6.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Karthik Poosa karthik.poosa@intel.com
[ Upstream commit a8ad8715472bb8f6a2ea8b4072a28151eb9f4f24 ]
Address potential overflow in result of left shift of a lower precision (u32) operand before assignment to higher precision (u64) variable.
v2: - Update commit message. (Himal)
Fixes: 4446fcf220ce ("drm/xe/hwmon: Expose power1_max_interval") Signed-off-by: Karthik Poosa karthik.poosa@intel.com Reviewed-by: Anshuman Gupta anshuman.gupta@intel.com Cc: Badal Nilawar badal.nilawar@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20240405130127.1392426-5-karth... Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com (cherry picked from commit 883232b47b81108b0252197c747f396ecd51455a) Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/xe/xe_hwmon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c index 174ed2185481e..a6f43446c779a 100644 --- a/drivers/gpu/drm/xe/xe_hwmon.c +++ b/drivers/gpu/drm/xe/xe_hwmon.c @@ -288,7 +288,7 @@ xe_hwmon_power1_max_interval_show(struct device *dev, struct device_attribute *a * As y can be < 2, we compute tau4 = (4 | x) << y * and then add 2 when doing the final right shift to account for units */ - tau4 = ((1 << x_w) | x) << y; + tau4 = (u64)((1 << x_w) | x) << y;
/* val in hwmon interface units (millisec) */ out = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w); @@ -328,7 +328,7 @@ xe_hwmon_power1_max_interval_store(struct device *dev, struct device_attribute * r = FIELD_PREP(PKG_MAX_WIN, PKG_MAX_WIN_DEFAULT); x = REG_FIELD_GET(PKG_MAX_WIN_X, r); y = REG_FIELD_GET(PKG_MAX_WIN_Y, r); - tau4 = ((1 << x_w) | x) << y; + tau4 = (u64)((1 << x_w) | x) << y; max_win = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
if (val > max_win)