kernel/timeout: Fix recursive spinlock in z_set_timeout_expiry()
The z_set_timeout_expiry() function was added in part to simply the
locking strategy, but it missed a case where a function it was calling
was re-locking the same spinlock. It "works"[1] in uniprocessor
environments, but can be a deadlock in SMP.
Fix this by moving the meat of the function to an unlocked utility,
use that locally, and turn the entry point into one that does locking.
Actually this only gets called from idle now, which is a use case that
will go away when TICKLESS_IDLE is removed as a separate feature (once
you know all timeouts are set tickless, you don't need to set it from
the idle entry at all).
Discovered via lucky inspection.
[1] It doesn't work. It releases the lock prematurely at the end of
the inner block. But in practice this wasn't discovered.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
1 file changed
