886995 Commits

Author SHA1 Message Date
Andrey Ignatov
9fab329d6a bpf: Remove unused new_flags in hierarchy_allows_attach()
new_flags is unused, remove it.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/2c49b30ab750f93cfef04a1e40b097d70c3a39a1.1576741281.git.rdna@fb.com
2019-12-19 21:22:25 -08:00
Andrey Ignatov
1020c1f24a bpf: Simplify __cgroup_bpf_attach
__cgroup_bpf_attach has a lot of identical code to handle two scenarios:
BPF_F_ALLOW_MULTI is set and unset.

Simplify it by splitting the two main steps:

* First, the decision is made whether a new bpf_prog_list entry should
  be allocated or existing entry should be reused for the new program.
  This decision is saved in replace_pl pointer;

* Next, replace_pl pointer is used to handle both possible states of
  BPF_F_ALLOW_MULTI flag (set / unset) instead of doing similar work for
  them separately.

This splitting, in turn, allows to make further simplifications:

* The check for attaching same program twice in BPF_F_ALLOW_MULTI mode
  can be done before allocating cgroup storage, so that if user tries to
  attach same program twice no alloc/free happens as it was before;

* pl_was_allocated becomes redundant so it's removed.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/c6193db6fe630797110b0d3ff06c125d093b834c.1576741281.git.rdna@fb.com
2019-12-19 21:22:25 -08:00
Alexei Starovoitov
c92bbaa0fd Merge branch 'simplify-do_redirect'
Björn Töpel says:

====================
This series aims to simplify the XDP maps and
xdp_do_redirect_map()/xdp_do_flush_map(), and to crank out some more
performance from XDP_REDIRECT scenarios.

The first part of the series simplifies all XDP_REDIRECT capable maps,
so that __XXX_flush_map() does not require the map parameter, by
moving the flush list from the map to global scope.

This results in that the map_to_flush member can be removed from
struct bpf_redirect_info, and its corresponding logic.

Simpler code, and more performance due to that checks/code per-packet
is moved to flush.

Pre-series performance:
  $ sudo taskset -c 22 ./xdpsock -i enp134s0f0 -q 20 -n 1 -r -z

   sock0@enp134s0f0:20 rxdrop xdp-drv
                  pps         pkts        1.00
  rx              20,797,350  230,942,399
  tx              0           0

  $ sudo ./xdp_redirect_cpu --dev enp134s0f0 --cpu 22 xdp_cpu_map0

  Running XDP/eBPF prog_name:xdp_cpu_map5_lb_hash_ip_pairs
  XDP-cpumap      CPU:to  pps            drop-pps    extra-info
  XDP-RX          20      7723038        0           0
  XDP-RX          total   7723038        0
  cpumap_kthread  total   0              0           0
  redirect_err    total   0              0
  xdp_exception   total   0              0

Post-series performance:
  $ sudo taskset -c 22 ./xdpsock -i enp134s0f0 -q 20 -n 1 -r -z

   sock0@enp134s0f0:20 rxdrop xdp-drv
                  pps         pkts        1.00
  rx              21,524,979  86,835,327
  tx              0           0

  $ sudo ./xdp_redirect_cpu --dev enp134s0f0 --cpu 22 xdp_cpu_map0

  Running XDP/eBPF prog_name:xdp_cpu_map5_lb_hash_ip_pairs
  XDP-cpumap      CPU:to  pps            drop-pps    extra-info
  XDP-RX          20      7840124        0           0
  XDP-RX          total   7840124        0
  cpumap_kthread  total   0              0           0
  redirect_err    total   0              0
  xdp_exception   total   0              0

Results: +3.5% and +1.5% for the ubenchmarks.

v1->v2 [1]:
  * Removed 'unused-variable' compiler warning (Jakub)

[1] https://lore.kernel.org/bpf/20191218105400.2895-1-bjorn.topel@gmail.com/
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-12-19 21:10:27 -08:00
Björn Töpel
1170beaa3f xdp: Simplify __bpf_tx_xdp_map()
The explicit error checking is not needed. Simply return the error
instead.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-9-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Björn Töpel
332f22a60e xdp: Remove map_to_flush and map swap detection
Now that all XDP maps that can be used with bpf_redirect_map() tracks
entries to be flushed in a global fashion, there is not need to track
that the map has changed and flush from xdp_do_generic_map()
anymore. All entries will be flushed in xdp_do_flush_map().

