linux_dsm_epyc7002/arch/powerpc/platforms
Ganesh Goudar 4ff753feab powerpc/pseries: Avoid using addr_to_pfn in real mode
When an UE or memory error exception is encountered the MCE handler
tries to find the pfn using addr_to_pfn() which takes effective
address as an argument, later pfn is used to poison the page where
memory error occurred, recent rework in this area made addr_to_pfn
to run in real mode, which can be fatal as it may try to access
memory outside RMO region.

Have two helper functions to separate things to be done in real mode
and virtual mode without changing any functionality. This also fixes
the following error as the use of addr_to_pfn is now moved to virtual
mode.

Without this change following kernel crash is seen on hitting UE.

[  485.128036] Oops: Kernel access of bad area, sig: 11 [#1]
[  485.128040] LE SMP NR_CPUS=2048 NUMA pSeries
[  485.128047] Modules linked in:
[  485.128067] CPU: 15 PID: 6536 Comm: insmod Kdump: loaded Tainted: G OE 5.7.0 #22
[  485.128074] NIP:  c00000000009b24c LR: c0000000000398d8 CTR: c000000000cd57c0
[  485.128078] REGS: c000000003f1f970 TRAP: 0300   Tainted: G OE (5.7.0)
[  485.128082] MSR:  8000000000001003 <SF,ME,RI,LE>  CR: 28008284  XER: 00000001
[  485.128088] CFAR: c00000000009b190 DAR: c0000001fab00000 DSISR: 40000000 IRQMASK: 1
[  485.128088] GPR00: 0000000000000001 c000000003f1fbf0 c000000001634300 0000b0fa01000000
[  485.128088] GPR04: d000000002220000 0000000000000000 00000000fab00000 0000000000000022
[  485.128088] GPR08: c0000001fab00000 0000000000000000 c0000001fab00000 c000000003f1fc14
[  485.128088] GPR12: 0000000000000008 c000000003ff5880 d000000002100008 0000000000000000
[  485.128088] GPR16: 000000000000ff20 000000000000fff1 000000000000fff2 d0000000021a1100
[  485.128088] GPR20: d000000002200000 c00000015c893c50 c000000000d49b28 c00000015c893c50
[  485.128088] GPR24: d0000000021a0d08 c0000000014e5da8 d0000000021a0818 000000000000000a
[  485.128088] GPR28: 0000000000000008 000000000000000a c0000000017e2970 000000000000000a
[  485.128125] NIP [c00000000009b24c] __find_linux_pte+0x11c/0x310
[  485.128130] LR [c0000000000398d8] addr_to_pfn+0x138/0x170
[  485.128133] Call Trace:
[  485.128135] Instruction dump:
[  485.128138] 3929ffff 7d4a3378 7c883c36 7d2907b4 794a1564 7d294038 794af082 3900ffff
[  485.128144] 79291f24 790af00e 78e70020 7d095214 <7c69502a> 2fa30000 419e011c 70690040
[  485.128152] ---[ end trace d34b27e29ae0e340 ]---

Fixes: 9ca766f989 ("powerpc/64s/pseries: machine check convert to use common event code")
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724063946.21378-1-ganeshgr@linux.ibm.com
2020-10-22 14:34:45 +11:00
..
4xx powerpc/4xx: Don't unmap NULL mbase 2020-05-28 23:24:36 +10:00
8xx mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
40x powerpc: Remove IBM405 Erratum #77 2020-05-28 23:24:36 +10:00
44x powerpc: Move flush_instruction_cache() prototype in asm/cacheflush.h 2020-09-02 11:00:21 +10:00
52xx powerpc updates for 5.9 2020-08-07 10:33:50 -07:00
82xx powerpc/82xx: Blacklist pq2_restart() for kprobe 2020-06-02 20:59:09 +10:00
83xx powerpc: Use simple i2c probe function 2020-09-02 11:00:20 +10:00
85xx powerpc/smp: Move ppc_md.cpu_die() to smp_ops.cpu_offline_self() 2020-09-18 19:59:43 +10:00
86xx mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
512x powerpc/512x: Use dma_request_chan() instead dma_request_slave_channel() 2020-01-06 16:25:29 +11:00
amigaone powerpc/32: drop unused ISA_DMA_THRESHOLD 2020-04-01 14:30:50 +11:00
cell powerpc updates for 5.9 2020-08-07 10:33:50 -07:00
chrp mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
embedded6xx powerpc: Drop _nmask_and_or_msr() 2020-09-02 11:00:20 +10:00
maple mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
pasemi powerpc: use for_each_child_of_node() macro 2020-07-29 22:30:33 +10:00
powermac powerpc: Remove support for PowerPC 601 2020-10-08 21:17:13 +11:00
powernv powerpc/powernv/dump: Handle multiple writes to ack attribute 2020-10-19 22:58:52 +11:00
ps3 powerpc/ps3: make two symbols static 2020-09-15 22:13:38 +10:00
pseries powerpc/pseries: Avoid using addr_to_pfn in real mode 2020-10-22 14:34:45 +11:00
fsl_uli1575.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
Kconfig powerpc: Remove CONFIG_PPC601_SYNC_FIX 2020-10-08 21:17:13 +11:00
Kconfig.cputype powerpc: Remove PowerPC 601 2020-10-08 21:17:13 +11:00
Makefile powerpc: Add -Werror at arch/powerpc level 2018-10-19 00:56:17 +11:00