From: Vladimir Sokolovsky <vlad@mellanox.com>
Date: Wed, 6 Feb 2019 23:42:42 +0000 (+0200)
Subject: Move bpf_prog_sub to be exported by compat
X-Git-Tag: vofed-4.17-1-rc1^0
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=refs%2Fheads%2Fofed_4_17_1;p=compat-rdma%2Fcompat.git

Move bpf_prog_sub to be exported by compat

Having bpf_prog_sub defined in the header file is causing compilation
issues on RHEL-7.6, since this OS does not really support XDP, it just
has only an empty implementation of it, so some parts can be missing.

The #include <linux/filter.h> caused the build issues, so we move the
backport to a compat C file and export it there, similar to upstream
where they also implement this function in a C file (kernel/bpf/syscall.c).

Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.com>
---

diff --git a/compat/Makefile b/compat/Makefile
index 6d174d4..954439f 100644
--- a/compat/Makefile
+++ b/compat/Makefile
@@ -15,5 +15,6 @@ compat-$(CONFIG_COMPAT_KERNEL_4_16) += compat-4.16.o
 
 compat-y += uuid.o
 compat-y += rhashtable.o
+compat-y += syscall.o
 
 compat-y += ../block/blk-mq-rdma.o
diff --git a/compat/syscall.c b/compat/syscall.c
new file mode 100644
index 0000000..abe22d5
--- /dev/null
+++ b/compat/syscall.c
@@ -0,0 +1,18 @@
+#ifdef HAVE_XDP_BUFF
+
+#ifndef HAVE_BPF_PROG_SUB
+#include <linux/filter.h>
+#include <linux/bpf.h>
+void bpf_prog_sub(struct bpf_prog *prog, int i)
+{
+	/* Only to be used for undoing previous bpf_prog_add() in some
+	 * error path. We still know that another entity in our call
+	 * path holds a reference to the program, thus atomic_sub() can
+	 * be safely used in such cases!
+	 */
+	WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
+}
+EXPORT_SYMBOL_GPL(bpf_prog_sub);
+#endif /* HAVE_BPF_PROG_SUB */
+
+#endif /* HAVE_XDP_BUFF */
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index b90db74..6575582 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -15,16 +15,9 @@ static inline struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
 #endif
 
 #ifndef HAVE_BPF_PROG_SUB
-#include <linux/filter.h>
-static inline void bpf_prog_sub(struct bpf_prog *prog, int i)
-{
-	/* Only to be used for undoing previous bpf_prog_add() in some
-	 * error path. We still know that another entity in our call
-	 * path holds a reference to the program, thus atomic_sub() can
-	 * be safely used in such cases!
-	 */
-	WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
-}
+struct bpf_prog;
+#define bpf_prog_sub LINUX_BACKPORT(bpf_prog_sub)
+void bpf_prog_sub(struct bpf_prog *prog, int i);
 #endif
 
 #endif /* HAVE_LINUX_BPF_H */