diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 8f92d665cb0f..5efe1de2209b 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -97,6 +97,21 @@
  * Other .text.* sections that are typically grouped separately, such as
  * .text.unlikely or .text.hot, must be matched explicitly before using
  * TEXT_MAIN.
+ *
+ * NOTE: builds *with* and *without* -ffunction-sections are both supported by
+ * this single macro.  Even with -ffunction-sections, there may be some objects
+ * NOT compiled with the flag due to the use of a specific Makefile override
+ * like cflags-y or AUTOFDO_PROFILE_foo.o.  So this single catchall rule is
+ * needed to support mixed object builds.
+ *
+ * One implication is that functions named startup(), exit(), split(),
+ * unlikely(), hot(), and unknown() are not allowed in the kernel due to the
+ * ambiguity of their section names with -ffunction-sections.  For example,
+ * .text.startup could be __attribute__((constructor)) code in a *non*
+ * ffunction-sections object, which should be placed in .init.text; or it could
+ * be an actual function named startup() in an ffunction-sections object, which
+ * should be placed in .text.  Objtool will detect and complain about any such
+ * ambiguously named functions.
  */
 #define TEXT_MAIN							\
 	.text								\
diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt
index 9e97fc25b2d8..f88f8d28513a 100644
--- a/tools/objtool/Documentation/objtool.txt
+++ b/tools/objtool/Documentation/objtool.txt
@@ -456,6 +456,13 @@ the objtool maintainers.
     these special names and does not use module_init() / module_exit()
     macros to create them.
 
+13. file.o: warning: func() function name creates ambiguity with -ffunctions-sections
+
+    Functions named startup(), exit(), split(), unlikely(), hot(), and
+    unknown() are not allowed due to the ambiguity of their section
+    names when compiled with -ffunction-sections.  For more information,
+    see the comment above TEXT_MAIN in include/asm-generic/vmlinux.lds.h.
+
 
 If the error doesn't seem to make sense, it could be a bug in objtool.
 Feel free to ask objtool maintainers for help.
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 57fac6ce3454..72c7f6f03350 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2663,6 +2663,37 @@ static int decode_sections(struct objtool_file *file)
 	return 0;
 }
 
+/*
+ * Certain function names are disallowed due to section name ambiguities
+ * introduced by -ffunction-sections.
+ *
+ * See the comment above TEXT_MAIN in include/asm-generic/vmlinux.lds.h.
+ */
+static int validate_function_names(struct objtool_file *file)
+{
+	struct symbol *func;
+	int warnings = 0;
+
+	for_each_sym(file->elf, func) {
+		if (!is_func_sym(func))
+			continue;
+
+		if (!strcmp(func->name, "startup")	|| strstarts(func->name, "startup.")	||
+		    !strcmp(func->name, "exit")		|| strstarts(func->name, "exit.")	||
+		    !strcmp(func->name, "split")	|| strstarts(func->name, "split.")	||
+		    !strcmp(func->name, "unlikely")	|| strstarts(func->name, "unlikely.")	||
+		    !strcmp(func->name, "hot")		|| strstarts(func->name, "hot.")	||
+		    !strcmp(func->name, "unknown")	|| strstarts(func->name, "unknown.")) {
+
+			WARN("%s() function name creates ambiguity with -ffunction-sections",
+			     func->name);
+			warnings++;
+		}
+	}
+
+	return warnings;
+}
+
 static bool is_special_call(struct instruction *insn)
 {
 	if (insn->type == INSN_CALL) {
@@ -4932,6 +4963,8 @@ int check(struct objtool_file *file)
 	if (!nr_insns)
 		goto out;
 
+	warnings += validate_function_names(file);
+
 	if (opts.retpoline)
 		warnings += validate_retpoline(file);