On Tue, 2017-08-29 at 18:09 +0200, Borislav Petkov wrote: > On Fri, Aug 18, 2017 at 05:27:46PM -0700, Ricardo Neri wrote: > > Even though memory addresses are unsigned, the operands used to compute the > > effective address do have a sign. This is true for ModRM.rm, SIB.base, > > SIB.index as well as the displacement bytes. Thus, signed variables shall > > be used when computing the effective address from these operands. Once the > > signed effective address has been computed, it is casted to an unsigned > > long to determine the linear address. > > > > Variables are renamed to better reflect the type of address being > > computed. > > > > Cc: Borislav Petkov <[email protected]> > > Cc: Andy Lutomirski <[email protected]> > > Cc: Dave Hansen <[email protected]> > > Cc: Adam Buchbinder <[email protected]> > > Cc: Colin Ian King <[email protected]> > > Cc: Lorenzo Stoakes <[email protected]> > > Cc: Qiaowei Ren <[email protected]> > > Cc: Peter Zijlstra <[email protected]> > > Cc: Nathan Howard <[email protected]> > > Cc: Adan Hawthorn <[email protected]> > > Cc: Joe Perches <[email protected]> > > Cc: Ravi V. Shankar <[email protected]> > > Cc: [email protected] > > Signed-off-by: Ricardo Neri <[email protected]> > > --- > > arch/x86/mm/mpx.c | 20 ++++++++++++++------ > > 1 file changed, 14 insertions(+), 6 deletions(-) > > I think you can simplify this function even more (diff ontop): > > diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c > index 9eec98022510..d0ec5c9b2a57 100644 > --- a/arch/x86/mm/mpx.c > +++ b/arch/x86/mm/mpx.c > @@ -139,7 +139,7 @@ static int get_reg_offset(struct insn *insn, struct > pt_regs *regs, > static void __user *mpx_get_addr_ref(struct insn *insn, struct pt_regs *regs) > { > int addr_offset, base_offset, indx_offset; > - unsigned long linear_addr; > + unsigned long linear_addr = -1; > long eff_addr, base, indx; > insn_byte_t sib; > > @@ -150,18 +150,18 @@ static void __user *mpx_get_addr_ref(struct insn *insn, > struct pt_regs *regs) > if (X86_MODRM_MOD(insn->modrm.value) == 3) { > addr_offset = get_reg_offset(insn, regs, REG_TYPE_RM); > if (addr_offset < 0) > - goto out_err; > + goto out; > > eff_addr = regs_get_register(regs, addr_offset); > } else { > if (insn->sib.nbytes) { > base_offset = get_reg_offset(insn, regs, REG_TYPE_BASE); > if (base_offset < 0) > - goto out_err; > + goto out; > This is a good suggestion. This is a good suggestion. > indx_offset = get_reg_offset(insn, regs, > REG_TYPE_INDEX); > if (indx_offset < 0) > - goto out_err; > + goto out; > > base = regs_get_register(regs, base_offset); > indx = regs_get_register(regs, indx_offset); > @@ -170,7 +170,7 @@ static void __user *mpx_get_addr_ref(struct insn *insn, > struct pt_regs *regs) > } else { > addr_offset = get_reg_offset(insn, regs, REG_TYPE_RM); > if (addr_offset < 0) > - goto out_err; > + goto out; > > eff_addr = regs_get_register(regs, addr_offset); > } > @@ -180,9 +180,8 @@ static void __user *mpx_get_addr_ref(struct insn *insn, > struct pt_regs *regs) > > linear_addr = (unsigned long)eff_addr; > > +out: > return (void __user *)linear_addr; > -out_err: > - return (void __user *)-1;
This is a good suggestion. I will work on it. By now my series comprises 28 patches. If you plan to review the rest of the series and you don't have major objections, could I work on these updates as increments from my v8 series? I think that with 28 patches in the series is becoming difficult to review. Thanks and BR, Ricardo
