On Mon, 2017-05-29 at 18:37 +0200, Borislav Petkov wrote: > On Fri, May 05, 2017 at 11:17:05AM -0700, Ricardo Neri wrote: > > We are not in a critical failure path. The invalid register type is caused > > when trying to decode invalid instruction bytes from a user-space program. > > Thus, simply print an error message. To prevent this warning from being > > abused from user space programs, use the rate-limited variant of printk. > > > > Cc: Borislav Petkov <b...@suse.de> > > Cc: Andy Lutomirski <l...@kernel.org> > > Cc: Dave Hansen <dave.han...@linux.intel.com> > > Cc: Adam Buchbinder <adam.buchbin...@gmail.com> > > Cc: Colin Ian King <colin.k...@canonical.com> > > Cc: Lorenzo Stoakes <lstoa...@gmail.com> > > Cc: Qiaowei Ren <qiaowei....@intel.com> > > Cc: Arnaldo Carvalho de Melo <a...@redhat.com> > > Cc: Masami Hiramatsu <mhira...@kernel.org> > > Cc: Adrian Hunter <adrian.hun...@intel.com> > > Cc: Kees Cook <keesc...@chromium.org> > > Cc: Thomas Garnier <thgar...@google.com> > > Cc: Peter Zijlstra <pet...@infradead.org> > > Cc: Dmitry Vyukov <dvyu...@google.com> > > Cc: Ravi V. Shankar <ravi.v.shan...@intel.com> > > Cc: x...@kernel.org > > Signed-off-by: Ricardo Neri <ricardo.neri-calde...@linux.intel.com> > > --- > > arch/x86/lib/insn-eval.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c > > index e746a6f..182e2ae 100644 > > --- a/arch/x86/lib/insn-eval.c > > +++ b/arch/x86/lib/insn-eval.c > > @@ -5,6 +5,7 @@ > > */ > > #include <linux/kernel.h> > > #include <linux/string.h> > > +#include <linux/ratelimit.h> > > #include <asm/inat.h> > > #include <asm/insn.h> > > #include <asm/insn-eval.h> > > @@ -85,9 +86,8 @@ static int get_reg_offset(struct insn *insn, struct > > pt_regs *regs, > > break; > > > > default: > > - pr_err("invalid register type"); > > - BUG(); > > - break; > > + printk_ratelimited(KERN_ERR "insn-eval: x86: invalid register > > type"); > > You can use pr_err_ratelimited() and define "insn-eval" with pr_fmt. > Look for examples in the tree.
Will do. I have looked at the examples. > > Btw, "insn-eval" is perhaps not the right name - since we're building > an instruction decoder, maybe it should be called "insn-dec" or so. I'm > looking at those other arch/x86/lib/insn.c, arch/x86/include/asm/inat.h > things and how they're starting to morph into one decoding facility, > AFAICT. I agree that insn-eval reads somewhat funny. I did not want to go with insn-dec.c as insn.c, in my opinion, already decodes the instruction (i.e., it finds prefixes, opcodes, ModRM, SIB and displacement bytes). In insn-eval.c I simply take those decoded parameters and evaluate them to obtain the values they contain (e.g., a specific memory location). Perhaps, insn-resolve.c could be a better name? Or maybe isnn-operands? Thanks and BR, Ricardo