On Wednesday, August 24, 2016 7:06:58 AM CEST Christophe JAILLET wrote: > The 2nd parameter of 'find_first_zero_bit' is the number of bits to search. > In this case, we are passing 'sizeof(vt8500_ports_in_use)'. > 'vt8500_ports_in_use' is an 'unsigned long'. So the sizeof is likely to > return 4 on a 32 bits kernel. > > A few lines below, we check if it is below VT8500_MAX_PORTS, which is 6. > > It is likely that the number of bits in a long was expected here. > > In order to fix it: > - use DECLARE_BITMAP when declaring the vt8500_ports_in_use > - use VT8500_MAX_PORTS as a maximum value when checking/setting bits in > this bitmap > - modify code now that 'vt8500_ports_in_use' has become a pointer > because of the use of DECLARE_BITMAP > > > It has been spotted by the following coccinelle script: > @@ > expression ret, x; > > @@ > * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...)); > > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> > --- > v2: - use of VT8500_MAX_PORTS instead of BITS_PER_LONG to better self > document the code > - declare vt8500_ports_in_use with DECLARE_BITMAP in order to self > document even better and to be foolproof should VT8500_MAX_PORTS > be changed one day Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
