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6c5f61023c
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Yonghong Song 6c5f61023c bpf: fix rcu lockdep warning for lpm_trie map_free callback 
Commit 9a3efb6b66 ("bpf: fix memory leak in lpm_trie map_free callback function")
fixed a memory leak and removed unnecessary locks in map_free callback function.
Unfortrunately, it introduced a lockdep warning. When lockdep checking is turned on,
running tools/testing/selftests/bpf/test_lpm_map will have:

  [   98.294321] =============================
  [   98.294807] WARNING: suspicious RCU usage
  [   98.295359] 4.16.0-rc2+ #193 Not tainted
  [   98.295907] -----------------------------
  [   98.296486] /home/yhs/work/bpf/kernel/bpf/lpm_trie.c:572 suspicious rcu_dereference_check() usage!
  [   98.297657]
  [   98.297657] other info that might help us debug this:
  [   98.297657]
  [   98.298663]
  [   98.298663] rcu_scheduler_active = 2, debug_locks = 1
  [   98.299536] 2 locks held by kworker/2:1/54:
  [   98.300152]  #0:  ((wq_completion)"events"){+.+.}, at: [<00000000196bc1f0>] process_one_work+0x157/0x5c0
  [   98.301381]  #1:  ((work_completion)(&map->work)){+.+.}, at: [<00000000196bc1f0>] process_one_work+0x157/0x5c0

Since actual trie tree removal happens only after no other
accesses to the tree are possible, replacing
  rcu_dereference_protected(*slot, lockdep_is_held(&trie->lock))
with
  rcu_dereference_protected(*slot, 1)
fixed the issue.

