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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-18 08:35:07 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-18 08:35:07 -0700 |
commit | 351267d941bffeddfaa55ba05c77f971b9f67cfe (patch) | |
tree | f3eff3a74a5e1ff95c3fb72a9e442322dd7910f5 | |
parent | 5aa43efe905bdf3f1bd3cfddf035f7ebee2590eb (diff) | |
parent | a705e07b9c80df27b6bb12f7a4cd4cf4ed2f728b (diff) | |
download | linux-stable-351267d941bffeddfaa55ba05c77f971b9f67cfe.tar.gz linux-stable-351267d941bffeddfaa55ba05c77f971b9f67cfe.tar.bz2 linux-stable-351267d941bffeddfaa55ba05c77f971b9f67cfe.zip |
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc fixes from Ingo Molnar:
"A CPU hotplug debuggability fix and three objtool false positive
warnings fixes for new GCC6 code generation patterns"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Use distinct name for cpu_hotplug.dep_map
objtool: Skip all "unreachable instruction" warnings for gcov kernels
objtool: Improve rare switch jump table pattern detection
objtool: Support '-mtune=atom' stack frame setup instruction
-rw-r--r-- | kernel/cpu.c | 2 | ||||
-rw-r--r-- | tools/objtool/arch/x86/decode.c | 9 | ||||
-rw-r--r-- | tools/objtool/builtin-check.c | 68 |
3 files changed, 45 insertions, 34 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 5df20d6d1520..29de1a9352c0 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -228,7 +228,7 @@ static struct { .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), #ifdef CONFIG_DEBUG_LOCK_ALLOC - .dep_map = {.name = "cpu_hotplug.lock" }, + .dep_map = STATIC_LOCKDEP_MAP_INIT("cpu_hotplug.dep_map", &cpu_hotplug.dep_map), #endif }; diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index c0c0b265e88e..b63a31be1218 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -98,6 +98,15 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, *type = INSN_FP_SETUP; break; + case 0x8d: + if (insn.rex_prefix.bytes && + insn.rex_prefix.bytes[0] == 0x48 && + insn.modrm.nbytes && insn.modrm.bytes[0] == 0x2c && + insn.sib.nbytes && insn.sib.bytes[0] == 0x24) + /* lea %(rsp), %rbp */ + *type = INSN_FP_SETUP; + break; + case 0x90: *type = INSN_NOP; break; diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 143b6cdd7f06..4490601a9235 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -97,6 +97,19 @@ static struct instruction *next_insn_same_sec(struct objtool_file *file, return next; } +static bool gcov_enabled(struct objtool_file *file) +{ + struct section *sec; + struct symbol *sym; + + list_for_each_entry(sec, &file->elf->sections, list) + list_for_each_entry(sym, &sec->symbol_list, list) + if (!strncmp(sym->name, "__gcov_.", 8)) + return true; + + return false; +} + #define for_each_insn(file, insn) \ list_for_each_entry(insn, &file->insn_list, list) @@ -713,6 +726,7 @@ static struct rela *find_switch_table(struct objtool_file *file, struct instruction *insn) { struct rela *text_rela, *rodata_rela; + struct instruction *orig_insn = insn; text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); if (text_rela && text_rela->sym == file->rodata->sym) { @@ -733,10 +747,16 @@ static struct rela *find_switch_table(struct objtool_file *file, /* case 3 */ func_for_each_insn_continue_reverse(file, func, insn) { - if (insn->type == INSN_JUMP_UNCONDITIONAL || - insn->type == INSN_JUMP_DYNAMIC) + if (insn->type == INSN_JUMP_DYNAMIC) break; + /* allow small jumps within the range */ + if (insn->type == INSN_JUMP_UNCONDITIONAL && + insn->jump_dest && + (insn->jump_dest->offset <= insn->offset || + insn->jump_dest->offset >= orig_insn->offset)) + break; + text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); if (text_rela && text_rela->sym == file->rodata->sym) @@ -1034,34 +1054,6 @@ static int validate_branch(struct objtool_file *file, return 0; } -static bool is_gcov_insn(struct instruction *insn) -{ - struct rela *rela; - struct section *sec; - struct symbol *sym; - unsigned long offset; - - rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); - if (!rela) - return false; - - if (rela->sym->type != STT_SECTION) - return false; - - sec = rela->sym->sec; - offset = rela->addend + insn->offset + insn->len - rela->offset; - - list_for_each_entry(sym, &sec->symbol_list, list) { - if (sym->type != STT_OBJECT) - continue; - - if (offset >= sym->offset && offset < sym->offset + sym->len) - return (!memcmp(sym->name, "__gcov0.", 8)); - } - - return false; -} - static bool is_kasan_insn(struct instruction *insn) { return (insn->type == INSN_CALL && @@ -1083,9 +1075,6 @@ static bool ignore_unreachable_insn(struct symbol *func, if (insn->type == INSN_NOP) return true; - if (is_gcov_insn(insn)) - return true; - /* * Check if this (or a subsequent) instruction is related to * CONFIG_UBSAN or CONFIG_KASAN. @@ -1146,6 +1135,19 @@ static int validate_functions(struct objtool_file *file) ignore_unreachable_insn(func, insn)) continue; + /* + * gcov produces a lot of unreachable + * instructions. If we get an unreachable + * warning and the file has gcov enabled, just + * ignore it, and all other such warnings for + * the file. + */ + if (!file->ignore_unreachables && + gcov_enabled(file)) { + file->ignore_unreachables = true; + continue; + } + WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset); warnings++; } |