[PATCH bpf-next v3] selftests/bpf: Set __BITS_PER_LONG if target is bpf for LoongArch

[Tiezhu Yang]

If target is bpf, there is no __loongarch__ definition, __BITS_PER_LONG
defaults to 32, __NR_nanosleep is not defined:

  #if defined(__ARCH_WANT_TIME32_SYSCALLS) || __BITS_PER_LONG != 32
  #define __NR_nanosleep 101
  __SC_3264(__NR_nanosleep, sys_nanosleep_time32, sys_nanosleep)
  #endif

Work around this problem, by explicitly setting __BITS_PER_LONG to
__loongarch_grlen which is defined by compiler as 64 for LA64, then
__NR_nanosleep can also be defined to fix the following build errors:

  clang  -g -Werror ... -target bpf -c progs/test_vmlinux.c ...
  progs/test_vmlinux.c:24:18: error: use of undeclared identifier '__NR_nanosleep'
          if (args->id != __NR_nanosleep)
                          ^
  progs/test_vmlinux.c:42:12: error: use of undeclared identifier '__NR_nanosleep'
          if (id != __NR_nanosleep)
                    ^
  progs/test_vmlinux.c:60:12: error: use of undeclared identifier '__NR_nanosleep'
          if (id != __NR_nanosleep)
                    ^
  3 errors generated.

This is similar with commit 36e70b9b06bf ("selftests, bpf: Fix broken
riscv build").

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
 tools/testing/selftests/bpf/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index b677dcd..f40606a 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -338,7 +338,8 @@ $(RESOLVE_BTFIDS): $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/resolve_btfids	\
 define get_sys_includes
 $(shell $(1) $(2) -v -E - </dev/null 2>&1 \
 	| sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
-$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__loongarch_grlen ' | awk '{printf("-D__BITS_PER_LONG=%d", $$3)}')
 endef
 
 # Determine target endianness.
-- 
2.1.0