about summary refs log tree commit diff
path: root/elf/ifuncmain6pie.c
diff options
context:
space:
mode:
authorH.J. Lu <hjl.tools@gmail.com>2021-01-04 14:25:39 -0800
committerH.J. Lu <hjl.tools@gmail.com>2021-01-13 11:50:08 -0800
commit7137d682ebfcb6db5dfc5f39724718699922f06c (patch)
tree8c5411bcab9fb79b6520c71fede2e3b431f219cc /elf/ifuncmain6pie.c
parentcf1290064598def8dfeddec3d86d98495aee1fba (diff)
downloadglibc-7137d682ebfcb6db5dfc5f39724718699922f06c.tar.gz
glibc-7137d682ebfcb6db5dfc5f39724718699922f06c.tar.xz
glibc-7137d682ebfcb6db5dfc5f39724718699922f06c.zip
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.
Diffstat (limited to 'elf/ifuncmain6pie.c')
-rw-r--r--elf/ifuncmain6pie.c14
1 files changed, 3 insertions, 11 deletions
diff --git a/elf/ifuncmain6pie.c b/elf/ifuncmain6pie.c
index 04faeb86ef..4a01906836 100644
--- a/elf/ifuncmain6pie.c
+++ b/elf/ifuncmain6pie.c
@@ -9,7 +9,6 @@
 #include "ifunc-sel.h"
 
 typedef int (*foo_p) (void);
-extern foo_p foo_ptr;
 
 static int
 one (void)
@@ -28,20 +27,17 @@ foo_ifunc (void)
 }
 
 extern int foo (void);
-extern foo_p get_foo (void);
+extern int call_foo (void);
 extern foo_p get_foo_p (void);
 
-foo_p my_foo_ptr = foo;
+foo_p foo_ptr = foo;
 
 int
 main (void)
 {
   foo_p p;
 
-  p = get_foo ();
-  if (p != foo)
-    abort ();
-  if ((*p) () != -30)
+  if (call_foo () != -30)
     abort ();
 
   p = get_foo_p ();
@@ -52,12 +48,8 @@ main (void)
 
   if (foo_ptr != foo)
     abort ();
-  if (my_foo_ptr != foo)
-    abort ();
   if ((*foo_ptr) () != -30)
     abort ();
-  if ((*my_foo_ptr) () != -30)
-    abort ();
   if (foo () != -30)
     abort ();