Merge branch 'acpi-apei'

* acpi-apei: (29 commits)
  efi: cper: Fix possible out-of-bounds access
  ACPI: APEI: Fix possible out-of-bounds access to BERT region
  MAINTAINERS: Add James Morse to the list of APEI reviewers
  ACPI / APEI: Add support for the SDEI GHES Notification type
  firmware: arm_sdei: Add ACPI GHES registration helper
  ACPI / APEI: Use separate fixmap pages for arm64 NMI-like notifications
  ACPI / APEI: Only use queued estatus entry during in_nmi_queue_one_entry()
  ACPI / APEI: Split ghes_read_estatus() to allow a peek at the CPER length
  ACPI / APEI: Make GHES estatus header validation more user friendly
  ACPI / APEI: Pass ghes and estatus separately to avoid a later copy
  ACPI / APEI: Let the notification helper specify the fixmap slot
  ACPI / APEI: Move locking to the notification helper
  arm64: KVM/mm: Move SEA handling behind a single 'claim' interface
  KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing
  ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue
  ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI
  ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors
  ACPI / APEI: Generalise the estatus queue's notify code
  ACPI / APEI: Don't update struct ghes' flags in read/clear estatus
  ACPI / APEI: Remove spurious GHES_TO_CLEAR check
  ...

MAINTAINERS

@@ -331,6 +331,7 @@ ACPI APEI
 M:	"Rafael J. Wysocki" <rjw@rjwysocki.net>
 M:	Len Brown <lenb@kernel.org>
 L:	linux-acpi@vger.kernel.org
+R:	James Morse <james.morse@arm.com>
 R:	Tony Luck <tony.luck@intel.com>
 R:	Borislav Petkov <bp@alien8.de>
 F:	drivers/acpi/apei/

arch/arm/include/asm/kvm_ras.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2018 - Arm Ltd */
+
+#ifndef __ARM_KVM_RAS_H__
+#define __ARM_KVM_RAS_H__
+
+#include <linux/types.h>
+
+static inline int kvm_handle_guest_sea(phys_addr_t addr, unsigned int esr)
+{
+	return -1;
+}
+
+#endif /* __ARM_KVM_RAS_H__ */

arch/arm/include/asm/system_misc.h

@@ -38,11 +38,6 @@ static inline void harden_branch_predictor(void)
 
 extern unsigned int user_debug;
 
-static inline int handle_guest_sea(phys_addr_t addr, unsigned int esr)
-{
-	return -1;
-}
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ASM_ARM_SYSTEM_MISC_H */

arch/arm64/include/asm/acpi.h

@@ -18,6 +18,7 @@
 
 #include <asm/cputype.h>
 #include <asm/io.h>
+#include <asm/ptrace.h>
 #include <asm/smp_plat.h>
 #include <asm/tlbflush.h>
 
@@ -110,9 +111,10 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
 
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 void __init acpi_init_cpus(void);
-
+int apei_claim_sea(struct pt_regs *regs);
 #else
 static inline void acpi_init_cpus(void) { }
+static inline int apei_claim_sea(struct pt_regs *regs) { return -ENOENT; }
 #endif /* CONFIG_ACPI */
 
 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL

arch/arm64/include/asm/daifflags.h

@@ -20,6 +20,7 @@
 
 #define DAIF_PROCCTX		0
 #define DAIF_PROCCTX_NOIRQ	PSR_I_BIT
+#define DAIF_ERRCTX		(PSR_I_BIT | PSR_A_BIT)
 
 /* mask/save/unmask/restore all exceptions, including interrupts. */
 static inline void local_daif_mask(void)

arch/arm64/include/asm/fixmap.h

@@ -55,7 +55,11 @@ enum fixed_addresses {
 #ifdef CONFIG_ACPI_APEI_GHES
 	/* Used for GHES mapping from assorted contexts */
 	FIX_APEI_GHES_IRQ,
-	FIX_APEI_GHES_NMI,
+	FIX_APEI_GHES_SEA,
+#ifdef CONFIG_ARM_SDE_INTERFACE
+	FIX_APEI_GHES_SDEI_NORMAL,
+	FIX_APEI_GHES_SDEI_CRITICAL,
+#endif
 #endif /* CONFIG_ACPI_APEI_GHES */
 
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0

arch/arm64/include/asm/kvm_ras.h

@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2018 - Arm Ltd */
+
+#ifndef __ARM64_KVM_RAS_H__
+#define __ARM64_KVM_RAS_H__
+
+#include <linux/acpi.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+
+#include <asm/acpi.h>
+
+/*
+ * Was this synchronous external abort a RAS notification?
+ * Returns '0' for errors handled by some RAS subsystem, or -ENOENT.
+ */
+static inline int kvm_handle_guest_sea(phys_addr_t addr, unsigned int esr)
+{
+	/* apei_claim_sea(NULL) expects to mask interrupts itself */
+	lockdep_assert_irqs_enabled();
+
+	return apei_claim_sea(NULL);
+}
+
+#endif /* __ARM64_KVM_RAS_H__ */

arch/arm64/include/asm/system_misc.h

@@ -46,8 +46,6 @@ extern void __show_regs(struct pt_regs *);
 
 extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
 
-int handle_guest_sea(phys_addr_t addr, unsigned int esr);
-
 #endif	/* __ASSEMBLY__ */
 
