Commit Graph
41905 Commits
Author SHA1 Message Date
Jakub Kicinski a685d0df75 Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2023-06-23

We've added 49 non-merge commits during the last 24 day(s) which contain
a total of 70 files changed, 1935 insertions(+), 442 deletions(-).

The main changes are:

1) Extend bpf_fib_lookup helper to allow passing the route table ID,
   from Louis DeLosSantos.

2) Fix regsafe() in verifier to call check_ids() for scalar registers,
   from Eduard Zingerman.

3) Extend the set of cpumask kfuncs with bpf_cpumask_first_and()
   and a rework of bpf_cpumask_any*() kfuncs. Additionally,
   add selftests, from David Vernet.

4) Fix socket lookup BPF helpers for tc/XDP to respect VRF bindings,
   from Gilad Sever.

5) Change bpf_link_put() to use workqueue unconditionally to fix it
   under PREEMPT_RT, from Sebastian Andrzej Siewior.

6) Follow-ups to address issues in the bpf_refcount shared ownership
   implementation, from Dave Marchevsky.

7) A few general refactorings to BPF map and program creation permissions
   checks which were part of the BPF token series, from Andrii Nakryiko.

8) Various fixes for benchmark framework and add a new benchmark
   for BPF memory allocator to BPF selftests, from Hou Tao.

9) Documentation improvements around iterators and trusted pointers,
   from Anton Protopopov.

10) Small cleanup in verifier to improve allocated object check,
    from Daniel T. Lee.

11) Improve performance of bpf_xdp_pointer() by avoiding access
    to shared_info when XDP packet does not have frags,
    from Jesper Dangaard Brouer.

12) Silence a harmless syzbot-reported warning in btf_type_id_size(),
    from Yonghong Song.

13) Remove duplicate bpfilter_umh_cleanup in favor of umd_cleanup_helper,
    from Jarkko Sakkinen.

14) Fix BPF selftests build for resolve_btfids under custom HOSTCFLAGS,
    from Viktor Malik.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (49 commits)
  bpf, docs: Document existing macros instead of deprecated
  bpf, docs: BPF Iterator Document
  selftests/bpf: Fix compilation failure for prog vrf_socket_lookup
  selftests/bpf: Add vrf_socket_lookup tests
  bpf: Fix bpf socket lookup from tc/xdp to respect socket VRF bindings
  bpf: Call __bpf_sk_lookup()/__bpf_skc_lookup() directly via TC hookpoint
  bpf: Factor out socket lookup functions for the TC hookpoint.
  selftests/bpf: Set the default value of consumer_cnt as 0
  selftests/bpf: Ensure that next_cpu() returns a valid CPU number
  selftests/bpf: Output the correct error code for pthread APIs
  selftests/bpf: Use producer_cnt to allocate local counter array
  xsk: Remove unused inline function xsk_buff_discard()
  bpf: Keep BPF_PROG_LOAD permission checks clear of validations
  bpf: Centralize permissions checks for all BPF map types
  bpf: Inline map creation logic in map_create() function
  bpf: Move unprivileged checks into map_create() and bpf_prog_load()
  bpf: Remove in_atomic() from bpf_link_put().
  selftests/bpf: Verify that check_ids() is used for scalars in regsafe()
  bpf: Verify scalar ids mapping in regsafe() using check_ids()
  selftests/bpf: Check if mark_chain_precision() follows scalar ids
  ...
====================

Link: https://lore.kernel.org/r/20230623211256.8409-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-24 14:52:28 -07:00
Jakub Kicinski a7384f3918 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

tools/testing/selftests/net/fcnal-test.sh
  d7a2fc1437 ("selftests: net: fcnal-test: check if FIPS mode is enabled")
  dd017c72dd ("selftests: fcnal: Test SO_DONTROUTE on TCP sockets.")
https://lore.kernel.org/all/5007b52c-dd16-dbf6-8d64-b9701bfa498b@tessares.net/
https://lore.kernel.org/all/20230619105427.4a0df9b3@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22 18:40:38 -07:00
Linus Torvalds 8a28a0b6f1 Merge tag 'net-6.4-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
 "Including fixes from ipsec, bpf, mptcp and netfilter.

