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powerpc/book3s: Print task info if we take a machine check in user mode

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For an MCE (Machine Check Exception) that hits while in user mode
MSR(PR=1), print the task info to the console MCE error log. This may
help to identify an application that triggered the MCE.

After this patch the MCE console looks like:

  Severe Machine check interrupt [Recovered]
    NIP: [0000000010039778] PID: 762 Comm: ebizzy
    Initiator: CPU
    Error type: SLB [Multihit]
      Effective address: 0000000010039778

  Severe Machine check interrupt [Not recovered]
    NIP: [0000000010039778] PID: 763 Comm: ebizzy
    Initiator: CPU
    Error type: UE [Page table walk ifetch]
      Effective address: 0000000010039778
  ebizzy[763]: unhandled signal 7 at 0000000010039778 nip 0000000010039778 lr 0000000010001b44 code 30004

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Michael Ellerman 2017-04-03 15:29:34 +10:00
parent 5b1d6fc2d4
commit 63f44d6514
3 changed files with 15 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/powerpc/include/asm/mce.h
View File

@ -207,7 +207,8 @@ extern void save_mce_event(struct pt_regs *regs, long handled,
extern int get_mce_event(struct machine_check_event *mce, bool release);
extern void release_mce_event(void);
extern void machine_check_queue_event(void);
extern void machine_check_print_event_info(struct machine_check_event *evt);
extern void machine_check_print_event_info(struct machine_check_event *evt,
bool user_mode);
extern uint64_t get_mce_fault_addr(struct machine_check_event *evt);
#endif /* __ASM_PPC64_MCE_H__ */

15
arch/powerpc/kernel/mce.c
View File

@ -228,12 +228,13 @@ static void machine_check_process_queued_event(struct irq_work *work)
while (__this_cpu_read(mce_queue_count) > 0) {
index = __this_cpu_read(mce_queue_count) - 1;
machine_check_print_event_info(
this_cpu_ptr(&mce_event_queue[index]));
this_cpu_ptr(&mce_event_queue[index]), false);
__this_cpu_dec(mce_queue_count);
}
}
void machine_check_print_event_info(struct machine_check_event *evt)
void machine_check_print_event_info(struct machine_check_event *evt,
bool user_mode)
{
const char *level, *sevstr, *subtype;
static const char *mc_ue_types[] = {
@ -311,7 +312,15 @@ void machine_check_print_event_info(struct machine_check_event *evt)
printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
evt->disposition == MCE_DISPOSITION_RECOVERED ?
"Recovered" : "Not recovered");
printk("%s NIP [%016llx]: %pS\n", level, evt->srr0, (void *)evt->srr0);
if (user_mode) {
printk("%s NIP: [%016llx] PID: %d Comm: %s\n", level,
evt->srr0, current->pid, current->comm);
} else {
printk("%s NIP [%016llx]: %pS\n", level, evt->srr0,
(void *)evt->srr0);
}
printk("%s Initiator: %s\n", level,
evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
switch (evt->error_type) {

2
arch/powerpc/platforms/powernv/opal.c
View File

@ -435,7 +435,7 @@ int opal_machine_check(struct pt_regs *regs)
evt.version);
return 0;
}
machine_check_print_event_info(&evt);
machine_check_print_event_info(&evt, user_mode(regs));
if (opal_recover_mce(regs, &evt))
return 1;