diff options
Diffstat (limited to 'pkg/sentry')
| -rw-r--r-- | pkg/sentry/hostfd/hostfd_unsafe.go | 46 |
1 files changed, 12 insertions, 34 deletions
diff --git a/pkg/sentry/hostfd/hostfd_unsafe.go b/pkg/sentry/hostfd/hostfd_unsafe.go index 5e9e60fc4..cd4dc67fb 100644 --- a/pkg/sentry/hostfd/hostfd_unsafe.go +++ b/pkg/sentry/hostfd/hostfd_unsafe.go @@ -34,24 +34,13 @@ func Preadv2(fd int32, dsts safemem.BlockSeq, offset int64, flags uint32) (uint6 n uintptr e syscall.Errno ) - // Avoid preadv2(2) if possible, since it's relatively new and thus least - // likely to be supported by the host kernel. - if flags == 0 { - if dsts.NumBlocks() == 1 { - // Use read() or pread() to avoid iovec allocation and copying. - dst := dsts.Head() - if offset == -1 { - n, _, e = syscall.Syscall(unix.SYS_READ, uintptr(fd), dst.Addr(), uintptr(dst.Len())) - } else { - n, _, e = syscall.Syscall6(unix.SYS_PREAD64, uintptr(fd), dst.Addr(), uintptr(dst.Len()), uintptr(offset), 0 /* pos_h */, 0 /* unused */) - } + if flags == 0 && dsts.NumBlocks() == 1 { + // Use read() or pread() to avoid iovec allocation and copying. + dst := dsts.Head() + if offset == -1 { + n, _, e = syscall.Syscall(unix.SYS_READ, uintptr(fd), dst.Addr(), uintptr(dst.Len())) } else { - iovs := safemem.IovecsFromBlockSeq(dsts) - if offset == -1 { - n, _, e = syscall.Syscall(unix.SYS_READV, uintptr(fd), uintptr((unsafe.Pointer)(&iovs[0])), uintptr(len(iovs))) - } else { - n, _, e = syscall.Syscall6(unix.SYS_PREADV, uintptr(fd), uintptr((unsafe.Pointer)(&iovs[0])), uintptr(len(iovs)), uintptr(offset), 0 /* pos_h */, 0 /* unused */) - } + n, _, e = syscall.Syscall6(unix.SYS_PREAD64, uintptr(fd), dst.Addr(), uintptr(dst.Len()), uintptr(offset), 0 /* pos_h */, 0 /* unused */) } } else { iovs := safemem.IovecsFromBlockSeq(dsts) @@ -77,24 +66,13 @@ func Pwritev2(fd int32, srcs safemem.BlockSeq, offset int64, flags uint32) (uint n uintptr e syscall.Errno ) - // Avoid pwritev2(2) if possible, since it's relatively new and thus least - // likely to be supported by the host kernel. - if flags == 0 { - if srcs.NumBlocks() == 1 { - // Use write() or pwrite() to avoid iovec allocation and copying. - src := srcs.Head() - if offset == -1 { - n, _, e = syscall.Syscall(unix.SYS_WRITE, uintptr(fd), src.Addr(), uintptr(src.Len())) - } else { - n, _, e = syscall.Syscall6(unix.SYS_PWRITE64, uintptr(fd), src.Addr(), uintptr(src.Len()), uintptr(offset), 0 /* pos_h */, 0 /* unused */) - } + if flags == 0 && srcs.NumBlocks() == 1 { + // Use write() or pwrite() to avoid iovec allocation and copying. + src := srcs.Head() + if offset == -1 { + n, _, e = syscall.Syscall(unix.SYS_WRITE, uintptr(fd), src.Addr(), uintptr(src.Len())) } else { - iovs := safemem.IovecsFromBlockSeq(srcs) - if offset == -1 { - n, _, e = syscall.Syscall(unix.SYS_WRITEV, uintptr(fd), uintptr((unsafe.Pointer)(&iovs[0])), uintptr(len(iovs))) - } else { - n, _, e = syscall.Syscall6(unix.SYS_PWRITEV, uintptr(fd), uintptr((unsafe.Pointer)(&iovs[0])), uintptr(len(iovs)), uintptr(offset), 0 /* pos_h */, 0 /* unused */) - } + n, _, e = syscall.Syscall6(unix.SYS_PWRITE64, uintptr(fd), src.Addr(), uintptr(src.Len()), uintptr(offset), 0 /* pos_h */, 0 /* unused */) } } else { iovs := safemem.IovecsFromBlockSeq(srcs) |