Re: [PATCH] drivers/base: cacheinfo: validate device node for all the caches

From: Sudeep Holla
Date: Mon Feb 23 2015 - 10:45:04 EST

On 23/02/15 15:14, Mark Rutland wrote:
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 <gregkh@xxxxxxxxxxxxxxxxxxx>
Reported-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
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


@@ -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",

Agreed, will update and send v2.

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 <mark.rutland@xxxxxxx>



To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at