apparmor: improve get_buffers macro by using get_cpu_ptr

Refactor get_buffers so the cpu_ptr can be obtained in the outer
layer, instead of inside the macro.

This also enables us to cleanup the code and use get_cpu_ptr,
to handle the preempt_disable()

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
This commit is contained in:
John Johansen 2018-05-04 02:18:07 -07:00
parent 52e7128ebb
commit 38125c2c2b

View file

@ -43,10 +43,11 @@ struct aa_buffers {
DECLARE_PER_CPU(struct aa_buffers, aa_buffers);
#define ASSIGN(FN, X, N) ((X) = FN(N))
#define EVAL1(FN, X) ASSIGN(FN, X, 0) /*X = FN(0)*/
#define EVAL2(FN, X, Y...) do { ASSIGN(FN, X, 1); EVAL1(FN, Y); } while (0)
#define EVAL(FN, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, X)
#define ASSIGN(FN, A, X, N) ((X) = FN(A, N))
#define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/
#define EVAL2(FN, A, X, Y...) \
do { ASSIGN(FN, A, X, 1); EVAL1(FN, A, Y); } while (0)
#define EVAL(FN, A, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, A, X)
#define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++)
@ -56,26 +57,24 @@ DECLARE_PER_CPU(struct aa_buffers, aa_buffers);
#define AA_BUG_PREEMPT_ENABLED(X) /* nop */
#endif
#define __get_buffer(N) ({ \
struct aa_buffers *__cpu_var; \
#define __get_buffer(C, N) ({ \
AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled"); \
__cpu_var = this_cpu_ptr(&aa_buffers); \
__cpu_var->buf[(N)]; })
(C)->buf[(N)]; })
#define __get_buffers(X...) EVAL(__get_buffer, X)
#define __get_buffers(C, X...) EVAL(__get_buffer, C, X)
#define __put_buffers(X, Y...) ((void)&(X))
#define get_buffers(X...) \
do { \
preempt_disable(); \
__get_buffers(X); \
struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers); \
__get_buffers(__cpu_var, X); \
} while (0)
#define put_buffers(X, Y...) \
do { \
__put_buffers(X, Y); \
preempt_enable(); \
put_cpu_ptr(&aa_buffers); \
} while (0)
#endif /* __AA_PATH_H */