Commit Graph

888792 Commits

Author SHA1 Message Date
Alexei Starovoitov 360301a6c2 selftests/bpf: Add unit tests for global functions
test_global_func[12] - check 512 stack limit.
test_global_func[34] - check 8 frame call chain limit.
test_global_func5    - check that non-ctx pointer cannot be passed into
                       a function that expects context.
test_global_func6    - check that ctx pointer is unmodified.
test_global_func7    - check that global function returns scalar.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-7-ast@kernel.org
2020-01-10 17:20:07 +01:00
Alexei Starovoitov e528d1c012 selftests/bpf: Modify a test to check global functions
Make two static functions in test_xdp_noinline.c global:
before: processed 2790 insns
after: processed 2598 insns

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-6-ast@kernel.org
2020-01-10 17:20:07 +01:00
Alexei Starovoitov 6db2d81a46 selftests/bpf: Add a test for a large global function
test results:
pyperf50 with always_inlined the same function five times: processed 46378 insns
pyperf50 with global function: processed 6102 insns

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-5-ast@kernel.org
2020-01-10 17:20:07 +01:00
Alexei Starovoitov 7608e4db6d selftests/bpf: Add fexit-to-skb test for global funcs
Add simple fexit prog type to skb prog type test when subprogram is a global
function.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-4-ast@kernel.org
2020-01-10 17:20:07 +01:00
Alexei Starovoitov 51c39bb1d5 bpf: Introduce function-by-function verification
New llvm and old llvm with libbpf help produce BTF that distinguish global and
static functions. Unlike arguments of static function the arguments of global
functions cannot be removed or optimized away by llvm. The compiler has to use
exactly the arguments specified in a function prototype. The argument type
information allows the verifier validate each global function independently.
For now only supported argument types are pointer to context and scalars. In
the future pointers to structures, sizes, pointer to packet data can be
supported as well. Consider the following example:

static int f1(int ...)
{
  ...
}

int f3(int b);

int f2(int a)
{
  f1(a) + f3(a);
}

int f3(int b)
{
  ...
}

int main(...)
{
  f1(...) + f2(...) + f3(...);
}

The verifier will start its safety checks from the first global function f2().
It will recursively descend into f1() because it's static. Then it will check
that arguments match for the f3() invocation inside f2(). It will not descend
into f3(). It will finish f2() that has to be successfully verified for all
possible values of 'a'. Then it will proceed with f3(). That function also has
to be safe for all possible values of 'b'. Then it will start subprog 0 (which
is main() function). It will recursively descend into f1() and will skip full
check of f2() and f3(), since they are global. The order of processing global
functions doesn't affect safety, since all global functions must be proven safe
based on their arguments only.

Such function by function verification can drastically improve speed of the
verification and reduce complexity.

Note that the stack limit of 512 still applies to the call chain regardless whether
functions were static or global. The nested level of 8 also still applies. The
same recursion prevention checks are in place as well.

The type information and static/global kind is preserved after the verification
hence in the above example global function f2() and f3() can be replaced later
by equivalent functions with the same types that are loaded and verified later
without affecting safety of this main() program. Such replacement (re-linking)
of global functions is a subject of future patches.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-3-ast@kernel.org
2020-01-10 17:20:07 +01:00
Alexei Starovoitov 2d3eb67f64 libbpf: Sanitize global functions
In case the kernel doesn't support BTF_FUNC_GLOBAL sanitize BTF produced by the
compiler for global functions.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-2-ast@kernel.org
2020-01-10 17:20:07 +01:00
Alexei Starovoitov f41aa387a7 Merge branch 'selftest-makefile-cleanup'
Andrii Nakryiko says:

====================
Fix issues with bpf_helper_defs.h usage in selftests/bpf. As part of that, fix
the way clean up is performed for libbpf and selftests/bpf. Some for Makefile
output clean ups as well.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-01-09 21:56:16 -08:00
Andrii Nakryiko 965b9fee28 selftests/bpf: Further clean up Makefile output
Further clean up Makefile output:
- hide "entering directory" messages;
- silvence sub-Make command echoing;
- succinct MKDIR messages.

Also remove few test binaries that are not produced anymore from .gitignore.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200110051716.1591485-4-andriin@fb.com
2020-01-09 21:55:08 -08:00
Andrii Nakryiko 6910d7d386 selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir
Reorder includes search path to ensure $(OUTPUT) and $(CURDIR) go before
libbpf's directory. Also fix bpf_helpers.h to include bpf_helper_defs.h in
such a way as to leverage includes search path. This allows selftests to not
use libbpf's local and potentially stale bpf_helper_defs.h. It's important
because selftests/bpf's Makefile only re-generates bpf_helper_defs.h in
seltests' output directory, not the one in libbpf's directory.

