| Message ID | 1461919995-21001-1-git-send-email-arnd@arndb.de |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h index ed73babc0dc9..fa5b42d44985 100644 --- a/arch/arm/include/asm/mmu_context.h +++ b/arch/arm/include/asm/mmu_context.h @@ -15,7 +15,6 @@ #include <linux/compiler.h> #include <linux/sched.h> -#include <linux/preempt.h> #include <asm/cacheflush.h> #include <asm/cachetype.h> #include <asm/proc-fns.h> diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h index a4441784503b..88d270706792 100644 --- a/include/linux/mmu_context.h +++ b/include/linux/mmu_context.h @@ -1,8 +1,6 @@ #ifndef _LINUX_MMU_CONTEXT_H #define _LINUX_MMU_CONTEXT_H -#include <asm/mmu_context.h> - struct mm_struct; void use_mm(struct mm_struct *mm); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c82ca6eccfec..baa2a5152658 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -78,6 +78,7 @@ #include <asm/switch_to.h> #include <asm/tlb.h> #include <asm/irq_regs.h> +#include <asm/mmu_context.h> #include <asm/mutex.h> #ifdef CONFIG_PARAVIRT #include <asm/paravirt.h>
The introduction of switch_mm_irqs_off() brought back an old bug regarding the use of preempt_enable_no_resched: As part of 62b94a08da1b ("sched/preempt: Take away preempt_enable_no_resched() from modules"), the definition of preempt_enable_no_resched() is only available in built-in code, not in loadable modules, so we can't generally use it from header files. However, the ARM version of finish_arch_post_lock_switch() calls preempt_enable_no_resched() and is defined as a static inline function in asm/mmu_context.h. This in turn means we cannot include asm/mmu_context.h from modules. With today's tip tree, asm/mmu_context.h gets included from linux/mmu_context.h, which is normally the exact pattern one would expect, but unfortunately, linux/mmu_context.h can be included from the vhost driver that is a loadable module, now causing this compile time error: In file included from ../include/linux/mmu_context.h:4:0, from ../drivers/vhost/vhost.c:18: ../arch/arm/include/asm/mmu_context.h: In function 'finish_arch_post_lock_switch': ../arch/arm/include/asm/mmu_context.h:88:3: error: implicit declaration of function 'preempt_enable_no_resched' [-Werror=implicit-function-declaration] preempt_enable_no_resched(); Andy already tried to fix the bug by including linux/preempt.h from asm/mmu_context.h, but that obviously didn't help. This reverts the earlier fix attempt and works around the problem by including both linux/mmu_context.h and asm/mmu_context.h from kernel/sched/core.c. This is not a good solution but seems less hacky than the alternatives. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler") Reverts: 88f10e37e150 ("sched/core, ARM: Include linux/preempt.h from asm/mmu_context.h") --- arch/arm/include/asm/mmu_context.h | 1 - include/linux/mmu_context.h | 2 -- kernel/sched/core.c | 1 + 3 files changed, 1 insertion(+), 3 deletions(-) -- 2.7.0