This patch abstracts the few architecture dependent tests that are perform when handling special section and switch tables. It enables any architecture to ignore a particular CPU feature or not to handle switch tables.
Signed-off-by: Raphael Gault <raphael.ga...@arm.com> --- tools/objtool/arch/arm64/Build | 1 + tools/objtool/arch/arm64/arch_special.c | 22 +++++++++++++++ .../objtool/arch/arm64/include/arch_special.h | 10 +++++-- tools/objtool/arch/x86/Build | 1 + tools/objtool/arch/x86/arch_special.c | 28 +++++++++++++++++++ tools/objtool/arch/x86/include/arch_special.h | 9 ++++++ tools/objtool/check.c | 15 ++++++++-- tools/objtool/special.c | 9 ++---- tools/objtool/special.h | 3 ++ 9 files changed, 87 insertions(+), 11 deletions(-) create mode 100644 tools/objtool/arch/arm64/arch_special.c create mode 100644 tools/objtool/arch/x86/arch_special.c diff --git a/tools/objtool/arch/arm64/Build b/tools/objtool/arch/arm64/Build index bf7a32c2b9e9..3d09be745a84 100644 --- a/tools/objtool/arch/arm64/Build +++ b/tools/objtool/arch/arm64/Build @@ -1,3 +1,4 @@ +objtool-y += arch_special.o objtool-y += decode.o objtool-y += orc_dump.o objtool-y += orc_gen.o diff --git a/tools/objtool/arch/arm64/arch_special.c b/tools/objtool/arch/arm64/arch_special.c new file mode 100644 index 000000000000..a21d28876317 --- /dev/null +++ b/tools/objtool/arch/arm64/arch_special.c @@ -0,0 +1,22 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +#include "../../special.h" +#include "arch_special.h" + +void arch_force_alt_path(unsigned short feature, + bool uaccess, + struct special_alt *alt) +{ +} diff --git a/tools/objtool/arch/arm64/include/arch_special.h b/tools/objtool/arch/arm64/include/arch_special.h index 63da775d0581..185103be8a51 100644 --- a/tools/objtool/arch/arm64/include/arch_special.h +++ b/tools/objtool/arch/arm64/include/arch_special.h @@ -30,7 +30,13 @@ #define ALT_ORIG_LEN_OFFSET 10 #define ALT_NEW_LEN_OFFSET 11 -#define X86_FEATURE_POPCNT (4 * 32 + 23) -#define X86_FEATURE_SMAP (9 * 32 + 20) +static inline bool arch_should_ignore_feature(unsigned short feature) +{ + return false; +} +static inline bool arch_support_switch_table(void) +{ + return false; +} #endif /* _ARM64_ARCH_SPECIAL_H */ diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build index 1f11b45999d0..63e167775bc8 100644 --- a/tools/objtool/arch/x86/Build +++ b/tools/objtool/arch/x86/Build @@ -1,3 +1,4 @@ +objtool-y += arch_special.o objtool-y += decode.o objtool-y += orc_dump.o objtool-y += orc_gen.o diff --git a/tools/objtool/arch/x86/arch_special.c b/tools/objtool/arch/x86/arch_special.c new file mode 100644 index 000000000000..6583a1770bb2 --- /dev/null +++ b/tools/objtool/arch/x86/arch_special.c @@ -0,0 +1,28 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +#include "../../special.h" +#include "arch_special.h" + +void arch_force_alt_path(unsigned short feature, + bool uaccess, + struct special_alt *alt) +{ + if (feature == X86_FEATURE_SMAP) { + if (uaccess) + alt->skip_orig = true; + else + alt->skip_alt = true; + } +} diff --git a/tools/objtool/arch/x86/include/arch_special.h b/tools/objtool/arch/x86/include/arch_special.h index 424ce47013e3..fce2b1193194 100644 --- a/tools/objtool/arch/x86/include/arch_special.h +++ b/tools/objtool/arch/x86/include/arch_special.h @@ -33,4 +33,13 @@ #define X86_FEATURE_POPCNT (4 * 32 + 23) #define X86_FEATURE_SMAP (9 * 32 + 20) +static inline bool arch_should_ignore_feature(unsigned short feature) +{ + return feature == X86_FEATURE_POPCNT; +} + +static inline bool arch_support_switch_table(void) +{ + return true; +} #endif /* _X86_ARCH_SPECIAL_H */ diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 1a7ee85e9878..0fba7b70d73a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -729,7 +729,7 @@ static int handle_group_alt(struct objtool_file *file, last_orig_insn = insn; } - if (next_insn_same_sec(file, last_orig_insn)) { + if (last_orig_insn && next_insn_same_sec(file, last_orig_insn)) { fake_jump = malloc(sizeof(*fake_jump)); if (!fake_jump) { WARN("malloc failed"); @@ -1045,6 +1045,17 @@ static struct rela *find_switch_table(struct objtool_file *file, if (find_symbol_containing(rodata_sec, table_offset)) continue; + /* + * If we are on arm64 architecture, we now that we + * are in presence of a switch table thanks to + * the `br <Xn>` insn. but we can't retrieve it yet. + * So we just ignore unreachable for this file. + */ + if (!arch_support_switch_table()) { + file->ignore_unreachables = true; + return NULL; + } + rodata_rela = find_rela_by_dest(rodata_sec, table_offset); if (rodata_rela) { /* @@ -1844,7 +1855,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first, insn = first; sec = insn->sec; - if (insn->alt_group && list_empty(&insn->alts)) { + if (!insn->visited && insn->alt_group && list_empty(&insn->alts)) { WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", sec, insn->offset); return 1; diff --git a/tools/objtool/special.c b/tools/objtool/special.c index b8ccee1b5382..7a0092d6e5b3 100644 --- a/tools/objtool/special.c +++ b/tools/objtool/special.c @@ -81,7 +81,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry, * feature path which is a "very very small percentage of * machines". */ - if (feature == X86_FEATURE_POPCNT) + if (arch_should_ignore_feature(feature)) alt->skip_orig = true; /* @@ -93,12 +93,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry, * find paths that see the STAC but take the NOP instead of * CLAC and the other way around. */ - if (feature == X86_FEATURE_SMAP) { - if (uaccess) - alt->skip_orig = true; - else - alt->skip_alt = true; - } + arch_force_alt_path(feature, uaccess, alt); } orig_rela = find_rela_by_dest(sec, offset + entry->orig); diff --git a/tools/objtool/special.h b/tools/objtool/special.h index 35061530e46e..90626a7e41cf 100644 --- a/tools/objtool/special.h +++ b/tools/objtool/special.h @@ -27,5 +27,8 @@ struct special_alt { }; int special_get_alts(struct elf *elf, struct list_head *alts); +void arch_force_alt_path(unsigned short feature, + bool uaccess, + struct special_alt *alt); #endif /* _SPECIAL_H */ -- 2.17.1
