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powerpc/mce: Handle UE event for memcpy_mcsafe 

If we take a UE on one of the instructions with a fixup entry, set nip
to continue execution at the fixup entry. Stop processing the event
further or print it.

Co-developed-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-6-santosh@fossix.org
alistair/sunxi64-5.4-dsi
Balbir Singh 2019-08-20 13:43:50 +05:30 committed by Michael Ellerman
parent 49ec9177b8
commit 895e3dceeb
3 changed files with 32 additions and 3 deletions
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4
arch/powerpc/include/asm/mce.h
View File

@ -122,7 +122,8 @@ struct machine_check_event {
enum MCE_UeErrorType ue_error_type:8;
u8 effective_address_provided;
u8 physical_address_provided;
u8 reserved_1[5];
u8 ignore_event;
u8 reserved_1[4];
u64 effective_address;
u64 physical_address;
u8 reserved_2[8];
@ -193,6 +194,7 @@ struct mce_error_info {
enum MCE_Initiator initiator:8;
enum MCE_ErrorClass error_class:8;
bool sync_error;
bool ignore_event;
};
#define MAX_MC_EVT 100

16
arch/powerpc/kernel/mce.c
View File

@ -149,6 +149,7 @@ void save_mce_event(struct pt_regs *regs, long handled,
if (phys_addr != ULONG_MAX) {
mce->u.ue_error.physical_address_provided = true;
mce->u.ue_error.physical_address = phys_addr;
mce->u.ue_error.ignore_event = mce_err->ignore_event;
machine_check_ue_event(mce);
}
}
@ -266,8 +267,17 @@ static void machine_process_ue_event(struct work_struct *work)
/*
* This should probably queued elsewhere, but
* oh! well
*
* Don't report this machine check because the caller has a
* asked us to ignore the event, it has a fixup handler which
* will do the appropriate error handling and reporting.
*/
if (evt->error_type == MCE_ERROR_TYPE_UE) {
if (evt->u.ue_error.ignore_event) {
__this_cpu_dec(mce_ue_count);
continue;
}
if (evt->u.ue_error.physical_address_provided) {
unsigned long pfn;
@ -301,6 +311,12 @@ 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;
evt = this_cpu_ptr(&mce_event_queue[index]);
if (evt->error_type == MCE_ERROR_TYPE_UE &&
evt->u.ue_error.ignore_event) {
__this_cpu_dec(mce_queue_count);
continue;
}
machine_check_print_event_info(evt, false, false);
__this_cpu_dec(mce_queue_count);
}

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

@ -11,6 +11,7 @@
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/extable.h>
#include <asm/mmu.h>
#include <asm/mce.h>
#include <asm/machdep.h>
@ -18,6 +19,7 @@
#include <asm/pte-walk.h>
#include <asm/sstep.h>
#include <asm/exception-64s.h>
#include <asm/extable.h>
/*
* Convert an address related to an mm to a PFN. NOTE: we are in real
@ -565,9 +567,18 @@ static int mce_handle_derror(struct pt_regs *regs,
return 0;
}
static long mce_handle_ue_error(struct pt_regs *regs)
static long mce_handle_ue_error(struct pt_regs *regs,
struct mce_error_info *mce_err)
{
long handled = 0;
const struct exception_table_entry *entry;
entry = search_kernel_exception_table(regs->nip);
if (entry) {
mce_err->ignore_event = true;
regs->nip = extable_fixup(entry);
return 1;
}
/*
* On specific SCOM read via MMIO we may get a machine check
@ -600,7 +611,7 @@ static long mce_handle_error(struct pt_regs *regs,
&phys_addr);
if (!handled && mce_err.error_type == MCE_ERROR_TYPE_UE)
handled = mce_handle_ue_error(regs);
handled = mce_handle_ue_error(regs, &mce_err);
save_mce_event(regs, handled, &mce_err, regs->nip, addr, phys_addr);