1554 Commits

Author SHA1 Message Date
Song Liu
d4b4dd6ce7 libbpf: Print hint when PERF_EVENT_IOC_SET_BPF returns -EPROTO
The kernel prevents potential unwinder warnings and crashes by blocking
BPF program with bpf_get_[stack|stackid] on perf_event without
PERF_SAMPLE_CALLCHAIN, or with exclude_callchain_[kernel|user]. Print a
hint message in libbpf to help the user debug such issues.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723180648.1429892-4-songliubraving@fb.com
2020-07-25 20:16:35 -07:00
Yonghong Song
cd31039a73 tools/libbpf: Add support for bpf map element iterator
Add map_fd to bpf_iter_attach_opts and flags to
bpf_link_create_opts. Later on, bpftool or selftest
will be able to create a bpf map element iterator
by passing map_fd to the kernel during link
creation time.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184117.590673-1-yhs@fb.com
2020-07-25 20:16:33 -07:00
David S. Miller
a57066b1a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The UDP reuseport conflict was a little bit tricky.

The net-next code, via bpf-next, extracted the reuseport handling
into a helper so that the BPF sk lookup code could invoke it.

At the same time, the logic for reuseport handling of unconnected
sockets changed via commit efc6b6f6c3113e8b203b9debfb72d81e0f3dcace
which changed the logic to carry on the reuseport result into the
rest of the lookup loop if we do not return immediately.

This requires moving the reuseport_has_conns() logic into the callers.

While we are here, get rid of inline directives as they do not belong
in foo.c files.

The other changes were cases of more straightforward overlapping
modifications.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-25 17:49:04 -07:00
Ian Rogers
da7a35062b libbpf bpf_helpers: Use __builtin_offsetof for offsetof
The non-builtin route for offsetof has a dependency on size_t from
stdlib.h/stdint.h that is undeclared and may break targets.
The offsetof macro in bpf_helpers may disable the same macro in other
headers that have a #ifdef offsetof guard. Rather than add additional
dependencies improve the offsetof macro declared here to use the
builtin that is available since llvm 3.7 (the first with a BPF backend).

Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200720061741.1514673-1-irogers@google.com
2020-07-21 13:26:25 -07:00
Alexey Budankov
d3da1f0900 libperf: Avoid counting of nonfilterable fdarray fds
Avoid counting of struct pollfd *entries objects with
fdarray_flag__nonfilterable flag by fdarray__filter().

Nonfilterable objects are still processed if requested revents have been
signaled for them.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/b5ab0d2c-b742-0032-e8d3-c8e2eb423c42@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-21 09:53:22 -03:00
Alexey Budankov
ab4c1f9f68 libperf: Add flags to fdarray fds objects
Store flags per struct pollfd *entries object in a bitmap of int size.

Implement fdarray_flag__nonfilterable flag to skip object from counting
by fdarray__filter().

Fixed fdarray test issue reported by kernel test robot.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/6b7d43ff-0801-d5dd-4e90-fcd86b17c1c8@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-21 09:52:51 -03:00
Alexey Budankov
59b4412f27 libperf: Avoid internal moving of fdarray fds
Avoid moving of fds by fdarray__filter() so fds indices returned by
fdarray__add() can be used for access and processing of objects at
struct pollfd *entries.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/676844f8-55d3-c628-23db-aa163a81519e@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-21 08:49:30 -03:00
Jakub Sitnicki
499dd29d90 libbpf: Add support for SK_LOOKUP program type
Make libbpf aware of the newly added program type, and assign it a
section name.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200717103536.397595-13-jakub@cloudflare.com
2020-07-17 20:18:17 -07:00
Ravi Bangoria
a2db71b912 libsubcmd: Fix OPT_CALLBACK_SET()
Any option macro with _SET suffix should set opt->set variable which is
not happening for OPT_CALLBACK_SET(). This is causing issues with perf
record --switch-output-event. Fix that.

Before:

  # ./perf record --overwrite -e sched:*switch,syscalls:sys_enter_mmap \
           --switch-output-event syscalls:sys_enter_mmap
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.297 MB perf.data (657 samples) ]

After:

  $ ./perf record --overwrite -e sched:*switch,syscalls:sys_enter_mmap \
          --switch-output-event syscalls:sys_enter_mmap
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2020061918144542 ]
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2020061918144608 ]
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2020061918144660 ]
  ^C[ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2020061918144784 ]
  [ perf record: Woken up 0 times to write data ]
  [ perf record: Dump perf.data.2020061918144803 ]
  [ perf record: Captured and wrote 0.419 MB perf.data.<timestamp> ]

