From c5d37467b152fe98f02ac1ff8188e32ecd0def95 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Mon, 17 Apr 2017 18:33:52 +0930 Subject: [PATCH] Undo dynamic symbol state after regular object sym type mismatch We already handle the case of an object file first defining a symbol that a later shared library also defines where the symbol types are incompatible. This patch handles the reverse, when a later object file defines an incompatible symbol defined by an earlier shared library. bfd/ * elflink.c (_bfd_elf_merge_symbol): Undo dynamic linking state when a regular object file defines a symbol with incompatible type to that defined by an earlier shared lib. ld/ * testsuite/ld-elf/indirect5a.c, * testsuite/ld-elf/indirect5b.c, * testsuite/ld-elf/indirect5.map, * testsuite/ld-elf/indirect5.out: New test. * testsuite/ld-elf/indirect6a.c: Likewise. * testsuite/ld-elf/indirect.exp (check_dynamic_syms): New proc. Run new tests and check dynsyms. --- bfd/ChangeLog | 6 ++++ bfd/elflink.c | 53 +++++++++++++++++++++------- ld/ChangeLog | 10 ++++++ ld/testsuite/ld-elf/indirect.exp | 74 +++++++++++++++++++++++++++++++++++++++ ld/testsuite/ld-elf/indirect5.map | 6 ++++ ld/testsuite/ld-elf/indirect5.out | 2 ++ ld/testsuite/ld-elf/indirect5a.c | 9 +++++ ld/testsuite/ld-elf/indirect5b.c | 15 ++++++++ ld/testsuite/ld-elf/indirect6a.c | 9 +++++ 9 files changed, 171 insertions(+), 13 deletions(-) create mode 100644 ld/testsuite/ld-elf/indirect5.map create mode 100644 ld/testsuite/ld-elf/indirect5.out create mode 100644 ld/testsuite/ld-elf/indirect5a.c create mode 100644 ld/testsuite/ld-elf/indirect5b.c create mode 100644 ld/testsuite/ld-elf/indirect6a.c diff --git a/bfd/ChangeLog b/bfd/ChangeLog index f26882f5..b113a8b 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2017-04-17 Alan Modra + + * elflink.c (_bfd_elf_merge_symbol): Undo dynamic linking + state when a regular object file defines a symbol with + incompatible type to that defined by an earlier shared lib. + 2017-04-13 Alan Modra * coffcode.h: Wrap some overly long _bfd_error_handler args. diff --git a/bfd/elflink.c b/bfd/elflink.c index dfcc51e..ec2032b 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -1242,23 +1242,50 @@ _bfd_elf_merge_symbol (bfd *abfd, oldfunc = (h->type != STT_NOTYPE && bed->is_function_type (h->type)); - /* If creating a default indirect symbol ("foo" or "foo@") from a - dynamic versioned definition ("foo@@") skip doing so if there is - an existing regular definition with a different type. We don't - want, for example, a "time" variable in the executable overriding - a "time" function in a shared library. */ - if (pold_alignment == NULL - && newdyn - && newdef - && !olddyn - && (olddef || h->root.type == bfd_link_hash_common) + if (!(newfunc && oldfunc) && ELF_ST_TYPE (sym->st_info) != h->type && ELF_ST_TYPE (sym->st_info) != STT_NOTYPE && h->type != STT_NOTYPE - && !(newfunc && oldfunc)) + && (newdef || bfd_is_com_section (sec)) + && (olddef || h->root.type == bfd_link_hash_common)) { - *skip = TRUE; - return TRUE; + /* If creating a default indirect symbol ("foo" or "foo@") from + a dynamic versioned definition ("foo@@") skip doing so if + there is an existing regular definition with a different + type. We don't want, for example, a "time" variable in the + executable overriding a "time" function in a shared library. */ + if (newdyn + && !olddyn) + { + *skip = TRUE; + return TRUE; + } + + /* When adding a symbol from a regular object file after we have + created indirect symbols, undo the indirection and any + dynamic state. */ + if (hi != h + && !newdyn + && olddyn) + { + h = hi; + (*bed->elf_backend_hide_symbol) (info, h, TRUE); + h->forced_local = 0; + h->ref_dynamic = 0; + h->def_dynamic = 0; + h->dynamic_def = 0; + if (h->root.u.undef.next || info->hash->undefs_tail == &h->root) + { + h->root.type = bfd_link_hash_undefined; + h->root.u.undef.abfd = abfd; + } + else + { + h->root.type = bfd_link_hash_new; + h->root.u.undef.abfd = NULL; + } + return TRUE; + } } /* Check TLS symbols. We don't check undefined symbols introduced diff --git a/ld/ChangeLog b/ld/ChangeLog index b55c436..793847d 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,13 @@ +2017-04-17 Alan Modra + + * testsuite/ld-elf/indirect5a.c, + * testsuite/ld-elf/indirect5b.c, + * testsuite/ld-elf/indirect5.map, + * testsuite/ld-elf/indirect5.out: New test. + * testsuite/ld-elf/indirect6a.c: Likewise. + * testsuite/ld-elf/indirect.exp (check_dynamic_syms): New