This means that the map_to_flush can be removed, and the corresponding
checks. Moving the flush logic to one place, xdp_do_flush_map(), give
a bulking behavior and performance boost.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-8-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Björn Töpel
cdfafe98ca xdp: Make cpumap flush_list common for all map instances
The cpumap flush list is used to track entries that need to flushed
from via the xdp_do_flush_map() function. This list used to be
per-map, but there is really no reason for that. Instead make the
flush list global for all devmaps, which simplifies __cpu_map_flush()
and cpu_map_alloc().

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-7-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Björn Töpel
96360004b8 xdp: Make devmap flush_list common for all map instances
The devmap flush list is used to track entries that need to flushed
from via the xdp_do_flush_map() function. This list used to be
per-map, but there is really no reason for that. Instead make the
flush list global for all devmaps, which simplifies __dev_map_flush()
and dev_map_init_map().

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-6-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Björn Töpel
e312b9e706 xsk: Make xskmap flush_list common for all map instances
The xskmap flush list is used to track entries that need to flushed
from via the xdp_do_flush_map() function. This list used to be
per-map, but there is really no reason for that. Instead make the
flush list global for all xskmaps, which simplifies __xsk_map_flush()
and xsk_map_alloc().

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-5-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Björn Töpel
fb5aacdf36 xdp: Fix graze->grace type-o in cpumap comments
Simple spelling fix.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-4-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Björn Töpel
4bc188c7f2 xdp: Simplify cpumap cleanup
After the RCU flavor consolidation [1], call_rcu() and
synchronize_rcu() waits for preempt-disable regions (NAPI) in addition
to the read-side critical sections. As a result of this, the cleanup
code in cpumap can be simplified

* There is no longer a need to flush in __cpu_map_entry_free, since we
  know that this has been done when the call_rcu() callback is
  triggered.

* When freeing the map, there is no need to explicitly wait for a
  flush. It's guaranteed to be done after the synchronize_rcu() call
  in cpu_map_free().

[1] https://lwn.net/Articles/777036/

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-3-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Björn Töpel
0536b85239 xdp: Simplify devmap cleanup
After the RCU flavor consolidation [1], call_rcu() and
synchronize_rcu() waits for preempt-disable regions (NAPI) in addition
to the read-side critical sections. As a result of this, the cleanup
code in devmap can be simplified

* There is no longer a need to flush in __dev_map_entry_free, since we
  know that this has been done when the call_rcu() callback is
  triggered.

* When freeing the map, there is no need to explicitly wait for a
  flush. It's guaranteed to be done after the synchronize_rcu() call
  in dev_map_free(). The rcu_barrier() is still needed, so that the
  map is not freed prior the elements.

[1] https://lwn.net/Articles/777036/

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-2-bjorn.topel@gmail.com
2019-12-19 21:09:43 -08:00
Aditya Pakki
5bf2fc1f9c bpf: Remove unnecessary assertion on fp_old
The two callers of bpf_prog_realloc - bpf_patch_insn_single and
bpf_migrate_filter dereference the struct fp_old, before passing
it to the function. Thus assertion to check fp_old is unnecessary
and can be removed.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191219175735.19231-1-pakki001@umn.edu
2019-12-19 22:24:15 +01:00
Andrii Nakryiko
7745ff9842 libbpf: Fix another __u64 printf warning
Fix yet another printf warning for %llu specifier on ppc64le. This time size_t
casting won't work, so cast to verbose `unsigned long long`.

Fixes: 166750bc1dd2 ("libbpf: Support libbpf-provided extern variables")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191219052103.3515-1-andriin@fb.com
2019-12-19 16:47:56 +01:00
Toke Høiland-Jørgensen
b5c7d0d0f7 libbpf: Fix printing of ulimit value
Naresh pointed out that libbpf builds fail on 32-bit architectures because
rlimit.rlim_cur is defined as 'unsigned long long' on those architectures.
Fix this by using %zu in printf and casting to size_t.