Fixes: 636eb4d001b1 ("libsubcmd: Introduce OPT_CALLBACK_SET()")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200619133412.50705-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-17 09:33:06 -03:00
Lorenzo Bianconi
4be556cf5a libbpf: Add SEC name for xdp programs attached to CPUMAP
As for DEVMAP, support SEC("xdp_cpumap/") as a short cut for loading
the program with type BPF_PROG_TYPE_XDP and expected attach type
BPF_XDP_CPUMAP.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/33174c41993a6d860d9c7c1f280a2477ee39ed11.1594734381.git.lorenzo@kernel.org
2020-07-16 17:00:32 +02:00
David S. Miller
07dd1b7e68 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-07-13

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

We've added 36 non-merge commits during the last 7 day(s) which contain
a total of 62 files changed, 2242 insertions(+), 468 deletions(-).

The main changes are:

1) Avoid trace_printk warning banner by switching bpf_trace_printk to use
   its own tracing event, from Alan.

2) Better libbpf support on older kernels, from Andrii.

3) Additional AF_XDP stats, from Ciara.

4) build time resolution of BTF IDs, from Jiri.

5) BPF_CGROUP_INET_SOCK_RELEASE hook, from Stanislav.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-13 18:04:05 -07:00
Andrii Nakryiko
0b20933d8c tools/bpftool: Strip away modifiers from global variables
Reliably remove all the type modifiers from read-only (.rodata) global
variable definitions, including cases of inner field const modifiers and
arrays of const values.

Also modify one of selftests to ensure that const volatile struct doesn't
prevent user-space from modifying .rodata variable.

Fixes: 985ead416df3 ("bpftool: Add skeleton codegen command")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200713232409.3062144-3-andriin@fb.com
2020-07-13 17:07:43 -07:00
Andrii Nakryiko
7c819e7013 libbpf: Support stripping modifiers for btf_dump
One important use case when emitting const/volatile/restrict is undesirable is
BPF skeleton generation of DATASEC layout. These are further memory-mapped and
can be written/read from user-space directly.

For important case of .rodata variables, bpftool strips away first-level
modifiers, to make their use on user-space side simple and not requiring extra
type casts to override compiler complaining about writing to const variables.

This logic works mostly fine, but breaks in some more complicated cases. E.g.:

    const volatile int params[10];

Because in BTF it's a chain of ARRAY -> CONST -> VOLATILE -> INT, bpftool
stops at ARRAY and doesn't strip CONST and VOLATILE. In skeleton this variable
will be emitted as is. So when used from user-space, compiler will complain
about writing to const array. This is problematic, as also mentioned in [0].

To solve this for arrays and other non-trivial cases (e.g., inner
const/volatile fields inside the struct), teach btf_dump to strip away any
modifier, when requested. This is done as an extra option on
btf_dump__emit_type_decl() API.

Reported-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200713232409.3062144-2-andriin@fb.com
2020-07-13 17:07:43 -07:00
David S. Miller
71930d6102 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
All conflicts seemed rather trivial, with some guidance from
Saeed Mameed on the tc_ct.c one.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-11 00:46:00 -07:00
Linus Torvalds
5a764898af Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Restore previous behavior of CAP_SYS_ADMIN wrt loading networking
    BPF programs, from Maciej Żenczykowski.

 2) Fix dropped broadcasts in mac80211 code, from Seevalamuthu
    Mariappan.

 3) Slay memory leak in nl80211 bss color attribute parsing code, from
    Luca Coelho.

 4) Get route from skb properly in ip_route_use_hint(), from Miaohe Lin.

 5) Don't allow anything other than ARPHRD_ETHER in llc code, from Eric
    Dumazet.

 6) xsk code dips too deeply into DMA mapping implementation internals.
    Add dma_need_sync and use it. From Christoph Hellwig

 7) Enforce power-of-2 for BPF ringbuf sizes. From Andrii Nakryiko.

 8) Check for disallowed attributes when loading flow dissector BPF
    programs. From Lorenz Bauer.

 9) Correct packet injection to L3 tunnel devices via AF_PACKET, from
    Jason A. Donenfeld.

10) Don't advertise checksum offload on ipa devices that don't support
    it. From Alex Elder.

11) Resolve several issues in TCP MD5 signature support. Missing memory
    barriers, bogus options emitted when using syncookies, and failure
    to allow md5 key changes in established states. All from Eric
    Dumazet.

12) Fix interface leak in hsr code, from Taehee Yoo.

13) VF reset fixes in hns3 driver, from Huazhong Tan.

14) Make loopback work again with ipv6 anycast, from David Ahern.

15) Fix TX starvation under high load in fec driver, from Tobias
    Waldekranz.