proc. + Run new tests and check dynsyms. + 2017-04-11 Alan Modra PR 21274 diff --git a/ld/testsuite/ld-elf/indirect.exp b/ld/testsuite/ld-elf/indirect.exp index 5c5382c..128d4a7 100644 --- a/ld/testsuite/ld-elf/indirect.exp +++ b/ld/testsuite/ld-elf/indirect.exp @@ -85,6 +85,9 @@ set build_tests { {"Build libindirect4c.so" "-shared" "-fPIC" {indirect4c.c} {} "libindirect4c.so"} + {"Build libindirect5.so" + "-shared -Wl,--version-script=indirect5.map" "-fPIC" + {indirect5b.c} {} "libindirect5.so"} {"Build libpr18720c.so" "-shared" "-fPIC" {pr18720c.c} {} "libpr18720c.so"} @@ -151,6 +154,18 @@ set run_tests { {"Run with libindirect4c.so 4" "-Wl,--no-as-needed tmpdir/libindirect4c.so tmpdir/indirect4b.o tmpdir/indirect4a.o" "" {dummy.c} "indirect4d" "indirect4.out"} + {"Run indirect5 1" + "-Wl,--no-as-needed tmpdir/libindirect5.so" "" + {indirect5a.c} "indirect5a" "indirect5.out"} + {"Run indirect5 2" + "-Wl,--no-as-needed tmpdir/indirect5a.o tmpdir/libindirect5.so" "" + {dummy.c} "indirect5b" "indirect5.out"} + {"Run indirect6 1" + "-Wl,--no-as-needed tmpdir/libindirect5.so" "" + {indirect6a.c} "indirect6a" "indirect5.out"} + {"Run indirect6 2" + "-Wl,--no-as-needed tmpdir/indirect6a.o tmpdir/libindirect5.so" "" + {dummy.c} "indirect6b" "indirect5.out"} {"Run with libpr18720c.so 1" "-Wl,--no-as-needed tmpdir/pr18720a.o tmpdir/pr18720b.o tmpdir/libpr18720c.so" "" {check-ptr-eq.c} "pr18720a" "pr18720.out"} @@ -178,3 +193,62 @@ set run_tests { } run_ld_link_exec_tests $run_tests + +# Check that "bar" is not dynamic in the executable +proc check_dynamic_syms { test } { + global nm + set cmd "$nm -D $test > dump.out" + send_log "$cmd\n" + catch "exec $cmd" comp_output + if ![string match "" $comp_output] then { + send_log "$comp_output\n" + return 0 + } + if { [string match "* bar\n*" [file_contents "dump.out"]] } then { + verbose "output is [file_contents "dump.out"]" + return 0 + } + return 1 +} + +foreach t [list indirect5a indirect5b indirect6a indirect6b] { + set testname [concat $t "dynsym"] + if { [check_dynamic_syms tmpdir/$t] } { + pass $testname + } else { + fail $testname + } +} + +send_log "$CC -fPIE -pie $srcdir/$subdir/main.c -o tmpdir/pie" +catch "exec $CC -fPIE -pie $srcdir/$subdir/main.c -o tmpdir/pie" exec_output +send_log "$exec_output" +if { ! [string match "" $exec_output] } { + return +} + +set pie_tests { + {"Run indirect5 3" + "-pie -Wl,--no-as-needed tmpdir/libindirect5.so" "" + {indirect5a.c} "indirect5c" "indirect5.out" "-fPIE"} + {"Run indirect5 4" + "-pie -Wl,--no-as-needed tmpdir/indirect5a.o tmpdir/libindirect5.so" "" + {dummy.c} "indirect5d" "indirect5.out" "-fPIE"} + {"Run indirect6 3" + "-pie -Wl,--no-as-needed tmpdir/libindirect5.so" "" + {indirect6a.c} "indirect6c" "indirect5.out" "-fPIE"} + {"Run indirect6 4" + "-pie -Wl,--no-as-needed tmpdir/indirect6a.o tmpdir/libindirect5.so" "-fPIE" + {dummy.c} "indirect6d" "indirect5.out" "-fPIE"} +} + +run_ld_link_exec_tests $pie_tests + +foreach t [list indirect5c indirect5d indirect6c indirect6d] { + set testname [concat $t "dynsym"] + if { [check_dynamic_syms tmpdir/$t] } { + pass $testname + } else { + fail $testname + } +} diff --git a/ld/testsuite/ld-elf/indirect5.map b/ld/testsuite/ld-elf/indirect5.map new file mode 100644 index 0000000..f62b414 --- /dev/null +++ b/ld/testsuite/ld-elf/indirect5.map @@ -0,0 +1,6 @@ +FOO +{ +global: + foo; + bar; +}; diff --git a/ld/testsuite/ld-elf/indirect5.out b/ld/testsuite/ld-elf/indirect5.out new file mode 100644 index 0000000..3bd1f0e --- /dev/null +++ b/ld/testsuite/ld-elf/indirect5.out @@ -0,0 +1,2 @@ +foo +bar diff --git a/ld/testsuite/ld-elf/indirect5a.c b/ld/testsuite/ld-elf/indirect5a.c new file mode 100644 index 0000000..9e150fe --- /dev/null +++ b/ld/testsuite/ld-elf/indirect5a.c @@ -0,0 +1,9 @@ +extern void foo (long *); +long bar; + +int +main (void) +{ + foo (&bar); + return 0; +} diff --git a/ld/testsuite/ld-elf/indirect5b.c b/ld/testsuite/ld-elf/indirect5b.c new file mode 100644 index 0000000..7659971 --- /dev/null +++ b/ld/testsuite/ld-elf/indirect5b.c @@ -0,0 +1,15 @@ +#include + +void +bar (void) +{ + printf ("bar\n"); +} + +void +foo (long *x) +{ + (void) x; + printf ("foo\n"); + bar (); +} diff --git a/ld/testsuite/ld-elf/indirect6a.c b/ld/testsuite/ld-elf/indirect6a.c new file mode 100644 index 0000000..1545db1 --- /dev/null +++ b/ld/testsuite/ld-elf/indirect6a.c @@ -0,0 +1,9 @@ +extern void foo (long *); +long bar = 1; + +int +main (void) +{ + foo (&bar); + return 0; +} -- 2.7.4