Also force regeneration of bpf_helper_defs.h when libbpf.a is updated to
reduce staleness.

Fixes: fa633a0f89 ("libbpf: Fix build on read-only filesystems")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200110051716.1591485-3-andriin@fb.com
2020-01-09 21:55:08 -08:00
Andrii Nakryiko 2031af28a4 libbpf,selftests/bpf: Fix clean targets
Libbpf's clean target should clean out generated files in $(OUTPUT) directory
and not make assumption that $(OUTPUT) directory is current working directory.

Selftest's Makefile should delegate cleaning of libbpf-generated files to
libbpf's Makefile. This ensures more robust clean up.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200110051716.1591485-2-andriin@fb.com
2020-01-09 21:55:08 -08:00
Andrii Nakryiko 492ab0205f libbpf: Make bpf_map order and indices stable
Currently, libbpf re-sorts bpf_map structs after all the maps are added and
initialized, which might change their relative order and invalidate any
bpf_map pointer or index taken before that. This is inconvenient and
error-prone. For instance, it can cause .kconfig map index to point to a wrong
map.

Furthermore, libbpf itself doesn't rely on any specific ordering of bpf_maps,
so it's just an unnecessary complication right now. This patch drops sorting
of maps and makes their relative positions fixed. If efficient index is ever
needed, it's better to have a separate array of pointers as a search index,
instead of reordering bpf_map struct in-place. This will be less error-prone
and will allow multiple independent orderings, if necessary (e.g., either by
section index or by name).

Fixes: 166750bc1d ("libbpf: Support libbpf-provided extern variables")
Reported-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200110034247.1220142-1-andriin@fb.com
2020-01-09 21:17:01 -08:00
Andrey Ignatov f5bfcd953d bpf: Document BPF_F_QUERY_EFFECTIVE flag
Document BPF_F_QUERY_EFFECTIVE flag, mostly to clarify how it affects
attach_flags what may not be obvious and what may lead to confision.

Specifically attach_flags is returned only for target_fd but if programs
are inherited from an ancestor cgroup then returned attach_flags for
current cgroup may be confusing. For example, two effective programs of
same attach_type can be returned but w/o BPF_F_ALLOW_MULTI in
attach_flags.

Simple repro:
  # bpftool c s /sys/fs/cgroup/path/to/task
  ID       AttachType      AttachFlags     Name
  # bpftool c s /sys/fs/cgroup/path/to/task effective
  ID       AttachType      AttachFlags     Name
  95043    ingress                         tw_ipt_ingress
  95048    ingress                         tw_ingress

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200108014006.938363-1-rdna@fb.com
2020-01-09 09:40:06 -08:00
Alexei Starovoitov 417759f7d4 Merge branch 'tcp-bpf-cc'
Martin Lau says:

====================
This series introduces BPF STRUCT_OPS.  It is an infra to allow
implementing some specific kernel's function pointers in BPF.
The first use case included in this series is to implement
TCP congestion control algorithm in BPF  (i.e. implement
struct tcp_congestion_ops in BPF).

There has been attempt to move the TCP CC to the user space
(e.g. CCP in TCP).   The common arguments are faster turn around,
get away from long-tail kernel versions in production...etc,
which are legit points.

BPF has been the continuous effort to join both kernel and
userspace upsides together (e.g. XDP to gain the performance
advantage without bypassing the kernel).  The recent BPF
advancements (in particular BTF-aware verifier, BPF trampoline,
BPF CO-RE...) made implementing kernel struct ops (e.g. tcp cc)
possible in BPF.

The idea is to allow implementing tcp_congestion_ops in bpf.
It allows a faster turnaround for testing algorithm in the
production while leveraging the existing (and continue growing) BPF
feature/framework instead of building one specifically for
userspace TCP CC.

Please see individual patch for details.

The bpftool support will be posted in follow-up patches.

v4:
- Expose tcp_ca_find() to tcp.h in patch 7.
  It is used to check the same bpf-tcp-cc
  does not exist to guarantee the register()
  will succeed.
- set_memory_ro() and then set_memory_x() only after all
  trampolines are written to the image in patch 6. (Daniel)
  spinlock is replaced by mutex because set_memory_*
  requires sleepable context.

