[AMD Public Use] Hi Anson, Please ignore the earlier comment. Thanks, Lijo -----Original Message----- From: Lazar, Lijo Sent: Friday, March 5, 2021 11:05 AM To: Anson Jacob <Anson.Jacob@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx Cc: Jacob, Anson <Anson.Jacob@xxxxxxx>; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Kuehling, Felix <Felix.Kuehling@xxxxxxx> Subject: RE: [PATCH] drm/amdkfd: Fix UBSAN shift-out-of-bounds warning [AMD Public Use] -----Original Message----- From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Anson Jacob Sent: Friday, March 5, 2021 1:39 AM To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx Cc: Jacob, Anson <Anson.Jacob@xxxxxxx>; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Kuehling, Felix <Felix.Kuehling@xxxxxxx> Subject: [PATCH] drm/amdkfd: Fix UBSAN shift-out-of-bounds warning If get_num_sdma_queues or get_num_xgmi_sdma_queues is 0, we end up doing a shift operation where the number of bits shifted equals number of bits in the operand. This behaviour is undefined. Set num_sdma_queues or num_xgmi_sdma_queues to ULLONG_MAX, if the count is >= number of bits in the operand. Bug: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.freedesktop.org%2Fdrm%2Famd%2F-%2Fissues%2F1472&data=04%7C01%7Clijo.lazar%40amd.com%7Cc731ee10b10b4728138808d8df496648%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637504853648181515%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=iNLxyPbJfbuUeKFA6ygwcBGDSRJcfgOGjMFNHwGzun0%3D&reserved=0 Reported-by: Lyude Paul <lyude@xxxxxxxxxx> Signed-off-by: Anson Jacob <Anson.Jacob@xxxxxxx> Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx> --- .../drm/amd/amdkfd/kfd_device_queue_manager.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c index c37e9c4b1fb4..e7a3c496237f 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -1128,6 +1128,9 @@ static int set_sched_resources(struct device_queue_manager *dqm) static int initialize_cpsch(struct device_queue_manager *dqm) { + uint64_t num_sdma_queues; + uint64_t num_xgmi_sdma_queues; + pr_debug("num of pipes: %d\n", get_pipes_per_mec(dqm)); mutex_init(&dqm->lock_hidden); @@ -1136,8 +1139,18 @@ static int initialize_cpsch(struct device_queue_manager *dqm) dqm->active_cp_queue_count = 0; dqm->gws_queue_count = 0; dqm->active_runlist = false; - dqm->sdma_bitmap = ~0ULL >> (64 - get_num_sdma_queues(dqm)); - dqm->xgmi_sdma_bitmap = ~0ULL >> (64 - get_num_xgmi_sdma_queues(dqm)); + + num_sdma_queues = get_num_sdma_queues(dqm); + if (num_sdma_queues >= BITS_PER_TYPE(dqm->sdma_bitmap)) < > No assumption about bitmap size here + dqm->sdma_bitmap = ULLONG_MAX; <> This assumes/fixes the max size. In that case why not make the earlier check also consistent? + else + dqm->sdma_bitmap = (BIT_ULL(num_sdma_queues) - 1); + + num_xgmi_sdma_queues = get_num_xgmi_sdma_queues(dqm); + if (num_xgmi_sdma_queues >= BITS_PER_TYPE(dqm->xgmi_sdma_bitmap)) + dqm->xgmi_sdma_bitmap = ULLONG_MAX; + else + dqm->xgmi_sdma_bitmap = (BIT_ULL(num_xgmi_sdma_queues) - 1); INIT_WORK(&dqm->hw_exception_work, kfd_process_hw_exception); -- 2.25.1 _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfx&data=04%7C01%7Clijo.lazar%40amd.com%7Cc731ee10b10b4728138808d8df496648%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637504853648191471%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=EpuPBBf03EMa0S7rOqI8JieOmcT3GvsnsQMaYujGgeY%3D&reserved=0 _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
