Commit Graph

1031976 Commits

Author SHA1 Message Date
Kumar Kartikeya Dwivedi
1d930fd2cd samples: bpf: Add redirect tracepoint statistics support
This implements per-errno reporting (for the ones we explicitly
recognize), adds some help output, and implements the stats retrieval
and printing functions.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-6-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
3231403894 samples: bpf: Add BPF support for redirect tracepoint
This adds the shared BPF file that will be used going forward for
sharing tracepoint programs among XDP redirect samples.

Since vmlinux.h conflicts with tools/include for READ_ONCE/WRITE_ONCE
and ARRAY_SIZE, they are copied in to xdp_sample.bpf.h along with other
helpers that will be required.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-5-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
156f886cf6 samples: bpf: Add basic infrastructure for XDP samples
This file implements some common helpers to consolidate differences in
features and functionality between the various XDP samples and give them
a consistent look, feel, and reporting capabilities.

This commit only adds support for receive statistics, which does not
rely on any tracepoint, but on the XDP program installed on the device
by each XDP redirect sample.

Some of the key features are:
 * A concise output format accompanied by helpful text explaining its
   fields.
 * An elaborate output format building upon the concise one, and folding
   out details in case of errors and staying out of view otherwise.
 * Printing driver names for devices redirecting packets.
 * Getting mac address for interface.
 * Printing summarized total statistics for the entire session.
 * Ability to dynamically switch between concise and verbose mode, using
   SIGQUIT (Ctrl + \).

In later patches, the support will be extended for each tracepoint with
its own custom output in concise and verbose mode.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-4-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
f2e85d4a75 tools: include: Add ethtool_drvinfo definition to UAPI header
Instead of copying the whole header in, just add the struct definitions
we need for now. In the future it can be synced as a copy of in-tree
header if required.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-3-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
50b796e645 samples: bpf: Fix a couple of warnings
cookie_uid_helper_example.c: In function ‘main’:
cookie_uid_helper_example.c:178:69: warning: ‘ -j ACCEPT’ directive
	writing 10 bytes into a region of size between 8 and 58
	[-Wformat-overflow=]
  178 |  sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
      |								       ^~~~~~~~~~
/home/kkd/src/linux/samples/bpf/cookie_uid_helper_example.c:178:9: note:
	‘sprintf’ output between 53 and 103 bytes into a destination of size 100
  178 |  sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  179 |         file);
      |         ~~~~~

Fix by using snprintf and a sufficiently sized buffer.

tracex4_user.c:35:15: warning: ‘write’ reading 12 bytes from a region of
	size 11 [-Wstringop-overread]
   35 |         key = write(1, "\e[1;1H\e[2J", 12); /* clear screen */
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Use size as 11.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-2-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Andrey Ignatov
d7af7e497f bpf: Fix possible out of bound write in narrow load handling
Fix a verifier bug found by smatch static checker in [0].

This problem has never been seen in prod to my best knowledge. Fixing it
still seems to be a good idea since it's hard to say for sure whether
it's possible or not to have a scenario where a combination of
convert_ctx_access() and a narrow load would lead to an out of bound
write.

When narrow load is handled, one or two new instructions are added to
insn_buf array, but before it was only checked that

	cnt >= ARRAY_SIZE(insn_buf)

And it's safe to add a new instruction to insn_buf[cnt++] only once. The
second try will lead to out of bound write. And this is what can happen
if `shift` is set.

Fix it by making sure that if the BPF_RSH instruction has to be added in
addition to BPF_AND then there is enough space for two more instructions
in insn_buf.

The full report [0] is below:

kernel/bpf/verifier.c:12304 convert_ctx_accesses() warn: offset 'cnt' incremented past end of array
kernel/bpf/verifier.c:12311 convert_ctx_accesses() warn: offset 'cnt' incremented past end of array

kernel/bpf/verifier.c
    12282
    12283 			insn->off = off & ~(size_default - 1);
    12284 			insn->code = BPF_LDX | BPF_MEM | size_code;
    12285 		}
    12286
    12287 		target_size = 0;
    12288 		cnt = convert_ctx_access(type, insn, insn_buf, env->prog,
    12289 					 &target_size);
    12290 		if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf) ||
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Bounds check.

    12291 		    (ctx_field_size && !target_size)) {
    12292 			verbose(env, "bpf verifier is misconfigured\n");
    12293 			return -EINVAL;
    12294 		}
    12295
    12296 		if (is_narrower_load && size < target_size) {
    12297 			u8 shift = bpf_ctx_narrow_access_offset(
    12298 				off, size, size_default) * 8;
    12299 			if (ctx_field_size <= 4) {
    12300 				if (shift)
    12301 					insn_buf[cnt++] = BPF_ALU32_IMM(BPF_RSH,
                                                         ^^^^^
increment beyond end of array

    12302 									insn->dst_reg,
    12303 									shift);
--> 12304 				insn_buf[cnt++] = BPF_ALU32_IMM(BPF_AND, insn->dst_reg,
                                                 ^^^^^
out of bounds write

    12305 								(1 << size * 8) - 1);
    12306 			} else {
    12307 				if (shift)
    12308 					insn_buf[cnt++] = BPF_ALU64_IMM(BPF_RSH,
    12309 									insn->dst_reg,
    12310 									shift);
    12311 				insn_buf[cnt++] = BPF_ALU64_IMM(BPF_AND, insn->dst_reg,
                                        ^^^^^^^^^^^^^^^
Same.

