[PATCH v2] audit: unify audit_filter_{uring(), inode_name(), syscall()}

audit_filter_uring(), audit_filter_inode_name() are substantially similar to audit_filter_syscall(). Move the core logic to __audit_filter_op() which can be parametrized for all three. On a Skylakex system, getpid() latency (all results aggregated across 12 boot cycles): Min Mean Median Max pstdev (ns) (ns) (ns) (ns) - 196.63 207.86 206.60 230.98 (+- 3.92%) + 183.73 196.95 192.31 232.49 (+- 6.04%) Performance counter stats for 'bin/getpid' (3 runs) go from: cycles 805.58 ( +- 4.11% ) instructions 1654.11 ( +- .05% ) IPC 2.06 ( +- 3.39% ) branches 430.02 ( +- .05% ) branch-misses 1.55 ( +- 7.09% ) L1-dcache-loads 440.01 ( +- .09% ) L1-dcache-load-misses 9.05 ( +- 74.03% ) to: cycles 765.37 ( +- 6.66% ) instructions 1677.07 ( +- 0.04% ) IPC 2.20 ( +- 5.90% ) branches 431.10 ( +- 0.04% ) branch-misses 1.60 ( +- 11.25% ) L1-dcache-loads 521.04 ( +- 0.05% ) L1-dcache-load-misses 6.92 ( +- 77.60% ) (Both aggregated over 12 boot cycles.) The increased L1-dcache-loads are due to some intermediate values now coming from the stack. The improvement in cycles is due to a slightly denser loop (the list parameter in the list_for_each_entry_rcu() exit check now comes from a register rather than a constant as before.) Signed-off-by: Ankur Arora <ankur.a.arora(a)oracle.com&gt; --- kernel/auditsc.c | 76 +++++++++++++++++++++++++----------------------- 1 file changed, 39 insertions(+), 37 deletions(-) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 2206cdf1ba2c..4991348e300a 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -807,6 +807,40 @@ static int audit_in_mask(const struct audit_krule *rule, unsigned long val) return rule->mask[word] & bit; } +/** + * __audit_filter_op - common filter helper for operations (syscall/uring/etc) + * @tsk: associated task + * @ctx: audit context + * @list: audit filter list + * @name: audit_name (can be NULL) + * @op: current syscall/uring_op + * + * Run the udit filters specified in @list against @tsk using @ctx, + * @name, and @op, as necessary; the caller is responsible for ensuring + * that the call is made while the RCU read lock is held. The @name + * parameter can be NULL, but all others must be specified. + * Returns 1/true if the filter finds a match, 0/false if none are found. + */ +static int __audit_filter_op(struct task_struct *tsk, + struct audit_context *ctx, + struct list_head *list, + struct audit_names *name, + unsigned long op) +{ + struct audit_entry *e; + enum audit_state state; + + list_for_each_entry_rcu(e, list, list) { + if (audit_in_mask(&e->rule, op) && + audit_filter_rules(tsk, &e->rule, ctx, name, + &state, false)) { + ctx->current_state = state; + return 1; + } + } + return 0; +} + /** * audit_filter_uring - apply filters to an io_uring operation * @tsk: associated task @@ -815,23 +849,12 @@ static int audit_in_mask(const struct audit_krule *rule, unsigned long val) static void audit_filter_uring(struct task_struct *tsk, struct audit_context *ctx) { - struct audit_entry *e; - enum audit_state state; - if (auditd_test_task(tsk)) return; rcu_read_lock(); - list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_URING_EXIT], - list) { - if (audit_in_mask(&e->rule, ctx->uring_op) && - audit_filter_rules(tsk, &e->rule, ctx, NULL, &state, - false)) { - rcu_read_unlock(); - ctx->current_state = state; - return; - } - } + __audit_filter_op(tsk, ctx, &audit_filter_list[AUDIT_FILTER_URING_EXIT], + NULL, ctx->uring_op); rcu_read_unlock(); } @@ -843,25 +866,13 @@ static void audit_filter_uring(struct task_struct *tsk, static void audit_filter_syscall(struct task_struct *tsk, struct audit_context *ctx) { - struct audit_entry *e; - enum audit_state state; - unsigned long major = ctx->major; - if (auditd_test_task(tsk)) return; rcu_read_lock(); - list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_EXIT], list) { - if (audit_in_mask(&e->rule, major) && - audit_filter_rules(tsk, &e->rule, ctx, NULL, - &state, false)) { - rcu_read_unlock(); - ctx->current_state = state; - return; - } - } + __audit_filter_op(tsk, ctx, &audit_filter_list[AUDIT_FILTER_EXIT], + NULL, ctx->major); rcu_read_unlock(); - return; } /* @@ -873,17 +884,8 @@ static int audit_filter_inode_name(struct task_struct *tsk, struct audit_context *ctx) { int h = audit_hash_ino((u32)n->ino); struct list_head *list = &audit_inode_hash[h]; - struct audit_entry *e; - enum audit_state state; - list_for_each_entry_rcu(e, list, list) { - if (audit_in_mask(&e->rule, ctx->major) && - audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) { - ctx->current_state = state; - return 1; - } - } - return 0; + return __audit_filter_op(tsk, ctx, list, n, ctx->major); } /* At syscall exit time, this filter is called if any audit_names have been -- 2.31.1