From: Maciej W. Rozycki Date: Tue, 5 Apr 2016 14:10:05 +0000 (+0100) Subject: ELF/LD: Avoid producing hidden and internal dynamic symbols X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1f599d0e7b5039c814731293043e247304ec006b;p=binutils-gdb.git ELF/LD: Avoid producing hidden and internal dynamic symbols Always turn hidden and internal symbols which have a dynamic index into local ones. This is required by the the ELF gABI[1]: "A hidden symbol contained in a relocatable object must be either removed or converted to STB_LOCAL binding by the link-editor when the relocatable object is included in an executable file or shared object." "An internal symbol contained in a relocatable object must be either removed or converted to STB_LOCAL binding by the link-editor when the relocatable object is included in an executable file or shared object." The ELF linker usually respects this requirement, however in the case where a dynamic symbol has been preallocated due to a reference of the default export class aka visibility from the object being linked, and then merged with a hidden or internal symbol definition from within the same object, then the original export class is carried over to the output dynamic symbol table, because while merging the generic ELF linker only converts affected dynamic symbols to local when they are defined or referenced by the object being linked and a dynamic object involved in the link both at a time. The dynamic symbol produced confuses then the dynamic loader at the run time -- the hidden or internal export class is ignored and the symbol follows preemption rules as with the default export class. In the MIPS target it happens when `mips_elf_record_global_got_symbol' creates a dynamic symbol when a call relocation is encountered. Additionally if the undefined symbol referred by such a relocation does specify the intended export class, then a local dynamic symbol is created instead, which is harmless and allowed, but useless. Normally no local dynamic symbols are created, except for a single dummy one at the beginning. Correct the problem by removing the extra check for a dynamic symbol being defined or referenced by the object being linked and a dynamic object involved in the link both at a time. The test cases included cover the internal and hidden symbol cases, as well as a protected symbol for a reference, the handling of which is unchanged by this fix. Both cases described above are covered, that is where an internal or hidden dynamic symbol is produced and where a local one is. NB this change affects CRIS results where some symbols in the static table produced in a final link are now converted from STV_HIDDEN to STB_LOCAL. This happens whenever the `elf_backend_hide_symbol' handler is called, so the affected symbols must have been chosen for entering into the dynamic symbol table, except in these test cases no such symbol table is produced. In fully linked binaries the static symbol table is only used for debugging though, so such a change is fine. References: [1] "System V Application Binary Interface - DRAFT - 24 April 2001", The Santa Cruz Operation, Inc., "Symbol Table", bfd/ PR ld/19908 * elflink.c (elf_link_add_object_symbols): Always turn hidden and internal symbols which have a dynamic index into local ones. ld/ PR ld/19908 * testsuite/ld-cris/tls-e-20.d: Adjust for hidden symbol handling fix. * testsuite/ld-cris/tls-e-20a.d: Likewise. * testsuite/ld-cris/tls-e-21.d: Likewise. * testsuite/ld-cris/tls-e-23.d: Likewise. * testsuite/ld-cris/tls-e-80.d: Likewise. * testsuite/ld-cris/tls-gd-3h.d: Likewise. * testsuite/ld-cris/tls-leie-19.d: