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From: Santosh Sivaraj <santosh@fossix.org>
To: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	Mahesh Salgaonkar <mahesh@linux.ibm.com>,
	Nicholas Piggin <npiggin@gmail.com>,
	Chandan Rajendra <chandan@linux.vnet.ibm.com>,
	Reza Arbab <arbab@linux.ibm.com>
Subject: [v2 06/12] powerpc/mce: Add fixup address to UE events
Date: Tue,  2 Jul 2019 10:49:26 +0530	[thread overview]
Message-ID: <20190702051932.511-7-santosh@fossix.org> (raw)
In-Reply-To: <20190702051932.511-1-santosh@fossix.org>

From: Reza Arbab <arbab@linux.ibm.com>

If the instruction causing a UE has an exception table entry with fixup
address, save it in the machine_check_event struct.

If a machine check notifier callback returns NOTIFY_STOP to indicate it
has handled the error, set nip to continue execution from the fixup
address.

Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
---
 arch/powerpc/include/asm/mce.h |  5 +++--
 arch/powerpc/kernel/mce.c      | 16 +++++++++++++++-
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
index 240dd1fdfe35..9d9661747adf 100644
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -122,11 +122,12 @@ struct machine_check_event {
 			enum MCE_UeErrorType ue_error_type:8;
 			u8		effective_address_provided;
 			u8		physical_address_provided;
+			u8		fixup_address_provided;
 			u8		process_event;
-			u8		reserved_1[4];
+			u8		reserved_1[3];
 			u64		effective_address;
 			u64		physical_address;
-			u8		reserved_2[8];
+			u64		fixup_address;
 		} ue_error;
 
 		struct {
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index 4a37928ab30e..0233c0ee45ab 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -15,10 +15,12 @@
 #include <linux/percpu.h>
 #include <linux/export.h>
 #include <linux/irq_work.h>
+#include <linux/extable.h>
 
 #include <asm/machdep.h>
 #include <asm/mce.h>
 #include <asm/nmi.h>
+#include <asm/extable.h>
 
 static DEFINE_PER_CPU(int, mce_nest_count);
 static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
@@ -151,6 +153,8 @@ void save_mce_event(struct pt_regs *regs, long handled,
 		mce->u.link_error.effective_address_provided = true;
 		mce->u.link_error.effective_address = addr;
 	} else if (mce->error_type == MCE_ERROR_TYPE_UE) {
+		const struct exception_table_entry *entry;
+
 		mce->u.ue_error.effective_address_provided = true;
 		mce->u.ue_error.effective_address = addr;
 		if (phys_addr != ULONG_MAX) {
@@ -158,6 +162,12 @@ void save_mce_event(struct pt_regs *regs, long handled,
 			mce->u.ue_error.physical_address = phys_addr;
 		}
 
+		entry = search_exception_tables(regs->nip);
+		if (entry) {
+			mce->u.ue_error.fixup_address_provided = true;
+			mce->u.ue_error.fixup_address = extable_fixup(entry);
+		}
+
 		mce->u.ue_error.process_event = true;
 	}
 	return;
@@ -666,8 +676,12 @@ long machine_check_notify(struct pt_regs *regs)
 
 	rc = blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
 	if (rc & NOTIFY_STOP_MASK) {
-		if (evt->error_type == MCE_ERROR_TYPE_UE)
+		if (evt->error_type == MCE_ERROR_TYPE_UE) {
+			if (evt->u.ue_error.fixup_address_provided)
+				regs->nip = evt->u.ue_error.fixup_address;
+
 			evt->u.ue_error.process_event = false;
+		}
 
 		if ((rc & NOTIFY_STOP_MASK) && (regs->msr & MSR_RI))
 			evt->disposition = MCE_DISPOSITION_RECOVERED;
-- 
2.20.1


  parent reply	other threads:[~2019-07-02  5:25 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-02  5:19 [v2 00/12] powerpc: implement machine check safe memcpy Santosh Sivaraj
2019-07-02  5:19 ` [v2 01/12] powerpc/mce: Make machine_check_ue_event() static Santosh Sivaraj
2019-07-02  5:19 ` [v2 02/12] powerpc/mce: Bug fixes for MCE handling in kernel space Santosh Sivaraj
2019-07-02  5:19 ` [v2 03/12] powerpc/mce: Add MCE notification chain Santosh Sivaraj
2019-07-02 14:55   ` Reza Arbab
2019-07-02  5:19 ` [v2 04/12] powerpc/mce: Move machine_check_ue_event() call Santosh Sivaraj
2019-07-02  5:19 ` [v2 05/12] powerpc/mce: Allow notifier callback to handle MCE Santosh Sivaraj
2019-07-02  5:19 ` Santosh Sivaraj [this message]
2019-07-02  5:19 ` [v2 07/12] powerpc/memcpy: Add memcpy_mcsafe for pmem Santosh Sivaraj
2019-07-02  5:19 ` [v2 08/12] powerpc/mce: Handle memcpy_mcsafe() Santosh Sivaraj
2019-07-02  5:19 ` [v2 09/12] powerpc/mce: Enable MCE notifiers in external modules Santosh Sivaraj
2019-07-02  6:17   ` Nicholas Piggin
2019-07-02  9:33     ` Mahesh Jagannath Salgaonkar
2019-07-03 17:20     ` Reza Arbab
2019-07-04  2:36       ` Nicholas Piggin
2019-07-05  2:50         ` Reza Arbab
2019-07-05  5:29           ` Nicholas Piggin
2019-07-08 15:23             ` Reza Arbab
2019-07-02  5:19 ` [v2 10/12] powerpc/memcpy_mcsafe: return remaining bytes Santosh Sivaraj
2019-07-02  5:19 ` [v2 11/12] powerpc: add machine check safe copy_to_user Santosh Sivaraj
2019-07-02  5:19 ` [v2 12/12] powerpc/64s: Save r13 in machine_check_common_early Santosh Sivaraj
2019-07-02  6:19   ` Nicholas Piggin

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