Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2019-12-27

The following pull-request contains BPF updates for your *net-next* tree.

We've added 127 non-merge commits during the last 17 day(s) which contain
a total of 110 files changed, 6901 insertions(+), 2721 deletions(-).

There are three merge conflicts. Conflicts and resolution looks as follows:

1) Merge conflict in net/bpf/test_run.c:

There was a tree-wide cleanup c593642c8be0 ("treewide: Use sizeof_field() macro")
which gets in the way with b590cb5f802d ("bpf: Switch to offsetofend in
BPF_PROG_TEST_RUN"):

  <<<<<<< HEAD
          if (!range_is_zero(__skb, offsetof(struct __sk_buff, priority) +
                             sizeof_field(struct __sk_buff, priority),
  =======
          if (!range_is_zero(__skb, offsetofend(struct __sk_buff, priority),
  >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c

There are a few occasions that look similar to this. Always take the chunk with
offsetofend(). Note that there is one where the fields differ in here:

  <<<<<<< HEAD
          if (!range_is_zero(__skb, offsetof(struct __sk_buff, tstamp) +
                             sizeof_field(struct __sk_buff, tstamp),
  =======
          if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs),
  >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c

Just take the one with offsetofend() /and/ gso_segs. Latter is correct due to
850a88cc4096 ("bpf: Expose __sk_buff wire_len/gso_segs to BPF_PROG_TEST_RUN").

2) Merge conflict in arch/riscv/net/bpf_jit_comp.c:

(I'm keeping Bjorn in Cc here for a double-check in case I got it wrong.)

  <<<<<<< HEAD
          if (is_13b_check(off, insn))
                  return -1;
          emit(rv_blt(tcc, RV_REG_ZERO, off >> 1), ctx);
  =======
          emit_branch(BPF_JSLT, RV_REG_T1, RV_REG_ZERO, off, ctx);
  >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c

Result should look like:

          emit_branch(BPF_JSLT, tcc, RV_REG_ZERO, off, ctx);

3) Merge conflict in arch/riscv/include/asm/pgtable.h:

  <<<<<<< HEAD
  =======
  #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
  #define VMALLOC_END      (PAGE_OFFSET - 1)
  #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)

  #define BPF_JIT_REGION_SIZE     (SZ_128M)
  #define BPF_JIT_REGION_START    (PAGE_OFFSET - BPF_JIT_REGION_SIZE)
  #define BPF_JIT_REGION_END      (VMALLOC_END)

  /*
   * Roughly size the vmemmap space to be large enough to fit enough
   * struct pages to map half the virtual address space. Then
   * position vmemmap directly below the VMALLOC region.
   */
  #define VMEMMAP_SHIFT \
          (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
  #define VMEMMAP_SIZE    BIT(VMEMMAP_SHIFT)
  #define VMEMMAP_END     (VMALLOC_START - 1)
  #define VMEMMAP_START   (VMALLOC_START - VMEMMAP_SIZE)

  #define vmemmap         ((struct page *)VMEMMAP_START)

  >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c

Only take the BPF_* defines from there and move them higher up in the
same file. Remove the rest from the chunk. The VMALLOC_* etc defines
got moved via 01f52e16b868 ("riscv: define vmemmap before pfn_to_page
calls"). Result:

  [...]
  #define __S101  PAGE_READ_EXEC
  #define __S110  PAGE_SHARED_EXEC
  #define __S111  PAGE_SHARED_EXEC

  #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
  #define VMALLOC_END      (PAGE_OFFSET - 1)
  #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)

  #define BPF_JIT_REGION_SIZE     (SZ_128M)
  #define BPF_JIT_REGION_START    (PAGE_OFFSET - BPF_JIT_REGION_SIZE)
  #define BPF_JIT_REGION_END      (VMALLOC_END)

  /*
   * Roughly size the vmemmap space to be large enough to fit enough
   * struct pages to map half the virtual address space. Then
   * position vmemmap directly below the VMALLOC region.
   */
  #define VMEMMAP_SHIFT \
          (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
  #define VMEMMAP_SIZE    BIT(VMEMMAP_SHIFT)
  #define VMEMMAP_END     (VMALLOC_START - 1)
  #define VMEMMAP_START   (VMALLOC_START - VMEMMAP_SIZE)

  [...]

