Samuel Thibault 768625f84b speakup: Fix 8bit characters from direct synth
[ Upstream commit b6c8dafc9d86eb77e502bb018ec4105e8d2fbf78 ]

When userland echoes 8bit characters to /dev/synth with e.g.

echo -e '\xe9' > /dev/synth

synth_write would get characters beyond 0x7f, and thus negative when
char is signed.  When given to synth_buffer_add which takes a u16, this
would sign-extend and produce a U+ffxy character rather than U+xy.
Users thus get garbled text instead of accents in their output.

Let's fix this by making sure that we read unsigned characters.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Fixes: 89fc2ae80b ("speakup: extend synth buffer to 16bit unicode characters")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240204155736.2oh4ot7tiaa2wpbh@begin
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:33 +02:00
2024-03-26 18:20:52 -04:00
2024-04-03 15:19:25 +02:00
2024-03-06 14:45:17 +00:00
2024-03-26 18:22:57 -04:00

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