Re: [PATCH] arch: ia64: kernel: perfmon: Check return value of insert_vm_struct()

From: Chen Gang
Date: Thu Sep 03 2015 - 23:41:32 EST


Hello Maintainers:

Please help check this patch when you have time.

Thanks.

On 8/24/15 01:18, Chen Gang wrote:
> In pfm_smpl_buffer_alloc, insert_vm_struct may also return -ENOMEM, so
> need check it too.
>
> And insert_vm_struct needn't consider about pfm_remap_buffer in failure
> process ("goto error" is enough):
>
> - pfm_remap_buffer doen't consider about remap_pfn_range.
>
> - It is about the relationship between vma and smpl_buf.
>
> - SO if both vma and smpl_buf are released ("goto error"), all things
> are OK.
>
> Signed-off-by: Chen Gang <gang.chen.5i5j@xxxxxxxxx>
> ---
> arch/ia64/kernel/perfmon.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
> index 60e02f7..ae77946 100644
> --- a/arch/ia64/kernel/perfmon.c
> +++ b/arch/ia64/kernel/perfmon.c
> @@ -2330,7 +2330,11 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t
> * now insert the vma in the vm list for the process, must be
> * done with mmap lock held
> */
> - insert_vm_struct(mm, vma);
> + if (insert_vm_struct(mm, vma)) {
> + DPRINT(("Can't insert vm structure.\n"));
> + up_write(&task->mm->mmap_sem);
> + goto error;
> + }
>
> vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file,
> vma_pages(vma));
> --
>
>
>

--
Chen Gang (éå)

Open, share, and attitude like air, water, and life which God blessed
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