Two small fixes for an UBSAN warning and to make debugging a little easier.
Stephen Boyd (2): drm/msm: Avoid div-by-zero in dpu_crtc_atomic_check() drm/msm: Drop debug print in _dpu_crtc_setup_lm_bounds()
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
The cstate->num_mixers member is only set to a non-zero value once dpu_encoder_virt_mode_set() is called, but the atomic check function can be called by userspace before that. Let's avoid the div-by-zero here and inside _dpu_crtc_setup_lm_bounds() by skipping this part of the atomic check if dpu_encoder_virt_mode_set() hasn't been called yet. This fixes an UBSAN warning:
UBSAN: Undefined behaviour in drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:860:31 division by zero CPU: 7 PID: 409 Comm: frecon Tainted: G S 5.4.31 #128 Hardware name: Google Trogdor (rev0) (DT) Call trace: dump_backtrace+0x0/0x14c show_stack+0x20/0x2c dump_stack+0xa0/0xd8 __ubsan_handle_divrem_overflow+0xec/0x110 dpu_crtc_atomic_check+0x97c/0x9d4 drm_atomic_helper_check_planes+0x160/0x1c8 drm_atomic_helper_check+0x54/0xbc drm_atomic_check_only+0x6a8/0x880 drm_atomic_commit+0x20/0x5c drm_atomic_helper_set_config+0x98/0xa0 drm_mode_setcrtc+0x308/0x5dc drm_ioctl_kernel+0x9c/0x114 drm_ioctl+0x2ac/0x4b0 drm_compat_ioctl+0xe8/0x13c __arm64_compat_sys_ioctl+0x184/0x324 el0_svc_common+0xa4/0x154 el0_svc_compat_handler+0x
Cc: Abhinav Kumar abhinavk@codeaurora.org Cc: Jeykumar Sankaran jsanka@codeaurora.org Cc: Jordan Crouse jcrouse@codeaurora.org Cc: Sean Paul seanpaul@chromium.org Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support") Signed-off-by: Stephen Boyd swboyd@chromium.org --- drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index f272a8d0f95b..74294b5ed93f 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -881,7 +881,7 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crtc, struct drm_plane *plane; struct drm_display_mode *mode;
- int cnt = 0, rc = 0, mixer_width, i, z_pos; + int cnt = 0, rc = 0, mixer_width = 0, i, z_pos;
struct dpu_multirect_plane_states multirect_plane[DPU_STAGE_MAX * 2]; int multirect_count = 0; @@ -914,9 +914,11 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crtc,
memset(pipe_staged, 0, sizeof(pipe_staged));
- mixer_width = mode->hdisplay / cstate->num_mixers; + if (cstate->num_mixers) { + mixer_width = mode->hdisplay / cstate->num_mixers;
- _dpu_crtc_setup_lm_bounds(crtc, state); + _dpu_crtc_setup_lm_bounds(crtc, state); + }
crtc_rect.x2 = mode->hdisplay; crtc_rect.y2 = mode->vdisplay;
On 2020-09-01 14:59, Stephen Boyd wrote:
The cstate->num_mixers member is only set to a non-zero value once dpu_encoder_virt_mode_set() is called, but the atomic check function can be called by userspace before that. Let's avoid the div-by-zero here and inside _dpu_crtc_setup_lm_bounds() by skipping this part of the atomic check if dpu_encoder_virt_mode_set() hasn't been called yet. This fixes an UBSAN warning:
UBSAN: Undefined behaviour in drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:860:31 division by zero CPU: 7 PID: 409 Comm: frecon Tainted: G S 5.4.31 #128 Hardware name: Google Trogdor (rev0) (DT) Call trace: dump_backtrace+0x0/0x14c show_stack+0x20/0x2c dump_stack+0xa0/0xd8 __ubsan_handle_divrem_overflow+0xec/0x110 dpu_crtc_atomic_check+0x97c/0x9d4 drm_atomic_helper_check_planes+0x160/0x1c8 drm_atomic_helper_check+0x54/0xbc drm_atomic_check_only+0x6a8/0x880 drm_atomic_commit+0x20/0x5c drm_atomic_helper_set_config+0x98/0xa0 drm_mode_setcrtc+0x308/0x5dc drm_ioctl_kernel+0x9c/0x114 drm_ioctl+0x2ac/0x4b0 drm_compat_ioctl+0xe8/0x13c __arm64_compat_sys_ioctl+0x184/0x324 el0_svc_common+0xa4/0x154 el0_svc_compat_handler+0x
Cc: Abhinav Kumar abhinavk@codeaurora.org Cc: Jeykumar Sankaran jsanka@codeaurora.org Cc: Jordan Crouse jcrouse@codeaurora.org Cc: Sean Paul seanpaul@chromium.org Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support") Signed-off-by: Stephen Boyd swboyd@chromium.org
Reviewed-by: Abhinav Kumar abhinavk@codeaurora.org
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index f272a8d0f95b..74294b5ed93f 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -881,7 +881,7 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crtc, struct drm_plane *plane; struct drm_display_mode *mode;