Likewise. * testsuite/ld-mips-elf/export-class-ref-lib.sd: New test. * testsuite/ld-mips-elf/export-hidden-ref.sd: New test. * testsuite/ld-mips-elf/export-internal-ref.sd: New test. * testsuite/ld-mips-elf/export-protected-ref.sd: New test. * testsuite/ld-mips-elf/export-class-ref-f0.s: New test source. * testsuite/ld-mips-elf/export-class-ref-f1.s: New test source. * testsuite/ld-mips-elf/export-class-ref-f2.s: New test source. * testsuite/ld-mips-elf/mips-elf.exp: Run the new tests. --- diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 42d112f3781..626e68a6aed 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2016-04-05 Maciej W. Rozycki + + * elflink.c (elf_link_add_object_symbols): Always turn hidden + and internal symbols which have a dynamic index into local + ones. + 2016-04-04 Nick Clifton PR 19872 diff --git a/bfd/elflink.c b/bfd/elflink.c index 445fb013258..42b3689048c 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -4583,7 +4583,7 @@ error_free_dyn: goto error_free_vers; } } - else if (dynsym && h->dynindx != -1) + else if (h->dynindx != -1) /* If the symbol already has a dynamic index, but visibility says it should not be visible, turn it into a local symbol. */ diff --git a/ld/ChangeLog b/ld/ChangeLog index ae7062af5e4..1e1aae7afc5 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,23 @@ +2016-04-05 Maciej W. Rozycki + + PR ld/19908 + * testsuite/ld-cris/tls-e-20.d: Adjust for hidden symbol + handling fix. + * testsuite/ld-cris/tls-e-20a.d: Likewise. + * testsuite/ld-cris/tls-e-21.d: Likewise. + * testsuite/ld-cris/tls-e-23.d: Likewise. + * testsuite/ld-cris/tls-e-80.d: Likewise. + * testsuite/ld-cris/tls-gd-3h.d: Likewise. + * testsuite/ld-cris/tls-leie-19.d: Likewise. + * testsuite/ld-mips-elf/export-class-ref-lib.sd: New test. + * testsuite/ld-mips-elf/export-hidden-ref.sd: New test. + * testsuite/ld-mips-elf/export-internal-ref.sd: New test. + * testsuite/ld-mips-elf/export-protected-ref.sd: New test. + * testsuite/ld-mips-elf/export-class-ref-f0.s: New test source. + * testsuite/ld-mips-elf/export-class-ref-f1.s: New test source. + * testsuite/ld-mips-elf/export-class-ref-f2.s: New test source. + * testsuite/ld-mips-elf/mips-elf.exp: Run the new tests. + 2016-04-05 Cupertino Miranda * testsuite/ld-discard/extern.d: Removed xfail for ARC. diff --git a/ld/testsuite/ld-cris/tls-e-20.d b/ld/testsuite/ld-cris/tls-e-20.d index 6b4e7142cea..eb323a59804 100644 --- a/ld/testsuite/ld-cris/tls-e-20.d +++ b/ld/testsuite/ld-cris/tls-e-20.d @@ -35,8 +35,8 @@ SYMBOL TABLE: 0+80094 l d \.text 0+ \.text 0+820b0 l d \.tdata 0+ \.tdata 0+820bc l d \.got 0+ \.got +0+ l \.tdata 0+4 x 0+820bc l O \.got 0+ _GLOBAL_OFFSET_TABLE_ -0+ g \.tdata 0+4 \.hidden x 0+80098 g F \.text 0+6 tlsdsofn2 0+8 g \.tdata 0+4 \.hidden x2 0+80094 g \.text 0+ _start diff --git a/ld/testsuite/ld-cris/tls-e-20a.d b/ld/testsuite/ld-cris/tls-e-20a.d index 13b3be8b824..7d5a95e8b26 100644 --- a/ld/testsuite/ld-cris/tls-e-20a.d +++ b/ld/testsuite/ld-cris/tls-e-20a.d @@ -43,8 +43,8 @@ SYMBOL TABLE: 0+ l df \*ABS\* 0+ .* 0+ l \.tdata 0+80 tls128 0+ l df \*ABS\* 0+ .