  Current release - regressions:

   - netfilter: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain

   - eth: mlx5e:
      - fix scheduling of IPsec ASO query while in atomic
      - free IRQ rmap and notifier on kernel shutdown

  Current release - new code bugs:

   - phy: manual remove LEDs to ensure correct ordering

  Previous releases - regressions:

   - mptcp: fix possible divide by zero in recvmsg()

   - dsa: revert "net: phy: dp83867: perform soft reset and retain
     established link"

  Previous releases - always broken:

   - sched: netem: acquire qdisc lock in netem_change()

   - bpf:
      - fix verifier id tracking of scalars on spill
      - fix NULL dereference on exceptions
      - accept function names that contain dots

   - netfilter: disallow element updates of bound anonymous sets

   - mptcp: ensure listener is unhashed before updating the sk status

   - xfrm:
      - add missed call to delete offloaded policies
      - fix inbound ipv4/udp/esp packets to UDPv6 dualstack sockets

   - selftests: fixes for FIPS mode

   - dsa: mt7530: fix multiple CPU ports, BPDU and LLDP handling

   - eth: sfc: use budget for TX completions

  Misc:

   - wifi: iwlwifi: add support for SO-F device with PCI id 0x7AF0"

* tag 'net-6.4-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (74 commits)
  revert "net: align SO_RCVMARK required privileges with SO_MARK"
  net: wwan: iosm: Convert single instance struct member to flexible array
  sch_netem: acquire qdisc lock in netem_change()
  selftests: forwarding: Fix race condition in mirror installation
  wifi: mac80211: report all unusable beacon frames
  mptcp: ensure listener is unhashed before updating the sk status
  mptcp: drop legacy code around RX EOF
  mptcp: consolidate fallback and non fallback state machine
  mptcp: fix possible list corruption on passive MPJ
  mptcp: fix possible divide by zero in recvmsg()
  mptcp: handle correctly disconnect() failures
  bpf: Force kprobe multi expected_attach_type for kprobe_multi link
  bpf/btf: Accept function names that contain dots
  Revert "net: phy: dp83867: perform soft reset and retain established link"
  net: mdio: fix the wrong parameters
  netfilter: nf_tables: Fix for deleting base chains with payload
  netfilter: nfnetlink_osf: fix module autoload
  netfilter: nf_tables: drop module reference after updating chain
  netfilter: nf_tables: disallow timeout for anonymous sets
  netfilter: nf_tables: disallow updates of anonymous sets
  ...
2023-06-22 17:59:51 -07:00
Linus Torvalds 5950a0066f Merge tag 'cgroup-for-6.4-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "It's late but here are two bug fixes. Both fix problems which can be
  severe but are very confined in scope. The risk to most use cases
  should be minimal.

   - Fix for an old bug which triggers if a cgroup subsystem is
     remounted to a different hierarchy while someone is reading its
     cgroup.procs/tasks file. The risk is pretty low given how seldom
     cgroup subsystems are moved across hierarchies.

   - We moved cpus_read_lock() outside of cgroup internal locks a while
     ago but forgot to update the legacy_freezer leading to lockdep
     triggers. Fixed"

* tag 'cgroup-for-6.4-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Do not corrupt task iteration when rebinding subsystem
  cgroup,freezer: hold cpu_hotplug_lock before freezer_mutex in freezer_css_{online,offline}()
2023-06-22 17:27:16 -07:00
Jakub Kicinski 59bb14bda2 Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2023-06-21

We've added 7 non-merge commits during the last 14 day(s) which contain
a total of 7 files changed, 181 insertions(+), 15 deletions(-).

The main changes are:

1) Fix a verifier id tracking issue with scalars upon spill,
   from Maxim Mikityanskiy.

2) Fix NULL dereference if an exception is generated while a BPF
   subprogram is running, from Krister Johansen.

