| Message ID | 20241119-ath11k-noinline-v1-1-4ec0a8aa30b2@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | wifi: ath11k: Fix clang+KASAN stack frame size warnings | expand |
Jeff Johnson <quic_jjohnson@quicinc.com> writes: > When compiling the ath11k driver using clang with KASAN enabled, the > following warning is observed: > > drivers/net/wireless/ath/ath11k/qmi.c:3199:13: warning: stack frame size (1560) exceeds limit (1024) in 'ath11k_qmi_driver_event_work' [-Wframe-larger-than] > > This is similar to the issue found in ath12k/qmi.c that was discussed > in [1] and fixed with [2]. The issue is that clang inlining can > explode stack usage. > > Just as in ath12k, ath11k_qmi_driver_event_work() itself is a pretty > lightweight function, but it dispatches to several other functions > which do the real work: > > ath11k_qmi_driver_event_work() > ath11k_qmi_event_server_arrive() > ath11k_qmi_fw_ind_register_send() > ath11k_qmi_host_cap_send() * > ath11k_qmi_event_load_bdf() > ath11k_qmi_event_mem_request() > ath11k_qmi_respond_fw_mem_request() > ath11k_qmi_event_load_bdf() > ath11k_qmi_wlanfw_m3_info_send() * > ath11k_qmi_m3_load() > ath11k_qmi_process_coldboot_calibration() > > Of these, the two marked with * have non-trivial stack usage. Mark > those functions as 'noinline_for_stack' to prevent them from being > inlined in ath12k_qmi_driver_event_work(), thereby eliminating the > excessive stack usage. > > Note that this approach is a bit more "surgical" than the ath12k > approach as only the two functions with the largest stack usage are > modified. > > Link: https://msgid.link/bc214795-1c51-4cb7-922f-67d6ef98bff2@quicinc.com # [1] > Link: https://patch.msgid.link/20241028-ath12k_qmi_driver_event_work-v1-1-0d532eb593fa@quicinc.com # [2] > Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Acked-by: Kalle Valo <kvalo@kernel.org>
diff --git a/drivers/net/wireless/ath/ath11k/qmi.c b/drivers/net/wireless/ath/ath11k/qmi.c index 7a22483b35cd..5759fc521316 100644 --- a/drivers/net/wireless/ath/ath11k/qmi.c +++ b/drivers/net/wireless/ath/ath11k/qmi.c @@ -1704,7 +1704,9 @@ static const struct qmi_elem_info qmi_wlfw_fw_init_done_ind_msg_v01_ei[] = { }, }; -static int ath11k_qmi_host_cap_send(struct ath11k_base *ab) +/* clang stack usage explodes if this is inlined */ +static noinline_for_stack +int ath11k_qmi_host_cap_send(struct ath11k_base *ab) { struct qmi_wlanfw_host_cap_req_msg_v01 req; struct qmi_wlanfw_host_cap_resp_msg_v01 resp; @@ -2570,7 +2572,9 @@ static void ath11k_qmi_m3_free(struct ath11k_base *ab) m3_mem->size = 0; } -static int ath11k_qmi_wlanfw_m3_info_send(struct ath11k_base *ab) +/* clang stack usage explodes if this is inlined */ +static noinline_for_stack +int ath11k_qmi_wlanfw_m3_info_send(struct ath11k_base *ab) { struct m3_mem_region *m3_mem = &ab->qmi.m3_mem; struct qmi_wlanfw_m3_info_req_msg_v01 req;
When compiling the ath11k driver using clang with KASAN enabled, the following warning is observed: drivers/net/wireless/ath/ath11k/qmi.c:3199:13: warning: stack frame size (1560) exceeds limit (1024) in 'ath11k_qmi_driver_event_work' [-Wframe-larger-than] This is similar to the issue found in ath12k/qmi.c that was discussed in [1] and fixed with [2]. The issue is that clang inlining can explode stack usage. Just as in ath12k, ath11k_qmi_driver_event_work() itself is a pretty lightweight function, but it dispatches to several other functions which do the real work: ath11k_qmi_driver_event_work() ath11k_qmi_event_server_arrive() ath11k_qmi_fw_ind_register_send() ath11k_qmi_host_cap_send() * ath11k_qmi_event_load_bdf() ath11k_qmi_event_mem_request() ath11k_qmi_respond_fw_mem_request() ath11k_qmi_event_load_bdf() ath11k_qmi_wlanfw_m3_info_send() * ath11k_qmi_m3_load() ath11k_qmi_process_coldboot_calibration() Of these, the two marked with * have non-trivial stack usage. Mark those functions as 'noinline_for_stack' to prevent them from being inlined in ath12k_qmi_driver_event_work(), thereby eliminating the excessive stack usage. Note that this approach is a bit more "surgical" than the ath12k approach as only the two functions with the largest stack usage are modified. Link: https://msgid.link/bc214795-1c51-4cb7-922f-67d6ef98bff2@quicinc.com # [1] Link: https://patch.msgid.link/20241028-ath12k_qmi_driver_event_work-v1-1-0d532eb593fa@quicinc.com # [2] Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> --- drivers/net/wireless/ath/ath11k/qmi.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)