Re: [PATCH 1/2] mm: Introducing arch_remap hook
From: Ingo Molnar <mingo@kernel.org>
Date: 2015-03-23 08:52:17
Also in:
linux-arch, linux-mm, linux-s390, linux-um, lkml
* Laurent Dufour [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Some architecture would like to be triggered when a memory area is moved through the mremap system call. This patch is introducing a new arch_remap mm hook which is placed in the path of mremap, and is called before the old area is unmapped (and the arch_unmap hook is called). To no break the build, this patch adds the empty hook definition to the architectures that were not using the generic hook's definition. Signed-off-by: Laurent Dufour <redacted> --- arch/s390/include/asm/mmu_context.h | 6 ++++++ arch/um/include/asm/mmu_context.h | 5 +++++ arch/unicore32/include/asm/mmu_context.h | 6 ++++++ arch/x86/include/asm/mmu_context.h | 6 ++++++ include/asm-generic/mm_hooks.h | 6 ++++++ mm/mremap.c | 9 +++++++-- 6 files changed, 36 insertions(+), 2 deletions(-)diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 8fb3802f8fad..ddd861a490ba 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h@@ -131,4 +131,10 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, { } +static inline void arch_remap(struct mm_struct *mm, + unsigned long old_start, unsigned long old_end, + unsigned long new_start, unsigned long new_end) +{ +} + #endif /* __S390_MMU_CONTEXT_H */diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h index 941527e507f7..f499b017c1f9 100644 --- a/arch/um/include/asm/mmu_context.h +++ b/arch/um/include/asm/mmu_context.h@@ -27,6 +27,11 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, struct vm_area_struct *vma) { } +static inline void arch_remap(struct mm_struct *mm, + unsigned long old_start, unsigned long old_end, + unsigned long new_start, unsigned long new_end) +{ +} /* * end asm-generic/mm_hooks.h functions */diff --git a/arch/unicore32/include/asm/mmu_context.h b/arch/unicore32/include/asm/mmu_context.h index 1cb5220afaf9..39a0a553172e 100644 --- a/arch/unicore32/include/asm/mmu_context.h +++ b/arch/unicore32/include/asm/mmu_context.h@@ -97,4 +97,10 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, { } +static inline void arch_remap(struct mm_struct *mm, + unsigned long old_start, unsigned long old_end, + unsigned long new_start, unsigned long new_end) +{ +} + #endifdiff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 883f6b933fa4..75cb71f4be1e 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h@@ -172,4 +172,10 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma, mpx_notify_unmap(mm, vma, start, end); } +static inline void arch_remap(struct mm_struct *mm, + unsigned long old_start, unsigned long old_end, + unsigned long new_start, unsigned long new_end) +{ +} + #endif /* _ASM_X86_MMU_CONTEXT_H */
So instead of spreading these empty prototypes around mmu_context.h files, why not add something like this to the PPC definition: #define __HAVE_ARCH_REMAP and define the empty prototype for everyone else? It's a bit like how the __HAVE_ARCH_PTEP_* namespace works. That should shrink this patch considerably. Thanks, Ingo