Fixes: 9a3efb6b66 ("bpf: fix memory leak in lpm_trie map_free callback function")
Reported-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-22 21:29:12 +01:00
..
bpf bpf: fix rcu lockdep warning for lpm_trie map_free callback 2018-02-22 21:29:12 +01:00
cgroup kernel/cpuset: current_cpuset_is_being_rebound can be boolean 2018-02-06 18:32:47 -08:00
configs KVM changes for 4.16 2018-02-10 13:16:35 -08:00
debug signal: Simplify and fix kdb_send_sig 2018-01-03 18:01:08 -06:00
events vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
gcov License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq irqdomain: Re-use DEFINE_SHOW_ATTRIBUTE() macro 2018-02-16 14:22:34 +00:00
livepatch Merge branch 'for-4.16/remove-immediate' into for-linus 2018-01-31 16:36:38 +01:00
locking locking/qspinlock: Ensure node->count is updated before initialising node 2018-02-13 14:50:14 +01:00
power x86/power: Fix swsusp_arch_resume prototype 2018-02-02 23:33:50 +01:00
printk vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
rcu SCSI misc on 20180131 2018-01-31 11:23:28 -08:00
sched sched/cpufreq: Remove unused SUGOV_KTHREAD_PRIORITY macro 2018-02-13 13:04:03 +01:00
time vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
trace bpf: fix bpf_prog_array_copy_to_user warning from perf event prog query 2018-02-14 08:59:37 -08:00
.gitignore
acct.c kernel/acct.c: fix the acct->needcheck check in check_free_space() 2018-01-04 16:45:09 -08:00
async.c kernel/async.c: revert "async: simplify lowest_in_progress()" 2018-02-06 18:32:44 -08:00
audit_fsnotify.c
audit_tree.c Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-11-14 14:08:20 -08:00
audit_watch.c audit/stable-4.13 PR 20170816 2017-08-16 16:48:34 -07:00
audit.c Audit: remove unused audit_log_secctx function 2017-11-10 16:08:47 -05:00
audit.h audit/stable-4.15 PR 20171113 2017-11-15 13:28:48 -08:00
auditfilter.c audit: filter PATH records keyed on filesystem magic 2017-11-10 16:08:56 -05:00
auditsc.c audit/stable-4.15 PR 20171113 2017-11-15 13:28:48 -08:00
backtracetest.c
bounds.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
capability.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat.c cpumask: make cpumask_size() return "unsigned int" 2018-02-06 18:32:45 -08:00
configs.c
context_tracking.c
cpu_pm.c PM / CPU: replace raw_notifier with atomic_notifier 2017-07-31 13:09:49 +02:00
cpu.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-31 12:30:34 -08:00
crash_core.c kdump: write correct address of mem_section into vmcoreinfo 2018-01-13 10:42:48 -08:00
crash_dump.c
cred.c
delayacct.c delayacct: Account blkio completion on the correct task 2018-01-16 03:29:36 +01:00
dma.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
elfcore.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
exec_domain.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
exit.c kernel/exit.c: export abort() to modules 2018-01-04 16:45:09 -08:00
extable.c kprobes, x86/alternatives: Use text_mutex to protect smp_alt_modules 2017-11-07 12:20:09 +01:00
fail_function.c error-injection: Support fault injection framework 2018-01-12 17:33:38 -08:00
fork.c Merge branch 'akpm' (patches from Andrew) 2018-02-06 22:15:42 -08:00
freezer.c
futex_compat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
futex.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
hung_task.c
irq_work.c irq/work: Improve the flag definitions 2018-01-08 19:43:15 +01:00
jump_label.c sched/core: Fix cpu.max vs. cpuhotplug deadlock 2018-01-24 10:03:44 +01:00
kallsyms.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
kcmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: detect double association with a single task 2018-02-06 18:32:46 -08:00
kexec_core.c x86/mm, kexec: Allow kexec to be used with SME 2017-07-18 11:38:04 +02:00
kexec_file.c resource: Provide resource struct in resource walk callback 2017-11-07 15:35:57 +01:00
kexec_internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kexec.c kdump: protect vmcoreinfo data under the crash memory 2017-07-12 16:26:00 -07:00
kmod.c kmod: move #ifdef CONFIG_MODULES wrapper to Makefile 2017-09-08 18:26:51 -07:00
kprobes.c kprobes: Propagate error from disarm_kprobe_ftrace() 2018-02-16 09:12:58 +01:00
ksysfs.c kexec: move vmcoreinfo out of the kernel's .bss section 2017-07-12 16:25:59 -07:00
kthread.c treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts 2017-11-21 16:35:54 -08:00
latencytop.c
Makefile error-injection: Support fault injection framework 2018-01-12 17:33:38 -08:00
memremap.c mm: Fix devm_memremap_pages() collision handling 2018-01-19 16:29:56 -08:00
module_signing.c
module-internal.h
module.c Modules updates for v4.16 2018-02-07 14:29:34 -08:00
notifier.c
nsproxy.c
padata.c padata: add SPDX identifier 2018-01-05 18:43:00 +11:00
panic.c kernel/panic.c: add TAINT_AUX 2017-11-17 16:10:04 -08:00
params.c kernel/params.c: improve STANDARD_PARAM_DEF readability 2017-10-03 17:54:26 -07:00
pid_namespace.c pid: remove pidhash 2017-11-17 16:10:04 -08:00
pid.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
profile.c
ptrace.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
range.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
reboot.c kernel/reboot.c: add devm_register_reboot_notifier() 2017-11-17 16:10:04 -08:00
relay.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
resource.c Merge branch 'akpm' (patches from Andrew) 2018-02-06 22:15:42 -08:00
seccomp.c Merge branch 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2018-01-31 13:44:45 -08:00
signal.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching 2018-01-31 13:02:18 -08:00
smp.c smp/core: Use lockdep to assert IRQs are disabled/enabled 2017-11-08 11:13:50 +01:00
smpboot.c watchdog/core, powerpc: Lock cpus across reconfiguration 2017-10-04 10:53:54 +02:00
smpboot.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
softirq.c softirq: Eliminate cond_resched_rcu_qs() in favor of cond_resched() 2017-12-04 10:28:58 -08:00
stacktrace.c
stop_machine.c
sys_ni.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sys.c fix typo in assignment of fs default overflow gid 2017-12-14 16:01:45 -06:00
sysctl_binary.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sysctl.c pipe: reject F_SETPIPE_SZ with size over UINT_MAX 2018-02-06 18:32:47 -08:00
task_work.c locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-17 13:57:15 +01:00
taskstats.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
test_kprobes.c kprobes: Disable the jprobes test code 2017-10-20 11:02:54 +02:00
torture.c torture: Save a line in stutter_wait(): while -> for 2017-12-11 09:18:30 -08:00
tracepoint.c tracepoint: Remove smp_read_barrier_depends() from comment 2017-12-04 10:52:56 -08:00
tsacct.c
ucount.c
uid16.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
umh.c kernel/umh.c: optimize 'proc_cap_handler()' 2017-11-17 16:10:01 -08:00
up.c smp: Avoid using two cache lines for struct call_single_data 2017-08-29 15:14:38 +02:00
user_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-11-16 12:20:15 -08:00
user-return-notifier.c
user.c userns: use union in {g,u}idmap struct 2017-10-31 17:22:58 -05:00
utsname_sysctl.c
utsname.c
watchdog_hld.c Merge branch 'linus' into core/urgent, to pick up dependent commits 2017-11-04 08:53:04 +01:00
watchdog.c Merge branch 'linus' into sched/core, to pick up fixes 2017-11-08 10:17:15 +01:00
workqueue_internal.h Merge branch 'for-4.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2017-11-06 12:26:49 -08:00
workqueue.c Staging/IIO patches for 4.16-rc1 2018-02-01 09:51:57 -08:00