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Jiri Olsa 05b24ff9b2 bpf: Prevent bpf program recursion for raw tracepoint probes
We got report from sysbot [1] about warnings that were caused by
bpf program attached to contention_begin raw tracepoint triggering
the same tracepoint by using bpf_trace_printk helper that takes
trace_printk_lock lock.

 Call Trace:
  <TASK>
  ? trace_event_raw_event_bpf_trace_printk+0x5f/0x90
  bpf_trace_printk+0x2b/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  __unfreeze_partials+0x5b/0x160
  ...

The can be reproduced by attaching bpf program as raw tracepoint on
contention_begin tracepoint. The bpf prog calls bpf_trace_printk
helper. Then by running perf bench the spin lock code is forced to
take slow path and call contention_begin tracepoint.

Fixing this by skipping execution of the bpf program if it's
already running, Using bpf prog 'active' field, which is being
currently used by trampoline programs for the same reason.

Moving bpf_prog_inc_misses_counter to syscall.c because
trampoline.c is compiled in just for CONFIG_BPF_JIT option.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reported-by: syzbot+2251879aa068ad9c960d@syzkaller.appspotmail.com
[1] https://lore.kernel.org/bpf/YxhFe3EwqchC%2FfYf@krava/T/#t
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220916071914.7156-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-21 18:05:44 -07:00
arch bpf: Move bpf_dispatcher function out of ftrace locations 2022-09-16 22:23:20 +02:00
block block-6.0-2022-08-26 2022-08-26 11:05:54 -07:00
certs Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation bpf: Use bpf_capable() instead of CAP_SYS_ADMIN for blinding decision 2022-09-16 22:11:57 +02:00
drivers net: moxa: fix endianness-related issues from 'sparse' 2022-09-06 10:24:42 +02:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-01 12:58:02 -07:00
include bpf: Prevent bpf program recursion for raw tracepoint probes 2022-09-21 18:05:44 -07:00
init arm64 fixes for -rc3 2022-08-26 11:32:53 -07:00
io_uring lsm/stable-6.0 PR 20220829 2022-08-31 09:23:16 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel bpf: Prevent bpf program recursion for raw tracepoint probes 2022-09-21 18:05:44 -07:00
lib This push fixes a boot performance regression due to an unnecessary 2022-08-31 09:47:06 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm slab fixes for 6.0-rc4 2022-09-01 09:14:56 -07:00
net bpf: Move nf_conn extern declarations to filter.h 2022-09-20 14:41:35 -07:00
samples samples/bpf: Replace blk_account_io_done() with __blk_account_io_done() 2022-09-20 17:25:59 -07:00
scripts Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-09-06 23:21:18 +02:00
security KEYS: Move KEY_LOOKUP_ to include/linux/key.h and define KEY_LOOKUP_ALL 2022-09-21 17:32:48 -07:00
sound ALSA: usb-audio: Add quirk for LH Labs Geek Out HD Audio 1V5 2022-08-28 09:42:14 +02:00
tools selftests/bpf: Add tests for dynamic pointers parameters in kfuncs 2022-09-21 17:33:43 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Drop unnecessary initialization of "ops" in kvm_ioctl_create_device() 2022-08-19 04:05:43 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap .mailmap: update Luca Ceresoli's e-mail address 2022-08-28 14:02:46 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS net: pcs: add new PCS driver for altera TSE PCS 2022-09-05 10:16:53 +01:00
Makefile Linux 6.0-rc3 2022-08-28 15:05:29 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.