* +0+80 l \.tdata 0+4 x 0+82168 l O \.got 0+ _GLOBAL_OFFSET_TABLE_ -0+80 g \.tdata 0+4 \.hidden x 0+800c4 g F \.text 0+6 tlsdsofn2 0+821b4 g O \.data 0+4 got7var5 0+88 g \.tdata 0+4 \.hidden x2 diff --git a/ld/testsuite/ld-cris/tls-e-21.d b/ld/testsuite/ld-cris/tls-e-21.d index fa56b9faad8..80ca3e37f77 100644 --- a/ld/testsuite/ld-cris/tls-e-21.d +++ b/ld/testsuite/ld-cris/tls-e-21.d @@ -19,7 +19,7 @@ private flags = 0: #... SYMBOL TABLE: #... -0+80 g \.tdata 0+4 \.hidden x +0+80 l \.tdata 0+4 x #... Contents of section \.text: #... diff --git a/ld/testsuite/ld-cris/tls-e-23.d b/ld/testsuite/ld-cris/tls-e-23.d index 499899edf76..a09d55ef901 100644 --- a/ld/testsuite/ld-cris/tls-e-23.d +++ b/ld/testsuite/ld-cris/tls-e-23.d @@ -19,7 +19,7 @@ private flags = 0: #... SYMBOL TABLE: #... -0+80 g \.tdata 0+4 \.hidden x +0+80 l \.tdata 0+4 x #... Contents of section \.text: #... diff --git a/ld/testsuite/ld-cris/tls-e-80.d b/ld/testsuite/ld-cris/tls-e-80.d index 7a6f4599e93..15ce3d7838b 100644 --- a/ld/testsuite/ld-cris/tls-e-80.d +++ b/ld/testsuite/ld-cris/tls-e-80.d @@ -42,8 +42,8 @@ SYMBOL TABLE: 0+820c0 l d \.tdata 0+ \.tdata 0+820d0 l d \.tbss 0+ \.tbss 0+820d0 l d \.got 0+ \.got +0+ l \.tdata 0+4 x 0+820d0 l O \.got 0+ _GLOBAL_OFFSET_TABLE_ -0+ g \.tdata 0+4 \.hidden x 0+800a0 g F \.text 0+6 tlsdsofn2 0+800a8 g F \.text 0+6 tlsfn12 0+c g \.tdata 0+4 \.hidden x2 diff --git a/ld/testsuite/ld-cris/tls-gd-3h.d b/ld/testsuite/ld-cris/tls-gd-3h.d index 78f109da8fa..898a670e164 100644 --- a/ld/testsuite/ld-cris/tls-gd-3h.d +++ b/ld/testsuite/ld-cris/tls-gd-3h.d @@ -19,7 +19,7 @@ private flags = 0: #... SYMBOL TABLE: #... -0+80 g \.tdata 0+4 \.hidden x +0+80 l \.tdata 0+4 x #... Contents of section \.text: #... diff --git a/ld/testsuite/ld-cris/tls-leie-19.d b/ld/testsuite/ld-cris/tls-leie-19.d index 6cf69b23f75..859e2e64dd8 100644 --- a/ld/testsuite/ld-cris/tls-leie-19.d +++ b/ld/testsuite/ld-cris/tls-leie-19.d @@ -26,13 +26,13 @@ private flags = 0: CONTENTS.* SYMBOL TABLE: #... -0+88 g .tdata 0+4 x +0+84 l \.tdata 0+4 x2 #... -0+84 g \.tdata 0+4 \.hidden x2 +0+80 l \.tdata 0+4 x1 #... -0+8c g .tdata 0+4 z +0+88 g .tdata 0+4 x #... -0+80 g \.tdata 0+4 \.hidden x1 +0+8c g .tdata 0+4 z #... Contents of section \.text: #... diff --git a/ld/testsuite/ld-mips-elf/export-class-ref-f0.s b/ld/testsuite/ld-mips-elf/export-class-ref-f0.s new file mode 100644 index 00000000000..675996d368d --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-class-ref-f0.s @@ -0,0 +1,37 @@ + .abicalls + .text + + .if refv == 3 + .protected f1 + .elseif refv == 2 + .hidden f1 + .elseif refv == 1 + .internal f1 + .endif + + .globl f0 + .ent f0 +f0: + .frame $sp, 32, $31 + .mask 0x80000000, -4 + .fmask 0x00000000, 0 + .set noreorder + .cpload $25 + .set reorder + addiu $sp, $sp, -32 + sw $31, 28($sp) + .cprestore 16 + + lw $25, %call16(f1)($28) + jalr $25 + lw $28, 16($sp) + + lw $25, %call16(f2)($28) + jalr $25 + lw $28, 16($sp) + + move $2, $0 + lw $31, 28($sp) + addiu $sp, $sp, 32 + jr $31 + .end f0 diff --git a/ld/testsuite/ld-mips-elf/export-class-ref-f1.s b/ld/testsuite/ld-mips-elf/export-class-ref-f1.s new file mode 100644 index 00000000000..299278da3ba --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-class-ref-f1.s @@ -0,0 +1,18 @@ + .abicalls + .text + + .globl f1 + .if defv == 3 + .protected f1 + .elseif defv == 2 + .hidden f1 + .elseif defv == 1 + .internal f1 + .endif + .ent f1 +f1: + .frame $sp, 0, $31 + .mask 0x00000000, 0 + .fmask 0x00000000, 0 + jr $31 + .end f1 diff --git a/ld/testsuite/ld-mips-elf/export-class-ref-f2.s b/ld/testsuite/ld-mips-elf/export-class-ref-f2.s new file mode 100644 index 00000000000..deecdd20f42 --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-class-ref-f2.s @@ -0,0 +1,20 @@ + .abicalls + .text + + .globl f1 + .ent f1 +f1: + .frame $sp, 0, $31 + .mask 0x00000000, 0 + .fmask 0x00000000, 0 + jr $31 + .end f1 + + .globl f2 + .ent f2 +f2: + .frame $sp, 0, $31 + .mask 0x00000000, 0 + .fmask 0x00000000, 0 + jr $31 + .end f2 diff --git a/ld/testsuite/ld-mips-elf/export-class-ref-lib.sd b/ld/testsuite/ld-mips-elf/export-class-ref-lib.sd