3) Fix a BTF verification failure when compiling kernel with LLVM_IAS=0,
   from Florent Revest.

4) Fix expected_attach_type enforcement for kprobe_multi link,
   from Jiri Olsa.

5) Fix a bpf_jit_dump issue for x86_64 to pick the correct JITed image,
   from Yonghong Song.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Force kprobe multi expected_attach_type for kprobe_multi link
  bpf/btf: Accept function names that contain dots
  selftests/bpf: add a test for subprogram extables
  bpf: ensure main program has an extable
  bpf: Fix a bpf_jit_dump issue for x86_64 with sysctl bpf_jit_enable.
  selftests/bpf: Add test cases to assert proper ID tracking on spill
  bpf: Fix verifier id tracking of scalars on spill
====================

Link: https://lore.kernel.org/r/20230621101116.16122-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-21 13:59:46 -07:00
Linus Torvalds dad9774dea Merge tag 'timers-urgent-2023-06-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "A single regression fix for a regression fix:

  For a long time the tick was aligned to clock MONOTONIC so that the
  tick event happened at a multiple of nanoseconds per tick starting
  from clock MONOTONIC = 0.

  At some point this changed as the refined jiffies clocksource which is
  used during boot before the TSC or other clocksources becomes usable,
  was adjusted with a boot offset, so that time 0 is closer to the point
  where the kernel starts.

  This broke the assumption in the tick code that when the tick setup
  happens early on ktime_get() will return a multiple of nanoseconds per
  tick. As a consequence applications which aligned their periodic
  execution so that it does not collide with the tick were not longer
  guaranteed that the tick period starts from time 0.

  The fix for this regression was to realign the tick when it is
  initially set up to a multiple of tick periods. That works as long as
  the underlying tick device supports periodic mode, but breaks under
  certain conditions when the tick device supports only one shot mode.

  Depending on the offset, the alignment delta to clock MONOTONIC can
  get in a range where the minimal programming delta of the underlying
  clock event device is larger than the calculated delta to the next
  tick. This results in a boot hang as the tick code tries to play catch
  up, but as the tick never fires jiffies are not advanced so it keeps
  trying for ever.

  Solve this by moving the tick alignement into the NOHZ / HIGHRES
  enablement code because at that point it is guaranteed that the
  underlying clocksource is high resolution capable and not longer
  depending on the tick.

  This is far before user space starts, so at the point where
  applications try to align their timers, the old behaviour of the tick
  happening at a multiple of nanoseconds per tick starting from clock
  MONOTONIC = 0 is restored"

* tag 'timers-urgent-2023-06-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/common: Align tick period during sched_timer setup
2023-06-21 12:36:34 -07:00
Jiri Olsa db8eae6bc5 bpf: Force kprobe multi expected_attach_type for kprobe_multi link
We currently allow to create perf link for program with
expected_attach_type == BPF_TRACE_KPROBE_MULTI.

This will cause crash when we call helpers like get_attach_cookie or
get_func_ip in such program, because it will call the kprobe_multi's
version (current->bpf_ctx context setup) of those helpers while it
expects perf_link's current->bpf_ctx context setup.

Making sure that we use BPF_TRACE_KPROBE_MULTI expected_attach_type
only for programs attaching through kprobe_multi link.

Fixes: ca74823c6e ("bpf: Add cookie support to programs attached with kprobe multi link")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230618131414.75649-1-jolsa@kernel.org
2023-06-21 10:40:26 +02:00
Florent Revest 9724160b39 bpf/btf: Accept function names that contain dots
When building a kernel with LLVM=1, LLVM_IAS=0 and CONFIG_KASAN=y, LLVM
leaves DWARF tags for the "asan.module_ctor" & co symbols. In turn,
pahole creates BTF_KIND_FUNC entries for these and this makes the BTF
metadata validation fail because they contain a dot.

