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author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-09-13 17:24:21 -0700 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-09-23 09:15:01 -0700 |
commit | 53ecfba259f54b6967a35d19f4a564e3bc07997f (patch) | |
tree | eaaeebe2a38abe1a401a0d2d40181abaefa80d48 /kernel/rcutorture.c | |
parent | 829f8ed2c963df7c23d1c644db6c4387eb1601fa (diff) | |
download | op-kernel-dev-53ecfba259f54b6967a35d19f4a564e3bc07997f.zip op-kernel-dev-53ecfba259f54b6967a35d19f4a564e3bc07997f.tar.gz |
rcu: only one evaluation of arg in rcu_dereference_check() unless sparse
The current version of the __rcu_access_pointer(), __rcu_dereference_check(),
and __rcu_dereference_protected() macros evaluate their "p" argument
three times, not counting typeof()s. This is bad news if that argument
contains a side effect. This commit therefore evaluates this argument
only once in normal kernel builds. However, the straightforward approach
defeats sparse's RCU-pointer checking, so when __CHECKER__ is defined,
the additional pair of evaluations of the "p" argument are performed in
order to permit sparse to detect misuse of RCU-protected pointers.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'kernel/rcutorture.c')
0 files changed, 0 insertions, 0 deletions