v3:
- Fix kbuild error by considering CONFIG_BPF_SYSCALL (kbuild)
- Support anonymous bitfield in patch 4 (Andrii, Yonghong)
- Push boundary safety check to a specific arch's trampoline function
  (in patch 6) (Yonghong).
  Reuse the WANR_ON_ONCE check in arch_prepare_bpf_trampoline() in x86.
- Check module field is 0 in udata in patch 6 (Yonghong)
- Check zero holes in patch 6 (Andrii)
- s/_btf_vmlinux/btf/ in patch 5 and 7 (Andrii)
- s/check_xxx/is_xxx/ in patch 7 (Andrii)
- Use "struct_ops/" convention in patch 11 (Andrii)
- Use the skel instead of bpf_object in patch 11 (Andrii)
- libbpf: Decide BPF_PROG_TYPE_STRUCT_OPS at open phase by using
          find_sec_def()
- libbpf: Avoid a debug message at open phase (Andrii)
- libbpf: Add bpf_program__(is|set)_struct_ops() for consistency (Andrii)
- libbpf: Add "struct_ops" to section_defs (Andrii)
- libbpf: Some code shuffling in init_kern_struct_ops() (Andrii)
- libbpf: A few safety checks (Andrii)

v2:
- Dropped cubic for now.  They will be reposted
  once there are more clarity in "jiffies" on both
  bpf side (about the helper) and
  tcp_cubic side (some of jiffies usages are being replaced
  by tp->tcp_mstamp)
- Remove unnecssary check on bitfield support from btf_struct_access()
  (Yonghong)
- BTF_TYPE_EMIT macro (Yonghong, Andrii)
- value_name's length check to avoid an unlikely
  type match during truncation case (Yonghong)
- BUILD_BUG_ON to ensure no trampoline-image overrun
  in the future (Yonghong)
- Simplify get_next_key() (Yonghong)
- Added comment to explain how to check mandatory
  func ptr in net/ipv4/bpf_tcp_ca.c (Yonghong)
- Rename "__bpf_" to "bpf_struct_ops_" for value prefix (Andrii)
- Add comment to highlight the bpf_dctcp.c is not necessarily
  the same as tcp_dctcp.c. (Alexei, Eric)
- libbpf: Renmae "struct_ops" to ".struct_ops" for elf sec (Andrii)
- libbpf: Expose struct_ops as a bpf_map (Andrii)
- libbpf: Support multiple struct_ops in SEC(".struct_ops") (Andrii)
- libbpf: Add bpf_map__attach_struct_ops()  (Andrii)
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-01-09 09:15:25 -08:00
Martin KaFai Lau 09903869f6 bpf: Add bpf_dctcp example
This patch adds a bpf_dctcp example.  It currently does not do
no-ECN fallback but the same could be done through the cgrp2-bpf.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200109003517.3856825-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 590a008882 bpf: libbpf: Add STRUCT_OPS support
This patch adds BPF STRUCT_OPS support to libbpf.

The only sec_name convention is SEC(".struct_ops") to identify the
struct_ops implemented in BPF,
e.g. To implement a tcp_congestion_ops:

SEC(".struct_ops")
struct tcp_congestion_ops dctcp = {
	.init           = (void *)dctcp_init,  /* <-- a bpf_prog */
	/* ... some more func prts ... */
	.name           = "bpf_dctcp",
};

Each struct_ops is defined as a global variable under SEC(".struct_ops")
as above.  libbpf creates a map for each variable and the variable name
is the map's name.  Multiple struct_ops is supported under
SEC(".struct_ops").

In the bpf_object__open phase, libbpf will look for the SEC(".struct_ops")
section and find out what is the btf-type the struct_ops is
implementing.  Note that the btf-type here is referring to
a type in the bpf_prog.o's btf.  A "struct bpf_map" is added
by bpf_object__add_map() as other maps do.  It will then
collect (through SHT_REL) where are the bpf progs that the
func ptrs are referring to.  No btf_vmlinux is needed in
the open phase.

In the bpf_object__load phase, the map-fields, which depend
on the btf_vmlinux, are initialized (in bpf_map__init_kern_struct_ops()).
It will also set the prog->type, prog->attach_btf_id, and
prog->expected_attach_type.  Thus, the prog's properties do
not rely on its section name.
[ Currently, the bpf_prog's btf-type ==> btf_vmlinux's btf-type matching
  process is as simple as: member-name match + btf-kind match + size match.
  If these matching conditions fail, libbpf will reject.
  The current targeting support is "struct tcp_congestion_ops" which
  most of its members are function pointers.
  The member ordering of the bpf_prog's btf-type can be different from
  the btf_vmlinux's btf-type. ]

Then, all obj->maps are created as usual (in bpf_object__create_maps()).