    12312 								(1ULL << size * 8) - 1);
    12313 			}
    12314 		}
    12315
    12316 		new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
    12317 		if (!new_prog)
    12318 			return -ENOMEM;
    12319
    12320 		delta += cnt - 1;
    12321
    12322 		/* keep walking new program and skip insns we just inserted */
    12323 		env->prog = new_prog;
    12324 		insn      = new_prog->insnsi + i + delta;
    12325 	}
    12326
    12327 	return 0;
    12328 }

[0] https://lore.kernel.org/bpf/20210817050843.GA21456@kili/

v1->v2:
- clarify that problem was only seen by static checker but not in prod;

Fixes: 46f53a65d2 ("bpf: Allow narrow loads with offset > 0")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210820163935.1902398-1-rdna@fb.com
2021-08-24 14:32:26 -07:00
Alexei Starovoitov
f63693e3ae Merge branch 'bpf: Allow bpf_get_netns_cookie in BPF_PROG_TYPE_SK_MSG'
Xu Liu says:

====================

We'd like to be able to identify netns from sk_msg hooks
to accelerate local process communication form different netns.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-08-24 14:17:53 -07:00
Xu Liu
6cbca1ee0d selftests/bpf: Test for get_netns_cookie
Add test to use get_netns_cookie() from BPF_PROG_TYPE_SK_MSG.

Signed-off-by: Xu Liu <liuxu623@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210820071712.52852-3-liuxu623@gmail.com
2021-08-24 14:17:53 -07:00
Xu Liu
fab60e29fc bpf: Allow bpf_get_netns_cookie in BPF_PROG_TYPE_SK_MSG
We'd like to be able to identify netns from sk_msg hooks
to accelerate local process communication form different netns.

Signed-off-by: Xu Liu <liuxu623@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210820071712.52852-2-liuxu623@gmail.com
2021-08-24 14:17:53 -07:00
Alexei Starovoitov
8c0bb89e8e Merge branch 'selftests/bpf: minor fixups'
Li Zhijian says:

====================
Fix a few issues reported by 0Day/LKP during runing selftests/bpf.

Changelog:
V2:
- folded previous similar standalone patch to [1/5], and add acked tag
  from Song Liu
- add acked tag to [2/5], [3/5] from Song Liu
- [4/5]: move test_bpftool.py to TEST_PROGS_EXTENDED, files in TEST_GEN_PROGS_EXTENDED
are generated by make. Otherwise, it will break out-of-tree install:
'make O=/kselftest-build SKIP_TARGETS= V=1 -C tools/testing/selftests install INSTALL_PATH=/kselftest-install'
- [5/5]: new patch
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-08-24 14:01:11 -07:00
Li Zhijian
00e1116031 selftests/bpf: Exit with KSFT_SKIP if no Makefile found
This would happend when we run the tests after install kselftests
 root@lkp-skl-d01 ~# /kselftests/run_kselftest.sh -t bpf:test_doc_build.sh
 TAP version 13
 1..1
 # selftests: bpf: test_doc_build.sh
 perl: warning: Setting locale failed.
 perl: warning: Please check that your locale settings:
         LANGUAGE = (unset),
         LC_ALL = (unset),
         LC_ADDRESS = "en_US.UTF-8",
         LC_NAME = "en_US.UTF-8",
         LC_MONETARY = "en_US.UTF-8",
         LC_PAPER = "en_US.UTF-8",
         LC_IDENTIFICATION = "en_US.UTF-8",
         LC_TELEPHONE = "en_US.UTF-8",
         LC_MEASUREMENT = "en_US.UTF-8",
         LC_TIME = "en_US.UTF-8",
         LC_NUMERIC = "en_US.UTF-8",
         LANG = "en_US.UTF-8"
     are supported and installed on your system.
 perl: warning: Falling back to the standard locale ("C").
 # skip:    bpftool files not found!
 #
 ok 1 selftests: bpf: test_doc_build.sh # SKIP

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210820025549.28325-1-lizhijian@cn.fujitsu.com
2021-08-24 14:01:10 -07:00
Li Zhijian
404bd9ff5d selftests/bpf: Add missing files required by test_bpftool.sh for installing
test_bpftool.sh relies on bpftool and test_bpftool.py.

'make install' will install bpftool to INSTALL_PATH/bpf/bpftool, and
export it to PATH so that it can be used after installing.

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210820015556.23276-5-lizhijian@cn.fujitsu.com
2021-08-24 14:01:10 -07:00
Li Zhijian
7a3bdca20b selftests/bpf: Add default bpftool built by selftests to PATH
For 'make run_tests':
selftests will build bpftool into tools/testing/selftests/bpf/tools/sbin/bpftool
by default.

==================
root@lkp-skl-d01 /opt/rootfs/v5.14-rc4# make -C tools/testing/selftests/bpf run_tests
make: Entering directory '/opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf'
  MKDIR    include
  MKDIR    libbpf
  MKDIR    bpftool
[...]
  GEN     /opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/tools/build/bpftool/profiler.skel.h
  CC      /opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/tools/build/bpftool/prog.o
  GEN     /opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/tools/build/bpftool/pid_iter.skel.h
  CC      /opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/tools/build/bpftool/pids.o
  LINK    /opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/tools/build/bpftool/bpftool
  INSTALL bpftool
  GEN      vmlinux.h
[...]
 # test_feature_dev_json (test_bpftool.TestBpftool) ... ERROR
 # test_feature_kernel (test_bpftool.TestBpftool) ... ERROR
 # test_feature_kernel_full (test_bpftool.TestBpftool) ... ERROR
 # test_feature_kernel_full_vs_not_full (test_bpftool.TestBpftool) ... ERROR
 # test_feature_macros (test_bpftool.TestBpftool) ... Error: bug: failed to retrieve CAP_BPF status: Invalid argument
 # ERROR
 #
 # ======================================================================
 # ERROR: test_feature_dev_json (test_bpftool.TestBpftool)
 # ----------------------------------------------------------------------
 # Traceback (most recent call last):
 #   File "/opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/test_bpftool.py", line 57, in wrapper
 #     return f(*args, iface, **kwargs)
 #   File "/opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/test_bpftool.py", line 82, in test_feature_dev_json
 #     res = bpftool_json(["feature", "probe", "dev", iface])
 #   File "/opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/test_bpftool.py", line 42, in bpftool_json
 #     res = _bpftool(args)
 #   File "/opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/test_bpftool.py", line 34, in _bpftool
 #     return subprocess.check_output(_args)
 #   File "/usr/lib/python3.7/subprocess.py", line 395, in check_output
 #     **kwargs).stdout
 #   File "/usr/lib/python3.7/subprocess.py", line 487, in run
 #     output=stdout, stderr=stderr)
 # subprocess.CalledProcessError: Command '['bpftool', '-j', 'feature', 'probe', 'dev', 'dummy0']' returned non-zero exit status 255.
 #
==================

