This is a note to let you know that I've just added the patch titled parisc/mm: Ensure IRQs are off in switch_mm() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: parisc-mm-ensure-irqs-are-off-in-switch_mm.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 649aa24254e85bf6bd7807dd372d083707852b1f Mon Sep 17 00:00:00 2001 From: Helge Deller <deller@xxxxxx> Date: Mon, 29 May 2017 17:14:16 +0200 Subject: parisc/mm: Ensure IRQs are off in switch_mm() From: Helge Deller <deller@xxxxxx> commit 649aa24254e85bf6bd7807dd372d083707852b1f upstream. This is because of commit f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler") in which switch_mm_irqs_off() is called by the scheduler, vs switch_mm() which is used by use_mm(). This patch lets the parisc code mirror the x86 and powerpc code, ie. it disables interrupts in switch_mm(), and optimises the scheduler case by defining switch_mm_irqs_off(). Signed-off-by: Helge Deller <deller@xxxxxx> Signed-off-by: Helge Deller <deller@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/parisc/include/asm/mmu_context.h | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/arch/parisc/include/asm/mmu_context.h +++ b/arch/parisc/include/asm/mmu_context.h @@ -49,15 +49,26 @@ static inline void load_context(mm_conte mtctl(__space_to_prot(context), 8); } -static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) +static inline void switch_mm_irqs_off(struct mm_struct *prev, + struct mm_struct *next, struct task_struct *tsk) { - if (prev != next) { mtctl(__pa(next->pgd), 25); load_context(next->context); } } +static inline void switch_mm(struct mm_struct *prev, + struct mm_struct *next, struct task_struct *tsk) +{ + unsigned long flags; + + local_irq_save(flags); + switch_mm_irqs_off(prev, next, tsk); + local_irq_restore(flags); +} +#define switch_mm_irqs_off switch_mm_irqs_off + #define deactivate_mm(tsk,mm) do { } while (0) static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next) Patches currently in stable-queue which might be from deller@xxxxxx are queue-4.9/parisc-use-compat_sys_keyctl.patch queue-4.9/mm-fix-overflow-check-in-expand_upwards.patch queue-4.9/parisc-dma-api-return-error-instead-of-bug_on-for-dma-ops-on-non-dma-devs.patch queue-4.9/parisc-mm-ensure-irqs-are-off-in-switch_mm.patch queue-4.9/parisc-report-sigsegv-instead-of-sigbus-when-running-out-of-stack.patch