16) MLD2 payload lengths not checked properly in bridge multicast code,
    from Linus Lüssing.

17) Packet scheduler code that wants to find the inner protocol
    currently only works for one level of VLAN encapsulation. Allow
    Q-in-Q situations to work properly here, from Toke
    Høiland-Jørgensen.

18) Fix route leak in l2tp, from Xin Long.

19) Resolve conflict between the sk->sk_user_data usage of bpf reuseport
    support and various protocols. From Martin KaFai Lau.

20) Fix socket cgroup v2 reference counting in some situations, from
    Cong Wang.

21) Cure memory leak in mlx5 connection tracking offload support, from
    Eli Britstein.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (146 commits)
  mlxsw: pci: Fix use-after-free in case of failed devlink reload
  mlxsw: spectrum_router: Remove inappropriate usage of WARN_ON()
  net: macb: fix call to pm_runtime in the suspend/resume functions
  net: macb: fix macb_suspend() by removing call to netif_carrier_off()
  net: macb: fix macb_get/set_wol() when moving to phylink
  net: macb: mark device wake capable when "magic-packet" property present
  net: macb: fix wakeup test in runtime suspend/resume routines
  bnxt_en: fix NULL dereference in case SR-IOV configuration fails
  libbpf: Fix libbpf hashmap on (I)LP32 architectures
  net/mlx5e: CT: Fix memory leak in cleanup
  net/mlx5e: Fix port buffers cell size value
  net/mlx5e: Fix 50G per lane indication
  net/mlx5e: Fix CPU mapping after function reload to avoid aRFS RX crash
  net/mlx5e: Fix VXLAN configuration restore after function reload
  net/mlx5e: Fix usage of rcu-protected pointer
  net/mxl5e: Verify that rpriv is not NULL
  net/mlx5: E-Switch, Fix vlan or qos setting in legacy mode
  net/mlx5: Fix eeprom support for SFP module
  cgroup: Fix sock_cgroup_data on big-endian.
  selftests: bpf: Fix detach from sockmap tests
  ...
2020-07-10 18:16:22 -07:00
Andrii Nakryiko
5c3320d7fe libbpf: Fix memory leak and optimize BTF sanitization
Coverity's static analysis helpfully reported a memory leak introduced by
0f0e55d8247c ("libbpf: Improve BTF sanitization handling"). While fixing it,
I realized that btf__new() already creates a memory copy, so there is no need
to do this. So this patch also fixes misleading btf__new() signature to make
data into a `const void *` input parameter. And it avoids unnecessary memory
allocation and copy in BTF sanitization code altogether.

Fixes: 0f0e55d8247c ("libbpf: Improve BTF sanitization handling")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200710011023.1655008-1-andriin@fb.com
2020-07-10 16:24:35 +02:00
Adrian Hunter
246eba8e90 perf tools: Add support for PERF_RECORD_TEXT_POKE
Add processing for PERF_RECORD_TEXT_POKE events. When a text poke event
is processed, then the kernel dso data cache is updated with the poked
bytes.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-10 08:20:01 -03:00
Jakub Bogusz
b2f9f1535b libbpf: Fix libbpf hashmap on (I)LP32 architectures
On ILP32, 64-bit result was shifted by value calculated for 32-bit long type
and returned value was much outside hashmap capacity.
As advised by Andrii Nakryiko, this patch uses different hashing variant for
architectures with size_t shorter than long long.

Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap")
Signed-off-by: Jakub Bogusz <qboosh@pld-linux.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200709225723.1069937-1-andriin@fb.com
2020-07-09 19:38:55 -07:00
Andrii Nakryiko
0e28948730 libbpf: Handle missing BPF_OBJ_GET_INFO_BY_FD gracefully in perf_buffer
perf_buffer__new() is relying on BPF_OBJ_GET_INFO_BY_FD availability for few
sanity checks. OBJ_GET_INFO for maps is actually much more recent feature than
perf_buffer support itself, so this causes unnecessary problems on old kernels
before BPF_OBJ_GET_INFO_BY_FD was added.

This patch makes those sanity checks optional and just assumes best if command
is not supported. If user specified something incorrectly (e.g., wrong map
type), kernel will reject it later anyway, except user won't get a nice
explanation as to why it failed. This seems like a good trade off for
supporting perf_buffer on old kernels.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200708015318.3827358-6-andriin@fb.com
2020-07-09 00:44:45 +02:00
Andrii Nakryiko
0f0e55d824 libbpf: Improve BTF sanitization handling
Change sanitization process to preserve original BTF, which might be used by
libbpf itself for Kconfig externs, CO-RE relocs, etc, even if kernel is old
and doesn't support BTF. To achieve that, if libbpf detects the need for BTF
sanitization, it would clone original BTF, sanitize it in-place, attempt to
load it into kernel, and if successful, will preserve loaded BTF FD in
original `struct btf`, while freeing sanitized local copy.