In a dramatic turn of event, this BTF verification failure can cause
the netfilter_bpf initialization to fail, causing netfilter_core to
free the netfilter_helper hashmap and netfilter_ftp to trigger a
use-after-free. The risk of u-a-f in netfilter will be addressed
separately but the existence of "asan.module_ctor" debug info under some
build conditions sounds like a good enough reason to accept functions
that contain dots in BTF.

Although using only LLVM=1 is the recommended way to compile clang-based
kernels, users can certainly do LLVM=1, LLVM_IAS=0 as well and we still
try to support that combination according to Nick. To clarify:

  - > v5.10 kernel, LLVM=1 (LLVM_IAS=0 is not the default) is recommended,
    but user can still have LLVM=1, LLVM_IAS=0 to trigger the issue

  - <= 5.10 kernel, LLVM=1 (LLVM_IAS=0 is the default) is recommended in
    which case GNU as will be used

Fixes: 1dc9285184 ("bpf: kernel side support for BTF Var and DataSec")
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Cc: Yonghong Song <yhs@meta.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/bpf/20230615145607.3469985-1-revest@chromium.org
2023-06-21 10:32:22 +02:00
Linus Torvalds 2e30b97343 Merge tag 'trace-v6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:

 - Fix MAINTAINERS file to point to proper mailing list for rtla and rv

   The mailing list pointed to linux-trace-devel instead of
   linux-trace-kernel. The former is for the tracing libraries and the
   latter is for anything in the Linux kernel tree. The wrong mailing
   list was used because linux-trace-kernel did not exist when rtla and
   rv were created.

 - User events:

    - Fix matching of dynamic events to their user events

      When user writes to dynamic_events file, a lookup of the
      registered dynamic events is made, but there were some cases that
      a match could be incorrectly made.

    - Add auto cleanup of user events

      Have the user events automatically get removed when the last
      reference (file descriptor) is closed. This was asked for to
      prevent leaks of user events hanging around needing admins to
      clean them up.

    - Add persistent logic (but not let user space use it yet)

      In some cases, having a persistent user event (one that does not
      get cleaned up automatically) is useful. But there's still debates
      about how to expose this to user space. The infrastructure is
      added, but the API is not.

    - Update the selftests

      Update the user event selftests to reflect the above changes"

* tag 'trace-v6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/user_events: Document auto-cleanup and remove dyn_event refs
  selftests/user_events: Adapt dyn_test to non-persist events
  selftests/user_events: Ensure auto cleanup works as expected
  tracing/user_events: Add auto cleanup and future persist flag
  tracing/user_events: Track refcount consistently via put/get
  tracing/user_events: Store register flags on events
  tracing/user_events: Remove user_ns walk for groups
  selftests/user_events: Add perf self-test for empty arguments events
  selftests/user_events: Clear the events after perf self-test
  selftests/user_events: Add ftrace self-test for empty arguments events
  tracing/user_events: Fix the incorrect trace record for empty arguments events
  tracing: Modify print_fields() for fields output order
  tracing/user_events: Handle matching arguments that is null from dyn_events
  tracing/user_events: Prevent same name but different args event
  tracing/rv/rtla: Update MAINTAINERS file to point to proper mailing list
2023-06-20 15:01:08 -07:00
Andrii Nakryiko 7f6719f7a8 bpf: Keep BPF_PROG_LOAD permission checks clear of validations
Move out flags validation and license checks out of the permission
checks. They were intermingled, which makes subsequent changes harder.
Clean this up: perform straightforward flag validation upfront, and
fetch and check license later, right where we use it. Also consolidate
capabilities check in one block, right after basic attribute sanity
checks.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230613223533.3689589-5-andrii@kernel.org
2023-06-19 14:04:04 +02:00
Andrii Nakryiko 6c3eba1c5e bpf: Centralize permissions checks for all BPF map types
This allows to do more centralized decisions later on, and generally
makes it very explicit which maps are privileged and which are not
(e.g., LRU_HASH and LRU_PERCPU_HASH, which are privileged HASH variants,
as opposed to unprivileged HASH and HASH_PERCPU; now this is explicit
and easy to verify).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230613223533.3689589-4-andrii@kernel.org
2023-06-19 14:04:04 +02:00
Andrii Nakryiko 22db41226b bpf: Inline map creation logic in map_create() function
Currently find_and_alloc_map() performs two separate functions: some
argument sanity checking and partial map creation workflow hanling.
Neither of those functions are self-sufficient and are augmented by
further checks and initialization logic in the caller (map_create()
function). So unify all the sanity checks, permission checks, and
creation and initialization logic in one linear piece of code in
map_create() instead. This also make it easier to further enhance
permission checks and keep them located in one place.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230613223533.3689589-3-andrii@kernel.org
2023-06-19 14:04:04 +02:00
Andrii Nakryiko 1d28635abc bpf: Move unprivileged checks into map_create() and bpf_prog_load()
Make each bpf() syscall command a bit more self-contained, making it
easier to further enhance it. We move sysctl_unprivileged_bpf_disabled
handling down to map_create() and bpf_prog_load(), two special commands
in this regard.

