[PATCH AUTOSEL 4.14 15/25] selftests: Set CC to clang in lib.mk if LLVM is set

[PATCH AUTOSEL 4.14 15/25] selftests: Set CC to clang in lib.mk if LLVM is set

[Sasha Levin]

From: Yonghong Song <yhs@fb.com>

[ Upstream commit 26e6dd1072763cd5696b75994c03982dde952ad9 ]

selftests/bpf/Makefile includes lib.mk. With the following command
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 V=1
some files are still compiled with gcc. This patch
fixed lib.mk issue which sets CC to gcc in all cases.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153413.3027426-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/lib.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index c9be64dc681d..cd3034602ea5 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -1,6 +1,10 @@
 # This mimics the top-level Makefile. We do it explicitly here so that this
 # Makefile can operate with or without the kbuild infrastructure.
+ifneq ($(LLVM),)
+CC := clang
+else
 CC := $(CROSS_COMPILE)gcc
+endif
 
 ifeq (0,$(MAKELEVEL))
 OUTPUT := $(shell pwd)
-- 
2.30.2

[PATCH AUTOSEL 4.14 20/25] samples/bpf: Fix broken tracex1 due to kprobe argument change

[Sasha Levin]

From: Yaqi Chen <chendotjs@gmail.com>

[ Upstream commit 137733d08f4ab14a354dacaa9a8fc35217747605 ]

>From commit c0bbbdc32feb ("__netif_receive_skb_core: pass skb by
reference"), the first argument passed into __netif_receive_skb_core
has changed to reference of a skb pointer.

This commit fixes by using bpf_probe_read_kernel.

Signed-off-by: Yaqi Chen <chendotjs@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210416154803.37157-1-chendotjs@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 samples/bpf/tracex1_kern.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/samples/bpf/tracex1_kern.c b/samples/bpf/tracex1_kern.c
index 107da148820f..9c74b45c5720 100644
--- a/samples/bpf/tracex1_kern.c
+++ b/samples/bpf/tracex1_kern.c
@@ -20,7 +20,7 @@
 SEC("kprobe/__netif_receive_skb_core")
 int bpf_prog1(struct pt_regs *ctx)
 {
-	/* attaches to kprobe netif_receive_skb,
+	/* attaches to kprobe __netif_receive_skb_core,
 	 * looks for packets on loobpack device and prints them
 	 */
 	char devname[IFNAMSIZ];
@@ -29,7 +29,7 @@ int bpf_prog1(struct pt_regs *ctx)
 	int len;
 
 	/* non-portable! works for the given kernel only */
-	skb = (struct sk_buff *) PT_REGS_PARM1(ctx);
+	bpf_probe_read_kernel(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx));
 	dev = _(skb->dev);
 	len = _(skb->len);
 
-- 
2.30.2