Introduces the CopyFileRange syscall which first appears in Linux 4.5.
Allows copying file content between file descriptors within the kernel
without transferring data to user space. This syscall also allows the
kernel to take advantage of reflinking or other fast copy methods on
supported file systems.
http://man7.org/linux/man-pages/man2/copy_file_range.2.html
Change-Id: Id365f1e5d4d5ddf7159478e3a13084c9576ebd5c
Reviewed-on: https://go-review.googlesource.com/39992
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Right now the process for adding in new constants, errors, or syscalls
for Linux is a pain and unreliable. The scripts are designed to be run
on the target architecture and use the header files installed on the
user's system. This makes it hard to generate files for all the
architectures or to have consistency between users. See golang/go#15282.
This CL fixes this issue by making all of the files for the 11 supported
architectures directly from source checkouts of Linux, glibc, and bluez.
This is done using Docker, the gcc cross-compilers, and qemu emulation.
Previously discussed here:
https://go-review.googlesource.com/c/37589/
A README.md file is also added to explain how all the parts of the build
system work.
In order to get the build working for all the architectures, I made
some changes to the other scripts called from mkall_linux.go:
- Files only used for generating linux code, moved to linux/
- linux/mksysnum.pl supports a specified CC compiler.
- The generated C code in mkerrors.sh changed to avoid a warning
- mkerrors.sh headers changed to fix powerpc64 bug in sys/ioctl.h
- linux/types.go no longer needs to export Ptrace structs in lowercase
Build instructions:
- Host system needs to be x86-64 Linux
- Install Docker (https://docs.docker.com/engine/installation/)
- ./mkall.sh (That's it!!!)
Change-Id: I87067c14442ba12f8d51991349a43a9d73f38ae0
Reviewed-on: https://go-review.googlesource.com/37943
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This CL introduces the Getrandom syscall. Allowing users of
sufficiently new kernels (3.17) to detect when the operating system
lacks enough entropy to generate cryptographic random data. See:
http://man7.org/linux/man-pages/man2/getrandom.2.html
As we have updated the syscall numbers, the Getrandom function can
just be generated normally. The only other change is to mkerrors.sh
to include the GRND_* flags for getrandom from <linux/random.h>.
It is important to note that currently the mkerrors.sh script cannot
actually be run as it has fallen behind the 4.10 kernel. The GRND_*
flags were added manually.
This was originally part of a larger commit that was split up.
See CL: https://go-review.googlesource.com/37570
Change-Id: I464088a9c9f7224abdcdae476b30a4f2f412d9f5
Reviewed-on: https://go-review.googlesource.com/37589
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Matt Layher <mdlayher@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
