On Thu, Nov 23, 2017 at 10:19:51AM +0100, Borislav Petkov wrote: > From: Borislav Petkov <[email protected]> > > In order to save on redundant structs definitions > insn_get_code_seg_params() was made to return two 4-bit values in a char > but clang complains: > > arch/x86/lib/insn-eval.c:780:10: warning: implicit conversion from 'int' to > 'char' > changes value from 132 to -124 [-Wconstant-conversion] > return INSN_CODE_SEG_PARAMS(4, 8); > ~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~ > ./arch/x86/include/asm/insn-eval.h:16:57: note: expanded from macro > 'INSN_CODE_SEG_PARAMS' > #define INSN_CODE_SEG_PARAMS(oper_sz, addr_sz) (oper_sz | (addr_sz << 4)) > > Those two values do get picked apart afterwards the opposite way of how > they were ORed so wrt to the LSByte, the return value is the same. > > But this function returns -EINVAL in the error case, which is an int. So > make it return an int which is the native word size anyway and thus fix > the clang warning. > > Signed-off-by: Borislav Petkov <[email protected]> > Reported-by: Kees Cook <[email protected]> > Reported-by: Nick Desaulniers <[email protected]> > Cc: [email protected]
Thanks Kees and Nick for finding this bug. Thanks Borislav for the quick fix! This change looks OK to me. BR, Ricardo
