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Don't use mem::transmute in SignalFd #1489

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Merged
merged 2 commits into from
Aug 18, 2021
Merged

Don't use mem::transmute in SignalFd #1489

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a5e0b72
Simplify definition of SIGNALFD_SIGINFO_SIZE
asomers Aug 11, 2021
cb2bdb5
Don't use mem::transmute in SignalFd
asomers Aug 11, 2021
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20 changes: 6 additions & 14 deletions src/sys/signalfd.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,8 @@ libc_bitflags!{
}

pub const SIGNALFD_NEW: RawFd = -1;
pub const SIGNALFD_SIGINFO_SIZE: usize = 128;
#[deprecated(since = "0.23.0", note = "use mem::size_of::<siginfo>() instead")]
pub const SIGNALFD_SIGINFO_SIZE: usize = mem::size_of::<siginfo>();

/// Creates a new file descriptor for reading signals.
///
Expand Down Expand Up @@ -98,15 +99,14 @@ impl SignalFd {
}

pub fn read_signal(&mut self) -> Result<Option<siginfo>> {
let mut buffer = mem::MaybeUninit::<[u8; SIGNALFD_SIGINFO_SIZE]>::uninit();
let mut buffer = mem::MaybeUninit::<siginfo>::uninit();

let size = mem::size_of_val(&buffer);
let res = Errno::result(unsafe {
libc::read(self.0,
buffer.as_mut_ptr() as *mut libc::c_void,
SIGNALFD_SIGINFO_SIZE as libc::size_t)
libc::read(self.0, buffer.as_mut_ptr() as *mut libc::c_void, size)
}).map(|r| r as usize);
match res {
Ok(SIGNALFD_SIGINFO_SIZE) => Ok(Some(unsafe { mem::transmute(buffer.assume_init()) })),
Ok(x) if x == size => Ok(Some(unsafe { buffer.assume_init() })),
Ok(_) => unreachable!("partial read on signalfd"),
Err(Errno::EAGAIN) => Ok(None),
Err(error) => Err(error)
Expand Down Expand Up @@ -144,14 +144,6 @@ impl Iterator for SignalFd {
#[cfg(test)]
mod tests {
use super::*;
use std::mem;
use libc;


#[test]
fn check_siginfo_size() {
assert_eq!(mem::size_of::<libc::signalfd_siginfo>(), SIGNALFD_SIGINFO_SIZE);
}

#[test]
fn create_signalfd() {
Expand Down