Let me know if there are any other issues.

Anyway, the main changes are:

1) Extend bpftool to produce a struct (aka "skeleton") tailored and specific
   to a provided BPF object file. This provides an alternative, simplified API
   compared to standard libbpf interaction. Also, add libbpf extern variable
   resolution for .kconfig section to import Kconfig data, from Andrii Nakryiko.

2) Add BPF dispatcher for XDP which is a mechanism to avoid indirect calls by
   generating a branch funnel as discussed back in bpfconf'19 at LSF/MM. Also,
   add various BPF riscv JIT improvements, from Björn Töpel.

3) Extend bpftool to allow matching BPF programs and maps by name,
   from Paul Chaignon.

4) Support for replacing cgroup BPF programs attached with BPF_F_ALLOW_MULTI
   flag for allowing updates without service interruption, from Andrey Ignatov.

5) Cleanup and simplification of ring access functions for AF_XDP with a
   bonus of 0-5% performance improvement, from Magnus Karlsson.

6) Enable BPF JITs for x86-64 and arm64 by default. Also, final version of
   audit support for BPF, from Daniel Borkmann and latter with Jiri Olsa.

7) Move and extend test_select_reuseport into BPF program tests under
   BPF selftests, from Jakub Sitnicki.

8) Various BPF sample improvements for xdpsock for customizing parameters
   to set up and benchmark AF_XDP, from Jay Jayatheerthan.

9) Improve libbpf to provide a ulimit hint on permission denied errors.
   Also change XDP sample programs to attach in driver mode by default,
   from Toke Høiland-Jørgensen.

10) Extend BPF test infrastructure to allow changing skb mark from tc BPF
    programs, from Nikita V. Shirokov.

11) Optimize prologue code sequence in BPF arm32 JIT, from Russell King.

12) Fix xdp_redirect_cpu BPF sample to manually attach to tracepoints after
    libbpf conversion, from Jesper Dangaard Brouer.

13) Minor misc improvements from various others.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 327 insertions, 11 deletions