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210820015556.23276-4-lizhijian@cn.fujitsu.com
2021-08-24 14:01:10 -07:00
Li Zhijian
5a980b5baf selftests/bpf: Make test_doc_build.sh work from script directory
Previously, it fails as below:
-------------
root@lkp-skl-d01 /opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf# ./test_doc_build.sh
++ realpath --relative-to=/opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf ./test_doc_build.sh
+ SCRIPT_REL_PATH=test_doc_build.sh
++ dirname test_doc_build.sh
+ SCRIPT_REL_DIR=.
++ realpath /opt/rootfs/v5.14-rc4/tools/testing/selftests/bpf/./../../../../
+ KDIR_ROOT_DIR=/opt/rootfs/v5.14-rc4
+ cd /opt/rootfs/v5.14-rc4
+ for tgt in docs docs-clean
+ make -s -C /opt/rootfs/v5.14-rc4/. docs
make: *** No rule to make target 'docs'.  Stop.
+ for tgt in docs docs-clean
+ make -s -C /opt/rootfs/v5.14-rc4/. docs-clean
make: *** No rule to make target 'docs-clean'.  Stop.
-----------

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210820015556.23276-3-lizhijian@cn.fujitsu.com
2021-08-24 14:01:10 -07:00
Li Zhijian
2d82d73da3 selftests/bpf: Enlarge select() timeout for test_maps
0Day robot observed that it's easily timeout on a heavy load host.
-------------------
 # selftests: bpf: test_maps
 # Fork 1024 tasks to 'test_update_delete'
 # Fork 1024 tasks to 'test_update_delete'
 # Fork 100 tasks to 'test_hashmap'
 # Fork 100 tasks to 'test_hashmap_percpu'
 # Fork 100 tasks to 'test_hashmap_sizes'
 # Fork 100 tasks to 'test_hashmap_walk'
 # Fork 100 tasks to 'test_arraymap'
 # Fork 100 tasks to 'test_arraymap_percpu'
 # Failed sockmap unexpected timeout
 not ok 3 selftests: bpf: test_maps # exit=1
 # selftests: bpf: test_lru_map
 # nr_cpus:8
-------------------
Since this test will be scheduled by 0Day to a random host that could have
only a few cpus(2-8), enlarge the timeout to avoid a false NG report.

In practice, i tried to pin it to only one cpu by 'taskset 0x01 ./test_maps',
and knew 10S is likely enough, but i still perfer to a larger value 30.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210820015556.23276-2-lizhijian@cn.fujitsu.com
2021-08-24 14:01:10 -07:00
Yucong Sun
a6258837c8 selftests/bpf: Reduce flakyness in timer_mim
This patch extends wait time in timer_mim. As observed in slow CI environment,
it is possible to have interrupt/preemption long enough to cause the test to
fail, almost 1 failure in 5 runs.

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210823213629.3519641-1-fallentree@fb.com
2021-08-23 18:01:47 -07:00
Alexei Starovoitov
4ed589a278 Merge branch 'Refactor cgroup_bpf internals to use more specific attach_type'
Dave Marchevsky says:

====================

The cgroup_bpf struct has a few arrays (effective, progs, and flags) of
size MAX_BPF_ATTACH_TYPE. These are meant to separate progs by their
attach type, currently represented by the bpf_attach_type enum.

There are some bpf_attach_type values which are not valid attach types
for cgroup bpf programs. Programs with these attach types will never be
handled by cgroup_bpf_{attach,detach} and thus will never be held in
cgroup_bpf structs. Even if such programs did make it into their
reserved slot in those arrays, they would never be executed.

Accordingly we can migrate to a new internal cgroup_bpf-specific enum
for these arrays, saving some bytes per cgroup and making it more
obvious which BPF programs belong there. netns_bpf_attach_type is an
existing example of this pattern, let's do similar for cgroup_bpf.

v1->v2: Address Daniel's comments
	* Reverse xmas tree ordering for def changes
	* Helper macro to reduce to_cgroup_bpf_attach_type boilerplate
		* checkpatch.pl complains: "ERROR: Macros with complex values should
		be enclosed in parentheses". Found some existing macros (do 'git grep
		"define case"') which get same complaint. Think it's fine to keep
		as-is since it's immediately undef'd.
	* Remove CG_BPF_ prefix from cgroup_bpf_attach_type
		* Although I agree that the prefix is redundant, the de-prefixed
		names feel a bit too 'general' given the internal use of the enum.
		e.g. when someone sees CGROUP_INET6_BIND it's not obvious that it
		should only be used in certain ways internally.
		* Don't feel strongly about this, just my thoughts as a noob to the
		internals.
	* Rebase onto latest bpf-next/master
		* No significant conflicts, some small boilerplate adjustments
		needed to catch up to Andrii's "bpf: Refactor BPF_PROG_RUN_ARRAY
		family of macros into functions" change
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-08-23 17:50:24 -07:00
Dave Marchevsky
6fc88c354f bpf: Migrate cgroup_bpf to internal cgroup_bpf_attach_type enum
Add an enum (cgroup_bpf_attach_type) containing only valid cgroup_bpf
attach types and a function to map bpf_attach_type values to the new
enum. Inspired by netns_bpf_attach_type.

Then, migrate cgroup_bpf to use cgroup_bpf_attach_type wherever
possible.  Functionality is unchanged as attach_type_to_prog_type
switches in bpf/syscall.c were preventing non-cgroup programs from
making use of the invalid cgroup_bpf array slots.

As a result struct cgroup_bpf uses 504 fewer bytes relative to when its
arrays were sized using MAX_BPF_ATTACH_TYPE.

bpf_cgroup_storage is notably not migrated as struct
bpf_cgroup_storage_key is part of uapi and contains a bpf_attach_type
member which is not meant to be opaque. Similarly, bpf_cgroup_link
continues to report its bpf_attach_type member to userspace via fdinfo
and bpf_link_info.

