Re: [PATCH v2 tip/perf/core 4/5] uprobes: simplify find_active_uprobe_rcu() VMA checks

[Oleg Nesterov]

On 10/01, Andrii Nakryiko 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.
> 
> Suggested-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> ---
>  kernel/events/uprobes.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>


> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> index a2e6a57f79f2..7bd9111b4e8b 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -2091,7 +2091,7 @@ 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
>