objtool: Fix Makefile to properly see if libelf is supported
PATCH 1/1 objtool: Fix Makefile to properly see if libelf is supported
When doing a make allmodconfig, I hit the following compile error:
In file included from builtin-check.c:32:0:
elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated.
In file included from special.h:22:0,
from special.c:26:
elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated.
In file included from elf.c:30:0:
elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated.
mv: cannot stat 'tools/objtool/.elf.o.tmp': No such file or directory tools/build/Makefile.build:77: recipe for target 'tools/objtool/elf.o' failed make[4]: *** [tools/objtool/elf.o] Error 1
make[4]: *** Waiting for unfinished jobs....
Digging into it, it appears that the $(shell ..) command in the Makefile does not give the proper result when it fails to find -lelf, and continues to compile objtool.
Instead, use the "try-run" makefile macro to perform the test. This gives a proper result for both cases.
---
Makefile +2 -1
@@ -1008,7 +1008,8 @@ prepare0: archprepare FORCE prepare: prepare0 prepare-objtool ifdef CONFIG_STACK_VALIDATION - has_libelf := $(shell echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - &> /dev/null && echo 1 || echo 0) + has_libelf := $(call try-run,\ + echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0) ifeq ($(has_libelf),1) objtool_target := tools/objtool FORCE else
Quoted 21 lines · Steven Rostedt
When doing a make allmodconfig, I hit the following compile error:
In file included from builtin-check.c:32:0:
elf.h:22:18: fatal error:gelf.h: No such file or directory compilation terminated.
In file included from special.h:22:0,from special.c:26:elf.h:22:18: fatal error:
gelf.h: No such file or directory compilation terminated.
In file included from elf.c:30:0:
elf.h:22:18: fatal error:gelf.h: No such file or directory compilation terminated.
mv: cannot stat 'tools/objtool/.elf.o.tmp': No such file or directorytools/build/Makefile.build:77: recipe for target 'tools/objtool/elf.o' failed make[4]: *** [tools/objtool/elf.o] Error 1
make[4]: *** Waiting for unfinished jobs....Digging into it, it appears that the $(shell ..) command in the
Makefiledoes not give the proper result when it fails to find -lelf, and continues to compile objtool.
Quoted 5 lines
Instead, use the "try-run" makefile macro to perform the test. This gives a proper result for both cases.
Fixes 442f04c34a1a4 ("objtool: Add tool to perform compile-time stack metadata validation")Signed-off-by Steven Rostedt <[email protected]>
Thanks!
Signature · 1 line
Josh
tip-bot for Steven Rostedt
merge botobjtool: Fix Makefile to properly see if libelf is supported
Commit-ID: c2bb9e32e2315971a8535fee77335c04a739d71d Gitweb: http://git.kernel.org/tip/c2bb9e32e2315971a8535fee77335c04a739d71d Author: Steven Rostedt <[email protected]> AuthorDate: Wed, 20 Apr 2016 11:32:35 -0400 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 22 Apr 2016 09:00:57 +0200
objtool: Fix Makefile to properly see if libelf is supported
When doing a make allmodconfig, I hit the following compile error:
In file included from builtin-check.c:32:0:
elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated.
...
Digging into it, it appears that the $(shell ..) command in the Makefile does not give the proper result when it fails to find -lelf, and continues to compile objtool.
Instead, use the "try-run" makefile macro to perform the test. This gives a proper result for both cases.
--- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
Makefile +2 -1
@@ -1008,7 +1008,8 @@ prepare0: archprepare FORCE prepare: prepare0 prepare-objtool ifdef CONFIG_STACK_VALIDATION - has_libelf := $(shell echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - &> /dev/null && echo 1 || echo 0) + has_libelf := $(call try-run,\ + echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0) ifeq ($(has_libelf),1) objtool_target := tools/objtool FORCE else