From 44c4ea11d335f8d5691e9ea5c38c3187ab568467 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sun, 14 Jun 2009 22:13:30 +0000 Subject: bfd/ 2009-06-14 H.J. Lu PR ld/10270 * elf32-i386.c (elf_i386_allocate_dynrelocs): Disallow dynamic IFUNC pointer in non-shared object. Use .got.plt for IFUNC definition in PIE. (elf_i386_allocate_dynrelocs): Resolve IFUNC definition in PIE locally. * elf64-x86-64.c (elf64_x86_64_allocate_dynrelocs): Disallow dynamic IFUNC pointer in non-shared object. Use .got.plt for IFUNC definition in PIE. (elf64_x86_64_relocate_section): Resolve IFUNC definition in PIE locally. ld/testsuite/ 2009-06-14 H.J. Lu PR ld/10270 * ld-ifunc/ifunc-9-x86.d: New. * ld-ifunc/ifunc-9-x86.s: Likewise. --- bfd/ChangeLog | 15 +++++++++++++++ bfd/elf32-i386.c | 30 +++++++++++++++++++++++++++--- bfd/elf64-x86-64.c | 30 +++++++++++++++++++++++++++--- 3 files changed, 69 insertions(+), 6 deletions(-) (limited to 'bfd') diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 5d8c8f3..4c6ccad 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,18 @@ +2009-06-14 H.J. Lu + + PR ld/10270 + * elf32-i386.c (elf_i386_allocate_dynrelocs): Disallow + dynamic IFUNC pointer in non-shared object. Use .got.plt + for IFUNC definition in PIE. + (elf_i386_allocate_dynrelocs): Resolve IFUNC definition in + PIE locally. + + * elf64-x86-64.c (elf64_x86_64_allocate_dynrelocs): Disallow + dynamic IFUNC pointer in non-shared object. Use .got.plt + for IFUNC definition in PIE. + (elf64_x86_64_relocate_section): Resolve IFUNC definition in + PIE locally. + 2009-06-13 H.J. Lu * elf32-i386.c (elf_i386_check_relocs): Properly report diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 7ac90c2..ee881d1 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -2143,6 +2143,27 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) { asection *plt, *gotplt, *relplt; + /* When a shared library references a STT_GNU_IFUNC symbol + defined in executable. the .got.plt slot in the shared library + will contain address of the .plt slot in the binary and only + its .got.plt will contain the resolved function that should be + called. Pointer equality won't work correctly. PIE should + be used if pointer equality is required here. */ + if (!info->shared + && (h->dynindx != -1 + || info->export_dynamic) + && h->pointer_equality_needed) + { + info->callbacks->einfo + (_("%F%P: dynamic STT_GNU_IFUNC symbool `%s' with pointer " + "equality in `%B' can not be used when making an " + "executable; recompile with -fPIE and relink with -pie\n"), + h->root.root.string, + h->root.u.def.section->owner); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + /* Return and discard space for dynamic relocations against it if it is never referenced in a non-shared object. */ if (!h->ref_regular) @@ -2210,8 +2231,9 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) not dynamic. 2. Use .got.plt in a non-shared object if pointer equality isn't needed. - 3. Use .got.plt if .got isn't used. - 4. Otherwise use .got so that it can be shared among different + 3. Use .got.plt in PIE. + 4. Use .got.plt if .got isn't used. + 5. Otherwise use .got so that it can be shared among different objects at run-time. We only need to relocate .got entry in shared object. */ if ((info->shared @@ -2219,6 +2241,7 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) || h->forced_local)) || (!info->shared && !h->pointer_equality_needed) + || (info->executable && info->shared) || htab->sgot == NULL) { /* Use .got.plt. */ @@ -3194,7 +3217,8 @@ elf_i386_relocate_section (bfd *output_bfd, + offset); if (h->dynindx == -1 - || h->forced_local) + || h->forced_local + || info->executable) { /* This symbol is resolved locally. */ outrel.r_info = ELF32_R_INFO (0, R_386_IRELATIVE); diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 27b1cbd..3767a86 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -1982,6 +1982,27 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) { asection *plt, *gotplt, *relplt; + /* When a shared library references a STT_GNU_IFUNC symbol + defined in executable. the .got.plt slot in the shared library + will contain address of the .plt slot in the binary and only + its .got.plt will contain the resolved function that should be + called. Pointer equality won't work correctly. PIE should + be used if pointer equality is required here. */ + if (!info->shared + && (h->dynindx != -1 + || info->export_dynamic) + && h->pointer_equality_needed) + { + info->callbacks->einfo + (_("%F%P: dynamic STT_GNU_IFUNC symbool `%s' with pointer " + "equality in `%B' can not be used when making an " + "executable; recompile with -fPIE and relink with -pie\n"), + h->root.root.string, + h->root.u.def.section->owner); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + /* Return and discard space for dynamic relocations against it if it is never referenced in a non-shared object. */ if (!h->ref_regular) @@ -2049,8 +2070,9 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) not dynamic. 2. Use .got.plt in a non-shared object if pointer equality isn't needed. - 3. Use .got.plt if .got isn't used. - 4. Otherwise use .got so that it can be shared among different + 3. Use .got.plt in PIE. + 4. Use .got.plt if .got isn't used. + 5. Otherwise use .got so that it can be shared among different objects at run-time. We only need to relocate .got entry in shared object. */ if ((info->shared @@ -2058,6 +2080,7 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) || h->forced_local)) || (!info->shared && !h->pointer_equality_needed) + || (info->executable && info->shared) || htab->sgot == NULL) { /* Use .got.plt. */ @@ -2914,7 +2937,8 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, + input_section->output_offset); if (h->dynindx == -1 - || h->forced_local) + || h->forced_local + || info->executable) { /* This symbol is resolved locally. */ outrel.r_info = ELF64_R_INFO (0, R_X86_64_IRELATIVE); -- cgit v1.1