Fixes: dc3a2d254782 ("libbpf: Print hint about ulimit when getting permission denied error")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191219090236.905059-1-toke@redhat.com
2019-12-19 16:25:52 +01:00
Alexei Starovoitov
580205dd4f selftests/bpf: Fix test_attach_probe
Fix two issues in test_attach_probe:

1. it was not able to parse /proc/self/maps beyond the first line,
   since %s means parse string until white space.
2. offset has to be accounted for otherwise uprobed address is incorrect.

Fixes: 1e8611bbdfc9 ("selftests/bpf: add kprobe/uprobe selftests")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191219020442.1922617-1-ast@kernel.org
2019-12-19 16:14:08 +01:00
Toke Høiland-Jørgensen
12dd14b230 libbpf: Add missing newline in opts validation macro
The error log output in the opts validation macro was missing a newline.

Fixes: 2ce8450ef5a3 ("libbpf: add bpf_object__open_{file, mem} w/ extensible opts")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191219120714.928380-1-toke@redhat.com
2019-12-19 16:08:46 +01:00
Daniel Borkmann
7800a3d54a Merge branch 'bpf-riscv-jit-improvements'
Björn Töpel says:

====================
This series contain one non-critical fix, support for far jumps, and
some optimizations for the BPF JIT.

Previously, the JIT only supported 12b branch targets for conditional
branches, and 21b for unconditional branches. Starting with this
series, 32b branching is supported.

As part of supporting far jumps, branch relaxation was introduced. The
idea is to start with a pessimistic jump (e.g. auipc/jalr) and for
each pass the JIT will have an opportunity to pick a better
instruction (e.g. jal) and shrink the image. Instead of two passes,
the JIT requires more passes. It typically converges after 3 passes.

The optimizations mentioned in the subject are for calls and tail
calls. In the tail call generation we can save one instruction by
using the offset in jalr. Calls are optimized by doing (auipc)/jal(r)
relative jumps instead of loading the entire absolute address and
doing jalr. This required that the JIT image allocator was made RISC-V
specific, so we can ensure that the JIT image and the kernel text are
in range (32b).

The last two patches of the series is not critical to the series, but
are two UAPI build issues for BPF events. A closer look from the
RV-folks would be much appreciated.

The test_bpf.ko module, selftests/bpf/test_verifier and
selftests/seccomp/seccomp_bpf pass all tests.

RISC-V is still missing proper kprobe and tracepoint support, so a lot
of BPF selftests cannot be run.

v1->v2: [1]
 * Removed unused function parameter from emit_branch()
 * Added patch to support far branch in tail call emit

[1] https://lore.kernel.org/bpf/20191209173136.29615-1-bjorn.topel@gmail.com/
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-12-19 16:04:18 +01:00
Björn Töpel
34bfc10a6e riscv, perf: Add arch specific perf_arch_bpf_user_pt_regs
RISC-V was missing a proper perf_arch_bpf_user_pt_regs macro for
CONFIG_PERF_EVENT builds.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-10-bjorn.topel@gmail.com
2019-12-19 16:03:31 +01:00
Björn Töpel
eb9928bed0 riscv, bpf: Add missing uapi header for BPF_PROG_TYPE_PERF_EVENT programs
Add missing uapi header the BPF_PROG_TYPE_PERF_EVENT programs by
exporting struct user_regs_struct instead of struct pt_regs which is
in-kernel only.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-9-bjorn.topel@gmail.com
2019-12-19 16:03:31 +01:00
Björn Töpel
e368b64f8b riscv, bpf: Optimize calls
Instead of using emit_imm() and emit_jalr() which can expand to six
instructions, start using jal or auipc+jalr.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-8-bjorn.topel@gmail.com
2019-12-19 16:03:31 +01:00
Björn Töpel
7f3631e88e riscv, bpf: Provide RISC-V specific JIT image alloc/free
This commit makes sure that the JIT images is kept close to the kernel
text, so BPF calls can use relative calling with auipc/jalr or jal
instead of loading the full 64-bit address and jalr.