 #endif	/* __ASM_SYSTEM_MISC_H */

arch/arm64/kernel/acpi.c

@@ -27,8 +27,10 @@
 #include <linux/smp.h>
 #include <linux/serial_core.h>
 
+#include <acpi/ghes.h>
 #include <asm/cputype.h>
 #include <asm/cpu_ops.h>
+#include <asm/daifflags.h>
 #include <asm/pgtable.h>
 #include <asm/smp_plat.h>
 
@@ -256,3 +258,32 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 		return __pgprot(PROT_NORMAL_NC);
 	return __pgprot(PROT_DEVICE_nGnRnE);
 }
+
+/*
+ * Claim Synchronous External Aborts as a firmware first notification.
+ *
+ * Used by KVM and the arch do_sea handler.
+ * @regs may be NULL when called from process context.
+ */
+int apei_claim_sea(struct pt_regs *regs)
+{
+	int err = -ENOENT;
+	unsigned long current_flags;
+
+	if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
+		return err;
+
+	current_flags = arch_local_save_flags();
+
+	/*
+	 * SEA can interrupt SError, mask it and describe this as an NMI so
+	 * that APEI defers the handling.
+	 */
+	local_daif_restore(DAIF_ERRCTX);
+	nmi_enter();
+	err = ghes_notify_sea();
+	nmi_exit();
+	local_daif_restore(current_flags);
+
+	return err;
+}

arch/arm64/mm/fault.c

@@ -18,6 +18,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/acpi.h>
 #include <linux/extable.h>
 #include <linux/signal.h>
 #include <linux/mm.h>
@@ -33,6 +34,7 @@
 #include <linux/preempt.h>
 #include <linux/hugetlb.h>
 
+#include <asm/acpi.h>
 #include <asm/bug.h>
 #include <asm/cmpxchg.h>
 #include <asm/cpufeature.h>
@@ -47,8 +49,6 @@
 #include <asm/tlbflush.h>
 #include <asm/traps.h>
 
-#include <acpi/ghes.h>
-
 struct fault_info {
 	int	(*fn)(unsigned long addr, unsigned int esr,
 		      struct pt_regs *regs);
@@ -643,19 +643,10 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 	inf = esr_to_fault_info(esr);
 
 	/*
-	 * Synchronous aborts may interrupt code which had interrupts masked.
-	 * Before calling out into the wider kernel tell the interested
-	 * subsystems.
+	 * Return value ignored as we rely on signal merging.
+	 * Future patches will make this more robust.
 	 */
-	if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
-		if (interrupts_enabled(regs))
-			nmi_enter();
-
-		ghes_notify_sea();
-
-		if (interrupts_enabled(regs))
-			nmi_exit();
-	}
+	apei_claim_sea(regs);
 
 	if (esr & ESR_ELx_FnV)
 		siaddr = NULL;
@@ -733,11 +724,6 @@ static const struct fault_info fault_info[] = {
 	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 63"			},
 };
 
-int handle_guest_sea(phys_addr_t addr, unsigned int esr)
-{
-	return ghes_notify_sea();
-}
-
 asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
 					 struct pt_regs *regs)
 {

drivers/acpi/apei/Kconfig

@@ -41,19 +41,9 @@ config ACPI_APEI_PCIEAER
 	  Turn on this option to enable the corresponding support.
 
 config ACPI_APEI_SEA
-	bool "APEI Synchronous External Abort logging/recovering support"
+	bool
 	depends on ARM64 && ACPI_APEI_GHES
 	default y
-	help
-	  This option should be enabled if the system supports
-	  firmware first handling of SEA (Synchronous External Abort).
-	  SEA happens with certain faults of data abort or instruction
-	  abort synchronous exceptions on ARMv8 systems. If a system
-	  supports firmware first handling of SEA, the platform analyzes
-	  and handles hardware error notifications from SEA, and it may then
-	  form a HW error record for the OS to parse and handle. This
-	  option allows the OS to look for such hardware error record, and
-	  take appropriate action.
 
 config ACPI_APEI_MEMORY_FAILURE
 	bool "APEI memory error recovering support"

drivers/acpi/apei/bert.c

@@ -42,22 +42,23 @@ static void __init bert_print_all(struct acpi_bert_region *region,
 	int remain = region_len;
 	u32 estatus_len;
 
-	if (!estatus->block_status)
-		return;
-
-	while (remain > sizeof(struct acpi_bert_region)) {
-		if (cper_estatus_check(estatus)) {
-			pr_err(FW_BUG "Invalid error record.\n");
-			return;
-		}
-
+	while (remain >= sizeof(struct acpi_bert_region)) {
 		estatus_len = cper_estatus_len(estatus);
 		if (remain < estatus_len) {
 			pr_err(FW_BUG "Truncated status block (length: %u).\n",
 			       estatus_len);
 			return;
 		}
 
