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 <bp(a)suse.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: Adam Buchbinder <adam.buchbinder(a)gmail.com> Cc: Colin Ian King <colin.king(a)canonical.com> Cc: Lorenzo Stoakes <lstoakes(a)gmail.com> Cc: Qiaowei Ren <qiaowei.ren(a)intel.com> Cc: Arnaldo Carvalho de Melo <acme(a)redhat.com> Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Adrian Hunter <adrian.hunter(a)intel.com> Cc: Kees Cook <keescook(a)chromium.org> Cc: Thomas Garnier <thgarnie(a)google.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Dmitry Vyukov <dvyukov(a)google.com> Cc: Ravi V. Shankar <ravi.v.shankar(a)intel.com> Cc: x86(a)kernel.org Signed-off-by: Ricardo Neri <ricardo.neri-calderon(a)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. 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. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --