Re: [PATCH v5 05/10] mmap locking API: convert mmap_sem call sites missed by coccinelle

[Laurent Dufour <ldufour@xxxxxxxxxxxxx>]

Le 22/04/2020 à 02:14, Michel Lespinasse a écrit :
> Convert the last few remaining mmap_sem rwsem calls to use the new
> mmap locking API. These were missed by coccinelle for some reason
> (I think coccinelle does not support some of the preprocessor
> constructs in these files ?)
>
> Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
> Reviewed-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>

Reviewed-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx>

> ---
>   arch/mips/mm/fault.c           | 10 +++++-----
>   arch/riscv/mm/pageattr.c       |  4 ++--
>   arch/x86/kvm/mmu/paging_tmpl.h |  8 ++++----
>   drivers/android/binder_alloc.c |  4 ++--
>   fs/proc/base.c                 |  6 +++---
>   5 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
> index f8d62cd83b36..9ef2dd39111e 100644
> --- a/arch/mips/mm/fault.c
> +++ b/arch/mips/mm/fault.c
> @@ -97,7 +97,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
>   	if (user_mode(regs))
>   		flags |= FAULT_FLAG_USER;
>   retry:
> -	down_read(&mm->mmap_sem);
> +	mmap_read_lock(mm);
>   	vma = find_vma(mm, address);
>   	if (!vma)
>   		goto bad_area;
> @@ -190,7 +190,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
>   		}
>   	}
>   
> -	up_read(&mm->mmap_sem);
> +	mmap_read_unlock(mm);
>   	return;
>   
>   /*
> @@ -198,7 +198,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
>    * Fix it, but check if it's kernel or user first..
>    */
>   bad_area:
> -	up_read(&mm->mmap_sem);
> +	mmap_read_unlock(mm);
>   
>   bad_area_nosemaphore:
>   	/* User mode accesses just cause a SIGSEGV */
> @@ -250,14 +250,14 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
>   	 * We ran out of memory, call the OOM killer, and return the userspace
>   	 * (which will retry the fault, or kill us if we got oom-killed).
>   	 */
> -	up_read(&mm->mmap_sem);
> +	mmap_read_unlock(mm);
>   	if (!user_mode(regs))
>   		goto no_context;
>   	pagefault_out_of_memory();
>   	return;
>   
>   do_sigbus:
> -	up_read(&mm->mmap_sem);
> +	mmap_read_unlock(mm);
>   
>   	/* Kernel mode? Handle exceptions or die */
>   	if (!user_mode(regs))
> diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
> index 728759eb530a..b9072c043222 100644
> --- a/arch/riscv/mm/pageattr.c
> +++ b/arch/riscv/mm/pageattr.c
> @@ -117,10 +117,10 @@ static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
>   	if (!numpages)
>   		return 0;
>   
> -	down_read(&init_mm.mmap_sem);
> +	mmap_read_lock(&init_mm);
>   	ret =  walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
>   				     &masks);
> -	up_read(&init_mm.mmap_sem);
> +	mmap_read_unlock(&init_mm);
>   
>   	flush_tlb_kernel_range(start, end);
>   
> diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
> index 9bdf9b7d9a96..40e5bb67cc09 100644
> --- a/arch/x86/kvm/mmu/paging_tmpl.h
> +++ b/arch/x86/kvm/mmu/paging_tmpl.h
> @@ -165,22 +165,22 @@ static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
>   		unsigned long pfn;
>   		unsigned long paddr;
>   
> -		down_read(&current->mm->mmap_sem);
> +		mmap_read_lock(current->mm);
>   		vma = find_vma_intersection(current->mm, vaddr, vaddr + PAGE_SIZE);
>   		if (!vma || !(vma->vm_flags & VM_PFNMAP)) {
> -			up_read(&current->mm->mmap_sem);
> +			mmap_read_unlock(current->mm);
>   			return -EFAULT;
>   		}
>   		pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
>   		paddr = pfn << PAGE_SHIFT;
>   		table = memremap(paddr, PAGE_SIZE, MEMREMAP_WB);
>   		if (!table) {
> -			up_read(&current->mm->mmap_sem);
> +			mmap_read_unlock(current->mm);
>   			return -EFAULT;
>   		}
>   		ret = CMPXCHG(&table[index], orig_pte, new_pte);
>   		memunmap(table);
> -		up_read(&current->mm->mmap_sem);
> +		mmap_read_unlock(current->mm);
>   	}
>   
>   	return (ret != orig_pte);
> diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
> index 5e063739a3a8..cbdc43ed0f9f 100644
> --- a/drivers/android/binder_alloc.c
> +++ b/drivers/android/binder_alloc.c
> @@ -932,7 +932,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
>   	mm = alloc->vma_vm_mm;
>   	if (!mmget_not_zero(mm))
>   		goto err_mmget;
> -	if (!down_read_trylock(&mm->mmap_sem))
> +	if (!mmap_read_trylock(mm))
>   		goto err_down_read_mmap_sem_failed;
>   	vma = binder_alloc_get_vma(alloc);
>   
> @@ -946,7 +946,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
>   
>   		trace_binder_unmap_user_end(alloc, index);
>   	}
> -	up_read(&mm->mmap_sem);
> +	mmap_read_unlock(mm);
>   	mmput(mm);
>   
>   	trace_binder_unmap_kernel_start(alloc, index);
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index 8fff3c955530..ebb356434652 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2314,7 +2314,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
>   	if (!mm)
>   		goto out_put_task;
>   
> -	ret = down_read_killable(&mm->mmap_sem);
> +	ret = mmap_read_lock_killable(mm);
>   	if (ret) {
>   		mmput(mm);
>   		goto out_put_task;
> @@ -2341,7 +2341,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
>   		p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
>   		if (!p) {
>   			ret = -ENOMEM;
> -			up_read(&mm->mmap_sem);
> +			mmap_read_unlock(mm);
>   			mmput(mm);
>   			goto out_put_task;
>   		}
> @@ -2350,7 +2350,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
>   		p->end = vma->vm_end;
>   		p->mode = vma->vm_file->f_mode;
>   	}
> -	up_read(&mm->mmap_sem);
> +	mmap_read_unlock(mm);
>   	mmput(mm);
>   
>   	for (i = 0; i < nr_files; i++) {