Commit Graph

916424 Commits

Author SHA1 Message Date
Stanislav Fomichev
57dc6f3b41 selftests/bpf: Use reno instead of dctcp
Andrey pointed out that we can use reno instead of dctcp for CC
tests and drop CONFIG_TCP_CONG_DCTCP=y requirement.

Fixes: beecf11bc2 ("bpf: Bpf_{g,s}etsockopt for struct bpf_sock_addr")
Suggested-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200501224320.28441-1-sdf@google.com
2020-05-01 16:51:07 -07:00
Andrii Nakryiko
138c67677f bpf: Fix use-after-free of bpf_link when priming half-fails
If bpf_link_prime() succeeds to allocate new anon file, but then fails to
allocate ID for it, link priming is considered to be failed and user is
supposed ot be able to directly kfree() bpf_link, because it was never exposed
to user-space.

But at that point file already keeps a pointer to bpf_link and will eventually
call bpf_link_release(), so if bpf_link was kfree()'d by caller, that would
lead to use-after-free.

Fix this by first allocating ID and only then allocating file. Adding ID to
link_idr is ok, because link at that point still doesn't have its ID set, so
no user-space process can create a new FD for it.

Fixes: a3b80e1078 ("bpf: Allocate ID for bpf_link")
Reported-by: syzbot+39b64425f91b5aab714d@syzkaller.appspotmail.com
Suggested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200501185622.3088964-1-andriin@fb.com
2020-05-01 15:13:05 -07:00
Stanislav Fomichev
beecf11bc2 bpf: Bpf_{g,s}etsockopt for struct bpf_sock_addr
Currently, bpf_getsockopt and bpf_setsockopt helpers operate on the
'struct bpf_sock_ops' context in BPF_PROG_TYPE_SOCK_OPS program.
Let's generalize them and make them available for 'struct bpf_sock_addr'.
That way, in the future, we can allow those helpers in more places.

As an example, let's expose those 'struct bpf_sock_addr' based helpers to
BPF_CGROUP_INET{4,6}_CONNECT hooks. That way we can override CC before the
connection is made.

v3:
* Expose custom helpers for bpf_sock_addr context instead of doing
  generic bpf_sock argument (as suggested by Daniel). Even with
  try_socket_lock that doesn't sleep we have a problem where context sk
  is already locked and socket lock is non-nestable.

v2:
* s/BPF_PROG_TYPE_CGROUP_SOCKOPT/BPF_PROG_TYPE_SOCK_OPS/

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200430233152.199403-1-sdf@google.com
2020-05-01 12:44:28 -07:00
Alexei Starovoitov
3dbb5b5040 Merge branch 'bpf_enable_stats'
Song Liu says:

====================
run_time_ns is a useful stats for BPF programs. However, it is gated by
sysctl kernel.bpf_stats_enabled. When multiple user space tools are
toggling kernl.bpf_stats_enabled at the same time, they may confuse each
other.

Solve this problem with a new BPF command BPF_ENABLE_STATS.

Changes v8 => v9:
  1. Clean up in selftest (Andrii).
  2. Not using static variable in test program (Andrii).

Changes v7 => v8:
  1. Change name BPF_STATS_RUNTIME_CNT => BPF_STATS_RUN_TIME (Alexei).
  2. Add CHECK_ATTR to bpf_enable_stats() (Alexei).
  3. Rebase (Andrii).
  4. Simplfy the selftest (Alexei).

Changes v6 => v7:
  1. Add test to verify run_cnt matches count measured by the program.

Changes v5 => v6:
  1. Simplify test program (Yonghong).
  2. Rebase (with some conflicts).

Changes v4 => v5:
  1. Use memset to zero bpf_attr in bpf_enable_stats() (Andrii).

Changes v3 => v4:
  1. Add libbpf support and selftest;
  2. Avoid cleaning trailing space.

