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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-BWhitelist: no X-Source-IP: 108.223.40.66 X-Source-L: No X-Exim-ID: 1xRBYS-00000001ERI-3aod X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 108-223-40-66.lightspeed.sntcca.sbcglobal.net [108.223.40.66]:35196 X-Source-Auth: guenter@roeck-us.net X-Email-Count: 7 X-Org: HG=direseller_whb_net_legacy;ORG=directi; X-Source-Cap: cm9lY2s7YWN0aXZzdG07YmgtMjUud2ViaG9zdGJveC5uZXQ= X-Local-Domain: yes X-CMAE-Envelope: MS4xfKZVorC6SsNrNQGAODw4Bgw6nRA7JKoazb4d/31IxcHho1suh3qHWxZyPiA1995ertrXhEDb3OoiA7jJFdyQu3dwfNLFbJ2e/LTR8bQqFuTgrAb8v5+U MUdqTX0s2hyj2boDmZTKf1d8VjuP4ZQEtync5931fit42pdTo/Ot+J7u2akq3W4Dw0n+U1V1pGtRWZxiZen2Fhcezmat9PnPrrZe3qkuvBIzV5SQSGu1Z/aZ On 11/11/26 03:11, David Laight wrote: > On Wed, 11 Nov 2026 14:48:31 +0800 > Zhu Jun wrote: > >> in_to_reg() narrows the sysfs value to u32 and multiplies it by 100 >> before clamping. A large positive voltage limit can consequently be >> programmed as zero instead of the maximum; 4294967296 mV reproduces this >> on a 64-bit system. >> >> Preserve the input width and clamp to the representable voltage range >> before multiplication. >> >> Fixes: cf0676fe42c8 ("[PATCH] w83627ehf: Add voltage inputs support") >> Signed-off-by: Zhu Jun >> --- >> drivers/hwmon/w83627ehf.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c >> index 9c08ab662dc6..5c04b9c52b76 100644 >> --- a/drivers/hwmon/w83627ehf.c >> +++ b/drivers/hwmon/w83627ehf.c >> @@ -293,8 +293,9 @@ static inline long in_from_reg(u8 reg, u8 nr, const u16 *scale_in) >> return DIV_ROUND_CLOSEST(reg * scale_in[nr], 100); >> } >> >> -static inline u8 in_to_reg(u32 val, u8 nr, const u16 *scale_in) >> +static inline u8 in_to_reg(unsigned long val, u8 nr, const u16 *scale_in) >> { >> + val = min(val, 255UL * scale_in[nr] / 100); > > You need to think about these more. > Either it really doesn't matter because no one would really try to write > an over large value unless they are trying to break things - and they can > just write zero, or you just need to stop the n * 100 + x overflowing. Writing 0 would be intentional. Writing a large value, however, _can_ be accidental (or just someone trying to find the highest possible value), so I accept such patches (and sometimes, if I have too much time, hunt for it as well). My module tests actually depend on it - they on purpose write a large value to see what happens. Thanks, Guenter > So at least avoid the extra divide by using: > val = min(val, (~0ul - 32768) / 100) > >> return clamp_val(DIV_ROUND_CLOSEST(val * 100, scale_in[nr]), 0, 255); > > Another clamp_val() that should never have been added. > The type checks are there for a reason, not to be killed by casts. > > David > >> } >> >