Once the maps are created and prog's properties are all set,
the libbpf will proceed to load all the progs.

bpf_map__attach_struct_ops() is added to register a struct_ops
map to a kernel subsystem.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200109003514.3856730-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 17328d618c bpf: Synch uapi bpf.h to tools/
This patch sync uapi bpf.h to tools/

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200109003512.3856559-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 206057fe02 bpf: Add BPF_FUNC_tcp_send_ack helper
Add a helper to send out a tcp-ack.  It will be used in the later
bpf_dctcp implementation that requires to send out an ack
when the CE state changed.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109004551.3900448-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 0baf26b0fc bpf: tcp: Support tcp_congestion_ops in bpf
This patch makes "struct tcp_congestion_ops" to be the first user
of BPF STRUCT_OPS.  It allows implementing a tcp_congestion_ops
in bpf.

The BPF implemented tcp_congestion_ops can be used like
regular kernel tcp-cc through sysctl and setsockopt.  e.g.
[root@arch-fb-vm1 bpf]# sysctl -a | egrep congestion
net.ipv4.tcp_allowed_congestion_control = reno cubic bpf_cubic
net.ipv4.tcp_available_congestion_control = reno bic cubic bpf_cubic
net.ipv4.tcp_congestion_control = bpf_cubic

There has been attempt to move the TCP CC to the user space
(e.g. CCP in TCP).   The common arguments are faster turn around,
get away from long-tail kernel versions in production...etc,
which are legit points.

BPF has been the continuous effort to join both kernel and
userspace upsides together (e.g. XDP to gain the performance
advantage without bypassing the kernel).  The recent BPF
advancements (in particular BTF-aware verifier, BPF trampoline,
BPF CO-RE...) made implementing kernel struct ops (e.g. tcp cc)
possible in BPF.  It allows a faster turnaround for testing algorithm
in the production while leveraging the existing (and continue growing)
BPF feature/framework instead of building one specifically for
userspace TCP CC.

This patch allows write access to a few fields in tcp-sock
(in bpf_tcp_ca_btf_struct_access()).

The optional "get_info" is unsupported now.  It can be added
later.  One possible way is to output the info with a btf-id
to describe the content.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003508.3856115-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 85d33df357 bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS
The patch introduces BPF_MAP_TYPE_STRUCT_OPS.  The map value
is a kernel struct with its func ptr implemented in bpf prog.
This new map is the interface to register/unregister/introspect
a bpf implemented kernel struct.

The kernel struct is actually embedded inside another new struct
(or called the "value" struct in the code).  For example,
"struct tcp_congestion_ops" is embbeded in:
struct bpf_struct_ops_tcp_congestion_ops {
	refcount_t refcnt;
	enum bpf_struct_ops_state state;
	struct tcp_congestion_ops data;  /* <-- kernel subsystem struct here */
}
The map value is "struct bpf_struct_ops_tcp_congestion_ops".
The "bpftool map dump" will then be able to show the
state ("inuse"/"tobefree") and the number of subsystem's refcnt (e.g.
number of tcp_sock in the tcp_congestion_ops case).  This "value" struct
is created automatically by a macro.  Having a separate "value" struct
will also make extending "struct bpf_struct_ops_XYZ" easier (e.g. adding
"void (*init)(void)" to "struct bpf_struct_ops_XYZ" to do some
initialization works before registering the struct_ops to the kernel
subsystem).  The libbpf will take care of finding and populating the
"struct bpf_struct_ops_XYZ" from "struct XYZ".

Register a struct_ops to a kernel subsystem:
1. Load all needed BPF_PROG_TYPE_STRUCT_OPS prog(s)
2. Create a BPF_MAP_TYPE_STRUCT_OPS with attr->btf_vmlinux_value_type_id
   set to the btf id "struct bpf_struct_ops_tcp_congestion_ops" of the
   running kernel.
   Instead of reusing the attr->btf_value_type_id,
   btf_vmlinux_value_type_id s added such that attr->btf_fd can still be
   used as the "user" btf which could store other useful sysadmin/debug
   info that may be introduced in the furture,
   e.g. creation-date/compiler-details/map-creator...etc.
3. Create a "struct bpf_struct_ops_tcp_congestion_ops" object as described
   in the running kernel btf.  Populate the value of this object.
   The function ptr should be populated with the prog fds.
4. Call BPF_MAP_UPDATE with the object created in (3) as
   the map value.  The key is always "0".

During BPF_MAP_UPDATE, the code that saves the kernel-func-ptr's
args as an array of u64 is generated.  BPF_MAP_UPDATE also allows
the specific struct_ops to do some final checks in "st_ops->init_member()"
(e.g. ensure all mandatory func ptrs are implemented).
If everything looks good, it will register this kernel struct
to the kernel subsystem.  The map will not allow further update
from this point.

Unregister a struct_ops from the kernel subsystem:
BPF_MAP_DELETE with key "0".

