glibc/elf/ifuncmain6pie.c
H.J. Lu 7137d682eb ifuncmain6pie: Remove the circular IFUNC dependency [BZ #20019]
On x86, ifuncmain6pie failed with:

[hjl@gnu-cfl-2 build-i686-linux]$ ./elf/ifuncmain6pie --direct
./elf/ifuncmain6pie: IFUNC symbol 'foo' referenced in '/export/build/gnu/tools-build/glibc-32bit/build-i686-linux/elf/ifuncmod6.so' is defined in the executable and creates an unsatisfiable circular dependency.
[hjl@gnu-cfl-2 build-i686-linux]$ readelf -rW elf/ifuncmod6.so | grep foo
00003ff4  00000706 R_386_GLOB_DAT         0000400c   foo_ptr
00003ff8  00000406 R_386_GLOB_DAT         00000000   foo
0000400c  00000401 R_386_32               00000000   foo
[hjl@gnu-cfl-2 build-i686-linux]$

Remove non-JUMP_SLOT relocations against foo in ifuncmod6.so, which
trigger the circular IFUNC dependency, and build ifuncmain6pie with
-Wl,-z,lazy.
2021-01-13 11:50:08 -08:00

58 lines
808 B
C

/* Test STT_GNU_IFUNC symbols in PIE:
1. Direct function call.
2. Function pointer.
3. Reference from a shared library.
*/
#include <stdlib.h>
#include "ifunc-sel.h"
typedef int (*foo_p) (void);
static int
one (void)
{
return -30;
}
void * foo_ifunc (void) __asm__ ("foo");
__asm__(".type foo, %gnu_indirect_function");
void *
inhibit_stack_protector
foo_ifunc (void)
{
return ifunc_one (one);
}
extern int foo (void);
extern int call_foo (void);
extern foo_p get_foo_p (void);
foo_p foo_ptr = foo;
int
main (void)
{
foo_p p;
if (call_foo () != -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;
}