From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Laurent Dufour <ldufour@linux.ibm.com>,
Nicholas Piggin <npiggin@gmail.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Sasha Levin <sashal@kernel.org>,
christophe.leroy@csgroup.eu, nathanl@linux.ibm.com,
adobriyan@gmail.com, sourabhjain@linux.ibm.com,
linuxppc-dev@lists.ozlabs.org
Subject: [PATCH AUTOSEL 5.18 30/49] powerpc/rtas: Keep MSR[RI] set when calling RTAS
Date: Wed, 1 Jun 2022 09:51:54 -0400 [thread overview]
Message-ID: <20220601135214.2002647-30-sashal@kernel.org> (raw)
In-Reply-To: <20220601135214.2002647-1-sashal@kernel.org>
From: Laurent Dufour <ldufour@linux.ibm.com>
[ Upstream commit b6b1c3ce06ca438eb24e0f45bf0e63ecad0369f5 ]
RTAS runs in real mode (MSR[DR] and MSR[IR] unset) and in 32-bit big
endian mode (MSR[SF,LE] unset).
The change in MSR is done in enter_rtas() in a relatively complex way,
since the MSR value could be hardcoded.
Furthermore, a panic has been reported when hitting the watchdog interrupt
while running in RTAS, this leads to the following stack trace:
watchdog: CPU 24 Hard LOCKUP
watchdog: CPU 24 TB:997512652051031, last heartbeat TB:997504470175378 (15980ms ago)
...
Supported: No, Unreleased kernel
CPU: 24 PID: 87504 Comm: drmgr Kdump: loaded Tainted: G E X 5.14.21-150400.71.1.bz196362_2-default #1 SLE15-SP4 (unreleased) 0d821077ef4faa8dfaf370efb5fdca1fa35f4e2c
NIP: 000000001fb41050 LR: 000000001fb4104c CTR: 0000000000000000
REGS: c00000000fc33d60 TRAP: 0100 Tainted: G E X (5.14.21-150400.71.1.bz196362_2-default)
MSR: 8000000002981000 <SF,VEC,VSX,ME> CR: 48800002 XER: 20040020
CFAR: 000000000000011c IRQMASK: 1
GPR00: 0000000000000003 ffffffffffffffff 0000000000000001 00000000000050dc
GPR04: 000000001ffb6100 0000000000000020 0000000000000001 000000001fb09010
GPR08: 0000000020000000 0000000000000000 0000000000000000 0000000000000000
GPR12: 80040000072a40a8 c00000000ff8b680 0000000000000007 0000000000000034
GPR16: 000000001fbf6e94 000000001fbf6d84 000000001fbd1db0 000000001fb3f008
GPR20: 000000001fb41018 ffffffffffffffff 000000000000017f fffffffffffff68f
GPR24: 000000001fb18fe8 000000001fb3e000 000000001fb1adc0 000000001fb1cf40
GPR28: 000000001fb26000 000000001fb460f0 000000001fb17f18 000000001fb17000
NIP [000000001fb41050] 0x1fb41050
LR [000000001fb4104c] 0x1fb4104c
Call Trace:
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
Oops: Unrecoverable System Reset, sig: 6 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
...
Supported: No, Unreleased kernel
CPU: 24 PID: 87504 Comm: drmgr Kdump: loaded Tainted: G E X 5.14.21-150400.71.1.bz196362_2-default #1 SLE15-SP4 (unreleased) 0d821077ef4faa8dfaf370efb5fdca1fa35f4e2c
NIP: 000000001fb41050 LR: 000000001fb4104c CTR: 0000000000000000
REGS: c00000000fc33d60 TRAP: 0100 Tainted: G E X (5.14.21-150400.71.1.bz196362_2-default)
MSR: 8000000002981000 <SF,VEC,VSX,ME> CR: 48800002 XER: 20040020
CFAR: 000000000000011c IRQMASK: 1
GPR00: 0000000000000003 ffffffffffffffff 0000000000000001 00000000000050dc
GPR04: 000000001ffb6100 0000000000000020 0000000000000001 000000001fb09010
GPR08: 0000000020000000 0000000000000000 0000000000000000 0000000000000000
GPR12: 80040000072a40a8 c00000000ff8b680 0000000000000007 0000000000000034
GPR16: 000000001fbf6e94 000000001fbf6d84 000000001fbd1db0 000000001fb3f008
GPR20: 000000001fb41018 ffffffffffffffff 000000000000017f fffffffffffff68f
GPR24: 000000001fb18fe8 000000001fb3e000 000000001fb1adc0 000000001fb1cf40
GPR28: 000000001fb26000 000000001fb460f0 000000001fb17f18 000000001fb17000
NIP [000000001fb41050] 0x1fb41050
LR [000000001fb4104c] 0x1fb4104c
Call Trace:
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
---[ end trace 3ddec07f638c34a2 ]---
This happens because MSR[RI] is unset when entering RTAS but there is no
valid reason to not set it here.