Introspect a struct_ops:
BPF_MAP_LOOKUP_ELEM with key "0".  The map value returned will
have the prog _id_ populated as the func ptr.

The map value state (enum bpf_struct_ops_state) will transit from:
INIT (map created) =>
INUSE (map updated, i.e. reg) =>
TOBEFREE (map value deleted, i.e. unreg)

The kernel subsystem needs to call bpf_struct_ops_get() and
bpf_struct_ops_put() to manage the "refcnt" in the
"struct bpf_struct_ops_XYZ".  This patch uses a separate refcnt
for the purose of tracking the subsystem usage.  Another approach
is to reuse the map->refcnt and then "show" (i.e. during map_lookup)
the subsystem's usage by doing map->refcnt - map->usercnt to filter out
the map-fd/pinned-map usage.  However, that will also tie down the
future semantics of map->refcnt and map->usercnt.

The very first subsystem's refcnt (during reg()) holds one
count to map->refcnt.  When the very last subsystem's refcnt
is gone, it will also release the map->refcnt.  All bpf_prog will be
freed when the map->refcnt reaches 0 (i.e. during map_free()).

Here is how the bpftool map command will look like:
[root@arch-fb-vm1 bpf]# bpftool map show
6: struct_ops  name dctcp  flags 0x0
	key 4B  value 256B  max_entries 1  memlock 4096B
	btf_id 6
[root@arch-fb-vm1 bpf]# bpftool map dump id 6
[{
        "value": {
            "refcnt": {
                "refs": {
                    "counter": 1
                }
            },
            "state": 1,
            "data": {
                "list": {
                    "next": 0,
                    "prev": 0
                },
                "key": 0,
                "flags": 2,
                "init": 24,
                "release": 0,
                "ssthresh": 25,
                "cong_avoid": 30,
                "set_state": 27,
                "cwnd_event": 28,
                "in_ack_event": 26,
                "undo_cwnd": 29,
                "pkts_acked": 0,
                "min_tso_segs": 0,
                "sndbuf_expand": 0,
                "cong_control": 0,
                "get_info": 0,
                "name": [98,112,102,95,100,99,116,99,112,0,0,0,0,0,0,0
                ],
                "owner": 0
            }
        }
    }
]

Misc Notes:
* bpf_struct_ops_map_sys_lookup_elem() is added for syscall lookup.
  It does an inplace update on "*value" instead returning a pointer
  to syscall.c.  Otherwise, it needs a separate copy of "zero" value
  for the BPF_STRUCT_OPS_STATE_INIT to avoid races.

* The bpf_struct_ops_map_delete_elem() is also called without
  preempt_disable() from map_delete_elem().  It is because
  the "->unreg()" may requires sleepable context, e.g.
  the "tcp_unregister_congestion_control()".

* "const" is added to some of the existing "struct btf_func_model *"
  function arg to avoid a compiler warning caused by this patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003505.3855919-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 27ae7997a6 bpf: Introduce BPF_PROG_TYPE_STRUCT_OPS
This patch allows the kernel's struct ops (i.e. func ptr) to be
implemented in BPF.  The first use case in this series is the
"struct tcp_congestion_ops" which will be introduced in a
latter patch.

This patch introduces a new prog type BPF_PROG_TYPE_STRUCT_OPS.
The BPF_PROG_TYPE_STRUCT_OPS prog is verified against a particular
func ptr of a kernel struct.  The attr->attach_btf_id is the btf id
of a kernel struct.  The attr->expected_attach_type is the member
"index" of that kernel struct.  The first member of a struct starts
with member index 0.  That will avoid ambiguity when a kernel struct
has multiple func ptrs with the same func signature.

For example, a BPF_PROG_TYPE_STRUCT_OPS prog is written
to implement the "init" func ptr of the "struct tcp_congestion_ops".
The attr->attach_btf_id is the btf id of the "struct tcp_congestion_ops"
of the _running_ kernel.  The attr->expected_attach_type is 3.

The ctx of BPF_PROG_TYPE_STRUCT_OPS is an array of u64 args saved
by arch_prepare_bpf_trampoline that will be done in the next
patch when introducing BPF_MAP_TYPE_STRUCT_OPS.

"struct bpf_struct_ops" is introduced as a common interface for the kernel
struct that supports BPF_PROG_TYPE_STRUCT_OPS prog.  The supporting kernel
struct will need to implement an instance of the "struct bpf_struct_ops".

The supporting kernel struct also needs to implement a bpf_verifier_ops.
During BPF_PROG_LOAD, bpf_struct_ops_find() will find the right
bpf_verifier_ops by searching the attr->attach_btf_id.