diff --git a/tools/bpf/bpftool/Documentation/bpftool-gen.rst b/tools/bpf/bpftool/Documentation/bpftool-gen.rst
new file mode 100644
index 000000000000..86a87da97d0b
--- /dev/null
+++ b/tools/bpf/bpftool/Documentation/bpftool-gen.rst
@@ -0,0 +1,305 @@
+================
+bpftool-gen
+================
+-------------------------------------------------------------------------------
+tool for BPF code-generation
+-------------------------------------------------------------------------------
+
+:Manual section: 8
+
+SYNOPSIS
+========
+
+	**bpftool** [*OPTIONS*] **gen** *COMMAND*
+
+	*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] }
+
+	*COMMAND* := { **skeleton | **help** }
+
+GEN COMMANDS
+=============
+
+|	**bpftool** **gen skeleton** *FILE*
+|	**bpftool** **gen help**
+
+DESCRIPTION
+===========
+	**bpftool gen skeleton** *FILE*
+		  Generate BPF skeleton C header file for a given *FILE*.
+
+		  BPF skeleton is an alternative interface to existing libbpf
+		  APIs for working with BPF objects. Skeleton code is intended
+		  to significantly shorten and simplify code to load and work
+		  with BPF programs from userspace side. Generated code is
+		  tailored to specific input BPF object *FILE*, reflecting its
+		  structure by listing out available maps, program, variables,
+		  etc. Skeleton eliminates the need to lookup mentioned
+		  components by name. Instead, if skeleton instantiation
+		  succeeds, they are populated in skeleton structure as valid
+		  libbpf types (e.g., struct bpf_map pointer) and can be
+		  passed to existing generic libbpf APIs.
+
+		  In addition to simple and reliable access to maps and
+		  programs, skeleton provides a storage for BPF links (struct
+		  bpf_link) for each BPF program within BPF object. When
+		  requested, supported BPF programs will be automatically
+		  attached and resulting BPF links stored for further use by
+		  user in pre-allocated fields in skeleton struct. For BPF
+		  programs that can't be automatically attached by libbpf,
+		  user can attach them manually, but store resulting BPF link
+		  in per-program link field. All such set up links will be
+		  automatically destroyed on BPF skeleton destruction. This
+		  eliminates the need for users to manage links manually and
+		  rely on libbpf support to detach programs and free up
+		  resources.
+
+		  Another facility provided by BPF skeleton is an interface to
+		  global variables of all supported kinds: mutable, read-only,
+		  as well as extern ones. This interface allows to pre-setup
+		  initial values of variables before BPF object is loaded and
+		  verified by kernel. For non-read-only variables, the same
+		  interface can be used to fetch values of global variables on
+		  userspace side, even if they are modified by BPF code.
+
+		  During skeleton generation, contents of source BPF object
+		  *FILE* is embedded within generated code and is thus not
+		  necessary to keep around. This ensures skeleton and BPF
+		  object file are matching 1-to-1 and always stay in sync.
+		  Generated code is dual-licensed under LGPL-2.1 and
+		  BSD-2-Clause licenses.
+
+		  It is a design goal and guarantee that skeleton interfaces
+		  are interoperable with generic libbpf APIs. User should
+		  always be able to use skeleton API to create and load BPF
+		  object, and later use libbpf APIs to keep working with
+		  specific maps, programs, etc.
+
+		  As part of skeleton, few custom functions are generated.
+		  Each of them is prefixed with object name, derived from
+		  object file name. I.e., if BPF object file name is
+		  **example.o**, BPF object name will be **example**. The
+		  following custom functions are provided in such case:
+
+		  - **example__open** and **example__open_opts**.
+		    These functions are used to instantiate skeleton. It
+		    corresponds to libbpf's **bpf_object__open()** API.
+		    **_opts** variants accepts extra **bpf_object_open_opts**
+		    options.
+
+		  - **example__load**.
+		    This function creates maps, loads and verifies BPF
+		    programs, initializes global data maps. It corresponds to
+		    libppf's **bpf_object__load** API.
+
+		  - **example__open_and_load** combines **example__open** and
+		    **example__load** invocations in one commonly used
+		    operation.
+
+		  - **example__attach** and **example__detach**
+		    This pair of functions allow to attach and detach,
+		    correspondingly, already loaded BPF object. Only BPF
+		    programs of types supported by libbpf for auto-attachment
+		    will be auto-attached and their corresponding BPF links
+		    instantiated. For other BPF programs, user can manually
+		    create a BPF link and assign it to corresponding fields in
+		    skeleton struct. **example__detach** will detach both
+		    links created automatically, as well as those populated by
+		    user manually.
+
+		  - **example__destroy**
+		    Detach and unload BPF programs, free up all the resources
+		    used by skeleton and BPF object.
+
+		  If BPF object has global variables, corresponding structs
+		  with memory layout corresponding to global data data section
+		  layout will be created. Currently supported ones are: *.data*,
+		  *.bss*, *.rodata*, and *.kconfig* structs/data sections.
+		  These data sections/structs can be used to set up initial
+		  values of variables, if set before **example__load**.
+		  Afterwards, if target kernel supports memory-mapped BPF
