On 06/08/2018 07:21 AM, Nicholas Piggin wrote:
> On Thu, 07 Jun 2018 22:59:04 +0530
> Mahesh J Salgaonkar <mah...@linux.vnet.ibm.com> wrote:
>
>> From: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
>>
>> Extract the MCE error details from RTAS extended log and display it to
>> console.
>>
>> With this patch you should now see mce logs like below:
>>
>> [ 142.371818] Severe Machine check interrupt [Recovered]
>> [ 142.371822] NIP [d00000000ca301b8]: init_module+0x1b8/0x338
>> [bork_kernel]
>> [ 142.371822] Initiator: CPU
>> [ 142.371823] Error type: SLB [Multihit]
>> [ 142.371824] Effective address: d00000000ca70000
>>
>> Signed-off-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
>> ---
>> arch/powerpc/include/asm/rtas.h | 5 +
>> arch/powerpc/platforms/pseries/ras.c | 128
>> +++++++++++++++++++++++++++++++++-
>> 2 files changed, 131 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/rtas.h
>> b/arch/powerpc/include/asm/rtas.h
>> index 3f2fba7ef23b..8100a95c133a 100644
>> --- a/arch/powerpc/include/asm/rtas.h
>> +++ b/arch/powerpc/include/asm/rtas.h
>> @@ -190,6 +190,11 @@ static inline uint8_t rtas_error_extended(const struct
>> rtas_error_log *elog)
>> return (elog->byte1 & 0x04) >> 2;
>> }
>>
>> +static inline uint8_t rtas_error_initiator(const struct rtas_error_log
>> *elog)
>> +{
>> + return (elog->byte2 & 0xf0) >> 4;
>> +}
>> +
>> #define rtas_error_type(x) ((x)->byte3)
>>
>> static inline
>> diff --git a/arch/powerpc/platforms/pseries/ras.c
>> b/arch/powerpc/platforms/pseries/ras.c
>> index e56759d92356..cd9446980092 100644
>> --- a/arch/powerpc/platforms/pseries/ras.c
>> +++ b/arch/powerpc/platforms/pseries/ras.c
>> @@ -422,7 +422,130 @@ int pSeries_system_reset_exception(struct pt_regs
>> *regs)
>> return 0; /* need to perform reset */
>> }
>>
>> -static int mce_handle_error(struct rtas_error_log *errp)
>> +#define VAL_TO_STRING(ar, val) ((val < ARRAY_SIZE(ar)) ? ar[val] :
>> "Unknown")
>> +
>> +static void pseries_print_mce_info(struct pt_regs *regs,
>> + struct rtas_error_log *errp, int disposition)
>> +{
>> + const char *level, *sevstr;
>> + struct pseries_errorlog *pseries_log;
>> + struct pseries_mc_errorlog *mce_log;
>> + uint8_t error_type, err_sub_type;
>> + uint8_t initiator = rtas_error_initiator(errp);
>> + uint64_t addr;
>> +
>> + static const char * const initiators[] = {
>> + "Unknown",
>> + "CPU",
>> + "PCI",
>> + "ISA",
>> + "Memory",
>> + "Power Mgmt",
>> + };
>> + static const char * const mc_err_types[] = {
>> + "UE",
>> + "SLB",
>> + "ERAT",
>> + "TLB",
>> + "D-Cache",
>> + "Unknown",
>> + "I-Cache",
>> + };
>> + static const char * const mc_ue_types[] = {
>> + "Indeterminate",
>> + "Instruction fetch",
>> + "Page table walk ifetch",
>> + "Load/Store",
>> + "Page table walk Load/Store",
>> + };
>> +
>> + /* SLB sub errors valid values are 0x0, 0x1, 0x2 */
>> + static const char * const mc_slb_types[] = {
>> + "Parity",
>> + "Multihit",
>> + "Indeterminate",
>> + };
>> +
>> + /* TLB and ERAT sub errors valid values are 0x1, 0x2, 0x3 */
>> + static const char * const mc_soft_types[] = {
>> + "Unknown",
>> + "Parity",
>> + "Multihit",
>> + "Indeterminate",
>> + };
>> +
>> + pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
>> + if (pseries_log == NULL)
>> + return;
>> +
>> + mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
>> +
>> + error_type = rtas_mc_error_type(mce_log);
>> + err_sub_type = rtas_mc_error_sub_type(mce_log);
>> +
>> + switch (rtas_error_severity(errp)) {
>> + case RTAS_SEVERITY_NO_ERROR:
>> + level = KERN_INFO;
>> + sevstr = "Harmless";
>> + break;
>> + case RTAS_SEVERITY_WARNING:
>> + level = KERN_WARNING;
>> + sevstr = "";
>> + break;
>> + case RTAS_SEVERITY_ERROR:
>> + case RTAS_SEVERITY_ERROR_SYNC:
>> + level = KERN_ERR;
>> + sevstr = "Severe";
>> + break;
>> + case RTAS_SEVERITY_FATAL:
>> + default:
>> + level = KERN_ERR;
>> + sevstr = "Fatal";
>> + break;
>> + }
>> +
>> + printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
>> + disposition == RTAS_DISP_FULLY_RECOVERED ?
>> + "Recovered" : "Not recovered");
>> + if (user_mode(regs)) {
>> + printk("%s NIP: [%016lx] PID: %d Comm: %s\n", level,
>> + regs->nip, current->pid, current->comm);
>> + } else {
>> + printk("%s NIP [%016lx]: %pS\n", level, regs->nip,
>> + (void *)regs->nip);
>> + }
>
> I think it's probably still useful to print pid/comm for kernel mode
> faults if !in_interrupt()... I see you're basically taking kernel/mce.c
> and doing the same thing.
>
> Is there any reasonable way to share code here?
I did think of doing that, but I wanted make this patch series simple
enough to be able to make backport easy for very old kernels. I will
work on consolidating the code as enhancement later.
Thanks,
-Mahesh.