new file mode 100644 index 00000000000..26b3e38e2d6 --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-class-ref-lib.sd @@ -0,0 +1,6 @@ +# Make sure `f1' is present in the dynamic symbol table, e.g.: +# Num: Value Size Type Bind Vis Ndx Name +# 6: 000002d0 8 FUNC GLOBAL DEFAULT 7 f1 +#... + *[0-9]+: +[0-9a-f]+ +[0-9]+ FUNC +GLOBAL +DEFAULT +[0-9]+ f1 +#pass diff --git a/ld/testsuite/ld-mips-elf/export-hidden-ref.sd b/ld/testsuite/ld-mips-elf/export-hidden-ref.sd new file mode 100644 index 00000000000..b1d62467da0 --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-hidden-ref.sd @@ -0,0 +1,7 @@ +# Make sure no hidden symbol is present in the dynamic symbol table, e.g.: +# Num: Value Size Type Bind Vis Ndx Name +# 6: 004003f0 8 FUNC GLOBAL HIDDEN 8 f1 +#failif +#... +.+ +HIDDEN +.+ +f1 +#pass diff --git a/ld/testsuite/ld-mips-elf/export-internal-ref.sd b/ld/testsuite/ld-mips-elf/export-internal-ref.sd new file mode 100644 index 00000000000..48515435ffb --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-internal-ref.sd @@ -0,0 +1,7 @@ +# Make sure no internal symbol is present in the dynamic symbol table, e.g.: +# Num: Value Size Type Bind Vis Ndx Name +# 6: 004003f0 8 FUNC GLOBAL INTERNAL 8 f1 +#failif +#... +.+ +INTERNAL +.+ +f1 +#pass diff --git a/ld/testsuite/ld-mips-elf/export-local-ref.sd b/ld/testsuite/ld-mips-elf/export-local-ref.sd new file mode 100644 index 00000000000..4ee4a42c3c6 --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-local-ref.sd @@ -0,0 +1,7 @@ +# Make sure no local symbol is present in the dynamic symbol table, e.g.: +# Num: Value Size Type Bind Vis Ndx Name +# 6: 004003f0 8 FUNC LOCAL DEFAULT 8 f1 +#failif +#... +.+ +LOCAL +.+ +f1 +#pass diff --git a/ld/testsuite/ld-mips-elf/export-protected-ref.sd b/ld/testsuite/ld-mips-elf/export-protected-ref.sd new file mode 100644 index 00000000000..af2cb98bd2e --- /dev/null +++ b/ld/testsuite/ld-mips-elf/export-protected-ref.sd @@ -0,0 +1,6 @@ +# Make sure a protected symbol is present in the dynamic symbol table, e.g.: +# Num: Value Size Type Bind Vis Ndx Name +# 6: 004003f0 8 FUNC GLOBAL PROTECTED 8 f1 +#... + *[0-9]+: +[0-9a-f]+ +[0-9]+ FUNC +GLOBAL +PROTECTED +[0-9]+ f1 +#pass diff --git a/ld/testsuite/ld-mips-elf/mips-elf.exp b/ld/testsuite/ld-mips-elf/mips-elf.exp index c5ce5bc7715..44677196839 100644 --- a/ld/testsuite/ld-mips-elf/mips-elf.exp +++ b/ld/testsuite/ld-mips-elf/mips-elf.exp @@ -899,3 +899,31 @@ if { $linux_gnu } { n32 -1 1 umips } } + +# PR ld/19908 export class tests. +if { $linux_gnu } { + run_ld_link_tests [list \ + [list "Shared library for MIPS export class symbol reference tests" \ + "$abi_ldflags(o32) -shared" "" \ + "$abi_asflags(o32)" \ + { export-class-ref-f2.s } \ + { { readelf --dyn-syms export-class-ref-lib.sd } } \ + "export-class-ref-lib.so"]] + foreach { class flag } { internal 1 hidden 2 protected 3 } { + run_ld_link_tests [list \ + [list "MIPS $class symbol reference test 1" \ + "$abi_ldflags(o32) -e f0" "tmpdir/export-class-ref-lib.so" \ + "$abi_asflags(o32) --defsym defv=$flag" \ + { export-class-ref-f0.s export-class-ref-f1.s } \ + [list [list readelf --dyn-syms export-$class-ref.sd] \ + [list readelf --dyn-syms export-local-ref.sd]] \ + "export-$class-ref"] \ + [list "MIPS $class symbol reference test 2" \ + "$abi_ldflags(o32) -e f0" "tmpdir/export-class-ref-lib.so" \ + "$abi_asflags(o32) --defsym defv=$flag --defsym refv=$flag" \ + { export-class-ref-f0.s export-class-ref-f1.s } \ + [list [list readelf --dyn-syms export-$class-ref.sd] \ + [list readelf --dyn-syms export-local-ref.sd]] \ + "export-$class-ref"]] + } +}