[tip:core/urgent] objtool: Upgrade libelf-devel warning to error for CONFIG_ORC_UNWINDER

From: tip-bot for Josh Poimboeuf
Date: Wed Oct 04 2017 - 05:38:27 EST


Commit-ID: 3dd40cb320fee7c23b574ab821ce140ccd1281c9
Gitweb: https://git.kernel.org/tip/3dd40cb320fee7c23b574ab821ce140ccd1281c9
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Tue, 3 Oct 2017 20:10:36 -0500
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 4 Oct 2017 08:02:18 +0200

objtool: Upgrade libelf-devel warning to error for CONFIG_ORC_UNWINDER

With CONFIG_ORC_UNWINDER, if the user doesn't have libelf-devel
installed, and they don't see the make warning, their ORC unwinder will
be silently broken. Upgrade the warning to an error.

Reported-and-tested-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/d9dfc39fb8240998820f9efb233d283a1ee96084.1507079417.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
Makefile | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index cf007a3..bc5c79e 100644
--- a/Makefile
+++ b/Makefile
@@ -933,7 +933,11 @@ ifdef CONFIG_STACK_VALIDATION
ifeq ($(has_libelf),1)
objtool_target := tools/objtool FORCE
else
- $(warning "Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
+ ifdef CONFIG_ORC_UNWINDER
+ $(error "Cannot generate ORC metadata for CONFIG_ORC_UNWINDER=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
+ else
+ $(warning "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
+ endif
SKIP_STACK_VALIDATION := 1
export SKIP_STACK_VALIDATION
endif