From 40b697e256ccdb88aaff424b44b4d300eb8460e8 Mon Sep 17 00:00:00 2001 From: Christian Gmeiner Date: Tue, 19 May 2020 07:30:15 +0200 Subject: drm/etnaviv: fix perfmon domain interation The GC860 has one GPU device which has a 2d and 3d core. In this case we want to expose perfmon information for both cores. The driver has one array which contains all possible perfmon domains with some meta data - doms_meta. Here we can see that for the GC860 two elements of that array are relevant: doms_3d: is at index 0 in the doms_meta array with 8 perfmon domains doms_2d: is at index 1 in the doms_meta array with 1 perfmon domain The userspace driver wants to get a list of all perfmon domains and their perfmon signals. This is done by iterating over all domains and their signals. If the userspace driver wants to access the domain with id 8 the kernel driver fails and returns invalid data from doms_3d with and invalid offset. This results in: Unable to handle kernel paging request at virtual address 00000000 On such a device it is not possible to use the userspace driver at all. The fix for this off-by-one error is quite simple. Reported-by: Paul Cercueil Tested-by: Paul Cercueil Fixes: ed1dd899baa3 ("drm/etnaviv: rework perfmon query infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Christian Gmeiner Signed-off-by: Lucas Stach --- drivers/gpu/drm/etnaviv/etnaviv_perfmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c index e6795bafcbb9..75f9db8f7bec 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c @@ -453,7 +453,7 @@ static const struct etnaviv_pm_domain *pm_domain(const struct etnaviv_gpu *gpu, if (!(gpu->identity.features & meta->feature)) continue; - if (meta->nr_domains < (index - offset)) { + if (index - offset >= meta->nr_domains) { offset += meta->nr_domains; continue; } -- cgit v1.2.3