The BPF JIT image region is 128 MB before the kernel text.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-7-bjorn.topel@gmail.com
2019-12-19 16:03:31 +01:00
Björn Töpel
fe8322b866 riscv, bpf: Optimize BPF tail calls
Remove one addi, and instead use the offset part of jalr.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-6-bjorn.topel@gmail.com
2019-12-19 16:03:31 +01:00
Björn Töpel
33203c02f2 riscv, bpf: Add support for far jumps and exits
This commit add support for far (offset > 21b) jumps and exits.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Luke Nelson <lukenels@cs.washington.edu>
Link: https://lore.kernel.org/bpf/20191216091343.23260-5-bjorn.topel@gmail.com
2019-12-19 16:03:30 +01:00
Björn Töpel
29d92edd9e riscv, bpf: Add support for far branching when emitting tail call
Start use the emit_branch() function in the tail call emitter in order
to support far branching.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-4-bjorn.topel@gmail.com
2019-12-19 16:03:30 +01:00
Björn Töpel
7d1ef13fea riscv, bpf: Add support for far branching
This commit adds branch relaxation to the BPF JIT, and with that
support for far (offset greater than 12b) branching.

The branch relaxation requires more than two passes to converge. For
most programs it is three passes, but for larger programs it can be
more.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Luke Nelson <lukenels@cs.washington.edu>
Link: https://lore.kernel.org/bpf/20191216091343.23260-3-bjorn.topel@gmail.com
2019-12-19 16:03:30 +01:00
Björn Töpel
f1003b787c riscv, bpf: Fix broken BPF tail calls
The BPF JIT incorrectly clobbered the a0 register, and did not flag
usage of s5 register when BPF stack was being used.

Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G")
Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-2-bjorn.topel@gmail.com
2019-12-19 16:03:30 +01:00
Alexei Starovoitov
a352a82496 Merge branch 'libbpf-extern-followups'
Andrii Nakryiko says:

====================
Based on latest feedback and discussions, this patch set implements the
following changes:

- Kconfig-provided externs have to be in .kconfig section, for which
  bpf_helpers.h provides convenient __kconfig macro (Daniel);
- instead of allowing to override Kconfig file path, switch this to ability to
  extend and override system Kconfig with user-provided custom values (Alexei);
- BTF is required when externs are used.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-12-18 17:33:52 -08:00
Andrii Nakryiko
630628cb7d libbpf: BTF is required when externs are present
BTF is required to get type information about extern variables.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191219002837.3074619-4-andriin@fb.com
2019-12-18 17:33:36 -08:00
Andrii Nakryiko
8601fd4221 libbpf: Allow to augment system Kconfig through extra optional config
Instead of all or nothing approach of overriding Kconfig file location, allow
to extend it with extra values and override chosen subset of values though
optional user-provided extra config, passed as a string through open options'
.kconfig option. If same config key is present in both user-supplied config
and Kconfig, user-supplied one wins. This allows applications to more easily
test various conditions despite host kernel's real configuration. If all of
BPF object's __kconfig externs are satisfied from user-supplied config, system
Kconfig won't be read at all.

Simplify selftests by not needing to create temporary Kconfig files.

Suggested-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191219002837.3074619-3-andriin@fb.com
2019-12-18 17:33:36 -08:00
Andrii Nakryiko
81bfdd087b libbpf: Put Kconfig externs into .kconfig section
Move Kconfig-provided externs into custom .kconfig section. Add __kconfig into
bpf_helpers.h for user convenience. Update selftests accordingly.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191219002837.3074619-2-andriin@fb.com
2019-12-18 17:33:36 -08:00
Andrii Nakryiko
d69587062c libbpf: Add bpf_link__disconnect() API to preserve underlying BPF resource
There are cases in which BPF resource (program, map, etc) has to outlive
userspace program that "installed" it in the system in the first place.
When BPF program is attached, libbpf returns bpf_link object, which
is supposed to be destroyed after no longer necessary through
bpf_link__destroy() API. Currently, bpf_link destruction causes both automatic
detachment and frees up any resources allocated to for bpf_link in-memory
representation. This is inconvenient for the case described above because of
coupling of detachment and resource freeing.

This patch introduces bpf_link__disconnect() API call, which marks bpf_link as
disconnected from its underlying BPF resouces. This means that when bpf_link
is destroyed later, all its memory resources will be freed, but BPF resource
itself won't be detached.