To ease disambiguation, bpf_attach_type variables are renamed from
'type' to 'atype' when changed to cgroup_bpf_attach_type.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210819092420.1984861-2-davemarchevsky@fb.com
2021-08-23 17:50:24 -07:00
Jiang Wang
d359902d5c af_unix: Fix NULL pointer bug in unix_shutdown
Commit 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap")
introduced a bug for af_unix SEQPACKET type. In unix_shutdown, the
unhash function will call prot->unhash(), which is NULL for SEQPACKET.
And kernel will panic. On ARM32, it will show following messages: (it
likely affects x86 too).

Fix the bug by checking the prot->unhash is NULL or not first.

Kernel log:
<--- cut here ---
 Unable to handle kernel NULL pointer dereference at virtual address
00000000
 pgd = 2fba1ffb
 *pgd=00000000
 Internal error: Oops: 80000005 [#1] PREEMPT SMP THUMB2
 Modules linked in:
 CPU: 1 PID: 1999 Comm: falkon Tainted: G        W
5.14.0-rc5-01175-g94531cfcbe79-dirty #9240
 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
 PC is at 0x0
 LR is at unix_shutdown+0x81/0x1a8
 pc : [<00000000>]    lr : [<c08f3311>]    psr: 600f0013
 sp : e45aff70  ip : e463a3c0  fp : beb54f04
 r10: 00000125  r9 : e45ae000  r8 : c4a56664
 r7 : 00000001  r6 : c4a56464  r5 : 00000001  r4 : c4a56400
 r3 : 00000000  r2 : c5a6b180  r1 : 00000000  r0 : c4a56400
 Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
 Control: 50c5387d  Table: 05aa804a  DAC: 00000051
 Register r0 information: slab PING start c4a56400 pointer offset 0
 Register r1 information: NULL pointer
 Register r2 information: slab task_struct start c5a6b180 pointer offset 0
 Register r3 information: NULL pointer
 Register r4 information: slab PING start c4a56400 pointer offset 0
 Register r5 information: non-paged memory
 Register r6 information: slab PING start c4a56400 pointer offset 100
 Register r7 information: non-paged memory
 Register r8 information: slab PING start c4a56400 pointer offset 612
 Register r9 information: non-slab/vmalloc memory
 Register r10 information: non-paged memory
 Register r11 information: non-paged memory
 Register r12 information: slab filp start e463a3c0 pointer offset 0
 Process falkon (pid: 1999, stack limit = 0x9ec48895)
 Stack: (0xe45aff70 to 0xe45b0000)
 ff60:                                     e45ae000 c5f26a00 00000000 00000125
 ff80: c0100264 c07f7fa3 beb54f04 fffffff7 00000001 e6f3fc0e b5e5e9ec beb54ec4
 ffa0: b5da0ccc c010024b b5e5e9ec beb54ec4 0000000f 00000000 00000000 beb54ebc
 ffc0: b5e5e9ec beb54ec4 b5da0ccc 00000125 beb54f58 00785238 beb5529c beb54f04
 ffe0: b5da1e24 beb54eac b301385c b62b6ee8 600f0030 0000000f 00000000 00000000
 [<c08f3311>] (unix_shutdown) from [<c07f7fa3>] (__sys_shutdown+0x2f/0x50)
 [<c07f7fa3>] (__sys_shutdown) from [<c010024b>]
(__sys_trace_return+0x1/0x16)
 Exception stack(0xe45affa8 to 0xe45afff0)

Fixes: 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/bpf/20210821180738.1151155-1-jiang.wang@bytedance.com
2021-08-23 14:56:01 +02:00
Prankur Gupta
f2a6ee924d selftests/bpf: Add tests for {set|get} socket option from setsockopt BPF
Adding selftests for the newly added functionality to call bpf_setsockopt()
and bpf_getsockopt() from setsockopt BPF programs.

Test Details:

1. BPF Program

   Checks for changes in IPV6_TCLASS(SOL_IPV6) via setsockopt
   If the cca for the socket is not cubic do nothing
   If the newly set value for IPV6_TCLASS is 45 (0x2d) (as per our use-case)
   then change the cc from cubic to reno

2. User Space Program

   Creates an AF_INET6 socket and set the cca for that to be "cubic"
   Attach the program and set the IPV6_TCLASS to 0x2d using setsockopt
   Verify the cca for the socket changed to reno

Signed-off-by: Prankur Gupta <prankgup@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210817224221.3257826-3-prankgup@fb.com
2021-08-20 01:10:01 +02:00
Prankur Gupta
2c531639de bpf: Add support for {set|get} socket options from setsockopt BPF
Add logic to call bpf_setsockopt() and bpf_getsockopt() from setsockopt BPF
programs. An example use case is when the user sets the IPV6_TCLASS socket
option, we would also like to change the tcp-cc for that socket.

We don't have any use case for calling bpf_setsockopt() from supposedly read-
only sys_getsockopt(), so it is made available to BPF_CGROUP_SETSOCKOPT only
at this point.

Signed-off-by: Prankur Gupta <prankgup@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210817224221.3257826-2-prankgup@fb.com
2021-08-20 01:04:52 +02:00
Stanislav Fomichev
44779a4b85 bpf: Use kvmalloc for map keys in syscalls
Same as previous patch but for the keys. memdup_bpfptr is renamed
to kvmemdup_bpfptr (and converted to kvmalloc).

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818235216.1159202-2-sdf@google.com
2021-08-20 00:09:49 +02:00
Stanislav Fomichev
f0dce1d9b7 bpf: Use kvmalloc for map values in syscall
Use kvmalloc/kvfree for temporary value when manipulating a map via
syscall. kmalloc might not be sufficient for percpu maps where the value
is big (and further multiplied by hundreds of CPUs).

Can be reproduced with netcnt test on qemu with "-smp 255".

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818235216.1159202-1-sdf@google.com
2021-08-20 00:09:38 +02:00
Yucong Sun
3666b167ea selftests/bpf: Adding delay in socketmap_listen to reduce flakyness
This patch adds a 1ms delay to reduce flakyness of the test.