Changes v2 => v3:
  1. Rename the command to BPF_ENABLE_STATS, and make it extendible.
  2. fix commit log;
  3. remove unnecessary headers.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-05-01 10:37:34 -07:00
Song Liu
31a9f7fe93 bpf: Add selftest for BPF_ENABLE_STATS
Add test for BPF_ENABLE_STATS, which should enable run_time_ns stats.

~/selftests/bpf# ./test_progs -t enable_stats  -v
test_enable_stats:PASS:skel_open_and_load 0 nsec
test_enable_stats:PASS:get_stats_fd 0 nsec
test_enable_stats:PASS:attach_raw_tp 0 nsec
test_enable_stats:PASS:get_prog_info 0 nsec
test_enable_stats:PASS:check_stats_enabled 0 nsec
test_enable_stats:PASS:check_run_cnt_valid 0 nsec
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200430071506.1408910-4-songliubraving@fb.com
2020-05-01 10:36:32 -07:00
Song Liu
0bee106716 libbpf: Add support for command BPF_ENABLE_STATS
bpf_enable_stats() is added to enable given stats.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200430071506.1408910-3-songliubraving@fb.com
2020-05-01 10:36:32 -07:00
Song Liu
d46edd671a bpf: Sharing bpf runtime stats with BPF_ENABLE_STATS
Currently, sysctl kernel.bpf_stats_enabled controls BPF runtime stats.
Typical userspace tools use kernel.bpf_stats_enabled as follows:

  1. Enable kernel.bpf_stats_enabled;
  2. Check program run_time_ns;
  3. Sleep for the monitoring period;
  4. Check program run_time_ns again, calculate the difference;
  5. Disable kernel.bpf_stats_enabled.

The problem with this approach is that only one userspace tool can toggle
this sysctl. If multiple tools toggle the sysctl at the same time, the
measurement may be inaccurate.

To fix this problem while keep backward compatibility, introduce a new
bpf command BPF_ENABLE_STATS. On success, this command enables stats and
returns a valid fd. BPF_ENABLE_STATS takes argument "type". Currently,
only one type, BPF_STATS_RUN_TIME, is supported. We can extend the
command to support other types of stats in the future.

With BPF_ENABLE_STATS, user space tool would have the following flow:

  1. Get a fd with BPF_ENABLE_STATS, and make sure it is valid;
  2. Check program run_time_ns;
  3. Sleep for the monitoring period;
  4. Check program run_time_ns again, calculate the difference;
  5. Close the fd.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200430071506.1408910-2-songliubraving@fb.com
2020-05-01 10:36:32 -07:00
Jakub Sitnicki
c321022244 selftests/bpf: Test allowed maps for bpf_sk_select_reuseport
Check that verifier allows passing a map of type:

 BPF_MAP_TYPE_REUSEPORT_SOCKARRARY, or
 BPF_MAP_TYPE_SOCKMAP, or
 BPF_MAP_TYPE_SOCKHASH

... to bpf_sk_select_reuseport helper.

Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200430104738.494180-1-jakub@cloudflare.com
2020-04-30 16:21:14 +02:00
Andrii Nakryiko
063e688133 libbpf: Fix false uninitialized variable warning
Some versions of GCC falsely detect that vi might not be initialized. That's
not true, but let's silence it with NULL initialization.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200430021436.1522502-1-andriin@fb.com
2020-04-30 16:16:01 +02:00
Luke Nelson
91f658587a bpf, riscv: Fix stack layout of JITed code on RV32
This patch fixes issues with stackframe unwinding and alignment in the
current stack layout for BPF programs on RV32.

In the current layout, RV32 fp points to the JIT scratch registers, rather
than to the callee-saved registers. This breaks stackframe unwinding,
which expects fp to point just above the saved ra and fp registers.

This patch fixes the issue by moving the callee-saved registers to be
stored on the top of the stack, pointed to by fp. This satisfies the
assumptions of stackframe unwinding.

This patch also fixes an issue with the old layout that the stack was
not aligned to 16 bytes.

