Re: [PATCH v4 tip/perf/core 3/4] uprobes: simplify find_active_uprobe_rcu() VMA checks

Masami Hiramatsu
2024-10-28T01:51:30Z

On Sun, 27 Oct 2024 18:08:17 -0700
Andrii Nakryiko <andrii@kernel.org> wrote:

> At the point where find_active_uprobe_rcu() is used we know that VMA in
> question has triggered software breakpoint, so we don't need to validate
> vma->vm_flags. Keep only vma->vm_file NULL check.
>

Looks good to me.

Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Thanks,

> Acked-by: Oleg Nesterov <oleg@redhat.com>
> Suggested-by: Oleg Nesterov <oleg@redhat.com>
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> ---
> kernel/events/uprobes.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> index 4ef4b51776eb..290c445768fa 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -2084,7 +2084,7 @@ static struct uprobe *find_active_uprobe_rcu(unsigned long bp_vaddr, int *is_swb
> mmap_read_lock(mm);
> vma = vma_lookup(mm, bp_vaddr);
> if (vma) {
> - if (valid_vma(vma, false)) {
> + if (vma->vm_file) {
> struct inode *inode = file_inode(vma->vm_file);
> loff_t offset = vaddr_to_offset(vma, bp_vaddr);
>
> --
> 2.43.5
>

--
Masami Hiramatsu (Google) <mhiramat@kernel.org>