On Wed, Nov 02, 2022 at 12:06:08PM +0100, Alexander Potapenko wrote: > Make sure usercopy hooks from linux/instrumented.h are invoked for > copy_from_user_nmi(). > This fixes KMSAN false positives reported when dumping opcodes for a > stack trace. > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > Cc: x86@xxxxxxxxxx > Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > --- > arch/x86/lib/usercopy.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c > index f1bb186171562..24b48af274173 100644 > --- a/arch/x86/lib/usercopy.c > +++ b/arch/x86/lib/usercopy.c > @@ -6,6 +6,7 @@ > > #include <linux/uaccess.h> > #include <linux/export.h> > +#include <linux/instrumented.h> > > #include <asm/tlbflush.h> > > @@ -44,7 +45,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) > * called from other contexts. > */ > pagefault_disable(); > + instrument_copy_from_user_before(to, from, n); > ret = raw_copy_from_user(to, from, n); > + instrument_copy_from_user_after(to, from, n, ret); > pagefault_enable(); > > return ret; > -- > 2.38.1.273.g43a17bfeac-goog >