Stacktrace from JITed code using the old stack layout:

  [   12.196249 ] [<c0402200>] walk_stackframe+0x0/0x96

Stacktrace using the new stack layout:

  [   13.062888 ] [<c0402200>] walk_stackframe+0x0/0x96
  [   13.063028 ] [<c04023c6>] show_stack+0x28/0x32
  [   13.063253 ] [<a403e778>] bpf_prog_82b916b2dfa00464+0x80/0x908
  [   13.063417 ] [<c09270b2>] bpf_test_run+0x124/0x39a
  [   13.063553 ] [<c09276c0>] bpf_prog_test_run_skb+0x234/0x448
  [   13.063704 ] [<c048510e>] __do_sys_bpf+0x766/0x13b4
  [   13.063840 ] [<c0485d82>] sys_bpf+0xc/0x14
  [   13.063961 ] [<c04010f0>] ret_from_syscall+0x0/0x2

The new code is also simpler to understand and includes an ASCII diagram
of the stack layout.

Tested on riscv32 QEMU virt machine.

Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Xi Wang <xi.wang@gmail.com>
Link: https://lore.kernel.org/bpf/20200430005127.2205-1-luke.r.nels@gmail.com
2020-04-30 16:14:50 +02:00
Arnd Bergmann
449e14bfdb bpf: Fix unused variable warning
Hiding the only using of bpf_link_type_strs[] in an #ifdef causes
an unused-variable warning:

kernel/bpf/syscall.c:2280:20: error: 'bpf_link_type_strs' defined but not used [-Werror=unused-variable]
 2280 | static const char *bpf_link_type_strs[] = {

Move the definition into the same #ifdef.

Fixes: f2e10bff16 ("bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200429132217.1294289-1-arnd@arndb.de
2020-04-30 00:21:22 +02:00
Jakub Sitnicki
0b9ad56b1e selftests/bpf: Use SOCKMAP for server sockets in bpf_sk_assign test
Update bpf_sk_assign test to fetch the server socket from SOCKMAP, now that
map lookup from BPF in SOCKMAP is enabled. This way the test TC BPF program
doesn't need to know what address server socket is bound to.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-4-jakub@cloudflare.com
2020-04-29 23:31:00 +02:00
Jakub Sitnicki
34a2cc6eee selftests/bpf: Test that lookup on SOCKMAP/SOCKHASH is allowed
Now that bpf_map_lookup_elem() is white-listed for SOCKMAP/SOCKHASH,
replace the tests which check that verifier prevents lookup on these map
types with ones that ensure that lookup operation is permitted, but only
with a release of acquired socket reference.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-3-jakub@cloudflare.com
2020-04-29 23:30:59 +02:00
Jakub Sitnicki
64d85290d7 bpf: Allow bpf_map_lookup_elem for SOCKMAP and SOCKHASH
White-list map lookup for SOCKMAP/SOCKHASH from BPF. Lookup returns a
pointer to a full socket and acquires a reference if necessary.

To support it we need to extend the verifier to know that:

 (1) register storing the lookup result holds a pointer to socket, if
     lookup was done on SOCKMAP/SOCKHASH, and that

 (2) map lookup on SOCKMAP/SOCKHASH is a reference acquiring operation,
     which needs a corresponding reference release with bpf_sk_release.

On sock_map side, lookup handlers exposed via bpf_map_ops now bump
sk_refcnt if socket is reference counted. In turn, bpf_sk_select_reuseport,
the only in-kernel user of SOCKMAP/SOCKHASH ops->map_lookup_elem, was
updated to release the reference.

Sockets fetched from a map can be used in the same way as ones returned by
BPF socket lookup helpers, such as bpf_sk_lookup_tcp. In particular, they
can be used with bpf_sk_assign to direct packets toward a socket on TC
ingress path.

Suggested-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-2-jakub@cloudflare.com
2020-04-29 23:30:59 +02:00
Quentin Monnet
0b3b9ca3d1 tools: bpftool: Make libcap dependency optional
The new libcap dependency is not used for an essential feature of
bpftool, and we could imagine building the tool without checks on
CAP_SYS_ADMIN by disabling probing features as an unprivileged users.

