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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-12 05:43:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-12 05:43:14 +0000 |
commit | 8dd16259287f58f9273002717ec4d27e97127719 (patch) | |
tree | 3863e62a53829a84037444beab3abd4ed9dfc7d0 /third_party/rust/getrandom/src/hermit.rs | |
parent | Releasing progress-linux version 126.0.1-1~progress7.99u1. (diff) | |
download | firefox-8dd16259287f58f9273002717ec4d27e97127719.tar.xz firefox-8dd16259287f58f9273002717ec4d27e97127719.zip |
Merging upstream version 127.0.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/getrandom/src/hermit.rs')
-rw-r--r-- | third_party/rust/getrandom/src/hermit.rs | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/third_party/rust/getrandom/src/hermit.rs b/third_party/rust/getrandom/src/hermit.rs index 570b03d9a5..c4f619417e 100644 --- a/third_party/rust/getrandom/src/hermit.rs +++ b/third_party/rust/getrandom/src/hermit.rs @@ -1,5 +1,11 @@ +//! Implementation for Hermit use crate::Error; -use core::{cmp::min, mem::MaybeUninit, num::NonZeroU32}; +use core::{mem::MaybeUninit, num::NonZeroU32}; + +/// Minimum return value which we should get from syscalls in practice, +/// because Hermit uses positive `i32`s for error codes: +/// https://github.com/hermitcore/libhermit-rs/blob/main/src/errno.rs +const MIN_RET_CODE: isize = -(i32::MAX as isize); extern "C" { fn sys_read_entropy(buffer: *mut u8, length: usize, flags: u32) -> isize; @@ -8,14 +14,16 @@ extern "C" { pub fn getrandom_inner(mut dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> { while !dest.is_empty() { let res = unsafe { sys_read_entropy(dest.as_mut_ptr() as *mut u8, dest.len(), 0) }; - if res < 0 { - // SAFETY: all Hermit error codes use i32 under the hood: - // https://github.com/hermitcore/libhermit-rs/blob/master/src/errno.rs - let code = unsafe { NonZeroU32::new_unchecked((-res) as u32) }; - return Err(code.into()); + // Positive `isize`s can be safely casted to `usize` + if res > 0 && (res as usize) <= dest.len() { + dest = &mut dest[res as usize..]; + } else { + let err = match res { + MIN_RET_CODE..=-1 => NonZeroU32::new(-res as u32).unwrap().into(), + _ => Error::UNEXPECTED, + }; + return Err(err); } - let len = min(res as usize, dest.len()); - dest = &mut dest[len..]; } Ok(()) } |