tools: bpf: Use local copy of headers including uapi/linux/filter.h

Pulling header files directly out of the kernel sources for inclusion in
userspace programs is highly error prone, not least because it bypasses
the kbuild infrastructure entirely and so may end up referencing other
header files that have not been generated.

Subsequent patches will cause compiler.h to pull in the ungenerated
asm/rwonce.h file via filter.h, breaking the build for tools/bpf:

  | $ make -C tools/bpf
  | make: Entering directory '/linux/tools/bpf'
  |   CC       bpf_jit_disasm.o
  |   LINK     bpf_jit_disasm
  |   CC       bpf_dbg.o
  | In file included from /linux/include/uapi/linux/filter.h:9,
  |                  from /linux/tools/bpf/bpf_dbg.c:41:
  | /linux/include/linux/compiler.h:247:10: fatal error: asm/rwonce.h: No such file or directory
  |  #include <asm/rwonce.h>
  |           ^~~~~~~~~~~~~~
  | compilation terminated.
  | make: *** [Makefile:61: bpf_dbg.o] Error 1
  | make: Leaving directory '/linux/tools/bpf'

Take a copy of the installed version of linux/filter.h  (i.e. the one
created by the 'headers_install' target) into tools/include/uapi/linux/
and adjust the BPF tool Makefile to reference the local include
directories instead of those in the main source tree.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Reported-by: Xiao Yang <ice_yangxiao@163.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/tools/bpf/Makefile b/tools/bpf/Makefile
index 6df1850..8a69258 100644 (file)
--- a/tools/bpf/Makefile
+++ b/tools/bpf/Makefile
@@ -9,7 +9,8 @@ MAKE = make
 INSTALL ?= install
 
 CFLAGS += -Wall -O2
-CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/include/uapi -I$(srctree)/include
+CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi \
+         -I$(srctree)/tools/include
 
 # This will work when bpf is built in tools env. where srctree
 # isn't set and when invoked from selftests build, where srctree

diff --git a/tools/include/uapi/linux/filter.h b/tools/include/uapi/linux/filter.h
new file mode 100644 (file)
index 0000000..eaef459
--- /dev/null
+++ b/tools/include/uapi/linux/filter.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Linux Socket Filter Data Structures
+ */
+
+#ifndef __LINUX_FILTER_H__
+#define __LINUX_FILTER_H__
+
+
+#include <linux/types.h>
+#include <linux/bpf_common.h>
+
+/*
+ * Current version of the filter code architecture.
+ */
+#define BPF_MAJOR_VERSION 1
+#define BPF_MINOR_VERSION 1
+
+/*
+ *     Try and keep these values and structures similar to BSD, especially
+ *     the BPF code definitions which need to match so you can share filters
+ */
+ 
+struct sock_filter {   /* Filter block */
+       __u16   code;   /* Actual filter code */
+       __u8    jt;     /* Jump true */
+       __u8    jf;     /* Jump false */
+       __u32   k;      /* Generic multiuse field */
+};
+
+struct sock_fprog {    /* Required for SO_ATTACH_FILTER. */
+       unsigned short          len;    /* Number of filter blocks */
+       struct sock_filter *filter;
+};
+
+/* ret - BPF_K and BPF_X also apply */
+#define BPF_RVAL(code)  ((code) & 0x18)
+#define         BPF_A           0x10
+
+/* misc */
+#define BPF_MISCOP(code) ((code) & 0xf8)
+#define         BPF_TAX         0x00
+#define         BPF_TXA         0x80
+
+/*
+ * Macros for filter block array initializers.
+ */
+#ifndef BPF_STMT
+#define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k }
+#endif
+#ifndef BPF_JUMP
+#define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k }
+#endif
+
+/*
+ * Number of scratch memory words for: BPF_ST and BPF_STX
+ */
+#define BPF_MEMWORDS 16
+
+/* RATIONALE. Negative offsets are invalid in BPF.
+   We use them to reference ancillary data.
+   Unlike introduction new instructions, it does not break
+   existing compilers/optimizers.
+ */
+#define SKF_AD_OFF    (-0x1000)
+#define SKF_AD_PROTOCOL 0
+#define SKF_AD_PKTTYPE         4
+#define SKF_AD_IFINDEX         8
+#define SKF_AD_NLATTR  12
+#define SKF_AD_NLATTR_NEST     16
+#define SKF_AD_MARK    20
+#define SKF_AD_QUEUE   24
+#define SKF_AD_HATYPE  28
+#define SKF_AD_RXHASH  32
+#define SKF_AD_CPU     36
+#define SKF_AD_ALU_XOR_X       40
+#define SKF_AD_VLAN_TAG        44
+#define SKF_AD_VLAN_TAG_PRESENT 48
+#define SKF_AD_PAY_OFFSET      52
+#define SKF_AD_RANDOM  56
+#define SKF_AD_VLAN_TPID       60
+#define SKF_AD_MAX     64
+
+#define SKF_NET_OFF    (-0x100000)
+#define SKF_LL_OFF     (-0x200000)
+
+#define BPF_NET_OFF    SKF_NET_OFF
+#define BPF_LL_OFF     SKF_LL_OFF
+
+#endif /* __LINUX_FILTER_H__ */