Make it so, in order to avoid a hard dependency on libcap, and to ease
packaging/embedding of bpftool.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429144506.8999-4-quentin@isovalent.com
2020-04-29 23:25:11 +02:00
Quentin Monnet
cf9bf71452 tools: bpftool: Allow unprivileged users to probe features
There is demand for a way to identify what BPF helper functions are
available to unprivileged users. To do so, allow unprivileged users to
run "bpftool feature probe" to list BPF-related features. This will only
show features accessible to those users, and may not reflect the full
list of features available (to administrators) on the system.

To avoid the case where bpftool is inadvertently run as non-root and
would list only a subset of the features supported by the system when it
would be expected to list all of them, running as unprivileged is gated
behind the "unprivileged" keyword passed to the command line. When used
by a privileged user, this keyword allows to drop the CAP_SYS_ADMIN and
to list the features available to unprivileged users. Note that this
addsd a dependency on libpcap for compiling bpftool.

Note that there is no particular reason why the probes were restricted
to root, other than the fact I did not need them for unprivileged and
did not bother with the additional checks at the time probes were added.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429144506.8999-3-quentin@isovalent.com
2020-04-29 23:25:11 +02:00
Quentin Monnet
e3450b79df tools: bpftool: For "feature probe" define "full_mode" bool as global
The "full_mode" variable used for switching between full or partial
feature probing (i.e. with or without probing helpers that will log
warnings in kernel logs) was piped from the main do_probe() function
down to probe_helpers_for_progtype(), where it is needed.

Define it as a global variable: the calls will be more readable, and if
other similar flags were to be used in the future, we could use global
variables as well instead of extending again the list of arguments with
new flags.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429144506.8999-2-quentin@isovalent.com
2020-04-29 23:25:11 +02:00
Alexei Starovoitov
fd9c40c575 Merge branch 'test_progs-asan'
Andrii Nakryiko says:

====================
Add necessary infra to build selftests with ASAN (or any other sanitizer). Fix
a bunch of found memory leaks and other memory access issues.

v1->v2:
  - don't add ASAN flavor, but allow extra flags for build (Alexei);
  - fix few more found issues, which somehow were missed first time.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-04-28 19:51:33 -07:00
Andrii Nakryiko
e4e8f4d047 selftests/bpf: Add runqslower binary to .gitignore
With recent changes, runqslower is being copied into selftests/bpf root
directory. So add it into .gitignore.

Fixes: b26d1e2b60 ("selftests/bpf: Copy runqslower to OUTPUT directory")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Veronika Kabatova <vkabatov@redhat.com>
Link: https://lore.kernel.org/bpf/20200429012111.277390-12-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
8d30e80a04 selftests/bpf: Fix bpf_link leak in ns_current_pid_tgid selftest
If condition is inverted, but it's also just not necessary.

Fixes: 1c1052e014 ("tools/testing/selftests/bpf: Add self-tests for new helper bpf_get_ns_current_pid_tgid.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Carlos Neira <cneirabustos@gmail.com>
Link: https://lore.kernel.org/bpf/20200429012111.277390-11-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
36d0b6159f selftests/bpf: Disable ASAN instrumentation for mmap()'ed memory read
AddressSanitizer assumes that all memory dereferences are done against memory
allocated by sanitizer's malloc()/free() code and not touched by anyone else.
Seems like this doesn't hold for perf buffer memory. Disable instrumentation
on perf buffer callback function.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-10-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
3521ffa2ee libbpf: Fix huge memory leak in libbpf_find_vmlinux_btf_id()
BTF object wasn't freed.

Fixes: a6ed02cac6 ("libbpf: Load btf_vmlinux only once per object.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200429012111.277390-9-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
13c908495e selftests/bpf: Fix invalid memory reads in core_relo selftest
Another one found by AddressSanitizer. input_len is bigger than actually
initialized data size.

Fixes: c7566a6969 ("selftests/bpf: Add field existence CO-RE relocs tests")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-8-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
9f56bb531a selftests/bpf: Fix memory leak in extract_build_id()
getline() allocates string, which has to be freed.

