From 632f0574167ad3f5d646dad6af87d976a703d93e Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Thu, 12 Oct 2017 15:45:25 +1100
Subject: [PATCH] powerpc/tm: Don't check for WARN in TM Bad Thing handling
References: bsc#1118338
Patch-mainline: v4.15-rc1
Git-commit: 632f0574167ad3f5d646dad6af87d976a703d93e
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 <mpe@ellerman.id.au>
Acked-By: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
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
--
2.19.2