until the GCC bug:

   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248

   is fixed.  */
asm (".protected global");

static int
one (void)
{
  return 1;
}

static int
minus_one (void)
{
  return -1;
}

static int
zero (void)
{
  return 0;
}

void * foo_ifunc (void) __asm__ ("foo");
__asm__(".type foo, %gnu_indirect_function");

void *
inhibit_stack_protector
foo_ifunc (void)
{
  return ifunc_sel (one, minus_one, zero);
}

void * foo_hidden_ifunc (void) __asm__ ("foo_hidden");
__asm__(".type foo_hidden, %gnu_indirect_function");

void *
inhibit_stack_protector
foo_hidden_ifunc (void)
{
  return ifunc_sel (minus_one, one, zero);
}

void * foo_protected_ifunc (void) __asm__ ("foo_protected");
__asm__(".type foo_protected, %gnu_indirect_function");

void *
inhibit_stack_protector
foo_protected_ifunc (void)
{
  return ifunc_sel (one, zero, minus_one);
}

/* Test hidden indirect function.  */
__asm__(".hidden foo_hidden");

/* Test protected indirect function.  */
__asm__(".protected foo_protected");

extern int foo (void);
extern int foo_hidden (void);
extern int foo_protected (void);
extern int ret_foo;
extern int ret_foo_hidden;
extern int ret_foo_protected;

#define FOO_P
typedef int (*foo_p) (void);

foo_p
get_foo_p (void)
{
  ret_foo = foo ();
  return foo;
}

foo_p
get_foo_hidden_p (void)
{
  ret_foo_hidden = foo_hidden ();
  return foo_hidden;
}

foo_p
get_foo_protected_p (void)
{
  ret_foo_protected = foo_protected ();
  return foo_protected;
}