From 1bf41f8a125b85cfe10f0945a686a49d14df1914 Mon Sep 17 00:00:00 2001
From: Laura Abbott <lauraa@codeaurora.org>
Date: Thu, 2 Dec 2010 11:20:32 -0800
Subject: [PATCH] modpost: Make section mismatches an error

If any section mismatches are detected the compilation will fail.
Section mismatches can go back to being warnings with
CONFIG_NO_ERROR_ON_MISMATCH=y.

Change-Id: I44f01f348703d2fdda77f2930bc290f6867b5b08
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
(cherry picked from commit d34cd35c3aacb219de789a61a140e7f095794a3f)
---
 scripts/Makefile.modpost |  1 +
 scripts/mod/modpost.c    | 28 ++++++++++++++++++++++------
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 08dce14f2dc8..c1bc4588806a 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -80,6 +80,7 @@ modpost = scripts/mod/modpost                    \
  $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
  $(if $(KBUILD_EXTMOD),-o $(modulesymfile))      \
  $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \
+ $(if $(CONFIG_NO_ERROR_ON_MISMATCH),,-E)	 \
  $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
  $(if $(cross_build),-c)
 
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index c4e7d1510f9d..70d211d0b992 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -37,6 +37,8 @@ static int all_versions = 0;
 static int external_module = 0;
 /* Warn about section mismatch in vmlinux if set to 1 */
 static int vmlinux_section_warnings = 1;
+/* Exit with an error when there is a section mismatch if set to 1 */
+static int section_error_on_mismatch;
 /* Only warn about unresolved symbols */
 static int warn_unresolved = 0;
 /* How a symbol is exported */
@@ -2113,7 +2115,7 @@ int main(int argc, char **argv)
 	struct ext_sym_list *extsym_iter;
 	struct ext_sym_list *extsym_start = NULL;
 
-	while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
+	while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:E")) != -1) {
 		switch (opt) {
 		case 'i':
 			kernel_read = optarg;
@@ -2151,6 +2153,9 @@ int main(int argc, char **argv)
 		case 'w':
 			warn_unresolved = 1;
 			break;
+		case 'E':
+			section_error_on_mismatch = 1;
+			break;
 		default:
 			exit(1);
 		}
@@ -2200,11 +2205,22 @@ int main(int argc, char **argv)
 
 	if (dump_write)
 		write_dump(dump_write);
-	if (sec_mismatch_count && !sec_mismatch_verbose)
-		warn("modpost: Found %d section mismatch(es).\n"
-		     "To see full details build your kernel with:\n"
-		     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
-		     sec_mismatch_count);
+
+	if (sec_mismatch_count && !sec_mismatch_verbose) {
+		merror(
+		"modpost: Found %d section mismatch(es).\n"
+		"To see full details build your kernel with:\n"
+		"'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
+		sec_mismatch_count);
+
+		if (section_error_on_mismatch) {
+			err |= 1;
+			printf(
+			"To build the kernel despite the mismatches, "
+			"build with:\n'make CONFIG_NO_ERROR_ON_MISMATCH=y'\n"
+			"(NOTE: This is not recommended)\n");
+		}
+	}
 
 	return err;
 }