From 25070364b0ce33eed46aa5d78ebebbec6accec7e Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sat, 16 May 2015 07:00:21 -0700 Subject: [PATCH] Don't generate PLT relocations for now binding There is no need for PLT relocations with -z now. We can use GOT relocations, which take less space, instead and replace 16-byte .plt entres with 8-byte .plt.got entries. bfd/ * elf32-i386.c (elf_i386_check_relocs): Create .plt.got section for now binding. (elf_i386_allocate_dynrelocs): Use .plt.got section for now binding. * elf64-x86-64.c (elf_x86_64_check_relocs): Create .plt.got section for now binding. (elf_x86_64_allocate_dynrelocs): Use .plt.got section for now binding. ld/testsuite/ * ld-i386/i386.exp: Run PR ld/17689 tests with -z now. * ld-x86-64/x86-64.exp: Likewise * ld-i386/pr17689now.rd: New file. * ld-x86-64/pr17689now.rd: Likewise --- bfd/ChangeLog | 11 +++++++++++ bfd/elf32-i386.c | 16 ++++++++++++++-- bfd/elf64-x86-64.c | 16 ++++++++++++++-- ld/testsuite/ChangeLog | 7 +++++++ ld/testsuite/ld-i386/i386.exp | 24 ++++++++++++++++++++++++ ld/testsuite/ld-i386/pr17689now.rd | 4 ++++ ld/testsuite/ld-x86-64/pr17689now.rd | 4 ++++ ld/testsuite/ld-x86-64/x86-64.exp | 24 ++++++++++++++++++++++++ 8 files changed, 102 insertions(+), 4 deletions(-) create mode 100644 ld/testsuite/ld-i386/pr17689now.rd create mode 100644 ld/testsuite/ld-x86-64/pr17689now.rd diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 3cc8839..3727e35 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,14 @@ +2015-05-16 H.J. Lu + + * elf32-i386.c (elf_i386_check_relocs): Create .plt.got section + for now binding. + (elf_i386_allocate_dynrelocs): Use .plt.got section for now + binding. + * elf64-x86-64.c (elf_x86_64_check_relocs): Create .plt.got + section for now binding. + (elf_x86_64_allocate_dynrelocs): Use .plt.got section for now + binding. + 2015-05-14 H.J. Lu * bfd.c (bfd_update_compression_header): Also write the zlib diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 815473d..c6ff746 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -1885,7 +1885,7 @@ do_size: if (use_plt_got && h != NULL && h->plt.refcount > 0 - && h->got.refcount > 0 + && ((info->flags & DF_BIND_NOW) || h->got.refcount > 0) && htab->plt_got == NULL) { /* Create the GOT procedure linkage table. */ @@ -2321,7 +2321,19 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) else if (htab->elf.dynamic_sections_created && (h->plt.refcount > 0 || eh->plt_got.refcount > 0)) { - bfd_boolean use_plt_got = eh->plt_got.refcount > 0; + bfd_boolean use_plt_got; + + if ((info->flags & DF_BIND_NOW)) + { + /* Don't use the regular PLT for DF_BIND_NOW. */ + h->plt.offset = (bfd_vma) -1; + + /* Use the GOT PLT. */ + h->got.refcount = 1; + eh->plt_got.refcount = 1; + } + + use_plt_got = eh->plt_got.refcount > 0; /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index e9b5601..01df230 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -2080,7 +2080,7 @@ do_size: if (use_plt_got && h != NULL && h->plt.refcount > 0 - && h->got.refcount > 0 + && ((info->flags & DF_BIND_NOW) || h->got.refcount > 0) && htab->plt_got == NULL) { /* Create the GOT procedure linkage table. */ @@ -2540,7 +2540,19 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) else if (htab->elf.dynamic_sections_created && (h->plt.refcount > 0 || eh->plt_got.refcount > 0)) { - bfd_boolean use_plt_got = eh->plt_got.refcount > 0; + bfd_boolean