From: Dmitry Torokhov Date: Thu, 3 Oct 2024 14:46:50 +0000 (-0700) Subject: HID: simplify snto32() X-Git-Tag: v6.12.46~153 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7a7ba33110698166b488a06cdc04a16ca3dba176;p=thirdparty%2Fkernel%2Fstable.git HID: simplify snto32() [ Upstream commit ae9b956cb26c0fd5a365629f2d723ab2fb14df79 ] snto32() does exactly what sign_extend32() does, but handles potentially malformed data coming from the device. Keep the checks, but then call sign_extend32() to perform the actual conversion. Signed-off-by: Dmitry Torokhov Link: https://patch.msgid.link/20241003144656.3786064-1-dmitry.torokhov@gmail.com Signed-off-by: Benjamin Tissoires Stable-dep-of: a6b87bfc2ab5 ("HID: core: Harden s32ton() against conversion to 0 bits") Signed-off-by: Sasha Levin --- diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index c2783d04c6e05..1a8e88624acfb 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1318,9 +1318,7 @@ alloc_err: EXPORT_SYMBOL_GPL(hid_open_report); /* - * Convert a signed n-bit integer to signed 32-bit integer. Common - * cases are done through the compiler, the screwed things has to be - * done by hand. + * Convert a signed n-bit integer to signed 32-bit integer. */ static s32 snto32(__u32 value, unsigned n) @@ -1331,12 +1329,7 @@ static s32 snto32(__u32 value, unsigned n) if (n > 32) n = 32; - switch (n) { - case 8: return ((__s8)value); - case 16: return ((__s16)value); - case 32: return ((__s32)value); - } - return value & (1 << (n - 1)) ? value | (~0U << n) : value; + return sign_extend32(value, n - 1); } s32 hid_snto32(__u32 value, unsigned n)