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([78.42.132.4]) by mrelayeu.kundenserver.de (mreue001) with ESMTPA (Nemesis) id 0LmT7D-1bUZuc1OD5-00aB0z; Fri, 29 Apr 2016 10:53:21 +0200 From: Arnd Bergmann To: Russell King , Ingo Molnar , Peter Zijlstra , Andy Lutomirski Cc: Arnd Bergmann , Borislav Petkov , Ard Biesheuvel , Thomas Gleixner , Frederic Weisbecker , Steven Rostedt , Mel Gorman , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] sched/core: don't include asm/mmu_context from drivers Date: Fri, 29 Apr 2016 10:52:32 +0200 Message-Id: <1461919995-21001-1-git-send-email-arnd@arndb.de> X-Mailer: git-send-email 2.7.0 X-Provags-ID: V03:K0:n7DUExSEnS0oMtkPvsS3c53nzaJ4VIGJU2IvXLVqhlukR3P2CRx d4hPhpnhaG41P0jO9Sfb2phEvqGYJ+E1kPOicPaer0bkhJyUN29iPClQzsEIlo1rDQc6V5o H5zAuFjR86L+oasw8OA/m3oADU2vVZDKDLQiv8JRWP+y9szLXCDrFWux0pzU79QsrzgFs3E cq1GQPwtt5xNpdzck91zQ== X-UI-Out-Filterresults: notjunk:1; V01:K0:RfU0GrhcT9E=:eTB4Mau3ywjnw+Cf/Ad4c5 VFsEgkmypYdPcvEFV1qF6AVdWkyOQLxCkFleKUE7F4EFnb9/H7+Mqu3kGIYd51W08W+oTeeQn jw7TD7bQQavCABK8l2Rp4oEfLDmAzNvRExhyURPWXnKRzh0r20cqMmcol1iRnAZdh6iC8BsHI Dpg8fOp+XYhv2JH6x3DLGJ7pa9SmkPpwmJCL5S7uDFmKpGp87pKmTEsUvgvQDIHnShaV2FUMS BoZlbNb/7GDU0jQDhUsxbMpSOYrbNCfucrh+SWiyZBpGvCywaN/HcADs9n/f+3lmySnKsMEi5 JRJq3aps6prGEjVUO3ZhO37XTYncLefueof8sA9YXfVynnjRgObmdGYu1L+HsbQ4GyPtPg/9A yIwlM0rcyMYYvOCItLNpt14HuYlLfAcp9J0aDXQbSU5cfdjmkv6Ts99nwqeHAWgO7tdWqqfk5 Tn1K2z7F6ymiG2I5ikPDe7Rjcs1wuDYzHUFeFRojrxXQXXXDYPexlzf9lzNQiPIyRhlgFh7s7 LXjIbugMmuvHnzAoiplvpC3ap2f076P2J93xDyNqx0+5Z9nmG8lVxLchminLif2KR3e9F09Li 23debkj/DvGEY26L/kD+DYP6lFlloUANctbJ4JDD01gPgTeeeIVQZXQtAQAPOAQpHVv8J2CPS Z7gc8Lz7rvFGjDlEturLd6Syt59iSsHNvTQd8dsTaBj8pfz1dD12npFTNd/WkbmiNmUU= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 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 #include -#include #include #include #include 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 - 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 #include #include +#include #include #ifdef CONFIG_PARAVIRT #include