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210819163609.2583758-1-fallentree@fb.com
2021-08-19 12:28:20 -07:00
Yonghong Song
594286b757 bpf: Fix NULL event->prog pointer access in bpf_overflow_handler
Andrii reported that libbpf CI hit the following oops when
running selftest send_signal:
  [ 1243.160719] BUG: kernel NULL pointer dereference, address: 0000000000000030
  [ 1243.161066] #PF: supervisor read access in kernel mode
  [ 1243.161066] #PF: error_code(0x0000) - not-present page
  [ 1243.161066] PGD 0 P4D 0
  [ 1243.161066] Oops: 0000 [#1] PREEMPT SMP NOPTI
  [ 1243.161066] CPU: 1 PID: 882 Comm: new_name Tainted: G           O      5.14.0-rc5 #1
  [ 1243.161066] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [ 1243.161066] RIP: 0010:bpf_overflow_handler+0x9a/0x1e0
  [ 1243.161066] Code: 5a 84 c0 0f 84 06 01 00 00 be 66 02 00 00 48 c7 c7 6d 96 07 82 48 8b ab 18 05 00 00 e8 df 55 eb ff 66 90 48 8d 75 48 48 89 e7 <ff> 55 30 41 89 c4 e8 fb c1 f0 ff 84 c0 0f 84 94 00 00 00 e8 6e 0f
  [ 1243.161066] RSP: 0018:ffffc900000c0d80 EFLAGS: 00000046
  [ 1243.161066] RAX: 0000000000000002 RBX: ffff8881002e0dd0 RCX: 00000000b4b47cf8
  [ 1243.161066] RDX: ffffffff811dcb06 RSI: 0000000000000048 RDI: ffffc900000c0d80
  [ 1243.161066] RBP: 0000000000000000 R08: 0000000000000000 R09: 1a9d56bb00000000
  [ 1243.161066] R10: 0000000000000001 R11: 0000000000080000 R12: 0000000000000000
  [ 1243.161066] R13: ffffc900000c0e00 R14: ffffc900001c3c68 R15: 0000000000000082
  [ 1243.161066] FS:  00007fc0be2d3380(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
  [ 1243.161066] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 1243.161066] CR2: 0000000000000030 CR3: 0000000104f8e000 CR4: 00000000000006e0
  [ 1243.161066] Call Trace:
  [ 1243.161066]  <IRQ>
  [ 1243.161066]  __perf_event_overflow+0x4f/0xf0
  [ 1243.161066]  perf_swevent_hrtimer+0x116/0x130
  [ 1243.161066]  ? __lock_acquire+0x378/0x2730
  [ 1243.161066]  ? __lock_acquire+0x372/0x2730
  [ 1243.161066]  ? lock_is_held_type+0xd5/0x130
  [ 1243.161066]  ? find_held_lock+0x2b/0x80
  [ 1243.161066]  ? lock_is_held_type+0xd5/0x130
  [ 1243.161066]  ? perf_event_groups_first+0x80/0x80
  [ 1243.161066]  ? perf_event_groups_first+0x80/0x80
  [ 1243.161066]  __hrtimer_run_queues+0x1a3/0x460
  [ 1243.161066]  hrtimer_interrupt+0x110/0x220
  [ 1243.161066]  __sysvec_apic_timer_interrupt+0x8a/0x260
  [ 1243.161066]  sysvec_apic_timer_interrupt+0x89/0xc0
  [ 1243.161066]  </IRQ>
  [ 1243.161066]  asm_sysvec_apic_timer_interrupt+0x12/0x20
  [ 1243.161066] RIP: 0010:finish_task_switch+0xaf/0x250
  [ 1243.161066] Code: 31 f6 68 90 2a 09 81 49 8d 7c 24 18 e8 aa d6 03 00 4c 89 e7 e8 12 ff ff ff 4c 89 e7 e8 ca 9c 80 00 e8 35 af 0d 00 fb 4d 85 f6 <58> 74 1d 65 48 8b 04 25 c0 6d 01 00 4c 3b b0 a0 04 00 00 74 37 f0
  [ 1243.161066] RSP: 0018:ffffc900001c3d18 EFLAGS: 00000282
  [ 1243.161066] RAX: 000000000000031f RBX: ffff888104cf4980 RCX: 0000000000000000
  [ 1243.161066] RDX: 0000000000000000 RSI: ffffffff82095460 RDI: ffffffff820adc4e
  [ 1243.161066] RBP: ffffc900001c3d58 R08: 0000000000000001 R09: 0000000000000001
  [ 1243.161066] R10: 0000000000000001 R11: 0000000000080000 R12: ffff88813bd2bc80
  [ 1243.161066] R13: ffff8881002e8000 R14: ffff88810022ad80 R15: 0000000000000000
  [ 1243.161066]  ? finish_task_switch+0xab/0x250
  [ 1243.161066]  ? finish_task_switch+0x70/0x250
  [ 1243.161066]  __schedule+0x36b/0xbb0
  [ 1243.161066]  ? _raw_spin_unlock_irqrestore+0x2d/0x50
  [ 1243.161066]  ? lockdep_hardirqs_on+0x79/0x100
  [ 1243.161066]  schedule+0x43/0xe0
  [ 1243.161066]  pipe_read+0x30b/0x450
  [ 1243.161066]  ? wait_woken+0x80/0x80
  [ 1243.161066]  new_sync_read+0x164/0x170
  [ 1243.161066]  vfs_read+0x122/0x1b0
  [ 1243.161066]  ksys_read+0x93/0xd0
  [ 1243.161066]  do_syscall_64+0x35/0x80
  [ 1243.161066]  entry_SYSCALL_64_after_hwframe+0x44/0xae

The oops can also be reproduced with the following steps:
  ./vmtest.sh -s
  # at qemu shell
  cd /root/bpf && while true; do ./test_progs -t send_signal

Further analysis showed that the failure is introduced with
commit b89fbfbb85 ("bpf: Implement minimal BPF perf link").
With the above commit, the following scenario becomes possible:
    cpu1                        cpu2
                                hrtimer_interrupt -> bpf_overflow_handler
    (due to closing link_fd)
    bpf_perf_link_release ->
    perf_event_free_bpf_prog ->
    perf_event_free_bpf_handler ->
      WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler)
      event->prog = NULL
                                bpf_prog_run(event->prog, &ctx)

In the above case, the event->prog is NULL for bpf_prog_run, hence
causing oops.