If kernel doesn't support any BTF, original btf and btf_ext will still be
preserved to be used later for CO-RE relocation and other BTF-dependent libbpf
features, which don't dependon kernel BTF support.

Patch takes care to not specify BTF and BTF.ext features when loading BPF
programs and/or maps, if it was detected that kernel doesn't support BTF
features.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200708015318.3827358-4-andriin@fb.com
2020-07-09 00:44:44 +02:00
Andrii Nakryiko
81372e1218 libbpf: Add btf__set_fd() for more control over loaded BTF FD
Add setter for BTF FD to allow application more fine-grained control in more
advanced scenarios. Storing BTF FD inside `struct btf` provides little benefit
and probably would be better done differently (e.g., btf__load() could just
return FD on success), but we are stuck with this due to backwards
compatibility. The main problem is that it's impossible to load BTF and than
free user-space memory, but keep FD intact, because `struct btf` assumes
ownership of that FD upon successful load and will attempt to close it during
btf__free(). To allow callers (e.g., libbpf itself for BTF sanitization) to
have more control over this, add btf__set_fd() to allow to reset FD
arbitrarily, if necessary.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200708015318.3827358-3-andriin@fb.com
2020-07-09 00:44:44 +02:00
Andrii Nakryiko
bfc96656a7 libbpf: Make BTF finalization strict
With valid ELF and valid BTF, there is no reason (apart from bugs) why BTF
finalization should fail. So make it strict and return error if it fails. This
makes CO-RE relocation more reliable, as they are not going to be just
silently skipped, if BTF finalization failed.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200708015318.3827358-2-andriin@fb.com
2020-07-09 00:44:44 +02:00
Arnaldo Carvalho de Melo
facbf0b982 Merge remote-tracking branch 'torvalds/master' into perf/core
To pick up fixes and move perf/core forward, minor conflict as
perf_evlist__add_dummy() lost its 'perf_' prefix as it operates on a
'struct evlist', not on a 'struct perf_evlist', i.e. its tools/perf/
specific, it is not in libperf.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-08 13:49:15 -03:00
Stanislav Fomichev
e8b012e9fa libbpf: Add support for BPF_CGROUP_INET_SOCK_RELEASE
Add auto-detection for the cgroup/sock_release programs.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200706230128.4073544-3-sdf@google.com
2020-07-08 01:07:35 +02:00
Jan Kiszka
e8f331aa91 tools lib traceevent: Fix reporting of unknown SVM exit reasons
On AMD, exist code -1 is also a possible value, but we use it for
terminating the list of known exit reasons. This leads to EXIT_ERR being
reported for unkown ones. Fix this by using an NULL string pointer as
terminal.

Link: http://lkml.kernel.org/r/5741D817.3070902@web.de
Link: http://lore.kernel.org/linux-trace-devel/20200702174950.123454-7-tz.stoyanov@gmail.com

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185705.759824282@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:02:35 -03:00
Steven Rostedt (VMware)
4e59ab93e2 tools lib traceevent: Change to SPDX License format
Replaced COPYING with a description of how the SPDX identifiers are
used.  Added a GPL-2.0 and LGPL-2.1 license file in the new LICENSES
directory.  Then removed all the license templates from the source files
and replaced them with the corresponding SPDX identifier.

Link: http://lore.kernel.org/linux-trace-devel/20200702174950.123454-6-tz.stoyanov@gmail.com

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185705.601167185@goodmis.org
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:02:20 -03:00
Steven Rostedt (VMware)
9b8179b38b tools lib traceevent: Add builtin handler for trace_marker_raw
When something is written into trace_marker_raw, it goes in as a binary.
But the printk_fmt() of the event that is created (raw_data)'s format
file only prints the first byte of data:

  print fmt: "id:%04x %08x", REC->id, (int)REC->buf[0]

This is not very useful if we want to see the full data output.

Implement the processing of the raw_data event like it is in the kernel.

Link: http://lore.kernel.org/linux-trace-devel/20200702174950.123454-5-tz.stoyanov@gmail.com

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185705.445969275@goodmis.org
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:01:54 -03:00
Tzvetomir Stoyanov (VMware)
0dfceeffae tools lib traceevent: Move kernel_stack event handler to "function" plugin.
The "kernel_stack" event handler does not depend on any trace-cmd
context, it can be used aside from the application. The code is moved to
libtraceevent "function" plugin.

