2022-04-01 14:52:34

by Marco Elver

[permalink] [raw]
Subject: Re: [PATCH] kcov: don't generate a warning on vm_insert_page()'s failure

On Thu, 31 Mar 2022 at 20:05, Aleksandr Nogikh <[email protected]> wrote:
>
> vm_insert_page()'s failure is not an unexpected condition, so don't do
> WARN_ONCE() in such a case.
>
> Instead, print a kernel message and just return an error code.
>
> Signed-off-by: Aleksandr Nogikh <[email protected]>
> ---
> kernel/kcov.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/kcov.c b/kernel/kcov.c
> index 475524bd900a..961536a03127 100644
> --- a/kernel/kcov.c
> +++ b/kernel/kcov.c
> @@ -475,8 +475,11 @@ static int kcov_mmap(struct file *filep, struct vm_area_struct *vma)
> vma->vm_flags |= VM_DONTEXPAND;
> for (off = 0; off < size; off += PAGE_SIZE) {
> page = vmalloc_to_page(kcov->area + off);
> - if (vm_insert_page(vma, vma->vm_start + off, page))
> - WARN_ONCE(1, "vm_insert_page() failed");
> + res = vm_insert_page(vma, vma->vm_start + off, page);
> + if (res) {
> + pr_warn_once("kcov: vm_insert_page() failed");

pr_*() should be terminated by "\n" -- sorry, I missed this.

> + return res;
> + }
> }
> return 0;
> exit:
> --
> 2.35.1.1094.g7c7d902a7c-goog
>