Re: [PATCH 1/3] powerpc/mm: move mmap_sem unlock up from do_sigbus

Aneesh Kumar K.V
2017-03-21T08:39:22Z

Laurent Dufour <ldufour@linux.vnet.ibm.com> writes:

> Move mmap_sem releasing in the do_sigbus()'s unique caller : mm_fault_error()
>
> No functional changes.
>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
> ---
> arch/powerpc/mm/fault.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index 62a50d6d1053..ee09604bbe12 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -119,8 +119,6 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address,
> siginfo_t info;
> unsigned int lsb = 0;
>
> - up_read(&current->mm->mmap_sem);
> -
> if (!user_mode(regs))
> return MM_FAULT_ERR(SIGBUS);
>
> @@ -184,8 +182,10 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
> return MM_FAULT_RETURN;
> }
>
> - if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE))
> + if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
> + up_read(&current->mm->mmap_sem);
> return do_sigbus(regs, addr, fault);
> + }
>
> /* We don't understand the fault code, this is fatal */
> BUG();
> --
> 2.7.4