This design allows to follow strict and resource-leak-free design by default,
while giving easy and straightforward way for user code to opt for keeping BPF
resource attached beyond lifetime of a bpf_link. For some BPF programs (i.e.,
FS-based tracepoints, kprobes, raw tracepoint, etc), user has to make sure to
pin BPF program to prevent kernel to automatically detach it on process exit.
This should typically be achived by pinning BPF program (or map in some cases)
in BPF FS.

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/20191218225039.2668205-1-andriin@fb.com
2019-12-18 17:17:47 -08:00
Nikita V. Shirokov
6de6c1f840 bpf: Allow to change skb mark in test_run
allow to pass skb's mark field into bpf_prog_test_run ctx
for BPF_PROG_TYPE_SCHED_CLS prog type. that would allow
to test bpf programs which are doing decision based on this
field

Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-12-18 17:05:58 -08:00
Andrii Nakryiko
dacce6412e bpftool: Work-around rst2man conversion bug
Work-around what appears to be a bug in rst2man convertion tool, used to
create man pages out of reStructureText-formatted documents. If text line
starts with dot, rst2man will put it in resulting man file verbatim. This
seems to cause man tool to interpret it as a directive/command (e.g., `.bs`), and
subsequently not render entire line because it's unrecognized one.

Enclose '.xxx' words in extra formatting to work around.

Fixes: cb21ac588546 ("bpftool: Add gen subcommand manpage")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com
Link: https://lore.kernel.org/bpf/20191218221707.2552199-1-andriin@fb.com
2019-12-18 17:03:52 -08:00
Andrii Nakryiko
7c43e0d6a5 bpftool: Simplify format string to not use positional args
Change format string referring to just single argument out of two available.
Some versions of libc can reject such format string.

Reported-by: Nikita Shirokov <tehnerd@tehnerd.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191218214314.2403729-1-andriin@fb.com
2019-12-18 17:02:16 -08:00
Alexei Starovoitov
58d8dc2a98 Merge branch 'skel-fixes'
Andrii Nakryiko says:

====================
Simplify skeleton usage by embedding source BPF object file inside skeleton
itself. This allows to keep skeleton and object file in sync at all times with
no chance of confusion.

Also, add bpftool-gen.rst manpage, explaining concepts and ideas behind
skeleton. In examples section it also includes a complete small BPF
application utilizing skeleton, as a demonstration of API.

Patch #2 also removes BPF_EMBED_OBJ, as there is currently no use of it.

v2->v3:
- (void) in no-args function (Alexei);
- bpftool-gen.rst code block formatting fix (Alexei);
- simplified xxx__create_skeleton to fill in obj and return error code;

v1->v2:
- remove whitespace from empty lines in code blocks (Yonghong).
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-12-17 22:16:40 -08:00
Andrii Nakryiko
cb21ac5885 bpftool: Add gen subcommand manpage
Add bpftool-gen.rst describing skeleton on the high level. Also include
a small, but complete, example BPF app (BPF side, userspace side, generated
skeleton) in example section to demonstrate skeleton API and its usage.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191218052552.2915188-4-andriin@fb.com
2019-12-17 22:16:36 -08:00
Andrii Nakryiko
3bf3c79b77 libbpf: Remove BPF_EMBED_OBJ macro from libbpf.h
Drop BPF_EMBED_OBJ and struct bpf_embed_data now that skeleton automatically
embeds contents of its source object file. While BPF_EMBED_OBJ is useful
independently of skeleton, we are currently don't have any use cases utilizing
it, so let's remove them until/if we need it.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191218052552.2915188-3-andriin@fb.com
2019-12-17 22:16:36 -08:00
Andrii Nakryiko
5dc7a8b211 bpftool, selftests/bpf: Embed object file inside skeleton
Embed contents of BPF object file used for BPF skeleton generation inside
skeleton itself. This allows to keep BPF object file and its skeleton in sync
at all times, and simpifies skeleton instantiation.

