[PATCH] elf: _dl_find_object may return 1 during early startup (bug 30515)

[Florian Weimer]

Success is reported with a 0 return value, and failure is -1.
Enhance the kitchen sink test elf/tst-audit28 to cover
_dl_find_object as well.

Fixes commit 5d28a8962dcb ("elf: Add _dl_find_object function")
and bug 30515.

Tested on x86_64-linux-gnu.

---
 elf/dl-find_object.c | 2 +-
 elf/tst-auditmod28.c | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/elf/dl-find_object.c b/elf/dl-find_object.c
index 928eb499cc..c1390ee10f 100644
--- a/elf/dl-find_object.c
+++ b/elf/dl-find_object.c
@@ -46,7 +46,7 @@ _dl_find_object_slow (void *pc, struct dl_find_object *result)
           struct dl_find_object_internal internal;
           _dl_find_object_from_map (l, &internal);
           _dl_find_object_to_external (&internal, result);
-          return 1;
+          return 0;
         }
 
   /* Object not found.  */
diff --git a/elf/tst-auditmod28.c b/elf/tst-auditmod28.c
index f6ab991398..ae9c277f5b 100644
--- a/elf/tst-auditmod28.c
+++ b/elf/tst-auditmod28.c
@@ -71,6 +71,15 @@ la_version (unsigned int current)
   TEST_VERIFY (dladdr1 (&_exit, &info, &extra_info, RTLD_DL_LINKMAP) != 0);
   TEST_VERIFY (extra_info == handle);
 
+  /* Check _dl_find_object.  */
+  struct dl_find_object dlfo;
+  TEST_COMPARE (_dl_find_object (__builtin_return_address (0), &dlfo), 0);
+  TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LD_SO);
+  TEST_COMPARE (_dl_find_object (dlsym (handle, "environ"), &dlfo), 0);
+  TEST_COMPARE_STRING (basename (dlfo.dlfo_link_map->l_name), LIBC_SO);
+  TEST_COMPARE (_dl_find_object ((void *) 1, &dlfo), -1);
+  TEST_COMPARE (_dl_find_object ((void *) -1, &dlfo), -1);
+
   /* Verify that dlmopen creates a new namespace.  */
   void *dlmopen_handle = xdlmopen (LM_ID_NEWLM, LIBC_SO, RTLD_NOW);
   TEST_VERIFY (dlmopen_handle != handle);

base-commit: 7f0d9e61f40c669fca3cfd1e342fa8236c7220b7