Link: http://lore.kernel.org/linux-trace-devel/20190726124308.18735-2-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200702174950.123454-4-tz.stoyanov@gmail.com

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185705.284789930@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:01:48 -03:00
Julia Cartwright
5973e6ebc0 tools lib traceevent: Add plugin for decoding syscalls/sys_enter_futex
The futex syscall is a complicated one.  It supports thirteen
multiplexed operations, each with different semantics and encodings for
the syscalls six arguments.

Manually decoding these arguments is tedious and error prone.

This plugin provides symbolic names for futex operations, futex flags,
and tries to be intelligent about the intent of specific arguments (for
example, waking operations use 'val' as an integer count, not just an
arbitrary value).

It doesn't do a full decode of the FUTEX_WAKE_OP's 'val3' argument,
however, this is a good starting point.

Link: http://lkml.kernel.org/r/20171207025649.12160-1-julia@ni.com
Link: http://lore.kernel.org/linux-trace-devel/20200702174950.123454-3-tz.stoyanov@gmail.com

Signed-off-by: Julia Cartwright <julia@ni.com>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185705.127175788@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:01:20 -03:00
Steven Rostedt (VMware)
5786362332 tools lib traceevent: Add offset option for function plugin
When the offset option is set for the function plugin enabled, it will
display the offset of the functions along with their names.  This helps
in finding exactly where a function was called by its parent.

  trace-cmd report -O parent -O offset
 [..]
        rcuc/163-1330  [163]   740.653251: function: _raw_spin_lock+0x0  <-- rcu_cpu_kthread+0x4d8

Link: http://lore.kernel.org/linux-trace-devel/20200702174950.123454-2-tz.stoyanov@gmail.com

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185704.986181512@goodmis.org
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:01:12 -03:00
Jan Kiszka
97b6c5394d tools lib traceevent: Add more SVM exit reasons
Exceptions require individual decoding (only feasible intercepts
listed), XSETBV was missing and the AVIC brought in two new exit codes.

Link: http://lkml.kernel.org/r/5741D822.3030203@web.de
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-10-tz.stoyanov@gmail.com

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185704.844582602@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:00:42 -03:00
Steven Rostedt (Red Hat)
3e14b100b0 tools lib traceevent: Add plugin for tlb_flush
The tlb_flush tracepoints uses enums that are not yet known by the
traceevent library. Add a plugin to handle that.

Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-9-tz.stoyanov@gmail.com

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185704.706977382@goodmis.org
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 09:00:35 -03:00
Tzvetomir Stoyanov (VMware)
e7a90882b0 tools lib traceevent: Optimize pretty_print() function
Each time the pretty_print() function is called to print an event, the
event's format string is parsed. As this format string does not change,
this parsing can be done only once - when the event struct is
initialized.

Link: https://lore.kernel.org/linux-trace-devel/20200529134929.537110-1-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-8-tz.stoyanov@gmail.com

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185704.559785000@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 08:59:58 -03:00
Tzvetomir Stoyanov (VMware)
487ae1f4a1 tools lib traceevent: Add support for more printk format specifiers
The printk format specifiers used in event's print format files extend
the standard printf formats. There are a lot of new options related to
printing pointers and kernel specific structures. Currently trace-cmd
does not support many of them.

Support for these new printk specifiers is added to the pretty_print()
function:

 - UUID/GUID address: %pU[bBlL]
 - Raw buffer as a hex string: %*ph[CDN]

These are improved:

 - MAC address: %pMF, %pM and %pmR
 - IPv4 adderss: %p[Ii]4[hnbl]

Function pretty_print() is refactored. The logic for printing pointers
%p[...] is moved to its own function.

Link: https://lore.kernel.org/linux-trace-devel/20200515053754.3695335-1-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-7-tz.stoyanov@gmail.com

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207605
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185704.401148804@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 08:35:23 -03:00
Tzvetomir Stoyanov (VMware)
4d70caefd0 tools lib traceevent: Introduced new traceevent API, for adding new plugins directories.
Implement new traceevent plugin API, which can be used to add new plugins
directories:

enum tep_plugin_load_priority {
	TEP_PLUGIN_FIRST,
	TEP_PLUGIN_LAST,
};

int tep_add_plugin_path(struct tep_handle *tep, char *path,
			enum tep_plugin_load_priority prio);

It adds the "path" as new plugin directory, in the context of the
handler "tep". The tep_load_plugins() API searches for plugins in this
new location. Depending of the priority "prio", the plugins from this
directory are loaded before (TEP_PLUGIN_FIRST) or after
(TEP_PLUGIN_LAST) the ordinary libtraceevent plugin locations.

