Without this fix 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 ]---
Signed-off-by: Ganesh Goudar <ganes...@linux.ibm.com>
---
V2: Leave bare metal code and save_mce_event as is.
V3: Have separate functions for realmode and virtual mode handling.
---
arch/powerpc/platforms/pseries/ras.c | 119 ++++++++++++++++-----------
1 file changed, 70 insertions(+), 49 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/ras.c
b/arch/powerpc/platforms/pseries/ras.c
index f3736fcd98fc..32fe3fad86b8 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -522,18 +522,55 @@ int pSeries_system_reset_exception(struct pt_regs *regs)
return 0; /* need to perform reset */
}
+static int mce_handle_err_realmode(int disposition, u8 error_type)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (disposition == RTAS_DISP_NOT_RECOVERED) {
+ switch (error_type) {
+ case MC_ERROR_TYPE_SLB:
+ case MC_ERROR_TYPE_ERAT:
+ /*
+ * Store the old slb content in paca before flushing.
+ * Print this when we go to virtual mode.
+ * There are chances that we may hit MCE again if there
+ * is a parity error on the SLB entry we trying to read
+ * for saving. Hence limit the slb saving to single
+ * level of recursion.
+ */
+ if (local_paca->in_mce == 1)
+ slb_save_contents(local_paca->mce_faulty_slbs);
+ flush_and_reload_slb();
+ disposition = RTAS_DISP_FULLY_RECOVERED;
+ break;
+ default:
+ break;
+ }
+ } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
+ /* Platform corrected itself but could be degraded */
+ pr_err("MCE: limited recovery, system may be degraded\n");
+ disposition = RTAS_DISP_FULLY_RECOVERED;
+ }
+#endif
+ return disposition;
+}
-static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
+static int mce_handle_err_virtmode(struct pt_regs *regs,
+ struct rtas_error_log *errp,
+ struct pseries_mc_errorlog *mce_log,
+ int disposition)
{
struct mce_error_info mce_err = { 0 };
- unsigned long eaddr = 0, paddr = 0;
- struct pseries_errorlog *pseries_log;
- struct pseries_mc_errorlog *mce_log;
- int disposition = rtas_error_disposition(errp);
int initiator = rtas_error_initiator(errp);
int severity = rtas_error_severity(errp);
+ unsigned long eaddr = 0, paddr = 0;
u8 error_type, err_sub_type;
+ if (!mce_log)
+ goto out;
+
+ error_type = mce_log->error_type;
+ err_sub_type = rtas_mc_error_sub_type(mce_log);
+
if (initiator == RTAS_INITIATOR_UNKNOWN)
mce_err.initiator = MCE_INITIATOR_UNKNOWN;
else if (initiator == RTAS_INITIATOR_CPU)
@@ -572,18 +609,7 @@ static int mce_handle_error(struct pt_regs *regs, struct
rtas_error_log *errp)
mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
mce_err.error_class = MCE_ECLASS_UNKNOWN;
- if (!rtas_error_extended(errp))
- goto out;
-
- pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
- if (pseries_log == NULL)
- goto out;
-
- mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
- error_type = mce_log->error_type;
- err_sub_type = rtas_mc_error_sub_type(mce_log);
-
- switch (mce_log->error_type) {
+ switch (error_type) {
case MC_ERROR_TYPE_UE:
mce_err.error_type = MCE_ERROR_TYPE_UE;
mce_common_process_ue(regs, &mce_err);
@@ -683,37 +709,32 @@ static int mce_handle_error(struct pt_regs *regs, struct
rtas_error_log *errp)
mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
break;
}
+out:
+ save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED,
+ &mce_err, regs->nip, eaddr, paddr);
+ return disposition;
+}
-#ifdef CONFIG_PPC_BOOK3S_64
- if (disposition == RTAS_DISP_NOT_RECOVERED) {
- switch (error_type) {
- case MC_ERROR_TYPE_SLB:
- case MC_ERROR_TYPE_ERAT:
- /*
- * Store the old slb content in paca before flushing.
- * Print this when we go to virtual mode.
- * There are chances that we may hit MCE again if there
- * is a parity error on the SLB entry we trying to read
- * for saving. Hence limit the slb saving to single
- * level of recursion.
- */
- if (local_paca->in_mce == 1)
- slb_save_contents(local_paca->mce_faulty_slbs);
- flush_and_reload_slb();
- disposition = RTAS_DISP_FULLY_RECOVERED;
- break;
- default:
- break;
- }
- } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
- /* Platform corrected itself but could be degraded */
- printk(KERN_ERR "MCE: limited recovery, system may "
- "be degraded\n");
- disposition = RTAS_DISP_FULLY_RECOVERED;
- }
-#endif
+static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
+{
+ struct pseries_errorlog *pseries_log;
+ struct pseries_mc_errorlog *mce_log = NULL;
+ int disposition = rtas_error_disposition(errp);
+ u8 error_type, err_sub_type;
+
+ if (!rtas_error_extended(errp))
+ goto out;
+
+ pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
+ if (!pseries_log)
+ goto out;
+
+ mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
+ error_type = mce_log->error_type;
+ err_sub_type = rtas_mc_error_sub_type(mce_log);
+
+ disposition = mce_handle_err_realmode(disposition, error_type);
-out:
/*
* Enable translation as we will be accessing per-cpu variables
* in save_mce_event() which may fall outside RMO region, also
@@ -724,10 +745,10 @@ static int mce_handle_error(struct pt_regs *regs, struct
rtas_error_log *errp)
* Note: All the realmode handling like flushing SLB entries for
* SLB multihit is done by now.
*/
+out:
mtmsr(mfmsr() | MSR_IR | MSR_DR);
- save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED,
- &mce_err, regs->nip, eaddr, paddr);
-
+ disposition = mce_handle_err_virtmode(regs, errp, mce_log,
+ disposition);
return disposition;
}
--
2.17.2
