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[binutils-gdb/binutils-2_26-branch] Treat common symbol in executable as definition
- From: H.J.Lu <hjl at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 9 Mar 2016 14:01:22 -0000
- Subject: [binutils-gdb/binutils-2_26-branch] Treat common symbol in executable as definition
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1134e6ce012575e6d0e99933d0d29cc7978af9af
commit 1134e6ce012575e6d0e99933d0d29cc7978af9af
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Mar 9 05:59:20 2016 -0800
Treat common symbol in executable as definition
Common symbol in executable is a definition, which overrides definition
from shared objects. When linker sees a new definition from a shared
object, the new dynamic definition should be overridden by the previous
common symbol in executable.
Backport from master
bfd/
PR ld/19579
* elflink.c (_bfd_elf_merge_symbol): Group common symbol checking
together.
* elflink.c (_bfd_elf_merge_symbol): Treat common symbol in
executable as definition if the new definition comes from a
shared library.
ld/
PR ld/19579
* testsuite/ld-elf/pr19579a.c: New file.
* testsuite/ld-elf/pr19579b.c: Likewise.
* testsuite/ld-elf/shared.exp: Run PR ld/19579 test.
Diff:
---
bfd/ChangeLog | 15 +++++++++++++++
bfd/elflink.c | 7 +++++--
ld/ChangeLog | 10 ++++++++++
ld/testsuite/ld-elf/pr19579a.c | 15 +++++++++++++++
ld/testsuite/ld-elf/pr19579b.c | 14 ++++++++++++++
ld/testsuite/ld-elf/shared.exp | 24 ++++++++++++++++++++++++
6 files changed, 83 insertions(+), 2 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 0a08b55..a8beecc 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,18 @@
+2016-03-09 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR ld/19579
+ Backport from master
+ 2016-03-08 H.J. Lu <hongjiu.lu@intel.com>
+
+ * elflink.c (_bfd_elf_merge_symbol): Group common symbol checking
+ together.
+
+ 2016-03-04 H.J. Lu <hongjiu.lu@intel.com>
+
+ * elflink.c (_bfd_elf_merge_symbol): Treat common symbol in
+ executable as definition if the new definition comes from a
+ shared library.
+
2016-03-09 Nick Clifton <nickc@redhat.com>
Alan Modra <amodra@gmail.com>
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 8fcaadd..842e85b 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -1485,13 +1485,16 @@ _bfd_elf_merge_symbol (bfd *abfd,
represent variables; this can cause confusion in principle, but
any such confusion would seem to indicate an erroneous program or
shared library. We also permit a common symbol in a regular
- object to override a weak symbol in a shared object. */
+ object to override a weak symbol in a shared object. A common
+ symbol in executable also overrides a symbol in a shared object. */
if (newdyn
&& newdef
&& (olddef
|| (h->root.type == bfd_link_hash_common
- && (newweak || newfunc))))
+ && (newweak
+ || newfunc
+ || (!olddyn && bfd_link_executable (info))))))
{
*override = TRUE;
newdef = FALSE;
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 1ee2dfa..2fa9ad3 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,13 @@
+2016-03-09 H.J. Lu <hongjiu.lu@intel.com>
+
+ Backport from master
+ 2016-03-04 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR ld/19579
+ * testsuite/ld-elf/pr19579a.c: New file.
+ * testsuite/ld-elf/pr19579b.c: Likewise.
+ * testsuite/ld-elf/shared.exp: Run PR ld/19579 test.
+
2016-03-04 H.J. Lu <hongjiu.lu@intel.com>
Backport from master
diff --git a/ld/testsuite/ld-elf/pr19579a.c b/ld/testsuite/ld-elf/pr19579a.c
new file mode 100644
index 0000000..e4a6eb1
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr19579a.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int foo[1];
+int bar[2];
+
+extern int *foo_p (void);
+extern int *bar_p (void);
+
+int
+main ()
+{
+ if (foo[0] == 0 && foo == foo_p () && bar[0] == 0 && bar == bar_p ())
+ printf ("PASS\n");
+ return 0;
+}
diff --git a/ld/testsuite/ld-elf/pr19579b.c b/ld/testsuite/ld-elf/pr19579b.c
new file mode 100644
index 0000000..d906545
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr19579b.c
@@ -0,0 +1,14 @@
+int foo[2];
+int bar[2] = { -1, -1 };
+
+int *
+foo_p (void)
+{
+ return foo;
+}
+
+int *
+bar_p (void)
+{
+ return bar;
+}
diff --git a/ld/testsuite/ld-elf/shared.exp b/ld/testsuite/ld-elf/shared.exp
index 731eef3..b8c12cb 100644
--- a/ld/testsuite/ld-elf/shared.exp
+++ b/ld/testsuite/ld-elf/shared.exp
@@ -524,6 +524,21 @@ if { [istarget *-*-linux*]
{} \
"libpr2404b.a" \
] \
+ [list \
+ "Build pr19579a.o" \
+ "" "-fPIE" \
+ {pr19579a.c} \
+ {} \
+ "libpr19579a.a" \
+ ] \
+ [list \
+ "Build libpr19579.so" \
+ "-shared" \
+ "-fPIC" \
+ {pr19579b.c} \
+ {} \
+ "libpr19579.so" \
+ ] \
]
run_ld_link_exec_tests [] [list \
[list \
@@ -580,5 +595,14 @@ if { [istarget *-*-linux*]
"pass.out" \
"-O2 -fPIC -I../bfd" \
] \
+ [list \
+ "Run pr19579" \
+ "-pie -z text tmpdir/pr19579a.o tmpdir/libpr19579.so" \
+ "" \
+ {dummy.c} \
+ "pr19579" \
+ "pass.out" \
+ "-fPIE" \
+ ] \
]
}