+		  arrays, same structs can be used to fetch and update
+		  (non-read-only) data from userspace, with same simplicity
+		  as for BPF side.
+
+	**bpftool gen help**
+		  Print short help message.
+
+OPTIONS
+=======
+	-h, --help
+		  Print short generic help message (similar to **bpftool help**).
+
+	-V, --version
+		  Print version number (similar to **bpftool version**).
+
+	-j, --json
+		  Generate JSON output. For commands that cannot produce JSON,
+		  this option has no effect.
+
+	-p, --pretty
+		  Generate human-readable JSON output. Implies **-j**.
+
+	-d, --debug
+		  Print all logs available from libbpf, including debug-level
+		  information.
+
+EXAMPLES
+========
+**$ cat example.c**
+::
+
+  #include <stdbool.h>
+  #include <linux/ptrace.h>
+  #include <linux/bpf.h>
+  #include "bpf_helpers.h"
+
+  const volatile int param1 = 42;
+  bool global_flag = true;
+  struct { int x; } data = {};
+
+  struct {
+  	__uint(type, BPF_MAP_TYPE_HASH);
+  	__uint(max_entries, 128);
+  	__type(key, int);
+  	__type(value, long);
+  } my_map SEC(".maps");
+
+  SEC("raw_tp/sys_enter")
+  int handle_sys_enter(struct pt_regs *ctx)
+  {
+  	static long my_static_var;
+  	if (global_flag)
+  		my_static_var++;
+  	else
+  		data.x += param1;
+  	return 0;
+  }
+
+  SEC("raw_tp/sys_exit")
+  int handle_sys_exit(struct pt_regs *ctx)
+  {
+  	int zero = 0;
+  	bpf_map_lookup_elem(&my_map, &zero);
+  	return 0;
+  }
+
+This is example BPF application with two BPF programs and a mix of BPF maps
+and global variables.
+
+**$ bpftool gen skeleton example.o**
+::
+
+  /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+  /* THIS FILE IS AUTOGENERATED! */
+  #ifndef __EXAMPLE_SKEL_H__
+  #define __EXAMPLE_SKEL_H__
+
+  #include <stdlib.h>
+  #include <libbpf.h>
+
+  struct example {
+  	struct bpf_object_skeleton *skeleton;
+  	struct bpf_object *obj;
+  	struct {
+  		struct bpf_map *rodata;
+  		struct bpf_map *data;
+  		struct bpf_map *bss;
+  		struct bpf_map *my_map;
+  	} maps;
+  	struct {
+  		struct bpf_program *handle_sys_enter;
+  		struct bpf_program *handle_sys_exit;
+  	} progs;
+  	struct {
+  		struct bpf_link *handle_sys_enter;
+  		struct bpf_link *handle_sys_exit;
+  	} links;
+  	struct example__bss {
+  		struct {
+  			int x;
+  		} data;
+  	} *bss;
+  	struct example__data {
+  		_Bool global_flag;
+  		long int handle_sys_enter_my_static_var;
+  	} *data;
+  	struct example__rodata {
+  		int param1;
+  	} *rodata;
+  };
+
+  static void example__destroy(struct example *obj);
+  static inline struct example *example__open_opts(
+                const struct bpf_object_open_opts *opts);
+  static inline struct example *example__open();
+  static inline int example__load(struct example *obj);
+  static inline struct example *example__open_and_load();
+  static inline int example__attach(struct example *obj);
+  static inline void example__detach(struct example *obj);
+
+  #endif /* __EXAMPLE_SKEL_H__ */
+
+**$ cat example_user.c**
+::
+
+  #include "example.skel.h"
+
+  int main()
+  {
+  	struct example *skel;
+  	int err = 0;
+
+  	skel = example__open();
+  	if (!skel)
+  		goto cleanup;
+
+  	skel->rodata->param1 = 128;
+
+  	err = example__load(skel);
+  	if (err)
+  		goto cleanup;
+
+  	err = example__attach(skel);
+  	if (err)
+  		goto cleanup;
+
+  	/* all libbpf APIs are usable */
+  	printf("my_map name: %s\n", bpf_map__name(skel->maps.my_map));
+  	printf("sys_enter prog FD: %d\n",
+  	       bpf_program__fd(skel->progs.handle_sys_enter));
+
+  	/* detach and re-attach sys_exit program */
+  	bpf_link__destroy(skel->links.handle_sys_exit);
+  	skel->links.handle_sys_exit =
+  		bpf_program__attach(skel->progs.handle_sys_exit);
+
+  	printf("my_static_var: %ld\n",
+  	       skel->bss->handle_sys_enter_my_static_var);
+
+  cleanup:
+  	example__destroy(skel);
+  	return err;
+  }
+
+**# ./example_user**
+::
+
+  my_map name: my_map
+  sys_enter prog FD: 8
+  my_static_var: 7
+
+This is a stripped-out version of skeleton generated for above example code.
+
+SEE ALSO
+========
+	**bpf**\ (2),
+	**bpf-helpers**\ (7),
+	**bpftool**\ (8),
+	**bpftool-map**\ (8),
+	**bpftool-prog**\ (8),
+	**bpftool-cgroup**\ (8),
+	**bpftool-feature**\ (8),
+	**bpftool-net**\ (8),
+	**bpftool-perf**\ (8),
+	**bpftool-btf**\ (8)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 1c0f7146aab0..cdeae8ae90ba 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -39,9 +39,9 @@ MAP COMMANDS
 |	**bpftool** **map freeze**     *MAP*
 |	**bpftool** **map help**
 |
-|	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
+|	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* | **name** *MAP_NAME* }
 |	*DATA* := { [**hex**] *BYTES* }
-|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
+|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* }
 |	*VALUE* := { *DATA* | *MAP* | *PROG* }
 |	*UPDATE_FLAGS* := { **any** | **exist** | **noexist** }
 |	*TYPE* := { **hash** | **array** | **prog_array** | **perf_event_array** | **percpu_hash**
@@ -55,8 +55,9 @@ DESCRIPTION
 ===========
 	**bpftool map { show | list }**   [*MAP*]
 		  Show information about loaded maps.  If *MAP* is specified
-		  show information only about given map, otherwise list all
-		  maps currently loaded on the system.
+		  show information only about given maps, otherwise list all
+		  maps currently loaded on the system.  In case of **name**,
+		  *MAP* may match several maps which will all be shown.
 