- int cnt = 0, rc = 0, mixer_width, i, z_pos;
int cnt = 0, rc = 0, mixer_width = 0, i, z_pos;
struct dpu_multirect_plane_states multirect_plane[DPU_STAGE_MAX * 2]; int multirect_count = 0;
@@ -914,9 +914,11 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crtc,
memset(pipe_staged, 0, sizeof(pipe_staged));
- mixer_width = mode->hdisplay / cstate->num_mixers;
- if (cstate->num_mixers) {
mixer_width = mode->hdisplay / cstate->num_mixers;
- _dpu_crtc_setup_lm_bounds(crtc, state);
_dpu_crtc_setup_lm_bounds(crtc, state);}
crtc_rect.x2 = mode->hdisplay; crtc_rect.y2 = mode->vdisplay;
On 2020-09-02 03:29, Stephen Boyd wrote:
The cstate->num_mixers member is only set to a non-zero value once dpu_encoder_virt_mode_set() is called, but the atomic check function can be called by userspace before that. Let's avoid the div-by-zero here and inside _dpu_crtc_setup_lm_bounds() by skipping this part of the atomic check if dpu_encoder_virt_mode_set() hasn't been called yet. This fixes an UBSAN warning:
UBSAN: Undefined behaviour in drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:860:31 division by zero CPU: 7 PID: 409 Comm: frecon Tainted: G S 5.4.31 #128 Hardware name: Google Trogdor (rev0) (DT) Call trace: dump_backtrace+0x0/0x14c show_stack+0x20/0x2c dump_stack+0xa0/0xd8 __ubsan_handle_divrem_overflow+0xec/0x110 dpu_crtc_atomic_check+0x97c/0x9d4 drm_atomic_helper_check_planes+0x160/0x1c8 drm_atomic_helper_check+0x54/0xbc drm_atomic_check_only+0x6a8/0x880 drm_atomic_commit+0x20/0x5c drm_atomic_helper_set_config+0x98/0xa0 drm_mode_setcrtc+0x308/0x5dc drm_ioctl_kernel+0x9c/0x114 drm_ioctl+0x2ac/0x4b0 drm_compat_ioctl+0xe8/0x13c __arm64_compat_sys_ioctl+0x184/0x324 el0_svc_common+0xa4/0x154 el0_svc_compat_handler+0x
Cc: Abhinav Kumar abhinavk@codeaurora.org Cc: Jeykumar Sankaran jsanka@codeaurora.org Cc: Jordan Crouse jcrouse@codeaurora.org Cc: Sean Paul seanpaul@chromium.org Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support") Signed-off-by: Stephen Boyd swboyd@chromium.org
Tested-by: Sai Prakash Ranjan saiprakash.ranjan@codeaurora.org
This function is called quite often if you have a blinking cursor on the screen, hello page flip. Let's drop this debug print here because it means enabling the print via the module parameter starts to spam the debug console.
Cc: Abhinav Kumar abhinavk@codeaurora.org Cc: Jeykumar Sankaran jsanka@codeaurora.org Cc: Jordan Crouse jcrouse@codeaurora.org Cc: Sean Paul seanpaul@chromium.org Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support") Signed-off-by: Stephen Boyd swboyd@chromium.org --- drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index 74294b5ed93f..2966e488bfd0 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -421,8 +421,6 @@ static void _dpu_crtc_setup_lm_bounds(struct drm_crtc *crtc,
trace_dpu_crtc_setup_lm_bounds(DRMID(crtc), i, r); } - - drm_mode_debug_printmodeline(adj_mode); }
static void _dpu_crtc_get_pcc_coeff(struct drm_crtc_state *state,
On 2020-09-01 14:59, Stephen Boyd wrote:
This function is called quite often if you have a blinking cursor on the screen, hello page flip. Let's drop this debug print here because it means enabling the print via the module parameter starts to spam the debug console.
Cc: Abhinav Kumar abhinavk@codeaurora.org Cc: Jeykumar Sankaran jsanka@codeaurora.org Cc: Jordan Crouse jcrouse@codeaurora.org Cc: Sean Paul seanpaul@chromium.org Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support") Signed-off-by: Stephen Boyd swboyd@chromium.org
Reviewed-by: Abhinav Kumar abhinavk@codeaurora.org
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index 74294b5ed93f..2966e488bfd0 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -421,8 +421,6 @@ static void _dpu_crtc_setup_lm_bounds(struct drm_crtc *crtc,
trace_dpu_crtc_setup_lm_bounds(DRMID(crtc), i, r);}
- drm_mode_debug_printmodeline(adj_mode);
}
static void _dpu_crtc_get_pcc_coeff(struct drm_crtc_state *state,
dri-devel@lists.freedesktop.org
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Stephen Boyd