Fixes: 81f77fd0de ("bpf: add selftest for stackmap with BPF_F_STACK_BUILD_ID")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200429012111.277390-7-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
f25d5416d6 selftests/bpf: Fix memory leak in test selector
Free test selector substrings, which were strdup()'ed.

Fixes: b65053cd94 ("selftests/bpf: Add whitelist/blacklist of test names to test_progs")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-6-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
229bf8bf4d libbpf: Fix memory leak and possible double-free in hashmap__clear
Fix memory leak in hashmap_clear() not freeing hashmap_entry structs for each
of the remaining entries. Also NULL-out bucket list to prevent possible
double-free between hashmap__clear() and hashmap__free().

Running test_progs-asan flavor clearly showed this problem.

Reported-by: Alston Tang <alston64@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-5-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
42fce2cfb4 selftests/bpf: Convert test_hashmap into test_progs test
Fold stand-alone test_hashmap test into test_progs.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-4-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
02995dd4bb selftests/bpf: Add SAN_CFLAGS param to selftests build to allow sanitizers
Add ability to specify extra compiler flags with SAN_CFLAGS for compilation of
all user-space C files.  This allows to build all of selftest programs with,
e.g., custom sanitizer flags, without requiring support for such sanitizers
from anyone compiling selftest/bpf.

As an example, to compile everything with AddressSanitizer, one would do:

  $ make clean && make SAN_CFLAGS="-fsanitize=address"

For AddressSanitizer to work, one needs appropriate libasan shared library
installed in the system, with version of libasan matching what GCC links
against. E.g., GCC8 needs libasan5, while GCC7 uses libasan4.

For CentOS 7, to build everything successfully one would need to:
  $ sudo yum install devtoolset-8-gcc devtoolset-libasan-devel
  $ scl enable devtoolset-8 bash # set up environment

For Arch Linux to run selftests, one would need to install gcc-libs package to
get libasan.so.5:
  $ sudo pacman -S gcc-libs

N.B. EXTRA_CFLAGS name wasn't used, because it's also used by libbpf's
Makefile and this causes few issues:
1. default "-g -Wall" flags are overriden;
2. compiling shared library with AddressSanitizer generates a bunch of symbols
   like: "_GLOBAL__sub_D_00099_0_btf_dump.c", "_GLOBAL__sub_D_00099_0_bpf.c",
   etc, which screws up versioned symbols check.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Julia Kartseva <hex@fb.com>
Link: https://lore.kernel.org/bpf/20200429012111.277390-3-andriin@fb.com
2020-04-28 19:48:05 -07:00
Andrii Nakryiko
76148faa16 selftests/bpf: Ensure test flavors use correct skeletons
Ensure that test runner flavors include their own skeletons from <flavor>/
directory. Previously, skeletons generated for no-flavor test_progs were used.
Apart from fixing correctness, this also makes it possible to compile only
flavors individually:

  $ make clean && make test_progs-no_alu32
  ... now succeeds ...

Fixes: 74b5a5968f ("selftests/bpf: Replace test_progs and test_maps w/ general rule")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-2-andriin@fb.com
2020-04-28 19:48:04 -07:00
Alexei Starovoitov
3271e8f3f6 Merge branch 'BTF-map-in-map'
Andrii Nakryiko says:

====================
This patch set teaches libbpf how to declare and initialize ARRAY_OF_MAPS and
HASH_OF_MAPS maps. See patch #3 for all the details.

Patch #1 refactors parsing BTF definition of map to re-use it cleanly for
inner map definition parsing.

Patch #2 refactors map creation and destruction logic for reuse. It also fixes
existing bug with not closing successfully created maps when bpf_object map
creation overall fails.

Patch #3 adds support for an extension of BTF-defined map syntax, as well as
parsing, recording, and use of relocations to allow declaratively initialize
outer maps with references to inner maps.

v1->v2:
  - rename __inner to __array (Alexei).
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-04-28 17:35:48 -07:00
Andrii Nakryiko
646f02ffdd libbpf: Add BTF-defined map-in-map support
As discussed at LPC 2019 ([0]), this patch brings (a quite belated) support
for declarative BTF-defined map-in-map support in libbpf. It allows to define
ARRAY_OF_MAPS and HASH_OF_MAPS BPF maps without any user-space initialization
code involved.

