glibc/elf/ifuncmain7.c
Nick Alcock de6591238b Do not stack-protect ifunc resolvers [BZ ]
When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.

We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves.  (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
2016-12-26 10:08:41 +01:00

73 lines
930 B
C

/* Test local STT_GNU_IFUNC symbols:
1. Direct function call.
2. Function pointer.
*/
#include <stdlib.h>
#include "ifunc-sel.h"
extern int foo (void);
static int
one (void)
{
return -30;
}
static void * foo_ifunc (void) __asm__ ("foo");
__asm__(".type foo, %gnu_indirect_function");
static void *
__attribute__ ((used))
inhibit_stack_protector
foo_ifunc (void)
{
return ifunc_one (one);
}
typedef int (*foo_p) (void);
foo_p foo_ptr = foo;
foo_p
__attribute__ ((noinline))
get_foo_p (void)
{
return foo_ptr;
}
foo_p
__attribute__ ((noinline))
get_foo (void)
{
return foo;
}
int
main (void)
{
foo_p p;
p = get_foo ();
if (p != foo)
abort ();
if ((*p) () != -30)
abort ();
p = get_foo_p ();
if (p != foo)
abort ();
if ((*p) () != -30)
abort ();
if (foo_ptr != foo)
abort ();
if ((*foo_ptr) () != -30)
abort ();
if (foo () != -30)
abort ();
return 0;
}