From 1134e6ce012575e6d0e99933d0d29cc7978af9af Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 9 Mar 2016 05:59:20 -0800 Subject: 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. --- 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(-) 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 0a08b556384..a8beeccbdba 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,18 @@ +2016-03-09 H.J. Lu + + PR ld/19579 + Backport from master + 2016-03-08 H.J. Lu + + * elflink.c (_bfd_elf_merge_symbol): Group common symbol checking + together. + + 2016-03-04 H.J. Lu + + * 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 Alan Modra diff --git a/bfd/elflink.c b/bfd/elflink.c index 8fcaaddfd44..842e85ba741 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 1ee2dfa392d..2fa9ad37636 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,13 @@ +2016-03-09 H.J. Lu + + Backport from master + 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. + 2016-03-04 H.J. Lu Backport from master 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 731eef30911..b8c12cb1f36 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" \ + ] \ ] } -- cgit v1.2.1