Hi,
Built clang kernel and installed kernel headers. After it, triggered linux-5.x/samples/bpf/ using clang compiler and after done with it, kernel image build is triggered again and it fails with below error. it seems bpf samples programs are in turn depend on kernel source, hence kernel build is triggered after finishing bpf sample compilation process. but kernel image build fails as given below.
{{
HOSTCC kernel/…/kernel/linux-5.4/samples/bpf//bpf_load.o
HOSTCC kernel/…/kernel/linux-5.4/samples/bpf//xdp1_user.o
HOSTCC kernel/…/kernel/linux-5.4/samples/bpf//cookie_uid_helper_example.o
HOSTCC kernel/…/kernel/linux-5.4/samples/bpf//test_lru_dist
HOSTCC /kernel/…/kernel/linux-5.4/samples/bpf//sock_example
HOSTCC kernel/…/kernel/linux-5.4/samples/bpf//fds_example.o
HOSTCC kernel/…/kernel/linux-5.4/samples/bpf//sockex1_user.o
HOSTCC /kernel/…/kernel/linux-5.4/samples/bpf//sockex2_user.o
HOSTCC /kernel/…/kernel/linux-5.4/samples/bpf//sockex3_user.o
HOSTCC /kernel/…/kernel/linux-5.4/samples/bpf//tracex1_user.o
HOSTCC /kernel/…/kernel/linux-5.4/samples/bpf//tracex2_user.o
…
…
CLANG-bpf kernel/…/kernel/linux-5.4/samples/bpf//tracex3_kern.o
CLANG-bpf kernel/…/kernel/linux-5.4/samples/bpf//tracex4_kern.o
CC /kernel/…/kernel/linux-5.4/samples/bpf//syscall_nrs.s
CLANG-bpf kernel/…/kernel/linux-5.4/samples/bpf//tracex6_kern.o
…
CLANG-bpf kernel/…/kernel/linux-5.4/samples/bpf//trace_event_kern.o
kernel/linux-5.4/samples/bpf//tracex1_kern.c:32:2: warning: implicit declaration of function ‘bpf_probe_read_kernel’ is invalid in C99 [-Wimplicit-function-declaration]
bpf_probe_read_kernel(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx));
^
1 warning generated.
,
5.4/samples/bpf//xdp_sample_pkts
HOSTLD /kernel/…/kernel/linux-5.4/samples/bpf//ibumad
HOSTLD /kernel/…/kernel/linux-5.4/samples/bpf//hbm
UPD /kernel/…/kernel/linux-5.4/samples/bpf//syscall_nrs.h
CLANG-bpf /kernel/…/kernel/linux-5.4/samples/bpf//tracex5_kern.o
Building modules, stage 2.
MODPOST 0 modules
===>generate image
prepare config file /…/kernel/configs/.config for capture kernel
compile capture kernel
CC arch/x86/boot/a20.o
AS arch/x86/boot/bioscall.o
CC arch/x86/boot/cmdline.o
AS arch/x86/boot/copy.o
HOSTCC arch/x86/boot/mkcpustr
CC arch/x86/boot/cpuflags.o
CC arch/x86/boot/cpucheck.o
CC arch/x86/boot/early_serial_console.o
CC arch/x86/boot/edd.o
CC arch/x86/boot/main.o
CC arch/x86/boot/memory.o
CC arch/x86/boot/pm.o
AS arch/x86/boot/pmjump.o
CC arch/x86/boot/regs.o
CC arch/x86/boot/printf.o
kernel/linux-5.4/arch/x86/boot/mkcpustr.c:18:10: fatal error: ‘…/kernel/cpu/capflags.c’ file not found
#include “…/kernel/cpu/capflags.c”
^~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
scripts/Makefile.host:107: recipe for target ‘arch/x86/boot/mkcpustr’ failed
make[5]: *** [arch/x86/boot/mkcpustr] Error 1
make[5]: *** Waiting for unfinished jobs…
LDS arch/x86/boot/compressed/vmlinux.lds
AS arch/x86/boot/compressed/head_64.o
CC arch/x86/boot/compressed/misc.o
CC arch/x86/boot/compressed/string.o
CC arch/x86/boot/compressed/cmdline.o
CC arch/x86/boot/compressed/error.o
HOSTCC arch/x86/boot/compressed/mkpiggy
CC arch/x86/boot/compressed/cpuflags.o
CC arch/x86/boot/compressed/early_serial_console.o
CC arch/x86/boot/compressed/kaslr.o
CC arch/x86/boot/compressed/kaslr_64.o
AS arch/x86/boot/compressed/mem_encrypt.o
CC arch/x86/boot/compressed/pgtable_64.o
CC arch/x86/boot/compressed/acpi.o
MKPIGGY arch/x86/boot/compressed/piggy.S
AS arch/x86/boot/compressed/piggy.o
kernel/linux-5.4/arch/x86/boot/compressed/misc.c:19:10: fatal error: ‘…/voffset.h’ file not found
#include “…/voffset.h”
^~~~~~~~~~~~~~
1 error generated.
kernel/linux-5.4/scripts/Makefile.build:262: recipe for target ‘arch/x86/boot/compressed/misc.o’ failed
make[6]: *** [arch/x86/boot/compressed/misc.o] Error 1
make[6]: *** Waiting for unfinished jobs…
/kernel/linux-5.4/arch/x86/boot/Makefile:112: recipe for target ‘arch/x86/boot/compressed/vmlinux’ failed
make[5]: *** [arch/x86/boot/compressed/vmlinux] Error 2
…
}}
it seems mkcapflags.sh script
present in below makefile must be triggered to avoid above error, but why it’s not triggered second time on top of existing built kernle? (arch/x86/kernle/cpu/Makefile)
{{
Any input will help in resolving this issue.
Regards
Koti