Currently, it is not possible to specify custom flags when building
samples/bpf. The flags are defined in TPROGS_CFLAGS/TPROGS_LDFLAGS
variables, however, when trying to override those from the make command,
compilation fails.
For example, when trying to build with PIE:
$ make -C samples/bpf TPROGS_CFLAGS="-fpie" TPROGS_LDFLAGS="-pie"
This is because samples/bpf/Makefile updates these variables, especially
appends include paths to TPROGS_CFLAGS and these updates are overridden
by setting the variables from the make command.
This patch introduces variables TPROGS_USER_CFLAGS/TPROGS_USER_LDFLAGS
for this purpose, which can be set from the make command and their
values are propagated to TPROGS_CFLAGS/TPROGS_LDFLAGS.
Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx>
---
samples/bpf/Makefile | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 90af76fa9dd8..5a9805edec93 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -150,6 +150,9 @@ always-y += ibumad_kern.o
always-y += hbm_out_kern.o
always-y += hbm_edt_kern.o
+TPROGS_CFLAGS = $(TPROGS_USER_CFLAGS)
+TPROGS_LDFLAGS = $(TPROGS_USER_LDFLAGS)
+
ifeq ($(ARCH), arm)
# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
# headers when arm instruction set identification is requested.
@@ -316,7 +319,7 @@ XDP_SAMPLE_CFLAGS += -Wall -O2 \
-I$(LIBBPF_INCLUDE) \
-I$(src)/../../tools/testing/selftests/bpf
-$(obj)/$(XDP_SAMPLE): TPROGS_CFLAGS = $(XDP_SAMPLE_CFLAGS)
+$(obj)/$(XDP_SAMPLE): TPROGS_CFLAGS = $(XDP_SAMPLE_CFLAGS) $(TPROGS_USER_CFLAGS)
$(obj)/$(XDP_SAMPLE): $(src)/xdp_sample_user.h $(src)/xdp_sample_shared.h
# Override includes for trace_helpers.o because __must_check won't be defined
# in our include path.
--
2.41.0
