From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com [IPv6:2607:f8b0:400e:c00::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3yd5Zb5MvlzDr42 for ; Fri, 17 Nov 2017 03:01:11 +1100 (AEDT) Received: by mail-pf0-x244.google.com with SMTP id i15so9592389pfa.3 for ; Thu, 16 Nov 2017 08:01:11 -0800 (PST) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin Subject: [PATCH 2/4] powerpc/64: do not trace irqs-off at interrupt return to soft-disabled context Date: Fri, 17 Nov 2017 02:00:50 +1000 Message-Id: <20171116160052.18672-3-npiggin@gmail.com> In-Reply-To: <20171116160052.18672-1-npiggin@gmail.com> References: <20171116160052.18672-1-npiggin@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , When an interrupt is returning to a soft-disabled context (which can happen for non-maskable interrupts or synchronous interrupts), it goes through the motions of soft-disabling again, including calling TRACE_DISABLE_INTS (i.e., trace_hardirqs_off()). This is not necessary, because we must already be soft-disabled in the interrupt context, it also may be causing crashes in the irq tracing code to re-enter as an nmi. Replace it with a warning to ensure that soft-interrupts are still disabled. Signed-off-by: Nicholas Piggin --- arch/powerpc/kernel/entry_64.S | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 3320bcac7192..36878b6ee8b8 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -911,9 +911,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) beq 1f rlwinm r7,r7,0,~PACA_IRQ_HARD_DIS stb r7,PACAIRQHAPPENED(r13) -1: li r0,0 - stb r0,PACASOFTIRQEN(r13); - TRACE_DISABLE_INTS +1: +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_BUG) + /* The interrupt should not have soft enabled. */ + lbz r7,PACASOFTIRQEN(r13) +1: tdnei r7,0 + EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING +#endif b .Ldo_restore /* -- 2.15.0