On Thu, 2017-10-12 at 15:45 +1100, Michael Ellerman wrote: > Currently when we take a TM Bad Thing program check exception, we > search the bug table to see if the program check was generated by a > WARN/WARN_ON etc. > > That makes no sense, the WARN macros use trap instructions, which > should never generate a TM Bad Thing exception. If they ever did that > would be a bug and we should oops. > > We do have some hand-coded bugs in tm.S, using EMIT_BUG_ENTRY, but > those are all BUGs not WARNs, and they all use trap instructions > anyway. Almost certainly this check was incorrectly copied from the > REASON_TRAP handling in the same function. > > Remove it. > > Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
LGTM Acked-By: Michael Neuling <mi...@neuling.org> > --- > arch/powerpc/kernel/traps.c | 9 ++------- > 1 file changed, 2 insertions(+), 7 deletions(-) > > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > index 9ae1924c7d1a..0e4099fef198 100644 > --- a/arch/powerpc/kernel/traps.c > +++ b/arch/powerpc/kernel/traps.c > @@ -1337,13 +1337,8 @@ void program_check_exception(struct pt_regs *regs) > * - A treclaim is attempted when non transactional. > * - A tend is illegally attempted. > * - writing a TM SPR when transactional. > - */ > - if (!user_mode(regs) && > - report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) { > - regs->nip += 4; > - goto bail; > - } > - /* If usermode caused this, it's done something illegal and > + * > + * If usermode caused this, it's done something illegal and > * gets a SIGILL slap on the wrist. We call it an illegal > * operand to distinguish from the instruction just being bad > * (e.g. executing a 'tend' on a CPU without TM!); it's an