Additionally, it allows to initialize outer map's slots with references to
respective inner maps at load time, also completely declaratively.

Despite a weak type system of C, the way BTF-defined map-in-map definition
works, it's actually quite hard to accidentally initialize outer map with
incompatible inner maps. This being C, of course, it's still possible, but
even that would be caught at load time and error returned with helpful debug
log pointing exactly to the slot that failed to be initialized.

As an example, here's a rather advanced HASH_OF_MAPS declaration and
initialization example, filling slots #0 and #4 with two inner maps:

  #include <bpf/bpf_helpers.h>

  struct inner_map {
          __uint(type, BPF_MAP_TYPE_ARRAY);
          __uint(max_entries, 1);
          __type(key, int);
          __type(value, int);
  } inner_map1 SEC(".maps"),
    inner_map2 SEC(".maps");

  struct outer_hash {
          __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
          __uint(max_entries, 5);
          __uint(key_size, sizeof(int));
          __array(values, struct inner_map);
  } outer_hash SEC(".maps") = {
          .values = {
                  [0] = &inner_map2,
                  [4] = &inner_map1,
          },
  };

Here's the relevant part of libbpf debug log showing pretty clearly of what's
going on with map-in-map initialization:

  libbpf: .maps relo #0: for 6 value 0 rel.r_offset 96 name 260 ('inner_map1')
  libbpf: .maps relo #0: map 'outer_arr' slot [0] points to map 'inner_map1'
  libbpf: .maps relo #1: for 7 value 32 rel.r_offset 112 name 249 ('inner_map2')
  libbpf: .maps relo #1: map 'outer_arr' slot [2] points to map 'inner_map2'
  libbpf: .maps relo #2: for 7 value 32 rel.r_offset 144 name 249 ('inner_map2')
  libbpf: .maps relo #2: map 'outer_hash' slot [0] points to map 'inner_map2'
  libbpf: .maps relo #3: for 6 value 0 rel.r_offset 176 name 260 ('inner_map1')
  libbpf: .maps relo #3: map 'outer_hash' slot [4] points to map 'inner_map1'
  libbpf: map 'inner_map1': created successfully, fd=4
  libbpf: map 'inner_map2': created successfully, fd=5
  libbpf: map 'outer_hash': created successfully, fd=7
  libbpf: map 'outer_hash': slot [0] set to map 'inner_map2' fd=5
  libbpf: map 'outer_hash': slot [4] set to map 'inner_map1' fd=4

Notice from the log above that fd=6 (not logged explicitly) is used for inner
"prototype" map, necessary for creation of outer map. It is destroyed
immediately after outer map is created.

See also included selftest with some extra comments explaining extra details
of usage. Additionally, similar initialization syntax and libbpf functionality
can be used to do initialization of BPF_PROG_ARRAY with references to BPF
sub-programs. This can be done in follow up patches, if there will be a demand
for this.

  [0] https://linuxplumbersconf.org/event/4/contributions/448/

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200429002739.48006-4-andriin@fb.com
2020-04-28 17:35:03 -07:00
Andrii Nakryiko
2d39d7c56f libbpf: Refactor map creation logic and fix cleanup leak
Factor out map creation and destruction logic to simplify code and especially
error handling. Also fix map FD leak in case of partially successful map
creation during bpf_object load operation.

