kernel/linux.git/include/linux/sched, branch v4.17.5

sched/core: Introduce set_special_state()

2018-05-04T05:54:54+00:00

Gaurav reported a perceived problem with TASK_PARKED, which turned out to be a broken wait-loop pattern in __kthread_parkme(), but the reported issue can (and does) in fact happen for states that do not do condition based sleeps. When the 'current->state = TASK_RUNNING' store of a previous (concurrent) try_to_wake_up() collides with the setting of a 'special' sleep state, we can loose the sleep state. Normal condition based wait-loops are immune to this problem, but for sleep states that are not condition based are subject to this problem. There already is a fix for TASK_DEAD. Abstract that and also apply it to TASK_STOPPED and TASK_TRACED, both of which are also without condition based wait-loop. Reported-by: Gaurav Kohli Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Oleg Nesterov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

exec: pass stack rlimit into mm layout functions

2018-04-11T17:28:37+00:00

Patch series "exec: Pin stack limit during exec". Attempts to solve problems with the stack limit changing during exec continue to be frustrated[1][2]. In addition to the specific issues around the Stack Clash family of flaws, Andy Lutomirski pointed out[3] other places during exec where the stack limit is used and is assumed to be unchanging. Given the many places it gets used and the fact that it can be manipulated/raced via setrlimit() and prlimit(), I think the only way to handle this is to move away from the "current" view of the stack limit and instead attach it to the bprm, and plumb this down into the functions that need to know the stack limits. This series implements the approach. [1] 04e35f4495dd ("exec: avoid RLIMIT_STACK races with prlimit()") [2] 779f4e1c6c7c ("Revert "exec: avoid RLIMIT_STACK races with prlimit()"") [3] to security@kernel.org, "Subject: existing rlimit races?" This patch (of 3): Since it is possible that the stack rlimit can change externally during exec (either via another thread calling setrlimit() or another process calling prlimit()), provide a way to pass the rlimit down into the per-architecture mm layout functions so that the rlimit can stay in the bprm structure instead of sitting in the signal structure until exec is finalized. Link: http://lkml.kernel.org/r/1518638796-20819-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Cc: Michal Hocko Cc: Ben Hutchings Cc: Willy Tarreau Cc: Hugh Dickins Cc: Oleg Nesterov Cc: "Jason A. Donenfeld" Cc: Rik van Riel Cc: Laura Abbott Cc: Greg KH Cc: Andy Lutomirski Cc: Ben Hutchings Cc: Brad Spengler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2018-04-07T18:11:41+00:00

Pull general security layer updates from James Morris: - Convert security hooks from list to hlist, a nice cleanup, saving about 50% of space, from Sargun Dhillon. - Only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill (as the secid can be determined from the cred), from Stephen Smalley. - Close a potential race in kernel_read_file(), by making the file unwritable before calling the LSM check (vs after), from Kees Cook. * 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: security: convert security hooks to use hlist exec: Set file unwritable before LSM check usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill

Merge tag 'v4.16-rc6' into next-general

2018-03-22T21:26:16+00:00

Merge to Linux 4.16-rc6 at the request of Jarkko, for his TPM updates.

sched/cpufreq: Provide migration hint

2018-03-09T06:59:20+00:00

It was suggested that a migration hint might be usefull for the CPU-freq governors. Signed-off-by: Peter Zijlstra (Intel) Cc: Juri Lelli Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Thomas Gleixner Cc: Viresh Kumar Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/nohz: Clean up nohz enter/exit

2018-03-09T06:59:19+00:00

The primary observation is that nohz enter/exit is always from the current CPU, therefore NOHZ_TICK_STOPPED does not in fact need to be an atomic. Secondary is that we appear to have 2 nearly identical hooks in the nohz enter code, set_cpu_sd_state_idle() and nohz_balance_enter_idle(). Fold the whole set_cpu_sd_state thing into nohz_balance_{enter,exit}_idle. Removes an atomic op from both enter and exit paths. Signed-off-by: Peter Zijlstra (Intel) Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

cpufreq/schedutil: Rewrite CPUFREQ_RT support

2018-03-09T06:59:15+00:00

Instead of trying to duplicate scheduler state to track if an RT task is running, directly use the scheduler runqueue state for it. This vastly simplifies things and fixes a number of bugs related to sugov and the scheduler getting out of sync wrt this state. As a consequence we not also update the remove cfs/dl state when iterating the shared mask. Signed-off-by: Peter Zijlstra (Intel) Cc: Juri Lelli Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Thomas Gleixner Cc: Viresh Kumar Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

cpufreq/schedutil: Remove unused CPUFREQ_DL

2018-03-09T06:59:14+00:00

Bitrot... Signed-off-by: Peter Zijlstra (Intel) Cc: Juri Lelli Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Thomas Gleixner Cc: Viresh Kumar Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

Merge branch 'linus' into sched/core, to pick up fixes

2018-03-09T06:32:20+00:00

Signed-off-by: Ingo Molnar

usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill

2018-03-06T22:05:53+00:00

commit d178bc3a708f39cbfefc3fab37032d3f2511b4ec ("user namespace: usb: make usb urbs user namespace aware (v2)") changed kill_pid_info_as_uid to kill_pid_info_as_cred, saving and passing a cred structure instead of uids. Since the secid can be obtained from the cred, drop the secid fields from the usb_dev_state and async structures, and drop the secid argument to kill_pid_info_as_cred. Replace the secid argument to security_task_kill with the cred. Update SELinux, Smack, and AppArmor to use the cred, which avoids the need for Smack and AppArmor to use a secid at all in this hook. Further changes to Smack might still be required to take full advantage of this change, since it should now be possible to perform capability checking based on the supplied cred. The changes to Smack and AppArmor have only been compile-tested. Signed-off-by: Stephen Smalley Acked-by: Paul Moore Acked-by: Casey Schaufler Acked-by: Greg Kroah-Hartman Acked-by: John Johansen Signed-off-by: James Morris