RTAS is expected to be called with MSR[RI] as specified in PAPR+ section
"7.2.1 Machine State":
R1–7.2.1–9. If called with MSR[RI] equal to 1, then RTAS must protect
its own critical regions from recursion by setting the MSR[RI] bit to
0 when in the critical regions.
Fixing this by reviewing the way MSR is compute before calling RTAS. Now a
hardcoded value meaning real mode, 32 bits big endian mode and Recoverable
Interrupt is loaded. In the case MSR[S] is set, it will remain set while
entering RTAS as only urfid can unset it (thanks Fabiano).
In addition a check is added in do_enter_rtas() to detect calls made with
MSR[RI] unset, as we are forcing it on later.
This patch has been tested on the following machines:
Power KVM Guest
P8 S822L (host Ubuntu kernel 5.11.0-49-generic)
PowerVM LPAR
P8 9119-MME (FW860.A1)
p9 9008-22L (FW950.00)
P10 9080-HEX (FW1010.00)
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220504101244.12107-1-ldufour@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kernel/entry_64.S | 24 ++++++++++++------------
arch/powerpc/kernel/rtas.c | 9 +++++++++
2 files changed, 21 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9581906b5ee9..da18f83ef883 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -330,22 +330,22 @@ _GLOBAL(enter_rtas)
clrldi r4,r4,2 /* convert to realmode address */
mtlr r4
- li r0,0
- ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI
- andc r0,r6,r0
-
- li r9,1
- rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG)
- ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI|MSR_LE
- andc r6,r0,r9
-
__enter_rtas:
- sync /* disable interrupts so SRR0/1 */
- mtmsrd r0 /* don't get trashed */
-
LOAD_REG_ADDR(r4, rtas)
ld r5,RTASENTRY(r4) /* get the rtas->entry value */
ld r4,RTASBASE(r4) /* get the rtas->base value */
+
+ /*
+ * RTAS runs in 32-bit big endian real mode, but leave MSR[RI] on as we
+ * may hit NMI (SRESET or MCE) while in RTAS. RTAS should disable RI in
+ * its critical regions (as specified in PAPR+ section 7.2.1). MSR[S]
+ * is not impacted by RFI_TO_KERNEL (only urfid can unset it). So if
+ * MSR[S] is set, it will remain when entering RTAS.
+ */
+ LOAD_REG_IMMEDIATE(r6, MSR_ME | MSR_RI)
+
+ li r0,0
+ mtmsrd r0,1 /* disable RI before using SRR0/1 */
mtspr SPRN_SRR0,r5
mtspr SPRN_SRR1,r6
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 1f42aabbbab3..6bc89d9ccf63 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -49,6 +49,15 @@ void enter_rtas(unsigned long);
static inline void do_enter_rtas(unsigned long args)
{
+ unsigned long msr;
+
+ /*
+ * Make sure MSR[RI] is currently enabled as it will be forced later
+ * in enter_rtas.