To fix the issue, check whether event->prog is NULL or not. If it
is, do not call bpf_prog_run. This seems working as the above
reproducible step runs more than one hour and I didn't see any
failures.

Fixes: b89fbfbb85 ("bpf: Implement minimal BPF perf link")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210819155209.1927994-1-yhs@fb.com
2021-08-19 11:49:19 -07:00
Daniel Borkmann
f9dabe016b bpf: Undo off-by-one in interpreter tail call count limit
The BPF interpreter as well as x86-64 BPF JIT were both in line by allowing
up to 33 tail calls (however odd that number may be!). Recently, this was
changed for the interpreter to reduce it down to 32 with the assumption that
this should have been the actual limit "which is in line with the behavior of
the x86 JITs" according to b61a28cf11 ("bpf: Fix off-by-one in tail call
count limiting").

Paul recently reported:

  I'm a bit surprised by this because I had previously tested the tail call
  limit of several JIT compilers and found it to be 33 (i.e., allowing chains
  of up to 34 programs). I've just extended a test program I had to validate
  this again on the x86-64 JIT, and found a limit of 33 tail calls again [1].

  Also note we had previously changed the RISC-V and MIPS JITs to allow up to
  33 tail calls [2, 3], for consistency with other JITs and with the interpreter.
  We had decided to increase these two to 33 rather than decrease the other
  JITs to 32 for backward compatibility, though that probably doesn't matter
  much as I'd expect few people to actually use 33 tail calls.

  [1] ae78874829
  [2] 96bc4432f5 ("bpf, riscv: Limit to 33 tail calls")
  [3] e49e6f6db0 ("bpf, mips: Limit to 33 tail calls")

Therefore, revert b61a28cf11 to re-align interpreter to limit a maximum of
33 tail calls. While it is unlikely to hit the limit for the vast majority,
programs in the wild could one way or another depend on this, so lets rather
be a bit more conservative, and lets align the small remainder of JITs to 33.
If needed in future, this limit could be slightly increased, but not decreased.

Fixes: b61a28cf11 ("bpf: Fix off-by-one in tail call count limiting")
Reported-by: Paul Chaignon <paul@cilium.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/CAO5pjwTWrC0_dzTbTHFPSqDwA56aVH+4KFGVqdq8=ASs0MqZGQ@mail.gmail.com
2021-08-19 18:33:37 +02:00
Xu Liu
374e74de96 selftests/bpf: Test for get_netns_cookie
Add test to use get_netns_cookie() from BPF_PROG_TYPE_SOCK_OPS.

Signed-off-by: Xu Liu <liuxu623@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818105820.91894-3-liuxu623@gmail.com
2021-08-19 00:30:14 +02:00
Xu Liu
6cf1770d63 bpf: Allow bpf_get_netns_cookie in BPF_PROG_TYPE_SOCK_OPS
We'd like to be able to identify netns from sockops hooks to
accelerate local process communication form different netns.

Signed-off-by: Xu Liu <liuxu623@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818105820.91894-2-liuxu623@gmail.com
2021-08-19 00:30:01 +02:00
Grant Seltzer
d20b41115a libbpf: Rename libbpf documentation index file
This patch renames a documentation libbpf.rst to index.rst. In order
for readthedocs.org to pick this file up and properly build the
documentation site.

It also changes the title type of the ABI subsection in the
naming convention doc. This is so that readthedocs.org doesn't treat this
section as a separate document.

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210818151313.49992-1-grantseltzer@gmail.com
2021-08-18 08:45:25 -07:00
Colin Ian King
8cacfc85b6 bpf: Remove redundant initialization of variable allow
The variable allow is being initialized with a value that is never read, it
is being updated later on. The assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817170842.495440-1-colin.king@canonical.com
2021-08-17 14:09:12 -07:00
Andrii Nakryiko
04d2319467 Merge branch 'selftests/bpf: fix flaky send_signal test'
Yonghong Song says:

====================

The bpf selftest send_signal() is flaky for its subtests trying to
send signals in softirq/nmi context. To reduce flakiness, the
signal-targetted process priority is boosted, which should minimize
preemption of that process and improve the possibility that
the underlying task in softirq/nmi context is the bpf_send_signal()
wanted task.

Patch #1 did a refactoring to use ASSERT_* instead of old CHECK macros.
Patch #2 did actual change of boosting priority.

Changelog:
  v1 -> v2:
    remove skip logic where the underlying task in interrupt context
    is not the intended one.
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-08-17 14:08:31 -07:00
Yonghong Song
b16ac5bf73 selftests/bpf: Fix flaky send_signal test
libbpf CI has reported send_signal test is flaky although
I am not able to reproduce it in my local environment.
But I am able to reproduce with on-demand libbpf CI ([1]).

Through code analysis, the following is possible reason.
The failed subtest runs bpf program in softirq environment.
Since bpf_send_signal() only sends to a fork of "test_progs"
process. If the underlying current task is
not "test_progs", bpf_send_signal() will not be triggered
and the subtest will fail.

To reduce the chances where the underlying process is not
the intended one, this patch boosted scheduling priority to
-20 (highest allowed by setpriority() call). And I did
10 runs with on-demand libbpf CI with this patch and I
didn't observe any failures.

