github/containerd
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 2 Wiki Activity

Merge pull request #1216 from tklauser/prctl-x-sys-unix

Browse Source 
Use Prctl() and associated constants from x/sys/unix
This commit is contained in:
Stephen Day 2017-07-19 11:11:40 -07:00 committed by GitHub
commit b5267baa88
1 changed files with 19 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
sys/prctl.go
View File

@ -1,7 +1,6 @@
// +build linux // +build linux
// Package osutils provide access to the Get Child and Set Child prctl // Package sys provides access to the Get Child and Set Child prctl flags.
// flags.
// See http://man7.org/linux/man-pages/man2/prctl.2.html // See http://man7.org/linux/man-pages/man2/prctl.2.html
package sys package sys
@ -11,30 +10,14 @@ import (
"golang.org/x/sys/unix" "golang.org/x/sys/unix"
) )
// PR_SET_CHILD_SUBREAPER allows setting the child subreaper.
// If arg2 is nonzero, set the "child subreaper" attribute of the
// calling process; if arg2 is zero, unset the attribute. When a
// process is marked as a child subreaper, all of the children
// that it creates, and their descendants, will be marked as
// having a subreaper. In effect, a subreaper fulfills the role
// of init(1) for its descendant processes. Upon termination of
// a process that is orphaned (i.e., its immediate parent has
// already terminated) and marked as having a subreaper, the
// nearest still living ancestor subreaper will receive a SIGCHLD
// signal and be able to wait(2) on the process to discover its
// termination status.
const prSetChildSubreaper = 36
// PR_GET_CHILD_SUBREAPER allows retrieving the current child
// subreaper.
// Returns the "child subreaper" setting of the caller, in the
// location pointed to by (int *) arg2.
const prGetChildSubreaper = 37
// GetSubreaper returns the subreaper setting for the calling process // GetSubreaper returns the subreaper setting for the calling process
func GetSubreaper() (int, error) { func GetSubreaper() (int, error) {
var i uintptr var i uintptr
if _, _, err := unix.RawSyscall(unix.SYS_PRCTL, prGetChildSubreaper, uintptr(unsafe.Pointer(&i)), 0); err != 0 { // PR_GET_CHILD_SUBREAPER allows retrieving the current child
// subreaper.
// Returns the "child subreaper" setting of the caller, in the
// location pointed to by (int *) arg2.
if err := unix.Prctl(unix.PR_GET_CHILD_SUBREAPER, uintptr(unsafe.Pointer(&i)), 0, 0, 0); err != nil {
return -1, err return -1, err
} }
return int(i), nil return int(i), nil
@ -42,8 +25,17 @@ func GetSubreaper() (int, error) {
// SetSubreaper sets the value i as the subreaper setting for the calling process // SetSubreaper sets the value i as the subreaper setting for the calling process
func SetSubreaper(i int) error { func SetSubreaper(i int) error {
if _, _, err := unix.RawSyscall(unix.SYS_PRCTL, prSetChildSubreaper, uintptr(i), 0); err != 0 { // PR_SET_CHILD_SUBREAPER allows setting the child subreaper.
return err // If arg2 is nonzero, set the "child subreaper" attribute of the
} // calling process; if arg2 is zero, unset the attribute. When a
return nil // process is marked as a child subreaper, all of the children
// that it creates, and their descendants, will be marked as
// having a subreaper. In effect, a subreaper fulfills the role
// of init(1) for its descendant processes. Upon termination of
// a process that is orphaned (i.e., its immediate parent has
// already terminated) and marked as having a subreaper, the
// nearest still living ancestor subreaper will receive a SIGCHLD
// signal and be able to wait(2) on the process to discover its
// termination status.
return unix.Prctl(unix.PR_SET_CHILD_SUBREAPER, uintptr(i), 0, 0, 0)
} }