From 07492f668d2173da7a2bda3707ff0985e0f460b6 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 4 Mar 2016 06:37:34 -0800 Subject: [PATCH] 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. bfd/ PR ld/19579 * 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. --- bfd/ChangeLog | 7 +++++++ bfd/elflink.c | 5 ++++- ld/ChangeLog | 7 +++++++ ld/testsuite/ld-elf/pr19579a.c | 15 +++++++++++++++ ld/testsuite/ld-elf/pr19579b.c | 14 ++++++++++++++ ld/testsuite/ld-elf/shared.exp | 24 ++++++++++++++++++++++++ 6 files changed, 71 insertions(+), 1 deletion(-) create mode 100644 ld/testsuite/ld-elf/pr19579a.c create mode 100644 ld/testsuite/ld-elf/pr19579b.c diff --git a/bfd/ChangeLog b/bfd/ChangeLog index b2cc5b85ba2..5f9f99d62f8 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,10 @@ +2016-03-04 H.J. Lu + + PR ld/19579 + * elflink.c (_bfd_elf_merge_symbol): Treat common symbol in + executable as definition if the new definition comes from a + shared library. + 2016-03-02 Alan Modra * Makefile.in: Regenerate. diff --git a/bfd/elflink.c b/bfd/elflink.c index 0e3abff5ce4..39157bf7789 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -1172,9 +1172,12 @@ _bfd_elf_merge_symbol (bfd *abfd, newdef = !bfd_is_und_section (sec) && !bfd_is_com_section (sec); + /* The old common symbol in executable is a definition if the new + definition comes from a shared library. */ olddef = (h->root.type != bfd_link_hash_undefined && h->root.type != bfd_link_hash_undefweak - && h->root.type != bfd_link_hash_common); + && (h->root.type != bfd_link_hash_common + || (!olddyn && newdyn && bfd_link_executable (info)))); /* NEWFUNC and OLDFUNC indicate whether the new or old symbol, respectively, appear to be a function. */ diff --git a/ld/ChangeLog b/ld/ChangeLog index 328e51d85b2..ac73cf8a20c 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,10 @@ +2016-03-04 H.J. Lu + + 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. + 2016-03-02 H.J. Lu * testsuite/ld-elf/pr19162.d: Skip hppa-*-*. diff --git a/ld/testsuite/ld-elf/pr19579a.c b/ld/testsuite/ld-elf/pr19579a.c new file mode 100644 index 00000000000..e4a6eb1ea9b --- /dev/null +++ b/ld/testsuite/ld-elf/pr19579a.c @@ -0,0 +1,15 @@ +#include + +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 00000000000..d9065458ed9 --- /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 678ab1bb31f..ef0747d610b 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 \ @@ -580,6 +595,15 @@ 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" \ + ] \ ] } -- 2.30.2