Started as a build error for bpftool. On latest DaveM net-git tree
(06a4ec1d9dc652), I got this build error, when building the bpftool:
cd tools/bpf/bpftool
$ make
Auto-detecting system features:
... libbfd: [ on ]
... disassembler-four-args: [ on ]
... zlib: [ on ]
... libcap: [ on ]
... clang-bpf-co-re: [ on ]
CC map_perf_ring.o
In file included from main.h:15,
from map_perf_ring.c:27:
/home/jbrouer/git/kernel/net/tools/include/tools/libc_compat.h:11:21: error: static declaration of ‘reallocarray’ follows non-static declaration
11 | static inline void *reallocarray(void *ptr, size_t nmemb, size_t size)
| ^~~~~~~~~~~~
In file included from map_perf_ring.c:14:
/usr/include/stdlib.h:559:14: note: previous declaration of ‘reallocarray’ was here
559 | extern void *reallocarray (void *__ptr, size_t __nmemb, size_t __size)
| ^~~~~~~~~~~~
make: *** [Makefile:177: map_perf_ring.o] Error 1
This were related to tools/build/feature ("Auto-detecting system features")
that had a stalled version of the test-reallocarray.d file:
In /home/jbrouer/git/kernel/net/tools/build/feature:
$ ll *realloc*
-rw-rw-r--. 1 jbrouer jbrouer 152 Oct 30 2019 test-reallocarray.c
-rw-rw-r--. 1 jbrouer jbrouer 1156 Oct 30 2019 test-reallocarray.d
-rw-rw-r--. 1 jbrouer jbrouer 321 Oct 30 2019 test-reallocarray.make.output
The 'make clean' target doesn't cleanup enough for the feature-test to be
compiled again. (Tested both make clean in tools/build/ and tools/bpf/bpftool).
If I delete test-reallocarray.d, then the feature-test is recompiled and I don't
get the error (as reallocarray is avail on this system). Files avail now:
In /home/jbrouer/git/kernel/net/tools/build/feature:
$ ll *realloc*
-rwxrwxr-x. 1 jbrouer jbrouer 21992 Aug 18 11:29 test-reallocarray.bin
-rw-rw-r--. 1 jbrouer jbrouer 152 Oct 30 2019 test-reallocarray.c
-rw-rw-r--. 1 jbrouer jbrouer 1398 Aug 18 11:29 test-reallocarray.d
-rw-rw-r--. 1 jbrouer jbrouer 0 Aug 18 11:29 test-reallocarray.make.output
Thus, given test-reallocarray.bin exist the compile test was success. This
indicate that my Fedora system in Oct 2019 didn't support reallocarray and
needed the workaround in tools/include/tools/libc_compat.h. I likely did some
upgrade or install some RPM in the meanwhile that changed the situation.
Regardless of how this got stalled, this needs to be fixed.
I propose that the make clean target should cause the feature tests to be
recompiled. Below change to tools/build/Makefile solves the issue locally in
tools/build/, but this isn't triggered when calling make clean in other tools
directories that use the feature tests.
What is the correct make clean fix?
- -
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
diff --git a/tools/build/Makefile b/tools/build/Makefile
index 727050c40f09..a59e60ecf5ad 100644
--- a/tools/build/Makefile
+++ b/tools/build/Makefile
@@ -37,6 +37,7 @@ all: $(OUTPUT)fixdep
clean:
$(call QUIET_CLEAN, fixdep)
$(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
+ $(Q)find $(if $(OUTPUT),$(OUTPUT),.)/feature -name '*.d' -delete -o -name '*.make.output' -delete
$(Q)rm -f $(OUTPUT)fixdep
$(OUTPUT)fixdep-in.o: FORCE
My distro:
$ lsb_release -a
LSB Version: :core-4.1-amd64:core-4.1-noarch
Distributor ID: Fedora
Description: Fedora release 31 (Thirty One)
Release: 31
Codename: ThirtyOne
