[PATCH 10/13] objtool: Add --Werror option
From: Josh Poimboeuf
Date: Fri Mar 14 2025 - 15:32:52 EST
Any objtool warning has the potential of reflecting (or triggering) a
major bug in the kernel or compiler which could result in crashing the
kernel or breaking the livepatch consistency model.
In preparation for failing the build on objtool errors/warnings, add a
new --Werror option.
[ jpoimboe: commit log, comments, error out on fatal errors too ]
Co-developed-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/builtin-check.c | 1 +
tools/objtool/check.c | 15 ++++++++++++---
tools/objtool/include/objtool/builtin.h | 1 +
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index 3de3afa0a19c..c201650efe49 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -101,6 +101,7 @@ static const struct option check_options[] = {
OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),
OPT_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"),
+ OPT_BOOLEAN(0, "Werror", &opts.werror, "return error on warnings"),
OPT_END(),
};
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 3ddaefe97f55..b574f2e8b07f 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4737,9 +4737,18 @@ int check(struct objtool_file *file)
out:
/*
- * For now, don't fail the kernel build on fatal warnings. These
- * errors are still fairly common due to the growing matrix of
- * supported toolchains and their recent pace of change.
+ * CONFIG_OBJTOOL_WERROR upgrades all warnings (and errors) to actual
+ * errors.
+ *
+ * Note that even "fatal" type errors don't actually return an error
+ * without CONFIG_OBJTOOL_WERROR. That probably needs improved at some
+ * point.
*/
+ if (opts.werror && (ret || warnings)) {
+ if (warnings)
+ WARN("%d warning(s) upgraded to errors", warnings);
+ return 1;
+ }
+
return 0;
}
diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
index 25cfa01758b9..b18f114cdaa4 100644
--- a/tools/objtool/include/objtool/builtin.h
+++ b/tools/objtool/include/objtool/builtin.h
@@ -39,6 +39,7 @@ struct opts {
bool sec_address;
bool stats;
bool verbose;
+ bool werror;
};
extern struct opts opts;
--
2.48.1