Link: http://lore.kernel.org/linux-trace-devel/20191007114947.17104-2-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-6-tz.stoyanov@gmail.com

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185704.248123446@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 08:35:23 -03:00
Tzvetomir Stoyanov (VMware)
74006289cf tools lib traceevent: Add interface for options to plugins
Add tep_plugin_add_option() and tep_plugin_print_options() to lib
traceevent library that allows plugins to have their own options. For
example, the function plugin by default does not print the parent, as it
uses the parent to do the indenting. The "parent" option is created by
the function plugin that will print the parent of the function like it
does in the trace file.

The tep_plugin_print_options() will print out the list of options that a
Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
plugin has defined.

Link: http://lore.kernel.org/linux-trace-devel/20190802110101.14759-3-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-5-tz.stoyanov@gmail.com

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185704.092654084@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 08:35:23 -03:00
Tzvetomir Stoyanov (VMware)
662081acfa tools lib traceevent: Add tep_load_plugins_hook() API
Add the API function tep_load_plugins_hook() to the traceevent API to
allow tools a common method to load in the plugins that are part of the
lib traceevent library.

Link: http://lore.kernel.org/linux-trace-devel/20190802110101.14759-4-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-4-tz.stoyanov@gmail.com

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185703.946652691@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-06 08:35:22 -03:00
David S. Miller
f91c031e65 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-07-04

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

We've added 73 non-merge commits during the last 17 day(s) which contain
a total of 106 files changed, 5233 insertions(+), 1283 deletions(-).

The main changes are:

1) bpftool ability to show PIDs of processes having open file descriptors
   for BPF map/program/link/BTF objects, relying on BPF iterator progs
   to extract this info efficiently, from Andrii Nakryiko.

2) Addition of BPF iterator progs for dumping TCP and UDP sockets to
   seq_files, from Yonghong Song.

3) Support access to BPF map fields in struct bpf_map from programs
   through BTF struct access, from Andrey Ignatov.

4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack
   via seq_file from BPF iterator progs, from Song Liu.

5) Make SO_KEEPALIVE and related options available to bpf_setsockopt()
   helper, from Dmitry Yakunin.

6) Optimize BPF sk_storage selection of its caching index, from Martin
   KaFai Lau.

7) Removal of redundant synchronize_rcu()s from BPF map destruction which
   has been a historic leftover, from Alexei Starovoitov.

8) Several improvements to test_progs to make it easier to create a shell
   loop that invokes each test individually which is useful for some CIs,
   from Jesper Dangaard Brouer.

9) Fix bpftool prog dump segfault when compiled without skeleton code on
   older clang versions, from John Fastabend.

10) Bunch of cleanups and minor improvements, from various others.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-04 17:48:34 -07:00
Tom Zanussi
2160d6c8a1 tools lib traceevent: Add proper KBUFFER_TYPE_TIME_STAMP handling
Kernel commit dc4e2801d400 (ring-buffer: Redefine the unimplemented
RINGBUF_TYPE_TIME_STAMP) changed the way the ring buffer timestamps work
- after that commit the previously unimplemented RINGBUF_TYPE_TIME_STAMP
type causes the time delta to be used as a timestamp rather than a delta
to be added to the timestamp.

The trace-cmd code didn't get updated to handle this, so misinterprets
the event data for this case, which causes a cascade of errors,
including trace-report not being able to identify synthetic (or any
other) events generated by the histogram code (which uses TIME_STAMP
mode).  For example, the following triggers along with the trace-cmd
shown cause an UNKNOWN_EVENT error and trace-cmd report crash:

  # echo 'wakeup_latency  u64 lat pid_t pid char comm[16]' > /sys/kernel/debug/tracing/synthetic_events

  # echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
  # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_wakeup).trace(wakeup_latency,$wakeup_lat,next_pid,next_comm) if next_comm=="ping"' > /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
  # echo 'hist:keys=comm,pid,lat:wakeup_lat=lat:sort=lat' > /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger

  # trace-cmd record -e wakeup_latency -e sched_wakeup -f comm==\"ping\" ping localhost -c 5

  # trace-cmd report
  CPU 0 is empty
  CPU 1 is empty
  CPU 2 is empty
  CPU 3 is empty
  CPU 5 is empty
  CPU 6 is empty
  CPU 7 is empty
  cpus=8
    ug! no event found for type 0
  [UNKNOWN TYPE 0]
    ug! no event found for type 11520
  Segmentation fault (core dumped)

After this patch we get the correct interpretation and the events are
shown properly:

