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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
parentcf1290064598def8dfeddec3d86d98495aee1fba (diff)
downloadglibc-7137d682ebfcb6db5dfc5f39724718699922f06c.tar.gz
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.
-rw-r--r--elf/Makefile2
-rw-r--r--elf/ifuncmain6pie.c14
-rw-r--r--elf/ifuncmod6.c8
3 files changed, 9 insertions, 15 deletions
diff --git a/elf/Makefile b/elf/Makefile
index 543800f4be..c41d11693b 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1403,6 +1403,8 @@ CFLAGS-ifuncmain7pie.c += $(pie-ccflag)
CFLAGS-ifuncmain9pie.c += $(pie-ccflag)
CFLAGS-tst-ifunc-textrel.c += $(pic-ccflag)
+LDFLAGS-ifuncmain6pie = -Wl,-z,lazy
+
$(objpfx)ifuncmain1pie: $(objpfx)ifuncmod1.so
$(objpfx)ifuncmain1staticpie: $(objpfx)ifuncdep1pic.o
$(objpfx)ifuncmain1vispie: $(objpfx)ifuncmod1.so
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 ();
diff --git a/elf/ifuncmod6.c b/elf/ifuncmod6.c
index 2e16c1d06d..2f6d0715e6 100644
--- a/elf/ifuncmod6.c
+++ b/elf/ifuncmod6.c
@@ -4,7 +4,7 @@ extern int foo (void);
typedef int (*foo_p) (void);
-foo_p foo_ptr = foo;
+extern foo_p foo_ptr;
foo_p
get_foo_p (void)
@@ -12,8 +12,8 @@ get_foo_p (void)
return foo_ptr;
}
-foo_p
-get_foo (void)
+int
+call_foo (void)
{
- return foo;
+ return foo ();
}