Commit 351267d9 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 5aa43efe a705e07b

kernel/cpu.c

+1 −1
Original line number Diff line number Diff line
@@ -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

};

tools/objtool/arch/x86/decode.c

+9 −0
Original line number Diff line number Diff line
@@ -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;

tools/objtool/builtin-check.c

+35 −33
Original line number Diff line number Diff line
@@ -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) {
@@ -733,8 +747,14 @@ 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,
@@ -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++;

			}

CRA Git | Maintained and supported by SUSTech CRA and CCSE