  # trace-cmd report
  CPU 0 is empty
  CPU 1 is empty
  CPU 2 is empty
  CPU 3 is empty
  CPU 5 is empty
  CPU 6 is empty
  CPU 7 is empty
  cpus=8
          <idle>-0     [004] 23284.341392: sched_wakeup:         ping:12031 [120] success=1 CPU:004
          <idle>-0     [004] 23284.341464: wakeup_latency:       lat=58, pid=12031, comm=ping
          <idle>-0     [004] 23285.365303: sched_wakeup:         ping:12031 [120] success=1 CPU:004
          <idle>-0     [004] 23285.365382: wakeup_latency:       lat=64, pid=12031, comm=ping
          <idle>-0     [004] 23286.389290: sched_wakeup:         ping:12031 [120] success=1 CPU:004
          <idle>-0     [004] 23286.389378: wakeup_latency:       lat=72, pid=12031, comm=ping
          <idle>-0     [004] 23287.413213: sched_wakeup:         ping:12031 [120] success=1 CPU:004
          <idle>-0     [004] 23287.413291: wakeup_latency:       lat=64, pid=12031, comm=ping

Link: http://lkml.kernel.org/r/1567628224.13841.4.camel@kernel.org
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-3-tz.stoyanov@gmail.com

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185703.785094515@goodmis.org
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-03 08:45:38 -03:00
Steven Rostedt (Red Hat)
374855c5e4 tools lib traceevent: Add API to read time information from kbuffer
Add the functions kbuffer_subbuf_timestamp() and kbuffer_ptr_delta() to
get the timing data stored in the ring buffer that is used to produced
the time stamps of the records.

This is useful for tools like trace-cmd to be able to display the
content of the read data to understand why the records show the time
stamps that they do.

Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-2-tz.stoyanov@gmail.com

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185703.619656282@goodmis.org
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-03 08:30:10 -03:00
Andrii Nakryiko
30ad688094 libbpf: Make bpf_endian co-exist with vmlinux.h
Make bpf_endian.h compatible with vmlinux.h. It is a frequent request from
users wanting to use bpf_endian.h in their BPF applications using CO-RE and
vmlinux.h.

To achieve that, re-implement byte swap macros and drop all the header
includes. This way it can be used both with linux header includes, as well as
with a vmlinux.h.

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/20200630152125.3631920-2-andriin@fb.com
2020-07-01 09:06:12 +02:00
David S. Miller
e708e2bd55 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2020-06-30

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

We've added 28 non-merge commits during the last 9 day(s) which contain
a total of 35 files changed, 486 insertions(+), 232 deletions(-).

The main changes are:

1) Fix an incorrect verifier branch elimination for PTR_TO_BTF_ID pointer
   types, from Yonghong Song.

2) Fix UAPI for sockmap and flow_dissector progs that were ignoring various
   arguments passed to BPF_PROG_{ATTACH,DETACH}, from Lorenz Bauer & Jakub Sitnicki.

3) Fix broken AF_XDP DMA hacks that are poking into dma-direct and swiotlb
   internals and integrate it properly into DMA core, from Christoph Hellwig.

4) Fix RCU splat from recent changes to avoid skipping ingress policy when
   kTLS is enabled, from John Fastabend.

5) Fix BPF ringbuf map to enforce size to be the power of 2 in order for its
   position masking to work, from Andrii Nakryiko.

6) Fix regression from CAP_BPF work to re-allow CAP_SYS_ADMIN for loading
   of network programs, from Maciej Żenczykowski.

7) Fix libbpf section name prefix for devmap progs, from Jesper Dangaard Brouer.

8) Fix formatting in UAPI documentation for BPF helpers, from Quentin Monnet.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-30 14:20:45 -07:00
Andrii Nakryiko
d929758101 libbpf: Support disabling auto-loading BPF programs
Currently, bpf_object__load() (and by induction skeleton's load), will always
attempt to prepare, relocate, and load into kernel every single BPF program
found inside the BPF object file. This is often convenient and the right thing
to do and what users expect.

But there are plenty of cases (especially with BPF development constantly
picking up the pace), where BPF application is intended to work with old
kernels, with potentially reduced set of features. But on kernels supporting
extra features, it would like to take a full advantage of them, by employing
extra BPF program. This could be a choice of using fentry/fexit over
kprobe/kretprobe, if kernel is recent enough and is built with BTF. Or BPF
program might be providing optimized bpf_iter-based solution that user-space
might want to use, whenever available. And so on.

With libbpf and BPF CO-RE in particular, it's advantageous to not have to
maintain two separate BPF object files to achieve this. So to enable such use
cases, this patch adds ability to request not auto-loading chosen BPF
programs. In such case, libbpf won't attempt to perform relocations (which
might fail due to old kernel), won't try to resolve BTF types for
BTF-aware (tp_btf/fentry/fexit/etc) program types, because BTF might not be
present, and so on. Skeleton will also automatically skip auto-attachment step
for such not loaded BPF programs.