Also switch existing selftests to not require BPF_EMBED_OBJ anymore.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191218052552.2915188-2-andriin@fb.com
2019-12-17 22:16:35 -08:00
Andrii Nakryiko
4a3d6c6a6e libbpf: Reduce log level for custom section names
Libbpf is trying to recognize BPF program type based on its section name
during bpf_object__open() phase. This is not strictly enforced and user code
has ability to specify/override correct BPF program type after open.  But if
BPF program is using custom section name, libbpf will still emit warnings,
which can be quite annoying to users. This patch reduces log level of
information messages emitted by libbpf if section name is not canonical. User
can still get a list of all supported section names as debug-level message.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191217234228.1739308-1-andriin@fb.com
2019-12-17 18:38:35 -08:00
Toke Høiland-Jørgensen
fb9a98e160 libbpf: Fix libbpf_common.h when installing libbpf through 'make install'
This fixes two issues with the newly introduced libbpf_common.h file:

- The header failed to include <string.h> for the definition of memset()
- The new file was not included in the install_headers rule in the Makefile

Both of these issues cause breakage when installing libbpf with 'make
install' and trying to use it in applications.

Fixes: 544402d4b493 ("libbpf: Extract common user-facing helpers")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191217112810.768078-1-toke@redhat.com
2019-12-18 00:19:31 +01:00
Andrii Nakryiko
92f7440ecc selftests/bpf: More succinct Makefile output
Similarly to bpftool/libbpf output, make selftests/bpf output succinct
per-item output line. Output is roughly as follows:

$ make
...
  CLANG-LLC [test_maps] pyperf600.o
  CLANG-LLC [test_maps] strobemeta.o
  CLANG-LLC [test_maps] pyperf100.o
  EXTRA-OBJ [test_progs] cgroup_helpers.o
  EXTRA-OBJ [test_progs] trace_helpers.o
     BINARY test_align
     BINARY test_verifier_log
   GEN-SKEL [test_progs] fexit_bpf2bpf.skel.h
   GEN-SKEL [test_progs] test_global_data.skel.h
   GEN-SKEL [test_progs] sendmsg6_prog.skel.h
...

To see the actual command invocation, verbose mode can be turned on with V=1
argument:

$ make V=1

... very verbose output ...

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191217061425.2346359-1-andriin@fb.com
2019-12-18 00:14:20 +01:00
Andrii Nakryiko
dbd8f6bae6 libbpf: Add zlib as a dependency in pkg-config template
List zlib as another dependency of libbpf in pkg-config template.
Verified it is correctly resolved to proper -lz flag:

$ make DESTDIR=/tmp/libbpf-install install
$ pkg-config --libs /tmp/libbpf-install/usr/local/lib64/pkgconfig/libbpf.pc
-L/usr/local/lib64 -lbpf
$ pkg-config --libs --static /tmp/libbpf-install/usr/local/lib64/pkgconfig/libbpf.pc
-L/usr/local/lib64 -lbpf -lelf -lz

Fixes: 166750bc1dd2 ("libbpf: Support libbpf-provided extern variables")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Cc: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/bpf/20191216183830.3972964-1-andriin@fb.com
2019-12-16 14:55:29 -08:00
Toke Høiland-Jørgensen
dc3a2d2547 libbpf: Print hint about ulimit when getting permission denied error
Probably the single most common error newcomers to XDP are stumped by is
the 'permission denied' error they get when trying to load their program
and 'ulimit -l' is set too low. For examples, see [0], [1].

Since the error code is UAPI, we can't change that. Instead, this patch
adds a few heuristics in libbpf and outputs an additional hint if they are
met: If an EPERM is returned on map create or program load, and geteuid()
shows we are root, and the current RLIMIT_MEMLOCK is not infinity, we
output a hint about raising 'ulimit -l' as an additional log line.

[0] https://marc.info/?l=xdp-newbies&m=157043612505624&w=2
[1] https://github.com/xdp-project/xdp-tutorial/issues/86

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191216181204.724953-1-toke@redhat.com
2019-12-16 14:52:34 -08:00
Toke Høiland-Jørgensen
d50ecc46d1 samples/bpf: Attach XDP programs in driver mode by default
When attaching XDP programs, userspace can set flags to request the attach
mode (generic/SKB mode, driver mode or hw offloaded mode). If no such flags
are requested, the kernel will attempt to attach in driver mode, and then
silently fall back to SKB mode if this fails.