A new "btf_struct_access" is also added to the bpf_verifier_ops such
that the supporting kernel struct can optionally provide its own specific
check on accessing the func arg (e.g. provide limited write access).

After btf_vmlinux is parsed, the new bpf_struct_ops_init() is called
to initialize some values (e.g. the btf id of the supporting kernel
struct) and it can only be done once the btf_vmlinux is available.

The R0 checks at BPF_EXIT is excluded for the BPF_PROG_TYPE_STRUCT_OPS prog
if the return type of the prog->aux->attach_func_proto is "void".

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003503.3855825-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 976aba002f bpf: Support bitfield read access in btf_struct_access
This patch allows bitfield access as a scalar.

It checks "off + size > t->size" to avoid accessing bitfield
end up accessing beyond the struct.  This check is done
outside of the loop since it is applicable to all access.

It also takes this chance to break early on the "off < moff" case.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003501.3855427-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 218b3f65f9 bpf: Add enum support to btf_ctx_access()
It allows bpf prog (e.g. tracing) to attach
to a kernel function that takes enum argument.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003459.3855366-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 275517ff45 bpf: Avoid storing modifier to info->btf_id
info->btf_id expects the btf_id of a struct, so it should
store the final result after skipping modifiers (if any).

It also takes this chanace to add a missing newline in one of the
bpf_log() messages.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003456.3855176-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau 65726b5b7e bpf: Save PTR_TO_BTF_ID register state when spilling to stack
This patch makes the verifier save the PTR_TO_BTF_ID register state when
spilling to the stack.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003454.3854870-1-kafai@fb.com
2020-01-09 08:45:32 -08:00
Stanislav Fomichev e43002242a selftests/bpf: Restore original comm in test_overhead
test_overhead changes task comm in order to estimate BPF trampoline
overhead but never sets the comm back to the original one.
We have the tests (like core_reloc.c) that have 'test_progs'
as hard-coded expected comm, so let's try to preserve the
original comm.

Currently, everything works because the order of execution is:
first core_recloc, then test_overhead; but let's make it a bit
future-proof.

Other related changes: use 'test_overhead' as new comm instead of
'test' to make it easy to debug and drop '\n' at the end.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Petar Penkov <ppenkov@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200108192132.189221-1-sdf@google.com
2020-01-09 08:42:07 -08:00
Michal Rostecki 2faef64aa6 bpftool: Add misc section and probe for large INSN limit
Introduce a new probe section (misc) for probes not related to concrete
map types, program types, functions or kernel configuration. Introduce a
probe for large INSN limit as the first one in that section.

Example outputs:

  # bpftool feature probe
  [...]
  Scanning miscellaneous eBPF features...
  Large program size limit is available

  # bpftool feature probe macros
  [...]
  /*** eBPF misc features ***/
  #define HAVE_HAVE_LARGE_INSN_LIMIT

  # bpftool feature probe -j | jq '.["misc"]'
  {
    "have_large_insn_limit": true
  }

Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Link: https://lore.kernel.org/bpf/20200108162428.25014-3-mrostecki@opensuse.org
2020-01-08 19:34:45 +01:00
Michal Rostecki 5ff0512003 libbpf: Add probe for large INSN limit
Introduce a new probe which checks whether kernel has large maximum
program size which was increased in the following commit:

c04c0d2b96 ("bpf: increase complexity limit and maximum program size")

Based on the similar check in Cilium[0], authored by Daniel Borkmann.

  [0] 657d0f585a

Co-authored-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Link: https://lore.kernel.org/bpf/20200108162428.25014-2-mrostecki@opensuse.org
2020-01-08 19:31:35 +01:00
Vincent Cheng 1ece2fbe9b ptp: clockmatrix: Rework clockmatrix version information.
Simplify and fix the version information displayed by the driver.
The new info better relects what is needed to support the hardware.

Prev:
Version: 4.8.0, Pipeline 22169 0x4001, Rev 0, Bond 5, CSR 311, IRQ 2

New:
Version: 4.8.0, Id: 0x4001  Hw Rev: 5  OTP Config Select: 15

- Remove pipeline, CSR and IRQ because version x.y.z already incorporates
  this information.
- Remove bond number because it is not used.
- Remove rev number because register was not implemented, always 0
- Add HW Rev ID register to replace rev number
- Add OTP config select to show the user configuration chosen by
  the configurable GPIO pins on start-up

Signed-off-by: Vincent Cheng <vincent.cheng.xh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:51:23 -08:00
YueHaibing 4addbcb387 enetc: Fix inconsistent IS_ERR and PTR_ERR
The proper pointer to be passed as argument is hw
Detected using Coccinelle.

