On 8/12/19 2:52 PM, Santosh Sivaraj wrote: > 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 <ar...@linux.ibm.com> > Signed-off-by: Reza Arbab <ar...@linux.ibm.com> > Cc: Mahesh Salgaonkar <mah...@linux.ibm.com> > Signed-off-by: Santosh Sivaraj <sant...@fossix.org>
Looks good to me. Reviewed-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com> Thanks, -Mahesh. > --- > arch/powerpc/include/asm/mce.h | 4 +++- > arch/powerpc/kernel/mce.c | 16 ++++++++++++++++ > arch/powerpc/kernel/mce_power.c | 15 +++++++++++++-- > 3 files changed, 32 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h > index f3a6036b6bc0..e1931c8c2743 100644 > --- a/arch/powerpc/include/asm/mce.h > +++ b/arch/powerpc/include/asm/mce.h > @@ -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 > diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c > index a3b122a685a5..ec4b3e1087be 100644 > --- a/arch/powerpc/kernel/mce.c > +++ b/arch/powerpc/kernel/mce.c > @@ -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); > } > diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c > index e74816f045f8..1dd87f6f5186 100644 > --- a/arch/powerpc/kernel/mce_power.c > +++ b/arch/powerpc/kernel/mce_power.c > @@ -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 physical address. > @@ -559,9 +561,18 @@ 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 > @@ -594,7 +605,7 @@ 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); > >