After the context is unpinned the backing memory can also be unpinned, so any accesses via the lrc_reg_state pointer can end up in unmapped memory. To avoid that, make sure to only access that memory if the context is pinned when printing its info.

v2: fix newline alignment

Fixes: 28ff6520a34d ("drm/i915/guc: Update GuC debugfs to support new GuC") Signed-off-by: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com Cc: John Harrison John.C.Harrison@Intel.com Cc: Matthew Brost matthew.brost@intel.com Cc: stable@vger.kernel.org # v5.15+ Reviewed-by: John Harrison John.C.Harrison@Intel.com --- .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 20 +++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index 12f1ba7ca9c1..158f78a0941f 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -5519,12 +5519,20 @@ static inline void guc_log_context(struct drm_printer *p, { drm_printf(p, "GuC lrc descriptor %u:\n", ce->guc_id.id); drm_printf(p, "\tHW Context Desc: 0x%08x\n", ce->lrc.lrca); - drm_printf(p, "\t\tLRC Head: Internal %u, Memory %u\n", - ce->ring->head, - ce->lrc_reg_state[CTX_RING_HEAD]); - drm_printf(p, "\t\tLRC Tail: Internal %u, Memory %u\n", - ce->ring->tail, - ce->lrc_reg_state[CTX_RING_TAIL]); + if (intel_context_pin_if_active(ce)) { + drm_printf(p, "\t\tLRC Head: Internal %u, Memory %u\n", + ce->ring->head, + ce->lrc_reg_state[CTX_RING_HEAD]); + drm_printf(p, "\t\tLRC Tail: Internal %u, Memory %u\n", + ce->ring->tail, + ce->lrc_reg_state[CTX_RING_TAIL]); + intel_context_unpin(ce); + } else { + drm_printf(p, "\t\tLRC Head: Internal %u, Memory not pinned\n", + ce->ring->head); + drm_printf(p, "\t\tLRC Tail: Internal %u, Memory not pinned\n", + ce->ring->tail); + } drm_printf(p, "\t\tContext Pin Count: %u\n", atomic_read(&ce->pin_count)); drm_printf(p, "\t\tGuC ID Ref Count: %u\n",