Fixes: 6517798dd3 ("enetc: Make MDIO accessors more generic and export to include/linux/fsl")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:46:42 -08:00
Dan Carpenter 0d6e5bfc9c enetc: Fix an off by one in enetc_setup_tc_txtime()
The priv->tx_ring[] has 16 elements but only priv->num_tx_rings are
set up, the rest are NULL.  This ">" comparison should be ">=" to avoid
a potential crash.

Fixes: 0d08c9ec7d ("enetc: add support time specific departure base on the qos etf")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:46:20 -08:00
David S. Miller cbefe2c957 Merge branch 'Documentation-stmmac-documentation-improvements'
Jose Abreu says:

====================
Documentation: stmmac documentation improvements

Converts stmmac documentation to RST format.

1) Adds missing entry of stmmac documentation to MAINTAINERS.

2) Converts stmmac documentation to RST format and adds some new info.

3) Adds the new RST file to the list of files.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:38:56 -08:00
Jose Abreu b053b28e93 Documentation: networking: Add stmmac to device drivers list
Add the stmmac RST file to the index.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:38:56 -08:00
Jose Abreu 2ffebffbe7 Documentation: networking: Convert stmmac documentation to RST format
Convert the documentation of the driver to RST format and delete the old
txt and old information that no longer applies.

Also, add some new information.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:38:56 -08:00
Jose Abreu 1501125460 MAINTAINERS: Add stmmac Ethernet driver documentation entry
Add the missing entry for the file that documents the stmicro Ethernet
driver stmmac.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:38:56 -08:00
Chen Zhou c68d724826 drivers: net: cisco_hdlc: use __func__ in debug message
Use __func__ to print the function name instead of hard coded string.
BTW, replace printk(KERN_DEBUG, ...) with netdev_dbg.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:33:35 -08:00
David S. Miller 10332dc220 Merge branch 'net-ch9200-code-cleanup'
Chen Zhou says:

====================
net: ch9200: code cleanup

patch 1 introduce __func__ in debug message.
patch 2 remove unnecessary return.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:30:36 -08:00
Chen Zhou 195234b885 net: ch9200: remove unnecessary return
The return is not needed, remove it.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:30:36 -08:00
Chen Zhou e64dec834e net: ch9200: use __func__ in debug message
Use __func__ to print the function name instead of hard coded string.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:30:36 -08:00
David S. Miller 58cf542a1a Merge branch 'ionic-driver-updates'
Shannon Nelson says:

====================
ionic: driver updates

These are a few little updates for the ionic network driver.

v2: dropped IBM msi patch
    added fix for a compiler warning
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:05:06 -08:00
Shannon Nelson 6be1a5ce1b ionic: clear compiler warning on hb use before set
Build checks have pointed out that 'hb' can theoretically
be used before set, so let's initialize it and get rid
of the compiler complaint.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:05:06 -08:00
Shannon Nelson c37d6e3f25 ionic: restrict received packets to mtu size
Make sure the NIC drops packets that are larger than the
specified MTU.

The front end of the NIC will accept packets larger than MTU and
will copy all the data it can to fill up the driver's posted
buffers - if the buffers are not long enough the packet will
then get dropped.  With the Rx SG buffers allocagted as full
pages, we are currently setting up more space than MTU size
available and end up receiving some packets that are larger
than MTU, up to the size of buffers posted.  To be sure the
NIC doesn't waste our time with oversized packets we need to
lie a little in the SG descriptor about how long is the last
SG element.

At dealloc time, we know the allocation was a page, so the
deallocation doesn't care about what length we put in the
descriptor.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:05:06 -08:00
Shannon Nelson 24cfa8c762 ionic: add Rx dropped packet counter
Add a counter for packets dropped by the driver, typically
for bad size or a receive error seen by the device.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:05:06 -08:00
Shannon Nelson 3daca28f15 ionic: drop use of subdevice tags
The subdevice concept is not being used in the driver, so
drop the references to it.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-07 13:05:06 -08:00
David S. Miller 5528e0d7f1 Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue
Jeff Kirsher says:

====================
1GbE Intel Wired LAN Driver Updates 2020-01-06

This series contains updates to igc to add basic support for
timestamping.

Vinicius adds basic support for timestamping and enables ptp4l/phc2sys
to work with i225 devices.  Initially, adds the ability to read and
adjust the PHC clock.  Patches 2 & 3 enable and retrieve hardware
timestamps.  Patch 4 implements the ethtool ioctl that ptp4l uses to
check what timestamping methods are supported.  Lastly, added support to
do timestamping using the "Start of Packet" signal from the PHY, which
is now supported in i225 devices.