Also swap the order of checks, calling bpf_capable() only if
sysctl_unprivileged_bpf_disabled is true, avoiding unnecessary audit
messages.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230613223533.3689589-2-andrii@kernel.org
2023-06-19 14:04:04 +02:00
Thomas Gleixner 13bb06f8dd tick/common: Align tick period during sched_timer setup
The tick period is aligned very early while the first clock_event_device is
registered. At that point the system runs in periodic mode and switches
later to one-shot mode if possible.

The next wake-up event is programmed based on the aligned value
(tick_next_period) but the delta value, that is used to program the
clock_event_device, is computed based on ktime_get().

With the subtracted offset, the device fires earlier than the exact time
frame. With a large enough offset the system programs the timer for the
next wake-up and the remaining time left is too small to make any boot
progress. The system hangs.

Move the alignment later to the setup of tick_sched timer. At this point
the system switches to oneshot mode and a high resolution clocksource is
available. At this point it is safe to align tick_next_period because
ktime_get() will now return accurate (not jiffies based) time.

[bigeasy: Patch description + testing].

Fixes: e9523a0d81 ("tick/common: Align tick period with the HZ tick.")
Reported-by: Mathias Krause <minipli@grsecurity.net>
Reported-by: "Bhatnagar, Rishabh" <risbhat@amazon.com>
Suggested-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Tested-by: Mathias Krause <minipli@grsecurity.net>
Acked-by: SeongJae Park <sj@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/5a56290d-806e-b9a5-f37c-f21958b5a8c0@grsecurity.net
Link: https://lore.kernel.org/12c6f9a3-d087-b824-0d05-0d18c9bc1bf3@amazon.com
Link: https://lore.kernel.org/r/20230615091830.RxMV2xf_@linutronix.de
2023-06-16 20:45:28 +02:00
Sebastian Andrzej Siewior ab5d47bd41 bpf: Remove in_atomic() from bpf_link_put().
bpf_free_inode() is invoked as a RCU callback. Usually RCU callbacks are
invoked within softirq context. By setting rcutree.use_softirq=0 boot
option the RCU callbacks will be invoked in a per-CPU kthread with
bottom halves disabled which implies a RCU read section.

On PREEMPT_RT the context remains fully preemptible. The RCU read
section however does not allow schedule() invocation. The latter happens
in mutex_lock() performed by bpf_trampoline_unlink_prog() originated
from bpf_link_put().

It was pointed out that the bpf_link_put() invocation should not be
delayed if originated from close(). It was also pointed out that other
invocations from within a syscall should also avoid the workqueue.
Everyone else should use workqueue by default to remain safe in the
future (while auditing the code, every caller was preemptible except for
the RCU case).