Overall, this feature allows to simplify development and deployment of
real-world BPF applications with complicated compatibility requirements.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200625232629.3444003-2-andriin@fb.com
2020-06-28 10:06:53 -07:00
Jesper Dangaard Brouer
7a64135f32 libbpf: Adjust SEC short cut for expected attach type BPF_XDP_DEVMAP
Adjust the SEC("xdp_devmap/") prog type prefix to contain a
slash "/" for expected attach type BPF_XDP_DEVMAP.  This is consistent
with other prog types like tracing.

Fixes: 2778797037a6 ("libbpf: Add SEC name for xdp programs attached to device map")
Suggested-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/159309521882.821855.6873145686353617509.stgit@firesoul
2020-06-25 22:36:00 +02:00
Andrii Nakryiko
192b6638ee libbpf: Prevent loading vmlinux BTF twice
Prevent loading/parsing vmlinux BTF twice in some cases: for CO-RE relocations
and for BTF-aware hooks (tp_btf, fentry/fexit, etc).

Fixes: a6ed02cac690 ("libbpf: Load btf_vmlinux only once per object.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200624043805.1794620-1-andriin@fb.com
2020-06-24 16:08:17 +02:00
Colin Ian King
135c783f47 libbpf: Fix spelling mistake "kallasyms" -> "kallsyms"
There is a spelling mistake in a pr_warn message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200623084207.149253-1-colin.king@canonical.com
2020-06-24 15:53:53 +02:00
Andrii Nakryiko
9c82a63cf3 libbpf: Fix CO-RE relocs against .text section
bpf_object__find_program_by_title(), used by CO-RE relocation code, doesn't
return .text "BPF program", if it is a function storage for sub-programs.
Because of that, any CO-RE relocation in helper non-inlined functions will
fail. Fix this by searching for .text-corresponding BPF program manually.

Adjust one of bpf_iter selftest to exhibit this pattern.

Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200619230423.691274-1-andriin@fb.com
2020-06-23 17:01:43 -07:00
Andrii Nakryiko
bd9bedf84b libbpf: Wrap source argument of BPF_CORE_READ macro in parentheses
Wrap source argument of BPF_CORE_READ family of macros into parentheses to
allow uses like this:

BPF_CORE_READ((struct cast_struct *)src, a, b, c);

Fixes: 7db3822ab991 ("libbpf: Add BPF_CORE_READ/BPF_CORE_READ_INTO helpers")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200619231703.738941-8-andriin@fb.com
2020-06-22 17:01:48 -07:00
Andrii Nakryiko
1c0c7074fe libbpf: Add support for extracting kernel symbol addresses
Add support for another (in addition to existing Kconfig) special kind of
externs in BPF code, kernel symbol externs. Such externs allow BPF code to
"know" kernel symbol address and either use it for comparisons with kernel
data structures (e.g., struct file's f_op pointer, to distinguish different
kinds of file), or, with the help of bpf_probe_user_kernel(), to follow
pointers and read data from global variables. Kernel symbol addresses are
found through /proc/kallsyms, which should be present in the system.

Currently, such kernel symbol variables are typeless: they have to be defined
as `extern const void <symbol>` and the only operation you can do (in C code)
with them is to take its address. Such extern should reside in a special
section '.ksyms'. bpf_helpers.h header provides __ksym macro for this. Strong
vs weak semantics stays the same as with Kconfig externs. If symbol is not
found in /proc/kallsyms, this will be a failure for strong (non-weak) extern,
but will be defaulted to 0 for weak externs.

If the same symbol is defined multiple times in /proc/kallsyms, then it will
be error if any of the associated addresses differs. In that case, address is
ambiguous, so libbpf falls on the side of caution, rather than confusing user
with randomly chosen address.

In the future, once kernel is extended with variables BTF information, such
ksym externs will be supported in a typed version, which will allow BPF
program to read variable's contents directly, similarly to how it's done for
fentry/fexit input arguments.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20200619231703.738941-3-andriin@fb.com
2020-06-22 17:01:48 -07:00
Andrii Nakryiko
2e33efe32e libbpf: Generalize libbpf externs support
Switch existing Kconfig externs to be just one of few possible kinds of more
generic externs. This refactoring is in preparation for ksymbol extern
support, added in the follow up patch. There are no functional changes
intended.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20200619231703.738941-2-andriin@fb.com
2020-06-22 17:01:48 -07:00