Re: [PATCH v8 18/27] mm: Introduce do_mmap_locked()

[Sean Christopherson]

On Tue, Aug 13, 2019 at 01:52:16PM -0700, Yu-cheng Yu wrote:
> There are a few places that need do_mmap() with mm->mmap_sem held.
> Create an in-line function for that.
> 
> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
> ---
>  include/linux/mm.h | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index bc58585014c9..275c385f53c6 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2394,6 +2394,24 @@ static inline void mm_populate(unsigned long addr, unsigned long len)
>  static inline void mm_populate(unsigned long addr, unsigned long len) {}
>  #endif
>  
> +static inline unsigned long do_mmap_locked(struct file *file,
> +	unsigned long addr, unsigned long len, unsigned long prot,
> +	unsigned long flags, vm_flags_t vm_flags, struct list_head *uf)
> +{
> +	struct mm_struct *mm = current->mm;
> +	unsigned long populate;
> +
> +	down_write(&mm->mmap_sem);
> +	addr = do_mmap(file, addr, len, prot, flags, vm_flags, 0,
> +		       &populate, uf);
> +	up_write(&mm->mmap_sem);
> +
> +	if (populate)
> +		mm_populate(addr, populate);
> +
> +	return addr;
> +}

Any reason not to put this in cet.c, as suggested by PeterZ?  All of the
calls from CET have identical params except for @len, e.g. you can add
'static unsigned long cet_mmap(unsigned long len)' and bury most of the
copy-paste code in there.

https://lkml.kernel.org/r/20190607074707.GD3463@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

> +
>  /* These take the mm semaphore themselves */
>  extern int __must_check vm_brk(unsigned long, unsigned long);
>  extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
> -- 
> 2.17.1
>