From 471a739a47aa7d582f0cdf9d392957d04632bae2 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 26 Jun 2019 00:20:23 +0200 Subject: PCI: PM: Avoid skipping bus-level PM on platforms without ACPI There are platforms that do not call pm_set_suspend_via_firmware(), so pm_suspend_via_firmware() returns 'false' on them, but the power states of PCI devices (PCIe ports in particular) are changed as a result of powering down core platform components during system-wide suspend. Thus the pm_suspend_via_firmware() checks in pci_pm_suspend_noirq() and pci_pm_resume_noirq() introduced by commit 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to- idle") are not sufficient to determine that devices left in D0 during suspend will remain in D0 during resume and so the bus-level power management can be skipped for them. For this reason, introduce a new global suspend flag, PM_SUSPEND_FLAG_NO_PLATFORM, set it for suspend-to-idle only and replace the pm_suspend_via_firmware() checks mentioned above with checks against this flag. Fixes: 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to-idle") Reported-by: Jon Hunter Tested-by: Jon Hunter Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg Reviewed-by: Mika Westerberg --- kernel/power/suspend.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 9505101ed2bc..096211299c07 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -493,6 +493,9 @@ int suspend_devices_and_enter(suspend_state_t state) pm_suspend_target_state = state; + if (state == PM_SUSPEND_TO_IDLE) + pm_set_suspend_no_platform(); + error = platform_suspend_begin(state); if (error) goto Close; -- cgit v1.2.3 From 97abc889ee296faf95ca0e978340fb7b942a3e32 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 28 Jun 2019 12:06:50 -0700 Subject: signal: remove the wrong signal_pending() check in restore_user_sigmask() This is the minimal fix for stable, I'll send cleanups later. Commit 854a6ed56839 ("signal: Add restore_user_sigmask()") introduced the visible change which breaks user-space: a signal temporary unblocked by set_user_sigmask() can be delivered even if the caller returns success or timeout. Change restore_user_sigmask() to accept the additional "interrupted" argument which should be used instead of signal_pending() check, and update the callers. Eric said: : For clarity. I don't think this is required by posix, or fundamentally to : remove the races in select. It is what linux has always done and we have : applications who care so I agree this fix is needed. : : Further in any case where the semantic change that this patch rolls back : (aka where allowing a signal to be delivered and the select like call to : complete) would be advantage we can do as well if not better by using : signalfd. : : Michael is there any chance we can get this guarantee of the linux : implementation of pselect and friends clearly documented. The guarantee : that if the system call completes successfully we are guaranteed that no : signal that is unblocked by using sigmask will be delivered? Link: http://lkml.kernel.org/r/20190604134117.GA29963@redhat.com Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()") Signed-off-by: Oleg Nesterov Reported-by: Eric Wong Tested-by: Eric Wong Acked-by: "Eric W. Biederman" Acked-by: Arnd Bergmann Acked-by: Deepa Dinamani Cc: Michael Kerrisk Cc: Jens Axboe Cc: Davidlohr Bueso Cc: Jason Baron Cc: Thomas Gleixner Cc: Al Viro Cc: David Laight Cc: [5.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/signal.c b/kernel/signal.c index d622eac9d169..edf8915ddd54 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2912,7 +2912,8 @@ EXPORT_SYMBOL(set_compat_user_sigmask); * This is useful for syscalls such as ppoll, pselect, io_pgetevents and * epoll_pwait where a new sigmask is passed in from userland for the syscalls. */ -void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved) +void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved, + bool interrupted) { if (!usigmask) @@ -2922,7 +2923,7 @@ void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved) * Restoring sigmask here can lead to delivering signals that the above * syscalls are intended to block because of the sigmask passed in. */ - if (signal_pending(current)) { + if (interrupted) { current->saved_sigmask = *sigsaved; set_restore_sigmask(); return; -- cgit v1.2.3 From 1bf4580e00a248a2c86269125390eb3648e1877c Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Fri, 28 Jun 2019 12:07:14 -0700 Subject: fork,memcg: alloc_thread_stack_node needs to set tsk->stack Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail") corrected two instances, but there was a third instance of this bug. Without setting tsk->stack, if memcg_charge_kernel_stack fails, it'll execute free_thread_stack() on a dangling pointer. Enterprise kernels are compiled with VMAP_STACK=y so this isn't critical, but custom VMAP_STACK=n builds should have some performance advantage, with the drawback of risking to fail fork because compaction didn't succeed. So as long as VMAP_STACK=n is a supported option it's worth fixing it upstream. Link: http://lkml.kernel.org/r/20190619011450.28048-1-aarcange@redhat.com Fixes: 9b6f7e163cd0 ("mm: rework memcg kernel stack accounting") Signed-off-by: Andrea Arcangeli Reviewed-by: Rik van Riel Acked-by: Roman Gushchin Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 399aca51ff75..61667909ce83 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -248,7 +248,11 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) struct page *page = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER); - return page ? page_address(page) : NULL; + if (likely(page)) { + tsk->stack = page_address(page); + return tsk->stack; + } + return NULL; #endif } -- cgit v1.2.3