alex/rp-hal-boards
1
0
Fork 0
mirror of https://github.com/italicsjenga/rp-hal-boards.git synced 2024-12-23 20:51:31 +11:00
Code Issues Packages Projects Releases Wiki Activity

Check watchdog load value max value before multiplying by 2, to avoid integer overflow

Browse source
This commit is contained in:
Jan Niehusmann 2022-10-12 22:39:14 +00:00
parent 39190c357f
commit 84b92edd30
1 changed files with 13 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
rp2040-hal/src/watchdog.rs
View file

@ -41,7 +41,7 @@ use fugit::MicrosDurationU32;
/// Watchdog peripheral
pub struct Watchdog {
watchdog: WATCHDOG,
delay_us: u32,
load_value: u32, // decremented by 2 per tick (µs)
}
impl Watchdog {
@ -49,7 +49,7 @@ impl Watchdog {
pub fn new(watchdog: WATCHDOG) -> Self {
Self {
watchdog,
delay_us: 0,
load_value: 0,
}
}
@ -110,7 +110,7 @@ impl Watchdog {
impl watchdog::Watchdog for Watchdog {
fn feed(&mut self) {
self.load_counter(self.delay_us)
self.load_counter(self.load_value)
}
}
@ -120,19 +120,23 @@ impl watchdog::WatchdogEnable for Watchdog {
fn start<T: Into<Self::Time>>(&mut self, period: T) {
const MAX_PERIOD: u32 = 0xFFFFFF;
let delay_us = period.into().to_micros();
if delay_us > MAX_PERIOD / 2 {
panic!(
"Period cannot exceed maximum load value of {} ({} microseconds))",
MAX_PERIOD,
MAX_PERIOD / 2
);
}
// Due to a logic error, the watchdog decrements by 2 and
// the load value must be compensated; see RP2040-E1
self.delay_us = period.into().to_micros() * 2;
if self.delay_us > MAX_PERIOD {
panic!("Period cannot exceed maximum load value of {}", MAX_PERIOD);
}
self.load_value = delay_us * 2;
self.enable(false);
unsafe {
self.configure_wdog_reset_triggers();
}
self.load_counter(self.delay_us);
self.load_counter(self.load_value);
self.enable(true);
}
}