 [1] https://github.com/libbpf/libbpf/actions/workflows/ondemand.yml

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817190923.3186725-1-yhs@fb.com
2021-08-17 14:08:30 -07:00
Yonghong Song
6f6cc42645 selftests/bpf: Replace CHECK with ASSERT_* macros in send_signal.c
Replace CHECK in send_signal.c with ASSERT_* macros as
ASSERT_* macros are generally preferred. There is no
funcitonality change.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817190918.3186400-1-yhs@fb.com
2021-08-17 14:08:30 -07:00
Andrii Nakryiko
87bb11ccfe Merge branch 'selftests/bpf: Improve the usability of test_progs'
Yucong Sun says:

====================

This short series adds two new switches to test_progs, "-a" and "-d",
adding support for both exact string matching, as well as '*' wildcards.
It also cleans up the output to make it possible to generate
allowlist/denylist using common cli tools.
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-08-17 11:31:52 -07:00
Yucong Sun
74339a8f86 selftests/bpf: Support glob matching for test selector.
This patch adds '-a' and '-d' arguments supporting both exact string match as
well as using '*' wildcard in test/subtests selection. '-a' and '-t' can
co-exists, same as '-d' and '-b', in which case they just add to the list of
allowed or denied test selectors.

Caveat: Same as the current substring matching mechanism, test and subtest
selector applies independently, 'a*/b*' will execute all tests matching "a*",
and with subtest name matching "b*", but tests matching "a*" that has no
subtests will also be executed.

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817044732.3263066-5-fallentree@fb.com
2021-08-17 11:31:29 -07:00
Yucong Sun
99c4fd8b92 selftests/bpf: Also print test name in subtest status message
This patch add test name in subtest status message line, making it possible to
grep ':OK' in the output to generate a list of passed test+subtest names, which
can be processed to generate argument list to be used with "-a", "-d" exact
string matching.

Example:

 #1/1 align/mov:OK
 ..
 #1/12 align/pointer variable subtraction:OK
 #1 align:OK

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817044732.3263066-4-fallentree@fb.com
2021-08-17 11:17:07 -07:00
Yucong Sun
f667d1d667 selftests/bpf: Correctly display subtest skip status
In skip_account(), test->skip_cnt is set to 0 at the end, this makes next print
statement never display SKIP status for the subtest. This patch moves the
accounting logic after the print statement, fixing the issue.

This patch also added SKIP status display for normal tests.

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817044732.3263066-3-fallentree@fb.com
2021-08-17 11:16:53 -07:00
Yucong Sun
26d82640d5 selftests/bpf: Skip loading bpf_testmod when using -l to list tests.
When using "-l", test_progs often is executed as non-root user,
load_bpf_testmod() will fail and output errors. This patch skips loading bpf
testmod when "-l" is specified, making output cleaner.

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817044732.3263066-2-fallentree@fb.com
2021-08-17 11:16:27 -07:00
Yucong Sun
857f75ea84 selftests/bpf: Add exponential backoff to map_delete_retriable in test_maps
Using a fixed delay of 1 microsecond has proven flaky in slow CPU environment,
e.g. Github Actions CI system. This patch adds exponential backoff with a cap
of 50ms to reduce the flakiness of the test. Initial delay is chosen at random
in the range [0ms, 5ms).

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817045713.3307985-1-fallentree@fb.com
2021-08-17 08:17:40 -07:00
Yucong Sun
3c3bd542ff selftests/bpf: Add exponential backoff to map_update_retriable in test_maps
Using a fixed delay of 1 microsecond has proven flaky in slow CPU environment,
e.g. Github Actions CI system. This patch adds exponential backoff with a cap
of 50ms to reduce the flakiness of the test. Initial delay is chosen at random
in the range [0ms, 5ms).

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210816175250.296110-1-fallentree@fb.com
2021-08-16 19:13:20 -07:00
Andrii Nakryiko
1e1e49df02 Merge branch 'sockmap: add sockmap support for unix stream socket'
Jiang Wang says:

====================

This patch series add support for unix stream type
for sockmap. Sockmap already supports TCP, UDP,
unix dgram types. The unix stream support is similar
to unix dgram.

Also add selftests for unix stream type in sockmap tests.
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-08-16 18:44:19 -07:00
Jiang Wang
31c50aeed5 selftest/bpf: Add new tests in sockmap for unix stream to tcp.
Add two new test cases in sockmap tests, where unix stream is
redirected to tcp and vice versa.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-6-jiang.wang@bytedance.com
2021-08-16 18:44:09 -07:00
Jiang Wang
75e0e27db6 selftest/bpf: Change udp to inet in some function names
This is to prepare for adding new unix stream tests.
Mostly renames, also pass the socket types as an argument.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-5-jiang.wang@bytedance.com
2021-08-16 18:43:55 -07:00
Jiang Wang
9b03152bd4 selftest/bpf: Add tests for sockmap with unix stream type.
Add two tests for unix stream to unix stream redirection
in sockmap tests.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-4-jiang.wang@bytedance.com
2021-08-16 18:43:46 -07:00
Jiang Wang
94531cfcbe af_unix: Add unix_stream_proto for sockmap
Previously, sockmap for AF_UNIX protocol only supports
dgram type. This patch add unix stream type support, which
is similar to unix_dgram_proto. To support sockmap, dgram
and stream cannot share the same unix_proto anymore, because
they have different implementations, such as unhash for stream
type (which will remove closed or disconnected sockets from the map),
so rename unix_proto to unix_dgram_proto and add a new
unix_stream_proto.

Also implement stream related sockmap functions.
And add dgram key words to those dgram specific functions.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-3-jiang.wang@bytedance.com
2021-08-16 18:43:39 -07:00
Jiang Wang
77462de14a af_unix: Add read_sock for stream socket types
To support sockmap for af_unix stream type, implement
read_sock, which is similar to the read_sock for unix
dgram sockets.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-2-jiang.wang@bytedance.com
2021-08-16 18:42:31 -07:00
Hengqi Chen
edce1a2486 selftests/bpf: Test btf__load_vmlinux_btf/btf__load_module_btf APIs
Add test for btf__load_vmlinux_btf/btf__load_module_btf APIs. The test
loads bpf_testmod module BTF and check existence of a symbol which is
known to exist.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210815081035.205879-1-hengqi.chen@gmail.com
2021-08-16 18:38:52 -07:00
grantseltzer
bb57164920 bpf: Reconfigure libbpf docs to remove unversioned API
This removes the libbpf_api.rst file from the kernel documentation.
The intention for this file was to pull documentation from comments
above API functions in libbpf. However, due to limitations of the
kernel documentation system, this API documentation could not be
versioned, which is counterintuative to how users expect to use it.
There is also currently no doc comments, making this a blank page.