use_plt_got; + + if ((info->flags & DF_BIND_NOW)) + { + /* Don't use the regular PLT for DF_BIND_NOW. */ + h->plt.offset = (bfd_vma) -1; + + /* Use the GOT PLT. */ + h->got.refcount = 1; + eh->plt_got.refcount = 1; + } + + use_plt_got = eh->plt_got.refcount > 0; /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index 43c7c24..e6a551c 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2015-05-16 H.J. Lu + + * ld-i386/i386.exp: Run PR ld/17689 tests with -z now. + * ld-x86-64/x86-64.exp: Likewise + * ld-i386/pr17689now.rd: New file. + * ld-x86-64/pr17689now.rd: Likewise + 2015-05-15 H.J. Lu PR binutis/18386 diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp index bbc6005..a26cffd 100644 --- a/ld/testsuite/ld-i386/i386.exp +++ b/ld/testsuite/ld-i386/i386.exp @@ -406,6 +406,14 @@ if { [isnative] "pr17689.so" \ ] \ [list \ + "Build pr17689.so with -z now" \ + "-shared -Wl,-z,now" \ + "-fPIC" \ + { pr17689a.c } \ + {{readelf {-Wr} pr17689now.rd}} \ + "pr17689now.so" \ + ] \ + [list \ "Build pr17689ver.so" \ "-shared -Wl,--version-script,pr17689a.t" \ "-fPIC" \ @@ -430,6 +438,14 @@ if { [isnative] "pr17689" \ ] \ [list \ + "Build pr17689 with PIE, -z now and GOTOFF" \ + "tmpdir/pr17689b.o tmpdir/pr17689.so -pie -Wl,-z,now" \ + "" \ + { dummy.c } \ + {{readelf {-Wr} pr17689now.rd}} \ + "pr17689now" \ + ] \ + [list \ "Build pr17689ver with PIE and GOTOFF" \ "tmpdir/pr17689b.o tmpdir/pr17689ver.so -pie" \ "" \ @@ -484,6 +500,14 @@ if { [isnative] "pr17689.out" \ ] \ [list \ + "Run pr17689 with PIE, -z now and GOTOFF" \ + "tmpdir/pr17689b.o tmpdir/pr17689.so -pie -z now" \ + "" \ + { dummy.c } \ + "pr17689now" \ + "pr17689.out" \ + ] \ + [list \ "Run pr17689ver with PIE and GOTOFF" \ "tmpdir/pr17689b.o tmpdir/pr17689ver.so -pie" \ "" \ diff --git a/ld/testsuite/ld-i386/pr17689now.rd b/ld/testsuite/ld-i386/pr17689now.rd new file mode 100644 index 0000000..9741df8 --- /dev/null +++ b/ld/testsuite/ld-i386/pr17689now.rd @@ -0,0 +1,4 @@ +#failif +#... +[0-9a-f ]+R_386_JUMP_SLOT +0+.* +#... diff --git a/ld/testsuite/ld-x86-64/pr17689now.rd b/ld/testsuite/ld-x86-64/pr17689now.rd new file mode 100644 index 0000000..8fd9371 --- /dev/null +++ b/ld/testsuite/ld-x86-64/pr17689now.rd @@ -0,0 +1,4 @@ +#failif +#... +[0-9a-f ]+R_X86_64_JUMP_SLOT +0+ +.* +#... diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp index a312271..8281dc4 100644 --- a/ld/testsuite/ld-x86-64/x86-64.exp +++ b/ld/testsuite/ld-x86-64/x86-64.exp @@ -440,6 +440,14 @@ if { [isnative] && [which $CC] != 0 } { "pr17689.so" \ ] \ [list \ + "Build pr17689now.so with -z now" \ + "-shared -Wl,-z,now" \ + "-fPIC" \ + { pr17689a.c } \ + {{readelf {-Wr} pr17689now.rd}} \ + "pr17689now.so" \ + ] \ + [list \ "Build pr17689 with PIE without -fPIE" \ "tmpdir/pr17689.so -pie" \ "" \ @@ -448,6 +456,14 @@ if { [isnative] && [which $CC] != 0 } { "pr17689" \ ] \ [list \ + "Build pr17689 with PIE -z now without -fPIE" \ + "tmpdir/pr17689.so -pie -Wl,-z,now" \ + "" \ + { pr17689b.S } \ + {{readelf {-Wr} pr17689now.rd}} \ + "pr17689now" \ + ] \ + [list \ "Build pr17827 with PIE without -fPIE" \ "tmpdir/pr17689.so -pie" \ "" \ @@ -493,6 +509,14 @@ if { [isnative] && [which $CC] != 0 } { "pr17689" \ "pr17689.out" \ ] \ + [list \ + "Run pr17689 with PIE -z now without -fPIE" \ + "tmpdir/pr17689.so -pie -z now" \ + "" \ + { pr17689b.S } \ + "pr17689now" \ + "pr17689.out" \ + ] \ ] if { [istarget "x86_64-*-linux*"] \ -- 2.7.4