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| author |   Paolo Bonzini <pbonzini@redhat.com> | 2017-08-01 17:24:04 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-08-10 12:28:56 +0200 |
| commit | 1dbb6704de91b169a58d0c8221624afd6a95cfc7 (patch) | |
| tree | 46273515a9b79413d2f00629b7e253189e903219 /net/ipv4/udp.c | |
| parent | locking/rwsem-xadd: Add killable versions of rwsem_down_read_failed() (diff) | |
| download | linux-dev-1dbb6704de91b169a58d0c8221624afd6a95cfc7.tar.xz linux-dev-1dbb6704de91b169a58d0c8221624afd6a95cfc7.zip | |
jump_label: Fix concurrent static_key_enable/disable()
static_key_enable/disable are trying to cap the static key count to
0/1. However, their use of key->enabled is outside jump_label_lock
so they do not really ensure that.
Rewrite them to do a quick check for an already enabled (respectively,
already disabled), and then recheck under the jump label lock. Unlike
static_key_slow_inc/dec, a failed check under the jump label lock does
not modify key->enabled.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1501601046-35683-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'net/ipv4/udp.c')
0 files changed, 0 insertions, 0 deletions