Unverified Commit cb9d8a2c authored by Richard Fitzgerald's avatar Richard Fitzgerald Committed by Mark Brown
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ASoC: cs35l56: Prevent bad sign extension in cs35l56_read_silicon_uid() 



Cast u8 values to u32 when using them to build a 32-bit unsigned value
that is then stored in a u64. This avoids the possibility of a bad sign
extension where the u8 is implicitly extended to an int, thus changing it
from an unsigned to a signed value.

Whether this is a real problem is debatable, but it does no harm to
ensure that the u8 are cast to a suitable type for shifting.

Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.cirrus.com>
Fixes: e1830f66 ("ASoC: cs35l56: Add helper functions for amp calibration")
Link: https://msgid.link/r/20240227100042.99-1-rf@opensource.cirrus.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b8614377

sound/soc/codecs/cs35l56-shared.c

+3 −2
Original line number Diff line number Diff line
@@ -658,9 +658,10 @@ static int cs35l56_read_silicon_uid(struct cs35l56_base *cs35l56_base, u64 *uid) 
		return ret;

	}



	unique_id = pte.lot[2] | (pte.lot[1] << 8) | (pte.lot[0] << 16);

	unique_id = (u32)pte.lot[2] | ((u32)pte.lot[1] << 8) | ((u32)pte.lot[0] << 16);

	unique_id <<= 32;

	unique_id |= pte.x | (pte.y << 8) | (pte.wafer_id << 16) | (pte.dvs << 24);

	unique_id |= (u32)pte.x | ((u32)pte.y << 8) | ((u32)pte.wafer_id << 16) |

		     ((u32)pte.dvs << 24);



	dev_dbg(cs35l56_base->dev, "UniqueID = %#llx\n", unique_id);