I am sorry Boris, I also missed this feedback. On Fri, 2017-06-09 at 15:02 +0200, Borislav Petkov wrote: > On Fri, May 05, 2017 at 11:17:21AM -0700, Ricardo Neri wrote: > > If the User-Mode Instruction Prevention CPU feature is available and > > enabled, a general protection fault will be issued if the instructions > > sgdt, sldt, sidt, str or smsw are executed from user-mode context > > (CPL > 0). If the fault was caused by any of the instructions protected > > by UMIP, fixup_umip_exception will emulate dummy results for these > > Please end function names with parentheses.
I have audited my commit messages to remove all instances of this error. > > > instructions. If emulation is successful, the result is passed to the > > user space program and no SIGSEGV signal is emitted. > > > > Please note that fixup_umip_exception also caters for the case when > > the fault originated while running in virtual-8086 mode. > > > > Cc: Andy Lutomirski <[email protected]> > > Cc: Andrew Morton <[email protected]> > > Cc: H. Peter Anvin <[email protected]> > > Cc: Borislav Petkov <[email protected]> > > Cc: Brian Gerst <[email protected]> > > Cc: Chen Yucong <[email protected]> > > Cc: Chris Metcalf <[email protected]> > > Cc: Dave Hansen <[email protected]> > > Cc: Fenghua Yu <[email protected]> > > Cc: Huang Rui <[email protected]> > > Cc: Jiri Slaby <[email protected]> > > Cc: Jonathan Corbet <[email protected]> > > Cc: Michael S. Tsirkin <[email protected]> > > Cc: Paul Gortmaker <[email protected]> > > Cc: Peter Zijlstra <[email protected]> > > Cc: Ravi V. Shankar <[email protected]> > > Cc: Shuah Khan <[email protected]> > > Cc: Vlastimil Babka <[email protected]> > > Cc: Tony Luck <[email protected]> > > Cc: Paolo Bonzini <[email protected]> > > Cc: Liang Z. Li <[email protected]> > > Cc: Alexandre Julliard <[email protected]> > > Cc: Stas Sergeev <[email protected]> > > Cc: [email protected] > > Cc: [email protected] > > Reviewed-by: Andy Lutomirski <[email protected]> > > Signed-off-by: Ricardo Neri <[email protected]> > > --- > > arch/x86/kernel/traps.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c > > index 3995d3a..cec548d 100644 > > --- a/arch/x86/kernel/traps.c > > +++ b/arch/x86/kernel/traps.c > > @@ -65,6 +65,7 @@ > > #include <asm/trace/mpx.h> > > #include <asm/mpx.h> > > #include <asm/vm86.h> > > +#include <asm/umip.h> > > > > #ifdef CONFIG_X86_64 > > #include <asm/x86_init.h> > > @@ -526,6 +527,9 @@ do_general_protection(struct pt_regs *regs, long > > error_code) > > RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); > > cond_local_irq_enable(regs); > > > > Almost definitely: > > if (static_cpu_has(X86_FEATURE_UMIP)) { > if (... I will make this update. > > > + if (user_mode(regs) && fixup_umip_exception(regs)) > > + return; > > We don't want to punish !UMIP machines. I will add this check. Thanks and BR, Ricardo