 		  Output will start with map ID followed by map type and
 		  zero or more named attributes (depending on kernel version).
@@ -66,7 +67,8 @@ DESCRIPTION
 		  as *FILE*.
 
 	**bpftool map dump**    *MAP*
-		  Dump all entries in a given *MAP*.
+		  Dump all entries in a given *MAP*.  In case of **name**,
+		  *MAP* may match several maps which will all be dumped.
 
 	**bpftool map update**  *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
 		  Update map entry for a given *KEY*.
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 7a374b3c851d..64ddf8a4c518 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -33,7 +33,7 @@ PROG COMMANDS
 |	**bpftool** **prog help**
 |
 |	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
-|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
+|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* }
 |	*TYPE* := {
 |		**socket** | **kprobe** | **kretprobe** | **classifier** | **action** |
 |		**tracepoint** | **raw_tracepoint** | **xdp** | **perf_event** | **cgroup/skb** |
@@ -53,8 +53,10 @@ DESCRIPTION
 ===========
 	**bpftool prog { show | list }** [*PROG*]
 		  Show information about loaded programs.  If *PROG* is
-		  specified show information only about given program, otherwise
-		  list all programs currently loaded on the system.
+		  specified show information only about given programs,
+		  otherwise list all programs currently loaded on the system.
+		  In case of **tag** or **name**, *PROG* may match several
+		  programs which will all be shown.
 
 		  Output will start with program ID followed by program type and
 		  zero or more named attributes (depending on kernel version).
@@ -68,11 +70,15 @@ DESCRIPTION
 		  performed via the **kernel.bpf_stats_enabled** sysctl knob.
 
 	**bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }]
-		  Dump eBPF instructions of the program from the kernel. By
+		  Dump eBPF instructions of the programs from the kernel. By
 		  default, eBPF will be disassembled and printed to standard
 		  output in human-readable format. In this case, **opcodes**
 		  controls if raw opcodes should be printed as well.
 
+		  In case of **tag** or **name**, *PROG* may match several
+		  programs which will all be dumped.  However, if **file** or
+		  **visual** is specified, *PROG* must match a single program.
+
 		  If **file** is specified, the binary image will instead be
 		  written to *FILE*.
 
@@ -80,15 +86,17 @@ DESCRIPTION
 		  built instead, and eBPF instructions will be presented with
 		  CFG in DOT format, on standard output.
 
-		  If the prog has line_info available, the source line will
+		  If the programs have line_info available, the source line will
 		  be displayed by default.  If **linum** is specified,
 		  the filename, line number and line column will also be
 		  displayed on top of the source line.
 
 	**bpftool prog dump jited**  *PROG* [{ **file** *FILE* | **opcodes** | **linum** }]
 		  Dump jited image (host machine code) of the program.
+
 		  If *FILE* is specified image will be written to a file,
 		  otherwise it will be disassembled and printed to stdout.
+		  *PROG* must match a single program when **file** is specified.
 
 		  **opcodes** controls if raw opcodes will be printed.
 
diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst
index 6a9c52ef84a9..34239fda69ed 100644
--- a/tools/bpf/bpftool/Documentation/bpftool.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool.rst
@@ -81,4 +81,5 @@ SEE ALSO
 	**bpftool-feature**\ (8),
 	**bpftool-net**\ (8),
 	**bpftool-perf**\ (8),
-	**bpftool-btf**\ (8)
+	**bpftool-btf**\ (8),
+	**bpftool-gen**\ (8),