This is a note to let you know that I've just added the patch titled
bpftool: Always disable stack protection for BPF objects
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpftool-always-disable-stack-protection-for-bpf-obje.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2eb65d82ea0e3730c3f6a4d7b8b1d0b79f10b1a0
Author: Holger Hoffstätte <holger@xxxxxxxxxxxxxxxxxxxxxx>
Date: Fri Jan 13 16:40:23 2023 +0100
bpftool: Always disable stack protection for BPF objects
[ Upstream commit 878625e1c7a10dfbb1fdaaaae2c4d2a58fbce627 ]
When the clang toolchain has stack protection enabled in order to be
consistent with gcc - which just happens to be the case on Gentoo -
the bpftool build fails:
[...]
clang \
-I. \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \
-g -O2 -Wall -target bpf -c skeleton/pid_iter.bpf.c -o pid_iter.bpf.o
clang \
-I. \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \
-g -O2 -Wall -target bpf -c skeleton/profiler.bpf.c -o profiler.bpf.o
skeleton/profiler.bpf.c:40:14: error: A call to built-in function '__stack_chk_fail' is not supported.
int BPF_PROG(fentry_XXX)
^
skeleton/profiler.bpf.c:94:14: error: A call to built-in function '__stack_chk_fail' is not supported.
int BPF_PROG(fexit_XXX)
^
2 errors generated.
[...]
Since stack-protector makes no sense for the BPF bits just unconditionally
disable it.
Bug: https://bugs.gentoo.org/890638
Signed-off-by: Holger Hoffstätte <holger@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/74cd9d2e-6052-312a-241e-2b514a75c92c@xxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 4a95c017ad4ce..a3794b3416014 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -187,7 +187,8 @@ $(OUTPUT)%.bpf.o: skeleton/%.bpf.c $(OUTPUT)vmlinux.h $(LIBBPF_BOOTSTRAP)
-I$(or $(OUTPUT),.) \
-I$(srctree)/tools/include/uapi/ \
-I$(LIBBPF_BOOTSTRAP_INCLUDE) \
- -g -O2 -Wall -target bpf -c $< -o $@
+ -g -O2 -Wall -fno-stack-protector \
+ -target bpf -c $< -o $@
$(Q)$(LLVM_STRIP) -g $@
$(OUTPUT)%.skel.h: $(OUTPUT)%.bpf.o $(BPFTOOL_BOOTSTRAP)
