Dear Guenter, Am 13.06.2018 um 00:12 schrieb Guenter Roeck:
On Tue, Jun 12, 2018 at 11:50:45PM +0200, Paul Menzel wrote:
Building Linux with the undefined behavior sanitizer (UBSAN), loading the module *nct6775* on the ASRock E350M1 shows the error below. ``` [ 28.322775] UBSAN: Undefined behaviour in drivers/hwmon/nct6775.c:4179:27 [ 28.322833] shift exponent 32 is too large for 32-bit type 'long unsigned int' ``` I believe this was introduced by commit cc66b3038254 (hwmon: (nct6775) Rework temperature source and label handling), but the same issue was already present before.I don't think so. The code used to be for (i = 0; i < data->temp_label_num - 1; i++) { Notice the "- 1". So it should be for (i = 0; i < 31; i++) { In practice it doesn't matter because "data->temp_mask & BIT(31 + 1)" will always be false, causing the last loop iteration to abort, but it is nevertheless wrong. Thanks a lot for the report. I'll prepare a patch.
Thank you for the instant response. I tested your proposed change, and, as expected, the error is gone.
Kind regards, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