+ */
+ msr = mfmsr();
+ BUG_ON(!(msr & MSR_RI));
+
enter_rtas(args);
srr_regs_clobbered(); /* rtas uses SRRs, invalidate */
--
2.35.1
next prev parent reply other threads:[~2022-06-01 13:57 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-01 13:51 [PATCH AUTOSEL 5.18 01/49] IB/rdmavt: add missing locks in rvt_ruc_loopback Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 02/49] PCI/ASPM: Make Intel DG2 L1 acceptable latency unlimited Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 03/49] ARM: dts: ox820: align interrupt controller node name with dtschema Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 04/49] ARM: dts: socfpga: " Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 05/49] ARM: dts: s5pv210: align DMA channels " Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 06/49] ASoC: amd: Add driver data to acp6x machine driver Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 07/49] arm64: dts: qcom: msm8994: Fix the cont_splash_mem address Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 08/49] arm64: dts: qcom: msm8994: Fix BLSP[12]_DMA channels count Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 09/49] PM / devfreq: rk3399_dmc: Disable edev on remove() Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 10/49] crypto: ccree - use fine grained DMA mapping dir Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 11/49] crypto: qat - fix off-by-one error in PFVF debug print Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 12/49] soc: ti: ti_sci_pm_domains: Check for null return of devm_kcalloc Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 13/49] fs: jfs: fix possible NULL pointer dereference in dbFree() Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 14/49] arm64: dts: qcom: sdm845-xiaomi-beryllium: fix typo in panel's vddio-supply property Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 15/49] arm64: Expand ESR_ELx_WFx_ISS_TI to match its ARMv8.7 definition Sasha Levin
2022-06-01 15:26 ` Marc Zyngier
2022-06-05 13:38 ` Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 16/49] ALSA: usb-audio: Add quirk bits for enabling/disabling generic implicit fb Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 17/49] ALSA: usb-audio: Move generic implicit fb quirk entries into quirks.c Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 18/49] ARM: OMAP1: clock: Fix UART rate reporting algorithm Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 19/49] selftests/resctrl: Change the default limited time to 120 seconds Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 20/49] powerpc/fadump: Fix fadump to work with a different endian capture kernel Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 21/49] fat: add ratelimit to fat*_ent_bread() Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 22/49] pinctrl: renesas: rzn1: Fix possible null-ptr-deref in sh_pfc_map_resources() Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 23/49] ARM: versatile: Add missing of_node_put in dcscb_init Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 24/49] ARM: dts: exynos: add atmel,24c128 fallback to Samsung EEPROM Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 25/49] arm64: dts: qcom: sc7280-idp: Configure CTS pin to bias-bus-hold for bluetooth Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 26/49] arm64: dts: qcom: sc7280-qcard: " Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 27/49] ARM: hisi: Add missing of_node_put after of_find_compatible_node Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 28/49] cpufreq: Avoid unnecessary frequency updates due to mismatch Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 29/49] PCI: microchip: Add missing chained_irq_enter()/exit() calls Sasha Levin
2022-06-01 13:51 ` Sasha Levin [this message]
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 31/49] PCI: Avoid pci_dev_lock() AB/BA deadlock with sriov_numvfs_store() Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 32/49] PCI: cadence: Clear FLR in device capabilities register Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 33/49] KVM: PPC: Book3S HV Nested: L2 LPCR should inherit L1 LPES setting Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 34/49] alpha: fix alloc_zeroed_user_highpage_movable() Sasha Levin
2022-06-01 13:51 ` [PATCH AUTOSEL 5.18 35/49] KVM: arm64: vgic: Do not ignore vgic_its_restore_cte failures Sasha Levin
2022-06-01 16:45 ` Marc Zyngier
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 36/49] cifs: fix signed integer overflow when fl_end is OFFSET_MAX Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 37/49] tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 38/49] cifs: return ENOENT for DFS lookup_cache_entry() Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 39/49] powerpc/powernv/vas: Assign real address to rx_fifo in vas_rx_win_attr Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 40/49] powerpc/xics: fix refcount leak in icp_opal_init() Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 41/49] powerpc/powernv: fix missing of_node_put in uv_init() Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 42/49] macintosh/via-pmu: Fix build failure when CONFIG_INPUT is disabled Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 43/49] powerpc/iommu: Add missing of_node_put in iommu_init_early_dart Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 44/49] fanotify: fix incorrect fmode_t casts Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 45/49] smb3: check for null tcon Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 46/49] RDMA/hfi1: Prevent panic when SDMA is disabled Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 47/49] cifs: do not use tcpStatus after negotiate completes Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 48/49] Input: gpio-keys - cancel delayed work only in case of GPIO Sasha Levin
2022-06-01 13:52 ` [PATCH AUTOSEL 5.18 49/49] drm: fix EDID struct for old ARM OABI format Sasha Levin
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