Commit fcebe8f2 authored by Jeremy Soller's avatar Jeremy Soller

Merge branch 'signed-seek' into 'master'

change seek sig to match posix - signed pos and result

See merge request redox-os/syscall!45
parents 7552c31f 940f3f1e
Pipeline #7852 failed with stages
in 1 minute and 56 seconds
......@@ -2,8 +2,10 @@ pub use self::scheme::Scheme;
pub use self::scheme_mut::SchemeMut;
pub use self::scheme_block::SchemeBlock;
pub use self::scheme_block_mut::SchemeBlockMut;
pub use self::seek::*;
mod scheme;
mod scheme_mut;
mod scheme_block;
mod scheme_block_mut;
mod seek;
......@@ -16,7 +16,7 @@ pub trait Scheme {
SYS_DUP => self.dup(packet.b, unsafe { slice::from_raw_parts(packet.c as *const u8, packet.d) }),
SYS_READ => self.read(packet.b, unsafe { slice::from_raw_parts_mut(packet.c as *mut u8, packet.d) }),
SYS_WRITE => self.write(packet.b, unsafe { slice::from_raw_parts(packet.c as *const u8, packet.d) }),
SYS_LSEEK => self.seek(packet.b, packet.c, packet.d),
SYS_LSEEK => self.seek(packet.b, packet.c as isize, packet.d).map(|o| o as usize),
SYS_FCHMOD => self.fchmod(packet.b, packet.c as u16),
SYS_FCHOWN => self.fchown(packet.b, packet.c as u32, packet.d as u32),
SYS_FCNTL => self.fcntl(packet.b, packet.c, packet.d),
......@@ -92,7 +92,7 @@ pub trait Scheme {
}
#[allow(unused_variables)]
fn seek(&self, id: usize, pos: usize, whence: usize) -> Result<usize> {
fn seek(&self, id: usize, pos: isize, whence: usize) -> Result<isize> {
Err(Error::new(EBADF))
}
......
use core::cmp;
use core::convert::TryFrom;
use crate::error::*;
use crate::flag::*;
/// Helper for seek calls
/// In most cases it's easier to use a usize to track the offset and buffer size internally,
/// but the seek interface uses isize. This wrapper ensures EOVERFLOW errors are returned
/// as appropriate if the value in the usize can't fit in the isize.
pub fn calc_seek_offset_usize(cur_offset: usize, pos: isize, whence: usize, buf_len: usize) -> Result<isize> {
let cur_offset = isize::try_from(cur_offset).or_else(|_| Err(Error::new(EOVERFLOW)))?;
let buf_len = isize::try_from(buf_len).or_else(|_| Err(Error::new(EOVERFLOW)))?;
calc_seek_offset_isize(cur_offset, pos, whence, buf_len)
}
/// Helper for seek calls
/// Result is guaranteed to be positive.
/// EOVERFLOW returned if the arguments would cause an overflow.
/// EINVAL returned if the new offset is out of bounds.
pub fn calc_seek_offset_isize(cur_offset: isize, pos: isize, whence: usize, buf_len: isize) -> Result<isize> {
let new_offset = match whence {
SEEK_CUR => pos.checked_add(cur_offset),
SEEK_END => pos.checked_add(buf_len),
SEEK_SET => Some(pos),
_ => None,
};
match new_offset {
Some(new_offset) if new_offset < 0 => Err(Error::new(EINVAL)),
Some(new_offset) => Ok(cmp::min(new_offset, buf_len)),
None => Err(Error::new(EOVERFLOW))
}
}
\ No newline at end of file
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