From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x242.google.com (mail-pf0-x242.google.com [IPv6:2607:f8b0:400e:c00::242]) (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 40F40h1PsbzF24Y for ; Mon, 2 Apr 2018 17:41:23 +1000 (AEST) Received: by mail-pf0-x242.google.com with SMTP id o16so3617294pfk.9 for ; Mon, 02 Apr 2018 00:41:23 -0700 (PDT) Date: Mon, 2 Apr 2018 17:41:03 +1000 From: Nicholas Piggin To: "Aneesh Kumar K.V" Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH V2] powerpc: Fix oops due to wrong access of lppaca on non virtualized platform Message-ID: <20180402174103.4d122fb3@roar.ozlabs.ibm.com> In-Reply-To: <20180402073337.22568-1-aneesh.kumar@linux.ibm.com> References: <20180402073337.22568-1-aneesh.kumar@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2 Apr 2018 13:03:37 +0530 "Aneesh Kumar K.V" wrote: > Commit 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not > virtualized") removed allocation of lppaca on non virtualized platform. But with > CONFIG_PPC_SPLPAR enabled, we do access lppaca non-virtualized platform in some > code paths. > > Fix this but adding runtime check for virtualized platform. > > Fixes: 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not virtualized") > > Signed-off-by: Aneesh Kumar K.V Thanks, this looks good to me... > --- > Changes from V1: > * update commit summary > > arch/powerpc/include/asm/lppaca.h | 3 +++ > arch/powerpc/include/asm/spinlock.h | 2 ++ > arch/powerpc/kernel/time.c | 3 +++ > 3 files changed, 8 insertions(+) > > diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h > index 65d589689f01..7c23ce8a5a4c 100644 > --- a/arch/powerpc/include/asm/lppaca.h > +++ b/arch/powerpc/include/asm/lppaca.h > @@ -34,6 +34,7 @@ > #include > #include > #include > +#include > > /* > * The lppaca is the "virtual processor area" registered with the hypervisor, > @@ -114,6 +115,8 @@ struct lppaca { > > static inline bool lppaca_shared_proc(struct lppaca *l) > { > + if (!firmware_has_feature(FW_FEATURE_SPLPAR)) > + return false; > return !!(l->__old_status & LPPACA_OLD_SHARED_PROC); > } > We should eventually clean this up. There's no need to pass in an lppaca here AFAIKS. Is it even per-CPU, does it change dynamically? We could set it up in a FW_FEATURE parameter at boot, which would could make some of these tests cheaper. > diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h > index b9ebc3085fb7..72dc4ddc2972 100644 > --- a/arch/powerpc/include/asm/spinlock.h > +++ b/arch/powerpc/include/asm/spinlock.h > @@ -56,6 +56,8 @@ > #define vcpu_is_preempted vcpu_is_preempted > static inline bool vcpu_is_preempted(int cpu) > { > + if (!firmware_has_feature(FW_FEATURE_SPLPAR)) > + return false; > return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1); > } > #endif > diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c > index f7d96a68ecaa..360e71d455cc 100644 > --- a/arch/powerpc/kernel/time.c > +++ b/arch/powerpc/kernel/time.c > @@ -266,6 +266,9 @@ void accumulate_stolen_time(void) > > static inline u64 calculate_stolen_time(u64 stop_tb) > { > + if (!firmware_has_feature(FW_FEATURE_SPLPAR)) > + return 0; > + > if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx)) > return scan_dispatch_log(stop_tb); >