The silent fallback is a major source of user confusion, as users will try
to load a program on a device without XDP support, and instead of an error
they will get the silent fallback behaviour, not notice, and then wonder
why performance is not what they were expecting.

In an attempt to combat this, let's switch all the samples to default to
explicitly requesting driver-mode attach. As part of this, ensure that all
the userspace utilities have a switch to enable SKB mode. For those that
have a switch to request driver mode, keep it but turn it into a no-op.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Link: https://lore.kernel.org/bpf/20191216110742.364456-1-toke@redhat.com
2019-12-16 07:05:38 -08:00
Toke Høiland-Jørgensen
450278977a samples/bpf: Set -fno-stack-protector when building BPF programs
It seems Clang can in some cases turn on stack protection by default, which
doesn't work with BPF. This was reported once before[0], but it seems the
flag to explicitly turn off the stack protector wasn't added to the
Makefile, so do that now.

The symptom of this is compile errors like the following:

error: <unknown>:0:0: in function bpf_prog1 i32 (%struct.__sk_buff*): A call to built-in function '__stack_chk_fail' is not supported.

[0] https://www.spinics.net/lists/netdev/msg556400.html

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191216103819.359535-1-toke@redhat.com
2019-12-16 07:03:12 -08:00
Toke Høiland-Jørgensen
5615ed472d samples/bpf: Add missing -lz to TPROGS_LDLIBS
Since libbpf now links against zlib, this needs to be included in the
linker invocation for the userspace programs in samples/bpf that link
statically against libbpf.

Fixes: 166750bc1dd2 ("libbpf: Support libbpf-provided extern variables")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/20191216102405.353834-1-toke@redhat.com
2019-12-16 06:58:10 -08:00
Prashant Bhole
5984dc6cb5 samples/bpf: Reintroduce missed build targets
Add xdp_redirect and per_socket_stats_example in build targets.
They got removed from build targets in Makefile reorganization.

Fixes: 1d97c6c2511f ("samples/bpf: Base target programs rules on Makefile.target")
Signed-off-by: Prashant Bhole <prashantbhole.linux@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191216071619.25479-1-prashantbhole.linux@gmail.com
2019-12-16 06:55:30 -08:00
Paul Chaignon
159ecc002b bpftool: Fix compilation warning on shadowed variable
The ident variable has already been declared at the top of the function
and doesn't need to be re-declared.

Fixes: 985ead416df39 ("bpftool: Add skeleton codegen command")
Signed-off-by: Paul Chaignon <paul.chaignon@orange.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216112733.GA28366@Omicron
2019-12-16 14:18:48 +01:00
Prashant Bhole
a79ac2d103 libbpf: Fix build by renaming variables
In btf__align_of() variable name 't' is shadowed by inner block
declaration of another variable with same name. Patch renames
variables in order to fix it.

  CC       sharedobjs/btf.o
btf.c: In function ‘btf__align_of’:
btf.c:303:21: error: declaration of ‘t’ shadows a previous local [-Werror=shadow]
  303 |   int i, align = 1, t;
      |                     ^
btf.c:283:25: note: shadowed declaration is here
  283 |  const struct btf_type *t = btf__type_by_id(btf, id);
      |

Fixes: 3d208f4ca111 ("libbpf: Expose btf__align_of() API")
Signed-off-by: Prashant Bhole <prashantbhole.linux@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191216082738.28421-1-prashantbhole.linux@gmail.com
2019-12-16 14:14:16 +01:00
Alexei Starovoitov
0849e10280 Merge branch 'support-flex-arrays'
Andrii Nakryiko says:

====================
Add support for flexible array accesses in a relocatable manner in BPF CO-RE.
It's a typical pattern in C, and kernel in particular, to provide
a fixed-length struct with zero-sized or dimensionless array at the end. In
such cases variable-sized array contents follows immediately after the end of
a struct. This patch set adds support for such access pattern by allowing
accesses to such arrays.

Patch #1 adds libbpf support. Patch #2 adds few test cases for validation.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-12-15 16:53:55 -08:00