Re: [PATCH 3/3] uprobes: document uprobe_register() vsuprobe_mmap() race

[Peter Zijlstra]

On Mon, 2012-06-04 at 16:53 +0200, Oleg Nesterov wrote:

I didn't check if its my error or not, however:

> @@ -850,6 +869,10 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
>  
>  		if (is_register) {
>  			err = install_breakpoint(uprobe, mm, vma, info->vaddr);
> +			/*
> +			 * We can race against uprobe_register(), see the

that should be uprobe_mmap(), since this is the register path ;-)

> +			 * comment near uprobe_hash().
> +			 */
>  			if (err == -EEXIST)
>  				err = 0;
>  		} else {
> @@ -1058,8 +1081,10 @@ int uprobe_mmap(struct vm_area_struct *vma)
>  			}
>  
>  			ret = install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
> -
> -			/* Ignore double add: */
> +			/*
> +			 * We can race against uprobe_register(), see the
> +			 * comment near uprobe_hash().
> +			 */
>  			if (ret == -EEXIST) {
>  				ret = 0;
>  

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/