Linux-5.4-rc3+: bpf: progs/test_core_reloc_ints.c:32:6: error: using builtin_preserve_access_index() without -g

Linux-5.4-rc3+: bpf: progs/test_core_reloc_ints.c:32:6: error: using builtin_preserve_access_index() without -g

[Prabhakar Kushwaha]

Hi All,

I am trying to build kselftest on Linux-5.4-rc3+ on ubuntu 18.04. I 
installed LLVM-9.0.0 and Clang-9.0.0 from below links after following 
steps from [1] because of discussion [2]

  https://releases.llvm.org/9.0.0/llvm-9.0.0.src.tar.xz
  https://releases.llvm.org/9.0.0/clang-tools-extra-9.0.0.src.tar.xz
  https://releases.llvm.org/9.0.0/cfe-9.0.0.src.tar.xz


After that I started this error.
make[2]: Leaving directory '/usr/src/tovards/linux/tools/lib/bpf'
(clang -I. -I./include/uapi -I../../../include/uapi 
-I/usr/src/tovards/linux/tools/testing/selftests/bpf/../usr/include 
-D__TARGET_ARCH_arm64 -idirafter /usr/local/include -idirafter 
/usr/local/lib/clang/9.0.0/include -idirafter 
/usr/include/aarch64-linux-gnu -idirafter /usr/include 
-Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm \
	-c progs/test_core_reloc_ints.c -o - || echo "clang failed") | \
llc -march=arm64 -mcpu=generic  -filetype=obj -o 
/usr/src/tovards/linux/tools/testing/selftests/bpf/test_core_reloc_ints.o
progs/test_core_reloc_ints.c:32:6: error: using 
builtin_preserve_access_index() without -g
         if (BPF_CORE_READ(&out->u8_field, &in->u8_field) ||
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
progs/test_core_reloc_ints.c:33:6: error: using 
builtin_preserve_access_index() without -g
             BPF_CORE_READ(&out->s8_field, &in->s8_field) ||
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
progs/test_core_reloc_ints.c:34:6: error: using 
builtin_preserve_access_index() without -g
             BPF_CORE_READ(&out->u16_field, &in->u16_field) ||
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
progs/test_core_reloc_ints.c:35:6: error: using 
builtin_preserve_access_index() without -g
             BPF_CORE_READ(&out->s16_field, &in->s16_field) ||
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
progs/test_core_reloc_ints.c:36:6: error: using 
builtin_preserve_access_index() without -g
             BPF_CORE_READ(&out->u32_field, &in->u32_field) ||
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
progs/test_core_reloc_ints.c:37:6: error: using 
builtin_preserve_access_index() without -g
             BPF_CORE_READ(&out->s32_field, &in->s32_field) ||
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
progs/test_core_reloc_ints.c:38:6: error: using 
builtin_preserve_access_index() without -g
             BPF_CORE_READ(&out->u64_field, &in->u64_field) ||
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
progs/test_core_reloc_ints.c:39:6: error: using 
builtin_preserve_access_index() without -g
             BPF_CORE_READ(&out->s64_field, &in->s64_field))
             ^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
                        __builtin_preserve_access_index(src))
                        ^
8 errors generated.
llc: error: llc: <stdin>:1:1: error: expected top-level entity
clang failed


In order to solve this error, I modifed bpf/Makefile as
  CLANG_CFLAGS = $(CLANG_SYS_INCLUDES) \
-              -Wno-compare-distinct-pointer-types
+              -Wno-compare-distinct-pointer-types -g


Now I am getting this error

(clang -I. -I./include/uapi -I../../../include/uapi 
-I/usr/src/tovards/linux/tools/testing/selftests/bpf/../usr/include 
-D__TARGET_ARCH_arm64 -idirafter /usr/local/include -idirafter 
/usr/local/lib/clang/9.0.0/include -idirafter 
/usr/include/aarch64-linux-gnu -idirafter /usr/include 
-Wno-compare-distinct-pointer-types -g -O2 -target bpf -emit-llvm \
	-c progs/test_core_reloc_ints.c -o - || echo "clang failed") | \
llc -march=arm64 -mcpu=generic  -filetype=obj -o 
/usr/src/tovards/linux/tools/testing/selftests/bpf/test_core_reloc_ints.o
LLVM ERROR: Cannot select: intrinsic %llvm.preserve.struct.access.index
Makefile:267: recipe for target 
'/usr/src/tovards/linux/tools/testing/selftests/bpf/test_core_reloc_ints.o' 
failed
make[1]: *** 
[/usr/src/tovards/linux/tools/testing/selftests/bpf/test_core_reloc_ints.o] 
Error 1


Please suggest!!


--prabhakar(pk)

[1] 
https://stackoverflow.com/questions/47255526/how-to-build-the-latest-clang-tidy

[2] https://www.mail-archive.com/netdev@vger.kernel.org/msg315096.html


Linux top-commit
----------------
commit bc88f85c6c09306bd21917e1ae28205e9cd775a7 (HEAD -> master, 
origin/master, origin/HEAD)
Author: Ben Dooks <ben.dooks@codethink.co.uk>
Date:   Wed Oct 16 12:24:58 2019 +0100

     kthread: make __kthread_queue_delayed_work static

     The __kthread_queue_delayed_work is not exported so
     make it static, to avoid the following sparse warning:

       kernel/kthread.c:869:6: warning: symbol 
'__kthread_queue_delayed_work' was not declared. Should it be static?

     Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>