Let bpf_link_put() use the worker unconditionally. Add
bpf_link_put_direct() which will directly free the resources and is used
by close() and from within __sys_bpf().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230614083430.oENawF8f@linutronix.de
2023-06-16 09:28:02 -07:00
Jakub Kicinski 173780ff18 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/linux/mlx5/driver.h
  617f5db1a6 ("RDMA/mlx5: Fix affinity assignment")
  dc13180824 ("net/mlx5: Enable devlink port for embedded cpu VF vports")
https://lore.kernel.org/all/20230613125939.595e50b8@canb.auug.org.au/

tools/testing/selftests/net/mptcp/mptcp_join.sh
  47867f0a7e ("selftests: mptcp: join: skip check if MIB counter not supported")
  425ba80312 ("selftests: mptcp: join: support RM_ADDR for used endpoints or not")
  45b1a1227a ("mptcp: introduces more address related mibs")
  0639fa230a ("selftests: mptcp: add explicit check for new mibs")
https://lore.kernel.org/netdev/20230609-upstream-net-20230610-mptcp-selftests-support-old-kernels-part-3-v1-0-2896fe2ee8a3@tessares.net/

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-15 22:19:41 -07:00
Beau Belgrave a65442edb4 tracing/user_events: Add auto cleanup and future persist flag
Currently user events need to be manually deleted via the delete IOCTL
call or via the dynamic_events file. Most operators and processes wish
to have these events auto cleanup when they are no longer used by
anything to prevent them piling without manual maintenance. However,
some operators may not want this, such as pre-registering events via the
dynamic_events tracefs file.

Update user_event_put() to attempt an auto delete of the event if it's
the last reference. The auto delete must run in a work queue to ensure
proper behavior of class->reg() invocations that don't expect the call
to go away from underneath them during the unregister. Add work_struct
to user_event struct to ensure we can do this reliably.

Add a persist flag, that is not yet exposed, to ensure we can toggle
between auto-cleanup and leaving the events existing in the future. When
a non-zero flag is seen during register, return -EINVAL to ensure ABI
is clear for the user processes while we work out the best approach for
persistent events.

Link: https://lkml.kernel.org/r/20230614163336.5797-4-beaub@linux.microsoft.com
Link: https://lore.kernel.org/linux-trace-kernel/20230518093600.3f119d68@rorschach.local.home/

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 13:43:27 -04:00
Beau Belgrave f0dbf6fd0b tracing/user_events: Track refcount consistently via put/get
Various parts of the code today track user_event's refcnt field directly
via a refcount_add/dec. This makes it hard to modify the behavior of the
last reference decrement in all code paths consistently. For example, in
the future we will auto-delete events upon the last reference going
away. This last reference could happen in many places, but we want it to
be consistently handled.

Add user_event_get() and user_event_put() for the add/dec. Update all
places where direct refcounts are being used to utilize these new
functions. In each location pass if event_mutex is locked or not. This
allows us to drop events automatically in future patches clearly. Ensure
when caller states the lock is held, it really is (or is not) held.

Link: https://lkml.kernel.org/r/20230614163336.5797-3-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 13:43:26 -04:00
Beau Belgrave b08d725805 tracing/user_events: Store register flags on events
Currently we don't have any available flags for user processes to use to
indicate options for user_events. We will soon have a flag to indicate
the event should or should not auto-delete once it's not being used by
anyone.

Add a reg_flags field to user_events and parameters to existing
functions to allow for this in future patches.

Link: https://lkml.kernel.org/r/20230614163336.5797-2-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 13:43:26 -04:00
Beau Belgrave ed0e0ae0c9 tracing/user_events: Remove user_ns walk for groups
During discussions it was suggested that user_ns is not a good place to
try to attach a tracing namespace. The current code has stubs to enable
that work that are very likely to change and incur a performance cost.

Remove the user_ns walk when creating a group and determining the system
name to use, since it's unlikely user_ns will be used in the future.

Link: https://lore.kernel.org/all/20230601-urenkel-holzofen-cd9403b9cadd@brauner/
Link: https://lore.kernel.org/linux-trace-kernel/20230601224928.301-1-beaub@linux.microsoft.com

Suggested-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 12:41:53 -04:00
sunliming 6f05dcabe5 tracing/user_events: Fix the incorrect trace record for empty arguments events
The user_events support events that has empty arguments. But the trace event
is discarded and not really committed when the arguments is empty. Fix this
by not attempting to copy in zero-length data.

