| commit 7b5bfe77836442b9aeb75cc520f0d1eb7f82be67 |
| Author: Florian Weimer <fweimer@redhat.com> |
| Date: Mon May 18 15:21:04 2020 +0200 |
| |
| elf: Assert that objects are relocated before their constructors run |
| |
| If we try to run constructors before relocation, this is always |
| a dynamic linker bug. An assert is easier to notice than a call |
| via an invalid function pointer (which may not even produce a valid |
| call stack). |
| |
| Reviewed-by: Carlos O'Donell <carlos@redhat.com> |
| |
| diff --git a/elf/dl-init.c b/elf/dl-init.c |
| index 45405cd0563845b4..99ce531d7b326f5f 100644 |
| |
| |
| @@ -16,6 +16,7 @@ |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| +#include <assert.h> |
| #include <stddef.h> |
| #include <ldsodefs.h> |
| |
| @@ -27,6 +28,11 @@ typedef void (*init_t) (int, char **, char **); |
| static void |
| call_init (struct link_map *l, int argc, char **argv, char **env) |
| { |
| + /* If the object has not been relocated, this is a bug. The |
| + function pointers are invalid in this case. (Executables do not |
| + need relocation, and neither do proxy objects.) */ |
| + assert (l->l_real->l_relocated || l->l_real->l_type == lt_executable); |
| + |
| if (l->l_init_called) |
| /* This object is all done. */ |
| return; |