Once the kernel comment documentation is actually contributed, it
will still exist in the kernel repository, just in the code itself.

A seperate site is being spun up to generate documentaiton from those
comments in a way in which it can be versioned properly.

This also reconfigures the bpf documentation index page to make it
easier to sync to the previously mentioned documentaiton site.

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210810020508.280639-1-grantseltzer@gmail.com
2021-08-16 17:25:03 -07:00
Daniel Borkmann
3a4ce01b24 Merge branch 'bpf-perf-link'
Andrii Nakryiko says:

====================
This patch set implements an ability for users to specify custom black box u64
value for each BPF program attachment, bpf_cookie, which is available to BPF
program at runtime. This is a feature that's critically missing for cases when
some sort of generic processing needs to be done by the common BPF program
logic (or even exactly the same BPF program) across multiple BPF hooks (e.g.,
many uniformly handled kprobes) and it's important to be able to distinguish
between each BPF hook at runtime (e.g., for additional configuration lookup).

The choice of restricting this to a fixed-size 8-byte u64 value is an explicit
design decision. Making this configurable by users adds unnecessary complexity
(extra memory allocations, extra complications on the verifier side to validate
accesses to variable-sized data area) while not really opening up new
possibilities. If user's use case requires storing more data per attachment,
it's possible to use either global array, or ARRAY/HASHMAP BPF maps, where
bpf_cookie would be used as an index into respective storage, populated by
user-space code before creating BPF link. This gives user all the flexibility
and control while keeping BPF verifier and BPF helper API simple.

Currently, similar functionality can only be achieved through:

  - code-generation and BPF program cloning, which is very complicated and
    unmaintainable;
  - on-the-fly C code generation and further runtime compilation, which is
    what BCC uses and allows to do pretty simply. The big downside is a very
    heavy-weight Clang/LLVM dependency and inefficient memory usage (due to
    many BPF program clones and the compilation process itself);
  - in some cases (kprobes and sometimes uprobes) it's possible to do function
    IP lookup to get function-specific configuration. This doesn't work for
    all the cases (e.g., when attaching uprobes to shared libraries) and has
    higher runtime overhead and additional programming complexity due to
    BPF_MAP_TYPE_HASHMAP lookups. Up until recently, before bpf_get_func_ip()
    BPF helper was added, it was also very complicated and unstable (API-wise)
    to get traced function's IP from fentry/fexit and kretprobe.

With libbpf and BPF CO-RE, runtime compilation is not an option, so to be able
to build generic tracing tooling simply and efficiently, ability to provide
additional bpf_cookie value for each *attachment* (as opposed to each BPF
program) is extremely important. Two immediate users of this functionality are
going to be libbpf-based USDT library (currently in development) and retsnoop
([0]), but I'm sure more applications will come once users get this feature in
their kernels.

To achieve above described, all perf_event-based BPF hooks are made available
through a new BPF_LINK_TYPE_PERF_EVENT BPF link, which allows to use common
LINK_CREATE command for program attachments and generally brings
perf_event-based attachments into a common BPF link infrastructure.

With that, LINK_CREATE gets ability to pass throught bpf_cookie value during
link creation (BPF program attachment) time. bpf_get_attach_cookie() BPF
helper is added to allow fetching this value at runtime from BPF program side.
BPF cookie is stored either on struct perf_event itself and fetched from the
BPF program context, or is passed through ambient BPF run context, added in
c7603cfa04 ("bpf: Add ambient BPF runtime context stored in current").

On the libbpf side of things, BPF perf link is utilized whenever is supported
by the kernel instead of using PERF_EVENT_IOC_SET_BPF ioctl on perf_event FD.
All the tracing attach APIs are extended with OPTS and bpf_cookie is passed
through corresponding opts structs.

Last part of the patch set adds few self-tests utilizing new APIs.

There are also a few refactorings along the way to make things cleaner and
easier to work with, both in kernel (BPF_PROG_RUN and BPF_PROG_RUN_ARRAY), and
throughout libbpf and selftests.

Follow-up patches will extend bpf_cookie to fentry/fexit programs.

While adding uprobe_opts, also extend it with ref_ctr_offset for specifying
USDT semaphore (reference counter) offset. Update attach_probe selftests to
validate its functionality. This is another feature (along with bpf_cookie)
required for implementing libbpf-based USDT solution.

  [0] https://github.com/anakryiko/retsnoop

v4->v5:
  - rebase on latest bpf-next to resolve merge conflict;
  - add ref_ctr_offset to uprobe_opts and corresponding selftest;
v3->v4:
  - get rid of BPF_PROG_RUN macro in favor of bpf_prog_run() (Daniel);
  - move #ifdef CONFIG_BPF_SYSCALL check into bpf_set_run_ctx (Daniel);
v2->v3:
  - user_ctx -> bpf_cookie, bpf_get_user_ctx -> bpf_get_attach_cookie (Peter);
  - fix BPF_LINK_TYPE_PERF_EVENT value fix (Jiri);
  - use bpf_prog_run() from bpf_prog_run_pin_on_cpu() (Yonghong);
v1->v2:
  - fix build failures on non-x86 arches by gating on CONFIG_PERF_EVENTS.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-08-17 00:45:17 +02:00
Andrii Nakryiko
4bd11e08e0 selftests/bpf: Add ref_ctr_offset selftests
Extend attach_probe selftests to specify ref_ctr_offset for uprobe/uretprobe
and validate that its value is incremented from zero.

Turns out that once uprobe is attached with ref_ctr_offset, uretprobe for the
same location/function *has* to use ref_ctr_offset as well, otherwise
perf_event_open() fails with -EINVAL. So this test uses ref_ctr_offset for
both uprobe and uretprobe, even though for the purpose of test uprobe would be
enough.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-17-andrii@kernel.org
2021-08-17 00:45:08 +02:00