mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

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: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: e1830f66f6 ("ASoC: cs35l56: Add helper functions for amp calibration")
Link: https://msgid.link/r/20240227100042.99-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Richard Fitzgerald 2024-02-27 10:00:42 +00:00 committed by Mark Brown
parent b861437765
commit cb9d8a2c6c
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
sound/soc/codecs/cs35l56-shared.c
View File

@ -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);