mirror of
https://github.com/sysprog21/lkmpg.git
synced 2024-11-22 04:09:18 +08:00
470fbcd97d
The code 'case -EINPROGRESS || -EBUSY: ' is the same as
'case -115 || -16 :' at compiler time, as both error code are
implemented with macro like '#define EBUSY 16'.
The code above is essentially the same as 'case 1:'. In C, there is no
real boolean value. Boolean-like value will be converted to 1 or 0.
It does not matter too much if the '-EINPROGRESS || -EBUSY' is
calculated at build time or at runtime. In both case, it will compare
the 'rc' with 1 in the switch expression. It will not compare the
'rc' with any real error code number. When the code is really '-EBUSY',
the execution will fallback to the default branch.
And in practice, most of the compilers will do this simple compile-time
static calculation, and generate code like
static int test_skcipher_result(struct skcipher_def *sk, int rc)
{
switch (rc) {
case 0:
break;
case 1:
rc = wait_for_completion_interruptible(&sk->result.completion);
/* code removed for conciseness */
break;
default:
pr_info("skcipher encrypt returned with %d result %d\n", rc,
sk->result.err);
break;
}
init_completion(&sk->result.completion);
return rc;
}
|
||
|---|---|---|
| .. | ||
| other | ||
| .clang-format | ||
| bottomhalf.c | ||
| chardev.c | ||
| chardev.h | ||
| chardev2.c | ||
| completions.c | ||
| cryptosha256.c | ||
| cryptosk.c | ||
| devicemodel.c | ||
| example_atomic.c | ||
| example_mutex.c | ||
| example_rwlock.c | ||
| example_spinlock.c | ||
| example_tasklet.c | ||
| hello-1.c | ||
| hello-2.c | ||
| hello-3.c | ||
| hello-4.c | ||
| hello-5.c | ||
| hello-sysfs.c | ||
| intrpt.c | ||
| ioctl.c | ||
| kbleds.c | ||
| Makefile | ||
| print_string.c | ||
| procfs1.c | ||
| procfs2.c | ||
| procfs3.c | ||
| procfs4.c | ||
| sched.c | ||
| sleep.c | ||
| start.c | ||
| static_key.c | ||
| stop.c | ||
| syscall-steal.c | ||
| vinput.c | ||
| vinput.h | ||
| vkbd.c | ||