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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 12:30:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 12:30:24 -0700 |
| commit | eac7078a0fff1e72cf2b641721e3f55ec7e5e21e (patch) | |
| tree | daf83e62d8313025a2c5e4ceb2d7f3c1b8ff057c /arch/x86 | |
| parent | 41bc10cabe96bbd0ff3e2813d15f9070bff57a03 (diff) | |
| parent | 43c6afee48d4d866d5eb984d3a5dbbc7d9b4e7bf (diff) | |
| download | linux-eac7078a0fff1e72cf2b641721e3f55ec7e5e21e.tar.bz2 | |
Merge tag 'pidfd-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull pidfd updates from Christian Brauner:
"This patchset makes it possible to retrieve pidfds at process creation
time by introducing the new flag CLONE_PIDFD to the clone() system
call. Linus originally suggested to implement this as a new flag to
clone() instead of making it a separate system call.
After a thorough review from Oleg CLONE_PIDFD returns pidfds in the
parent_tidptr argument. This means we can give back the associated pid
and the pidfd at the same time. Access to process metadata information
thus becomes rather trivial.
As has been agreed, CLONE_PIDFD creates file descriptors based on
anonymous inodes similar to the new mount api. They are made
unconditional by this patchset as they are now needed by core kernel
code (vfs, pidfd) even more than they already were before (timerfd,
signalfd, io_uring, epoll etc.). The core patchset is rather small.
The bulky looking changelist is caused by David's very simple changes
to Kconfig to make anon inodes unconditional.
A pidfd comes with additional information in fdinfo if the kernel
supports procfs. The fdinfo file contains the pid of the process in
the callers pid namespace in the same format as the procfs status
file, i.e. "Pid:\t%d".
To remove worries about missing metadata access this patchset comes
with a sample/test program that illustrates how a combination of
CLONE_PIDFD and pidfd_send_signal() can be used to gain race-free
access to process metadata through /proc/<pid>.
Further work based on this patchset has been done by Joel. His work
makes pidfds pollable. It finished too late for this merge window. I
would prefer to have it sitting in linux-next for a while and send it
for inclusion during the 5.3 merge window"
* tag 'pidfd-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
samples: show race-free pidfd metadata access
signal: support CLONE_PIDFD with pidfd_send_signal
clone: add CLONE_PIDFD
Make anon_inodes unconditional
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/Kconfig | 1 |
2 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0a3cc347143f..e7212731cffb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -44,7 +44,6 @@ config X86 # select ACPI_LEGACY_TABLES_LOOKUP if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI - select ANON_INODES select ARCH_32BIT_OFF_T if X86_32 select ARCH_CLOCKSOURCE_DATA select ARCH_CLOCKSOURCE_INIT diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index 72fa955f4a15..fc042419e670 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -27,7 +27,6 @@ config KVM depends on X86_LOCAL_APIC select PREEMPT_NOTIFIERS select MMU_NOTIFIER - select ANON_INODES select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQFD select IRQ_BYPASS_MANAGER |