GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-21 14:11:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

core-process-v5.4

Browse source 
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCXXe8mQAKCRCRxhvAZXjc
 ou7oAQCszihkNfpjORSSSOqenMDrxxDW++A7TIOLuq7UyZQl8QD+LM1wvT/xypfJ
 ORD9XX8+Wrv07AQn85fZBEFXGrnengk=
 =o+VL
 -----END PGP SIGNATURE-----

Merge tag 'core-process-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull pidfd/waitid updates from Christian Brauner:
 "This contains two features and various tests.

  First, it adds support for waiting on process through pidfds by adding
  the P_PIDFD type to the waitid() syscall. This completes the basic
  functionality of the pidfd api (cf. [1]). In the meantime we also have
  a new adition to the userspace projects that make use of the pidfd
  api. The qt project was nice enough to send a mail pointing out that
  they have a pr up to switch to the pidfd api (cf. [2]).

  Second, this tag contains an extension to the waitid() syscall to make
  it possible to wait on the current process group in a race free manner
  (even though the actual problem is very unlikely) by specifing 0
  together with the P_PGID type. This extension traces back to a
  discussion on the glibc development mailing list.

  There are also a range of tests for the features above. Additionally,
  the test-suite which detected the pidfd-polling race we fixed in [3]
  is included in this tag"

[1] https://lwn.net/Articles/794707/
[2] https://codereview.qt-project.org/c/qt/qtbase/+/108456
[3] commit b191d6491b ("pidfd: fix a poll race when setting exit_state")

* tag 'core-process-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  waitid: Add support for waiting for the current process group
  tests: add pidfd poll tests
  tests: move common definitions and functions into pidfd.h
  pidfd: add pidfd_wait tests
  pidfd: add P_PIDFD to waitid()
This commit is contained in:
Linus Torvalds 2019-09-16 09:28:19 -07:00
commit c17112a5c4
12 changed files with 473 additions and 26 deletions
Download patch file Download diff file Expand all files Collapse all files

38
kernel/exit.c
View file

@ -1554,6 +1554,23 @@ end:
return retval;
}
static struct pid *pidfd_get_pid(unsigned int fd)
{
struct fd f;
struct pid *pid;
f = fdget(fd);
if (!f.file)
return ERR_PTR(-EBADF);
pid = pidfd_pid(f.file);
if (!IS_ERR(pid))
get_pid(pid);
fdput(f);
return pid;
}
static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
int options, struct rusage *ru)
{
@ -1576,19 +1593,32 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
type = PIDTYPE_PID;
if (upid <= 0)
return -EINVAL;
pid = find_get_pid(upid);
break;
case P_PGID:
type = PIDTYPE_PGID;
if (upid <= 0)
if (upid < 0)
return -EINVAL;
if (upid)
pid = find_get_pid(upid);
else
pid = get_task_pid(current, PIDTYPE_PGID);
break;
case P_PIDFD:
type = PIDTYPE_PID;
if (upid < 0)
return -EINVAL;
pid = pidfd_get_pid(upid);
if (IS_ERR(pid))
return PTR_ERR(pid);
break;
default:
return -EINVAL;
}
if (type < PIDTYPE_MAX)
pid = find_get_pid(upid);
wo.wo_type = type;
wo.wo_pid = pid;
wo.wo_flags = options;