On Fri, Feb 08, 2019 at 12:05:01AM -0800, Christoph Hellwig wrote: > On Thu, Feb 07, 2019 at 09:07:20AM -0700, Nathan Chancellor wrote: > > Clang warns several times in the scsi subsystem (trimmed for brevity): > > > > drivers/scsi/hpsa.c:6209:7: warning: overflow converting case value to > > switch condition type (2147762695 to 18446744071562347015) [-Wswitch] > > case CCISS_GETBUSTYPES: > > ^ > > drivers/scsi/hpsa.c:6208:7: warning: overflow converting case value to > > switch condition type (2147762694 to 18446744071562347014) [-Wswitch] > > case CCISS_GETHEARTBEAT: > > ^ > > > > The root cause is that the _IOC macro can generate really large numbers, > > which don't fit into type 'int', which is used for the cmd parameter in > > the ioctls in scsi_host_template. My research into how GCC and Clang are > > handling this at a low level didn't prove fruitful. However, looking at > > the rest of the kernel tree, all ioctls use an 'unsigned int' for the > > cmd parameter, which will fit all of the _IOC values in the scsi/ata > > subsystems. > > > > Make that change because none of the ioctls expect a negative value for > > any command, it brings the ioctls inline with the reset of the kernel, > > and it removes ambiguity, which is never good when dealing with compilers. > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/85 > > Link: https://github.com/ClangBuiltLinux/linux/issues/154 > > Link: https://github.com/ClangBuiltLinux/linux/issues/157 > > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > > Acked-by: Bradley Grove <bgrove@xxxxxxxxxxxx> > > Acked-by: Don Brace <don.brace@xxxxxxxxxxxxx> > > Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx> > > Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > Looks good: > > Reviewed-by: Christoph Hellwig <hch@xxxxxx> Thank you for the review, it is much appreciated! Nathan