+		/* No more error records. */
+		if (!estatus->block_status)
+			return;
+
+		if (cper_estatus_check(estatus)) {
+			pr_err(FW_BUG "Invalid error record.\n");
+			return;
+		}
+
 		pr_info_once("Error records from previous boot:\n");
 
 		cper_estatus_print(KERN_INFO HW_ERR, estatus);
@@ -70,10 +71,6 @@ static void __init bert_print_all(struct acpi_bert_region *region,
 		estatus->block_status = 0;
 
 		estatus = (void *)estatus + estatus_len;
-		/* No more error records. */
-		if (!estatus->block_status)
-			return;
-
 		remain -= estatus_len;
 	}
 }

drivers/acpi/apei/einj.c

@@ -644,8 +644,8 @@ static int error_type_set(void *data, u64 val)
 	return 0;
 }
 
-DEFINE_SIMPLE_ATTRIBUTE(error_type_fops, error_type_get,
-			error_type_set, "0x%llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(error_type_fops, error_type_get, error_type_set,
+			 "0x%llx\n");
 
 static int error_inject_set(void *data, u64 val)
 {
@@ -656,8 +656,7 @@ static int error_inject_set(void *data, u64 val)
 		error_param3, error_param4);
 }
 
-DEFINE_SIMPLE_ATTRIBUTE(error_inject_fops, NULL,
-			error_inject_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(error_inject_fops, NULL, error_inject_set, "%llu\n");
 
 static int einj_check_table(struct acpi_table_einj *einj_tab)
 {
@@ -709,10 +708,10 @@ static int __init einj_init(void)
 
 	debugfs_create_file("available_error_type", S_IRUSR, einj_debug_dir,
 			    NULL, &available_error_type_fops);
-	debugfs_create_file("error_type", S_IRUSR | S_IWUSR, einj_debug_dir,
-			    NULL, &error_type_fops);
-	debugfs_create_file("error_inject", S_IWUSR, einj_debug_dir,
-			    NULL, &error_inject_fops);
+	debugfs_create_file_unsafe("error_type", 0600, einj_debug_dir,
+				   NULL, &error_type_fops);
+	debugfs_create_file_unsafe("error_inject", 0200, einj_debug_dir,
+				   NULL, &error_inject_fops);
 
 	apei_resources_init(&einj_resources);
 	einj_exec_ctx_init(&ctx);

drivers/acpi/apei/erst.c

@@ -938,17 +938,17 @@ static struct pstore_info erst_info = {
 };
 
 #define CPER_CREATOR_PSTORE						\
-	UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\
-		0x64, 0x90, 0xb8, 0x9d)
+	GUID_INIT(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\
+		  0x64, 0x90, 0xb8, 0x9d)
 #define CPER_SECTION_TYPE_DMESG						\
-	UUID_LE(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,	\
-		0x94, 0x19, 0xeb, 0x12)
+	GUID_INIT(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,	\
+		  0x94, 0x19, 0xeb, 0x12)
 #define CPER_SECTION_TYPE_DMESG_Z					\
-	UUID_LE(0x4f118707, 0x04dd, 0x4055, 0xb5, 0xdd, 0x95, 0x6d,	\
-		0x34, 0xdd, 0xfa, 0xc6)
+	GUID_INIT(0x4f118707, 0x04dd, 0x4055, 0xb5, 0xdd, 0x95, 0x6d,	\
+		  0x34, 0xdd, 0xfa, 0xc6)
 #define CPER_SECTION_TYPE_MCE						\
-	UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\
-		0x04, 0x4a, 0x38, 0xfc)
+	GUID_INIT(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\
+		  0x04, 0x4a, 0x38, 0xfc)
 
 struct cper_pstore_record {
 	struct cper_record_header hdr;
@@ -1012,7 +1012,7 @@ static ssize_t erst_reader(struct pstore_record *record)
 		rc = -EIO;
 		goto out;
 	}
-	if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
+	if (!guid_equal(&rcd->hdr.creator_id, &CPER_CREATOR_PSTORE))
 		goto skip;
 
 	record->buf = kmalloc(len, GFP_KERNEL);
@@ -1024,15 +1024,12 @@ static ssize_t erst_reader(struct pstore_record *record)
 	record->id = record_id;
 	record->compressed = false;
 	record->ecc_notice_size = 0;
-	if (uuid_le_cmp(rcd->sec_hdr.section_type,
-			CPER_SECTION_TYPE_DMESG_Z) == 0) {
+	if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_DMESG_Z)) {
 		record->type = PSTORE_TYPE_DMESG;
 		record->compressed = true;
-	} else if (uuid_le_cmp(rcd->sec_hdr.section_type,
-			CPER_SECTION_TYPE_DMESG) == 0)
+	} else if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_DMESG))
 		record->type = PSTORE_TYPE_DMESG;
-	else if (uuid_le_cmp(rcd->sec_hdr.section_type,
-			     CPER_SECTION_TYPE_MCE) == 0)
+	else if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_MCE))
 		record->type = PSTORE_TYPE_MCE;
 	else
 		record->type = PSTORE_TYPE_MAX;