Fixes: 57a00f4164 ("libbpf: Add auto-pinning of maps when loading BPF objects")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200429002739.48006-3-andriin@fb.com
2020-04-28 17:35:03 -07:00
Andrii Nakryiko
41017e56af libbpf: Refactor BTF-defined map definition parsing logic
Factor out BTF map definition logic into stand-alone routine for easier reuse
for map-in-map case.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429002739.48006-2-andriin@fb.com
2020-04-28 17:35:03 -07:00
Alexei Starovoitov
1f427a8077 Merge branch 'bpf_link-observability'
Andrii Nakryiko says:

====================
This patch series adds various observability APIs to bpf_link:
  - each bpf_link now gets ID, similar to bpf_map and bpf_prog, by which
    user-space can iterate over all existing bpf_links and create limited FD
    from ID;
  - allows to get extra object information with bpf_link general and
    type-specific information;
  - implements `bpf link show` command which lists all active bpf_links in the
    system;
  - implements `bpf link pin` allowing to pin bpf_link by ID or from other
    pinned path.

v2->v3:
  - improve spin locking around bpf_link ID (Alexei);
  - simplify bpf_link_info handling and fix compilation error on sh arch;
v1->v2:
  - simplified `bpftool link show` implementation (Quentin);
  - fixed formatting of bpftool-link.rst (Quentin);
  - fixed attach type printing logic (Quentin);
rfc->v1:
  - dropped read-only bpf_links (Alexei);
  - fixed bug in bpf_link_cleanup() not removing ID;
  - fixed bpftool link pinning search logic;
  - added bash-completion and man page.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-04-28 17:28:05 -07:00
Andrii Nakryiko
5d085ad2e6 bpftool: Add link bash completions
Extend bpftool's bash-completion script to handle new link command and its
sub-commands.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200429001614.1544-11-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
7464d013cc bpftool: Add bpftool-link manpage
Add bpftool-link manpage with information and examples of link-related
commands.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200429001614.1544-10-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
c5481f9a95 bpftool: Add bpf_link show and pin support
Add `bpftool link show` and `bpftool link pin` commands.

Example plain output for `link show` (with showing pinned paths):

[vmuser@archvm bpf]$ sudo ~/local/linux/tools/bpf/bpftool/bpftool -f link
1: tracing  prog 12
        prog_type tracing  attach_type fentry
        pinned /sys/fs/bpf/my_test_link
        pinned /sys/fs/bpf/my_test_link2
2: tracing  prog 13
        prog_type tracing  attach_type fentry
3: tracing  prog 14
        prog_type tracing  attach_type fentry
4: tracing  prog 15
        prog_type tracing  attach_type fentry
5: tracing  prog 16
        prog_type tracing  attach_type fentry
6: tracing  prog 17
        prog_type tracing  attach_type fentry
7: raw_tracepoint  prog 21
        tp 'sys_enter'
8: cgroup  prog 25
        cgroup_id 584  attach_type egress
9: cgroup  prog 25
        cgroup_id 599  attach_type egress
10: cgroup  prog 25
        cgroup_id 614  attach_type egress
11: cgroup  prog 25
        cgroup_id 629  attach_type egress

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200429001614.1544-9-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
50325b1761 bpftool: Expose attach_type-to-string array to non-cgroup code
Move attach_type_strings into main.h for access in non-cgroup code.
bpf_attach_type is used for non-cgroup attach types quite widely now. So also
complete missing string translations for non-cgroup attach types.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200429001614.1544-8-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
2c2837b09e selftests/bpf: Test bpf_link's get_next_id, get_fd_by_id, and get_obj_info
Extend bpf_obj_id selftest to verify bpf_link's observability APIs.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-7-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
0dbc866832 libbpf: Add low-level APIs for new bpf_link commands
Add low-level API calls for bpf_link_get_next_id() and
bpf_link_get_fd_by_id().

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-6-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
f2e10bff16 bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link
Add ability to fetch bpf_link details through BPF_OBJ_GET_INFO_BY_FD command.
Also enhance show_fdinfo to potentially include bpf_link type-specific
information (similarly to obj_info).

