commit 7b1f9406761331cf35fe521fbdb592beecf68a2c Author: H.J. Lu Date: Fri Sep 28 13:31:19 2018 -0700 i386: Use _dl_runtime_[resolve|profile]_shstk for SHSTK [BZ #23716] When elf_machine_runtime_setup is called to set up resolver, it should use _dl_runtime_resolve_shstk or _dl_runtime_profile_shstk if SHSTK is enabled by kernel. Tested on i686 with and without --enable-cet as well as on CET emulator with --enable-cet. [BZ #23716] * sysdeps/i386/dl-cet.c: Removed. * sysdeps/i386/dl-machine.h (_dl_runtime_resolve_shstk): New prototype. (_dl_runtime_profile_shstk): Likewise. (elf_machine_runtime_setup): Use _dl_runtime_profile_shstk or _dl_runtime_resolve_shstk if SHSTK is enabled by kernel. Signed-off-by: H.J. Lu diff --git a/sysdeps/i386/dl-cet.c b/sysdeps/i386/dl-cet.c deleted file mode 100644 index 5d9a4e8d5179b572..0000000000000000 --- a/sysdeps/i386/dl-cet.c +++ /dev/null @@ -1,67 +0,0 @@ -/* Linux/i386 CET initializers function. - Copyright (C) 2018 Free Software Foundation, Inc. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - - -#define LINKAGE static inline -#define _dl_cet_check cet_check -#include -#undef _dl_cet_check - -#ifdef SHARED -void -_dl_cet_check (struct link_map *main_map, const char *program) -{ - cet_check (main_map, program); - - if ((GL(dl_x86_feature_1)[0] & GNU_PROPERTY_X86_FEATURE_1_SHSTK)) - { - /* Replace _dl_runtime_resolve and _dl_runtime_profile with - _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk, - respectively if SHSTK is enabled. */ - extern void _dl_runtime_resolve (Elf32_Word) attribute_hidden; - extern void _dl_runtime_resolve_shstk (Elf32_Word) attribute_hidden; - extern void _dl_runtime_profile (Elf32_Word) attribute_hidden; - extern void _dl_runtime_profile_shstk (Elf32_Word) attribute_hidden; - unsigned int i; - struct link_map *l; - Elf32_Addr *got; - - if (main_map->l_info[DT_JMPREL]) - { - got = (Elf32_Addr *) D_PTR (main_map, l_info[DT_PLTGOT]); - if (got[2] == (Elf32_Addr) &_dl_runtime_resolve) - got[2] = (Elf32_Addr) &_dl_runtime_resolve_shstk; - else if (got[2] == (Elf32_Addr) &_dl_runtime_profile) - got[2] = (Elf32_Addr) &_dl_runtime_profile_shstk; - } - - i = main_map->l_searchlist.r_nlist; - while (i-- > 0) - { - l = main_map->l_initfini[i]; - if (l->l_info[DT_JMPREL]) - { - got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]); - if (got[2] == (Elf32_Addr) &_dl_runtime_resolve) - got[2] = (Elf32_Addr) &_dl_runtime_resolve_shstk; - else if (got[2] == (Elf32_Addr) &_dl_runtime_profile) - got[2] = (Elf32_Addr) &_dl_runtime_profile_shstk; - } - } - } -} -#endif diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 1afdcbd9ea2626e4..f6cfb90e21015250 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -67,6 +67,11 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) Elf32_Addr *got; extern void _dl_runtime_resolve (Elf32_Word) attribute_hidden; extern void _dl_runtime_profile (Elf32_Word) attribute_hidden; + extern void _dl_runtime_resolve_shstk (Elf32_Word) attribute_hidden; + extern void _dl_runtime_profile_shstk (Elf32_Word) attribute_hidden; + /* Check if SHSTK is enabled by kernel. */ + bool shstk_enabled + = (GL(dl_x86_feature_1)[0] & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0; if (l->l_info[DT_JMPREL] && lazy) { @@ -93,7 +98,9 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) end in this function. */ if (__glibc_unlikely (profile)) { - got[2] = (Elf32_Addr) &_dl_runtime_profile; + got[2] = (shstk_enabled + ? (Elf32_Addr) &_dl_runtime_profile_shstk + : (Elf32_Addr) &_dl_runtime_profile); if (GLRO(dl_profile) != NULL && _dl_name_match_p (GLRO(dl_profile), l)) @@ -104,7 +111,9 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) else /* This function will get called to fix up the GOT entry indicated by the offset on the stack, and then jump to the resolved address. */ - got[2] = (Elf32_Addr) &_dl_runtime_resolve; + got[2] = (shstk_enabled + ? (Elf32_Addr) &_dl_runtime_resolve_shstk + : (Elf32_Addr) &_dl_runtime_resolve); } return lazy;