+
+long lttng_channel_syscall_mask(struct lttng_channel *channel,
+ struct lttng_kernel_syscall_mask __user *usyscall_mask)
+{
+ uint32_t len, sc_tables_len, bitmask_len;
+ int ret = 0, bit;
+ char *tmp_mask;
+ struct lttng_syscall_filter *filter;
+
+ ret = get_user(len, &usyscall_mask->len);
+ if (ret)
+ return ret;
+ sc_tables_len = get_sc_tables_len();
+ bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
+ if (len < sc_tables_len) {
+ return put_user(sc_tables_len, &usyscall_mask->len);
+ }
+ /* Array is large enough, we can copy array to user-space. */
+ tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
+ if (!tmp_mask)
+ return -ENOMEM;
+ filter = channel->sc_filter;
+
+ for (bit = 0; bit < ARRAY_SIZE(sc_table); bit++) {
+ bt_bitfield_write_be(tmp_mask, char, bit, 1,
+ filter ? test_bit(bit, filter->sc) : 1);
+ }
+ for (; bit < sc_tables_len; bit++) {
+ bt_bitfield_write_be(tmp_mask, char, bit, 1,
+ filter ? test_bit(bit - ARRAY_SIZE(sc_table),
+ filter->sc_compat) : 1);
+ }
+ if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
+ ret = -EFAULT;
+ kfree(tmp_mask);
+ return ret;
+}