Also introduce enum bpf_link_type stored in bpf_link itself and expose it in
UAPI. bpf_link_tracing also now will store and return bpf_attach_type.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-5-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
2d602c8cf4 bpf: Support GET_FD_BY_ID and GET_NEXT_ID for bpf_link
Add support to look up bpf_link by ID and iterate over all existing bpf_links
in the system. GET_FD_BY_ID code handles not-yet-ready bpf_link by checking
that its ID hasn't been set to non-zero value yet. Setting bpf_link's ID is
done as the very last step in finalizing bpf_link, together with installing
FD. This approach allows users of bpf_link in kernel code to not worry about
races between user-space and kernel code that hasn't finished attaching and
initializing bpf_link.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-4-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
a3b80e1078 bpf: Allocate ID for bpf_link
Generate ID for each bpf_link using IDR, similarly to bpf_map and bpf_prog.
bpf_link creation, initialization, attachment, and exposing to user-space
through FD and ID is a complicated multi-step process, abstract it away
through bpf_link_primer and bpf_link_prime(), bpf_link_settle(), and
bpf_link_cleanup() internal API. They guarantee that until bpf_link is
properly attached, user-space won't be able to access partially-initialized
bpf_link either from FD or ID. All this allows to simplify bpf_link attachment
and error handling code.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-3-andriin@fb.com
2020-04-28 17:27:08 -07:00
Andrii Nakryiko
f9d041271c bpf: Refactor bpf_link update handling
Make bpf_link update support more generic by making it into another
bpf_link_ops methods. This allows generic syscall handling code to be agnostic
to various conditionally compiled features (e.g., the case of
CONFIG_CGROUP_BPF). This also allows to keep link type-specific code to remain
static within respective code base. Refactor existing bpf_cgroup_link code and
take advantage of this.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429001614.1544-2-andriin@fb.com
2020-04-28 17:27:07 -07:00
Alexei Starovoitov
9b329d0dbe selftests/bpf: fix test_sysctl_prog with alu32
Similar to commit b7a0d65d80 ("bpf, testing: Workaround a verifier failure for test_progs")
fix test_sysctl_prog.c as well.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-04-28 15:31:59 -07:00
Zou Wei
a6bbdf2e75 libbpf: Remove unneeded semicolon in btf_dump_emit_type
Fixes the following coccicheck warning:

 tools/lib/bpf/btf_dump.c:661:4-5: Unneeded semicolon

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1588064829-70613-1-git-send-email-zou_wei@huawei.com
2020-04-28 21:47:47 +02:00
Veronika Kabatova
b26d1e2b60 selftests/bpf: Copy runqslower to OUTPUT directory
$(OUTPUT)/runqslower makefile target doesn't actually create runqslower
binary in the $(OUTPUT) directory. As lib.mk expects all
TEST_GEN_PROGS_EXTENDED (which runqslower is a part of) to be present in
the OUTPUT directory, this results in an error when running e.g. `make
install`:

rsync: link_stat "tools/testing/selftests/bpf/runqslower" failed: No
       such file or directory (2)

Copy the binary into the OUTPUT directory after building it to fix the
error.

Fixes: 3a0d3092a4 ("selftests/bpf: Build runqslower from selftests")
Signed-off-by: Veronika Kabatova <vkabatov@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200428173742.2988395-1-vkabatov@redhat.com
2020-04-28 21:27:20 +02:00
Daniel Borkmann
0b54142e4b Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull in Christoph Hellwig's series that changes the sysctl's ->proc_handler
methods to take kernel pointers instead. It gets rid of the set_fs address
space overrides used by BPF. As per discussion, pull in the feature branch
into bpf-next as it relates to BPF sysctl progs.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200427071508.GV23230@ZenIV.linux.org.uk/T/
2020-04-28 21:23:38 +02:00
Christoph Hellwig
8c1b2bf16d bpf, cgroup: Remove unused exports
Except for a few of the networking hooks called from modular ipv4
or ipv6 code, all of hooks are just called from guaranteed to be
built-in code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/20200424064338.538313-2-hch@lst.de
2020-04-27 22:20:22 +02:00
Mao Wenan
e411eb257b libbpf: Return err if bpf_object__load failed
bpf_object__load() has various return code, when it failed to load
object, it must return err instead of -EINVAL.

Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200426063635.130680-3-maowenan@huawei.com
2020-04-27 14:43:20 +02:00