On Mon, Feb 16, 2015 at 02:10:16PM +0000, Sudeep Holla wrote:
> On architectures that depend on DT for obtaining cache hierarcy, we need
> to validate the device node for all the cache indices, failing to do so
> might result in wrong information being exposed to the userspace.
>
> This is quite possible on initial/incomplete versions of the device
> trees. In such cases, it's better to bail out if all the required device
> nodes are not present.
>
> This patch adds checks for the validation of device node for all the
> caches and doesn't initialise the cacheinfo if there's any error.
>
> Cc: Greg Kroah-Hartman <[email protected]>
> Reported-by: Mark Rutland <[email protected]>
> Signed-off-by: Sudeep Holla <[email protected]>
> ---
> drivers/base/cacheinfo.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
> index 6e64563361f0..7015bf05c828 100644
> --- a/drivers/base/cacheinfo.c
> +++ b/drivers/base/cacheinfo.c
> @@ -62,15 +62,21 @@ static int cache_setup_of_node(unsigned int cpu)
> return -ENOENT;
> }
>
> - while (np && index < cache_leaves(cpu)) {
> + while (index < cache_leaves(cpu)) {
> this_leaf = this_cpu_ci->info_list + index;
> if (this_leaf->level != 1)
> np = of_find_next_cache_node(np);
> else
> np = of_node_get(np);/* cpu node itself */
> + if (!np)
> + break;
> this_leaf->of_node = np;
> index++;
> }
> +
> + if (index != cache_leaves(cpu)) /* not all OF nodes populated */
> + return -ENOENT;
> +
> return 0;
> }
>
> @@ -189,8 +195,10 @@ static int detect_cache_attributes(unsigned int cpu)
> * will be set up here only if they are not populated already
> */
> ret = cache_shared_cpu_map_setup(cpu);
> - if (ret)
> + if (ret) {
> + pr_err("failed to setup cache hierarcy from DT\n");
It would probably be better if this were something like:
pr_warn("Unable to detect cache hierarcy from DT for CPU %d\n",
cpu);
Otherwise, this looks sane to me, and it would be nice to have this in
ASAP so as to avoid exposing erroneous information to userspace. So:
Acked-by: Mark Rutland <[email protected]>
Thanks,
Mark.
> goto free_ci;
> + }
> return 0;
>
> free_ci:
> --
> 1.9.1
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