While i225 does support multiple PTP domains, with multiple timestamping
registers, we currently only support one PTP domain and use only one of
the timestamping registers for implementation purposes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 18:44:48 -08:00
David S. Miller 1b935183ae Merge branch 'Unique-mv88e6xxx-IRQ-names'
Andrew Lunn says:

====================
Unique mv88e6xxx IRQ names

There are a few boards which have multiple mv88e6xxx switches. With
such boards, it can be hard to determine which interrupts belong to
which switches. Make the interrupt names unique by including the
device name in the interrupt name. For the SERDES interrupt, also
include the port number. As a result of these patches ZII devel C
looks like:

 50:          0  gpio-vf610  27 Level     mv88e6xxx-0.1:00
 54:          0  mv88e6xxx-g1   3 Edge      mv88e6xxx-0.1:00-g1-atu-prob
 56:          0  mv88e6xxx-g1   5 Edge      mv88e6xxx-0.1:00-g1-vtu-prob
 58:          0  mv88e6xxx-g1   7 Edge      mv88e6xxx-0.1:00-g2
 61:          0  mv88e6xxx-g2   1 Edge      !mdio-mux!mdio@1!switch@0!mdio:01
 62:          0  mv88e6xxx-g2   2 Edge      !mdio-mux!mdio@1!switch@0!mdio:02
 63:          0  mv88e6xxx-g2   3 Edge      !mdio-mux!mdio@1!switch@0!mdio:03
 64:          0  mv88e6xxx-g2   4 Edge      !mdio-mux!mdio@1!switch@0!mdio:04
 70:          0  mv88e6xxx-g2  10 Edge      mv88e6xxx-0.1:00-serdes-10
 75:          0  mv88e6xxx-g2  15 Edge      mv88e6xxx-0.1:00-watchdog
 76:          5  gpio-vf610  26 Level     mv88e6xxx-0.2:00
 80:          0  mv88e6xxx-g1   3 Edge      mv88e6xxx-0.2:00-g1-atu-prob
 82:          0  mv88e6xxx-g1   5 Edge      mv88e6xxx-0.2:00-g1-vtu-prob
 84:          4  mv88e6xxx-g1   7 Edge      mv88e6xxx-0.2:00-g2
 87:          2  mv88e6xxx-g2   1 Edge      !mdio-mux!mdio@2!switch@0!mdio:01
 88:          0  mv88e6xxx-g2   2 Edge      !mdio-mux!mdio@2!switch@0!mdio:02
 89:          0  mv88e6xxx-g2   3 Edge      !mdio-mux!mdio@2!switch@0!mdio:03
 90:          0  mv88e6xxx-g2   4 Edge      !mdio-mux!mdio@2!switch@0!mdio:04
 95:          3  mv88e6xxx-g2   9 Edge      mv88e6xxx-0.2:00-serdes-9
 96:          0  mv88e6xxx-g2  10 Edge      mv88e6xxx-0.2:00-serdes-10
101:          0  mv88e6xxx-g2  15 Edge      mv88e6xxx-0.2:00-watchdog

Interrupt names like !mdio-mux!mdio@2!switch@0!mdio:01 are created by
phylib for the integrated PHYs. The mv88e6xxx driver does not
determine these names.
====================

Tested-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 18:30:15 -08:00
Andrew Lunn 8ddf0b5693 net: dsa: mv88e6xxx: Unique ATU and VTU IRQ names
Dynamically generate a unique interrupt name for the VTU and ATU,
based on the device name.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 18:30:15 -08:00
Andrew Lunn 06acd1148b net: dsa: mv88e6xxx: Unique g2 IRQ name
Dynamically generate a unique g2 interrupt name, based on the
device name.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 18:30:14 -08:00
Andrew Lunn 8b4db28914 net: dsa: mv88e6xxx: Unique watchdog IRQ name
Dynamically generate a unique watchdog interrupt name, based on the
device name.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 18:30:14 -08:00
Andrew Lunn e6f2f6b824 net: dsa: mv88e6xxx: Unique SERDES interrupt names
Dynamically generate a unique SERDES interrupt name, based on the
device name and the port the SERDES is for. For example:

 95:          3  mv88e6xxx-g2   9 Edge      mv88e6xxx-0.2:00-serdes-9
 96:          0  mv88e6xxx-g2  10 Edge      mv88e6xxx-0.2:00-serdes-10

The 0.2:00 indicates the switch and -9 indicates port 9.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 18:30:14 -08:00
Andrew Lunn 3095383a8a net: dsa: mv88e6xxx: Unique IRQ name
Dynamically generate a unique switch interrupt name, based on the
device name.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 18:30:14 -08:00