Fix stdio descriptors in exec by removing cloexec if present. Use dup2 instead of dup

This commit is contained in:
Jeremy Soller 2017-04-16 09:33:13 -06:00
parent 28a7429977
commit 1bc9e5da23
3 changed files with 18 additions and 9 deletions

View File

@ -270,19 +270,22 @@ impl Command {
}
if let Some(fd) = stdio.stderr.fd() {
let _ = syscall::close(2);
t!(cvt(syscall::dup(fd, &[])));
let _ = syscall::close(fd);
t!(cvt(syscall::dup2(fd, 2, &[])));
let mut flags = t!(cvt(syscall::fcntl(2, syscall::F_GETFL, 0)));
flags &= ! syscall::O_CLOEXEC;
t!(cvt(syscall::fcntl(2, syscall::F_SETFL, flags)));
}
if let Some(fd) = stdio.stdout.fd() {
let _ = syscall::close(1);
t!(cvt(syscall::dup(fd, &[])));
let _ = syscall::close(fd);
t!(cvt(syscall::dup2(fd, 1, &[])));
let mut flags = t!(cvt(syscall::fcntl(1, syscall::F_GETFL, 0)));
flags &= ! syscall::O_CLOEXEC;
t!(cvt(syscall::fcntl(1, syscall::F_SETFL, flags)));
}
if let Some(fd) = stdio.stdin.fd() {
let _ = syscall::close(0);
t!(cvt(syscall::dup(fd, &[])));
let _ = syscall::close(fd);
t!(cvt(syscall::dup2(fd, 0, &[])));
let mut flags = t!(cvt(syscall::fcntl(0, syscall::F_GETFL, 0)));
flags &= ! syscall::O_CLOEXEC;
t!(cvt(syscall::fcntl(0, syscall::F_SETFL, flags)));
}
if let Some(g) = self.gid {

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@ -71,6 +71,11 @@ pub fn dup(fd: usize, buf: &[u8]) -> Result<usize> {
unsafe { syscall3(SYS_DUP, fd, buf.as_ptr() as usize, buf.len()) }
}
/// Copy and transform a file descriptor
pub fn dup2(fd: usize, newfd: usize, buf: &[u8]) -> Result<usize> {
unsafe { syscall4(SYS_DUP2, fd, newfd, buf.as_ptr() as usize, buf.len()) }
}
/// Replace the current process with a new executable
pub fn execve(path: &str, args: &[[usize; 2]]) -> Result<usize> {
unsafe { syscall4(SYS_EXECVE, path.as_ptr() as usize, path.len(),

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@ -28,6 +28,7 @@ pub const SYS_UNLINK: usize = SYS_CLASS_PATH | 10;
pub const SYS_CLOSE: usize = SYS_CLASS_FILE | 6;
pub const SYS_DUP: usize = SYS_CLASS_FILE | SYS_RET_FILE | 41;
pub const SYS_DUP2: usize = SYS_CLASS_FILE | SYS_RET_FILE | 63;
pub const SYS_READ: usize = SYS_CLASS_FILE | SYS_ARG_MSLICE | 3;
pub const SYS_WRITE: usize = SYS_CLASS_FILE | SYS_ARG_SLICE | 4;
pub const SYS_LSEEK: usize = SYS_CLASS_FILE | 19;