From a3747075ae478f27bf3e0643021a85fb6cdad0e3 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 12 May 2015 13:11:48 -0700 Subject: [PATCH] Allocate the first .plt entry space only if needed Commit dd7e64d45b317128f5fe813a8da0b13b4ad046ae may optimize out i386/x86-64 JUMP_SLOT relocation. If there is no JUMP_SLOT relocation left, we don't need to the first .plt entry. This patch allocates space for the first .plt entry only if we also reserve space for a PLT slot for JUMP_SLOT relocation. bfd/ * elf32-i386.c (elf_i386_allocate_dynrelocs): Allocate space for the first .plt entry only if needed. * elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Likewise. ld/testsuite/ * ld-i386/i386.exp: Run pltgot-1 for Linux targets. * ld-x86-64/x86-64.exp: Likewise. * ld-i386/pltgot-1.d: New file. * ld-i386/pltgot-1.s: Likewise. * ld-x86-64/pltgot-1.d: Likewise. * ld-x86-64/pltgot-1.s: Likewise. --- bfd/ChangeLog | 6 ++++++ bfd/elf32-i386.c | 13 +++++++------ bfd/elf64-x86-64.c | 9 ++++----- ld/testsuite/ChangeLog | 9 +++++++++ ld/testsuite/ld-i386/i386.exp | 8 ++++++++ ld/testsuite/ld-i386/pltgot-1.d | 8 ++++++++ ld/testsuite/ld-i386/pltgot-1.s | 6 ++++++ ld/testsuite/ld-x86-64/pltgot-1.d | 8 ++++++++ ld/testsuite/ld-x86-64/pltgot-1.s | 6 ++++++ ld/testsuite/ld-x86-64/x86-64.exp | 1 + 10 files changed, 63 insertions(+), 11 deletions(-) create mode 100644 ld/testsuite/ld-i386/pltgot-1.d create mode 100644 ld/testsuite/ld-i386/pltgot-1.s create mode 100644 ld/testsuite/ld-x86-64/pltgot-1.d create mode 100644 ld/testsuite/ld-x86-64/pltgot-1.s diff --git a/bfd/ChangeLog b/bfd/ChangeLog index d27830b..398476b 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2015-05-12 H.J. Lu + + * elf32-i386.c (elf_i386_allocate_dynrelocs): Allocate space + for the first .plt entry only if needed. + * elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Likewise. + 2015-05-11 H.J. Lu * Makefile.am (ALL_MACHINES): Add cpu-iamcu.lo. diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index f7a7818..815473d 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -2338,15 +2338,16 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) asection *s = htab->elf.splt; asection *got_s = htab->plt_got; - /* If this is the first .plt entry, make room for the special - first entry. */ - if (s->size == 0) - s->size = plt_entry_size; - if (use_plt_got) eh->plt_got.offset = got_s->size; else - h->plt.offset = s->size; + { + /* If this is the first .plt entry, make room for the + special first entry. */ + if (s->size == 0) + s->size = plt_entry_size; + h->plt.offset = s->size; + } /* If this symbol is not defined in a regular file, and we are not generating a shared library, then set the symbol to this diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 34e0f83..e9b5601 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -2558,15 +2558,14 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) asection *bnd_s = htab->plt_bnd; asection *got_s = htab->plt_got; - /* If this is the first .plt entry, make room for the special - first entry. */ - if (s->size == 0) - s->size = plt_entry_size; - if (use_plt_got) eh->plt_got.offset = got_s->size; else { + /* If this is the first .plt entry, make room for the + special first entry. */ + if (s->size == 0) + s->size = plt_entry_size; h->plt.offset = s->size; if (bnd_s) eh->plt_bnd.offset = bnd_s->size; diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index 89f695c..f7bd9b7 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2015-05-12 H.J. Lu + + * ld-i386/i386.exp: Run pltgot-1 for Linux targets. + * ld-x86-64/x86-64.exp: Likewise. + * ld-i386/pltgot-1.d: New file. + * ld-i386/pltgot-1.s: Likewise. + * ld-x86-64/pltgot-1.d: Likewise. + * ld-x86-64/pltgot-1.s: Likewise. + 2015-05-11 H.J. Lu * ld-i386/i386.exp (iamcu_tests): Run iamcu-4. diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp index 2e59522..bbc6005 100644 --- a/ld/testsuite/ld-i386/i386.exp +++ b/ld/testsuite/ld-i386/i386.exp @@ -493,3 +493,11 @@ if { [isnative] ] \ ] } + +if { !([istarget "i?86-*-linux*"] + || [istarget "x86_64-*-linux*"]) } { + return +} + +# Linux only tests +run_dump_test "pltgot-1" diff --git a/ld/testsuite/ld-i386/pltgot-1.d b/ld/testsuite/ld-i386/pltgot-1.d new file mode 100644 index 0000000..6629635 --- /dev/null +++ b/ld/testsuite/ld-i386/pltgot-1.d @@ -0,0 +1,8 @@ +#ld: -shared -melf_i386 +#readelf: -S --wide +#as: --32 + +#failif +#... + +\[ [0-9]+\] \.plt +PROGBITS +.* +#... diff --git a/ld/testsuite/ld-i386/pltgot-1.s b/ld/testsuite/ld-i386/pltgot-1.s new file mode 100644 index 0000000..0e23078 --- /dev/null +++ b/ld/testsuite/ld-i386/pltgot-1.s @@ -0,0 +1,6 @@ + .text + .globl plt + .type plt, @function +plt: + call *puts@GOT(%ebx) + jmp puts@PLT diff --git a/ld/testsuite/ld-x86-64/pltgot-1.d b/ld/testsuite/ld-x86-64/pltgot-1.d new file mode 100644 index 0000000..9a6c2fd6 --- /dev/null +++ b/ld/testsuite/ld-x86-64/pltgot-1.d @@ -0,0 +1,8 @@ +#ld: -shared -melf_x86_64 +#readelf: -S --wide +#as: --64 + +#failif +#... + +\[ [0-9]+\] \.plt +PROGBITS +.* +#... diff --git a/ld/testsuite/ld-x86-64/pltgot-1.s b/ld/testsuite/ld-x86-64/pltgot-1.s new file mode 100644 index 0000000..2197c75 --- /dev/null +++ b/ld/testsuite/ld-x86-64/pltgot-1.s @@ -0,0 +1,6 @@ + .text + .globl plt + .type plt, @function +plt: + call *puts@GOTPCREL(%rip) + jmp puts@PLT diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp index 8352ad9..58e598e 100644 --- a/ld/testsuite/ld-x86-64/x86-64.exp +++ b/ld/testsuite/ld-x86-64/x86-64.exp @@ -549,3 +549,4 @@ if { ![istarget "x86_64-*-linux*"]} { # Linux only tests run_dump_test "pr17618" +run_dump_test "pltgot-1" -- 2.7.4