Link: https://lkml.kernel.org/r/20230606062027.1008398-2-sunliming@kylinos.cn

Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 12:41:52 -04:00
sunliming e70bb54d7a tracing: Modify print_fields() for fields output order
Now the print_fields() print trace event fields in reverse order. Modify
it to the positive sequence.

Example outputs for a user event:
	test0 u32 count1; u32 count2

Output before:
	example-2547    [000] .....   325.666387: test0: count2=0x2 (2) count1=0x1 (1)

Output after:
	example-2742    [002] .....   429.769370: test0: count1=0x1 (1) count2=0x2 (2)

Link: https://lore.kernel.org/linux-trace-kernel/20230525085232.5096-1-sunliming@kylinos.cn

Fixes: 80a76994b2 ("tracing: Add "fields" option to show raw trace event fields")
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 12:41:52 -04:00
sunliming cfac4ed727 tracing/user_events: Handle matching arguments that is null from dyn_events
When A registering user event from dyn_events has no argments, it will pass the
matching check, regardless of whether there is a user event with the same name
and arguments. Add the matching check when the arguments of registering user
event is null.

Link: https://lore.kernel.org/linux-trace-kernel/20230529065110.303440-1-sunliming@kylinos.cn

Signed-off-by: sunliming <sunliming@kylinos.cn>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 12:41:52 -04:00
sunliming ba470eebc2 tracing/user_events: Prevent same name but different args event
User processes register name_args for events. If the same name but different
args event are registered. The trace outputs of second event are printed
as the first event. This is incorrect.

Return EADDRINUSE back to the user process if the same name but different args
event has being registered.

Link: https://lore.kernel.org/linux-trace-kernel/20230529032100.286534-1-sunliming@kylinos.cn

Signed-off-by: sunliming <sunliming@kylinos.cn>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14 12:41:52 -04:00
Eduard Zingerman 1ffc85d929 bpf: Verify scalar ids mapping in regsafe() using check_ids()
Make sure that the following unsafe example is rejected by verifier:

1: r9 = ... some pointer with range X ...
2: r6 = ... unbound scalar ID=a ...
3: r7 = ... unbound scalar ID=b ...
4: if (r6 > r7) goto +1
5: r6 = r7
6: if (r6 > X) goto ...
--- checkpoint ---
7: r9 += r7
8: *(u64 *)r9 = Y

This example is unsafe because not all execution paths verify r7 range.
Because of the jump at (4) the verifier would arrive at (6) in two states:
I.  r6{.id=b}, r7{.id=b} via path 1-6;
II. r6{.id=a}, r7{.id=b} via path 1-4, 6.

Currently regsafe() does not call check_ids() for scalar registers,
thus from POV of regsafe() states (I) and (II) are identical. If the
path 1-6 is taken by verifier first, and checkpoint is created at (6)
the path [1-4, 6] would be considered safe.

Changes in this commit:
- check_ids() is modified to disallow mapping multiple old_id to the
  same cur_id.
- check_scalar_ids() is added, unlike check_ids() it treats ID zero as
  a unique scalar ID.
- check_scalar_ids() needs to generate temporary unique IDs, field
  'tmp_id_gen' is added to bpf_verifier_env::idmap_scratch to
  facilitate this.
- regsafe() is updated to:
  - use check_scalar_ids() for precise scalar registers.
  - compare scalar registers using memcmp only for explore_alu_limits
    branch. This simplifies control flow for scalar case, and has no
    measurable performance impact.
- check_alu_op() is updated to avoid generating bpf_reg_state::id for
  constant scalar values when processing BPF_MOV. ID is needed to
  propagate range information for identical values, but there is
  nothing to propagate for constants.

Fixes: 75748837b7 ("bpf: Propagate scalar ranges through register assignments.")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230613153824.3324830-4-eddyz87@gmail.com
2023-06-13 15:15:08 -07:00