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powerpc/powernv: Machine check exception handling.

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Add basic error handling in machine check exception handler.

- If MSR_RI isn't set, we can not recover.
- Check if disposition set to OpalMCE_DISPOSITION_RECOVERED.
- Check if address at fault is inside kernel address space, if not then send
  SIGBUS to process if we hit exception when in userspace.
- If address at fault is not provided then and if we get a synchronous machine
  check while in userspace then kill the task.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Mahesh Salgaonkar 2013-10-30 20:06:13 +05:30 committed by Benjamin Herrenschmidt
parent 28446de2ce
commit b63a0ffe35
3 changed files with 70 additions and 1 deletions
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1
arch/powerpc/include/asm/mce.h
View File

@ -193,5 +193,6 @@ extern void release_mce_event(void);
extern void machine_check_queue_event(void);
extern void machine_check_process_queued_event(void);
extern void machine_check_print_event_info(struct machine_check_event *evt);
extern uint64_t get_mce_fault_addr(struct machine_check_event *evt);
#endif /* __ASM_PPC64_MCE_H__ */

27
arch/powerpc/kernel/mce.c
View File

@ -316,3 +316,30 @@ void machine_check_print_event_info(struct machine_check_event *evt)
break;
}
}
uint64_t get_mce_fault_addr(struct machine_check_event *evt)
{
switch (evt->error_type) {
case MCE_ERROR_TYPE_UE:
if (evt->u.ue_error.effective_address_provided)
return evt->u.ue_error.effective_address;
break;
case MCE_ERROR_TYPE_SLB:
if (evt->u.slb_error.effective_address_provided)
return evt->u.slb_error.effective_address;
break;
case MCE_ERROR_TYPE_ERAT:
if (evt->u.erat_error.effective_address_provided)
return evt->u.erat_error.effective_address;
break;
case MCE_ERROR_TYPE_TLB:
if (evt->u.tlb_error.effective_address_provided)
return evt->u.tlb_error.effective_address;
break;
default:
case MCE_ERROR_TYPE_UNKNOWN:
break;
}
return 0;
}
EXPORT_SYMBOL(get_mce_fault_addr);

43
arch/powerpc/platforms/powernv/opal.c
View File

@ -18,6 +18,7 @@
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/kobject.h>
#include <asm/opal.h>
#include <asm/firmware.h>
@ -251,6 +252,44 @@ int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
return written;
}
static int opal_recover_mce(struct pt_regs *regs,
struct machine_check_event *evt)
{
int recovered = 0;
uint64_t ea = get_mce_fault_addr(evt);
if (!(regs->msr & MSR_RI)) {
/* If MSR_RI isn't set, we cannot recover */
recovered = 0;
} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
/* Platform corrected itself */
recovered = 1;
} else if (ea && !is_kernel_addr(ea)) {
/*
* Faulting address is not in kernel text. We should be fine.
* We need to find which process uses this address.
* For now, kill the task if we have received exception when
* in userspace.
*
* TODO: Queue up this address for hwpoisioning later.
*/
if (user_mode(regs) && !is_global_init(current)) {
_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
recovered = 1;
} else
recovered = 0;
} else if (user_mode(regs) && !is_global_init(current) &&
evt->severity == MCE_SEV_ERROR_SYNC) {
/*
* If we have received a synchronous error when in userspace
* kill the task.
*/
_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
recovered = 1;
}
return recovered;
}
int opal_machine_check(struct pt_regs *regs)
{
struct machine_check_event evt;
@ -266,7 +305,9 @@ int opal_machine_check(struct pt_regs *regs)
}
machine_check_print_event_info(&evt);
return evt.severity == MCE_SEV_FATAL ? 0 : 1;
if (opal_recover_mce(regs, &evt))
return 1;
return 0;
}
static irqreturn_t opal_interrupt(int irq, void *data)