Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

Pull EFI updates for v4.20 from Ard Biesheuvel:

- Add support for enlisting the help of the EFI firmware to create memory
  reservations that persist across kexec.
- Add page fault handling to the runtime services support code on x86 so
  we can gracefully recover from buggy EFI firmware.
- Fix command line handling on x86 for the boot path that omits the stub's
  PE/COFF entry point.
- Other assorted fixes.

6 files changed, 141 insertions, 46 deletions

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 2a29dd9c986d..249eb70691b0 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -52,7 +52,8 @@ struct efi __read_mostly efi = {
 	.properties_table	= EFI_INVALID_TABLE_ADDR,
 	.mem_attr_table		= EFI_INVALID_TABLE_ADDR,
 	.rng_seed		= EFI_INVALID_TABLE_ADDR,
-	.tpm_log		= EFI_INVALID_TABLE_ADDR
+	.tpm_log		= EFI_INVALID_TABLE_ADDR,
+	.mem_reserve		= EFI_INVALID_TABLE_ADDR,
 };
 EXPORT_SYMBOL(efi);
 
@@ -484,6 +485,7 @@ static __initdata efi_config_table_type_t common_tables[] = {
 	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
 	{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
 	{LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
+	{LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve},
 	{NULL_GUID, NULL, NULL},
 };
 
@@ -591,6 +593,29 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
 		early_memunmap(tbl, sizeof(*tbl));
 	}
 
+	if (efi.mem_reserve != EFI_INVALID_TABLE_ADDR) {
+		unsigned long prsv = efi.mem_reserve;
+
+		while (prsv) {
+			struct linux_efi_memreserve *rsv;
+
+			/* reserve the entry itself */
+			memblock_reserve(prsv, sizeof(*rsv));
+
+			rsv = early_memremap(prsv, sizeof(*rsv));
+			if (rsv == NULL) {
+				pr_err("Could not map UEFI memreserve entry!\n");
+				return -ENOMEM;
+			}
+
+			if (rsv->size)
+				memblock_reserve(rsv->base, rsv->size);
+
+			prsv = rsv->next;
+			early_memunmap(rsv, sizeof(*rsv));
+		}
+	}
+
 	return 0;
 }
 
@@ -937,6 +962,38 @@ bool efi_is_table_address(unsigned long phys_addr)
 	return false;
 }
 
+static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
+
+int efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
+{
+	struct linux_efi_memreserve *rsv, *parent;
+
+	if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
+		return -ENODEV;
+
+	rsv = kmalloc(sizeof(*rsv), GFP_KERNEL);
+	if (!rsv)
+		return -ENOMEM;
+
+	parent = memremap(efi.mem_reserve, sizeof(*rsv), MEMREMAP_WB);
+	if (!parent) {
+		kfree(rsv);
+		return -ENOMEM;
+	}
+
+	rsv->base = addr;
+	rsv->size = size;
+
+	spin_lock(&efi_mem_reserve_persistent_lock);
+	rsv->next = parent->next;
+	parent->next = __pa(rsv);
+	spin_unlock(&efi_mem_reserve_persistent_lock);
+
+	memunmap(parent);
+
+	return 0;
+}
+
 #ifdef CONFIG_KEXEC
 static int update_efi_random_seed(struct notifier_block *nb,
 				  unsigned long code, void *unused)
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 14c40a7750d1..c51627660dbb 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -16,7 +16,8 @@ cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ -O2 \
 cflags-$(CONFIG_ARM64)		:= $(subst -pg,,$(KBUILD_CFLAGS)) -fpie \
 				   $(DISABLE_STACKLEAK_PLUGIN)
 cflags-$(CONFIG_ARM)		:= $(subst -pg,,$(KBUILD_CFLAGS)) \
-				   -fno-builtin -fpic -mno-single-pic-base
+				   -fno-builtin -fpic \
+				   $(call cc-option,-mno-single-pic-base)
 
 cflags-$(CONFIG_EFI_ARMSTUB)	+= -I$(srctree)/scripts/dtc/libfdt
 
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 6920033de6d4..30ac0c975f8a 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -69,6 +69,31 @@ static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg)
 	return si;
 }
 
+void install_memreserve_table(efi_system_table_t *sys_table_arg)
+{
+	struct linux_efi_memreserve *rsv;
+	efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
+	efi_status_t status;
+
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
+				(void **)&rsv);
+	if (status != EFI_SUCCESS) {
+		pr_efi_err(sys_table_arg, "Failed to allocate memreserve entry!\n");
+		return;
+	}
+
+	rsv->next = 0;
+	rsv->base = 0;
+	rsv->size = 0;
+
+	status = efi_call_early(install_configuration_table,
+				&memreserve_table_guid,
+				rsv);
+	if (status != EFI_SUCCESS)
+		pr_efi_err(sys_table_arg, "Failed to install memreserve config table!\n");
+}
+
+
 /*
  * This function handles the architcture specific differences between arm and
  * arm64 regarding where the kernel image must be loaded and any memory that
@@ -235,6 +260,8 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 		}
 	}
 
+	install_memreserve_table(sys_table);
+
 	new_fdt_addr = fdt_addr;
 	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
 				&new_fdt_addr, efi_get_max_fdt_addr(dram_base),
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index aa66cbf23512..a19d845bdb06 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/drivers/firmware/efi/runtime-wrappers.c
@@ -45,39 +45,7 @@
 #define __efi_call_virt(f, args...) \
 	__efi_call_virt_pointer(efi.systab->runtime, f, args)
 
-/* efi_runtime_service() function identifiers */
-enum efi_rts_ids {
-	GET_TIME,
-	SET_TIME,
-	GET_WAKEUP_TIME,
-	SET_WAKEUP_TIME,
-	GET_VARIABLE,
-	GET_NEXT_VARIABLE,
-	SET_VARIABLE,
-	QUERY_VARIABLE_INFO,
-	GET_NEXT_HIGH_MONO_COUNT,
-	UPDATE_CAPSULE,
-	QUERY_CAPSULE_CAPS,
-};
-
-/*
- * efi_runtime_work:	Details of EFI Runtime Service work
- * @arg<1-5>:		EFI Runtime Service function arguments
- * @status:		Status of executing EFI Runtime Service
- * @efi_rts_id:		EFI Runtime Service function identifier
- * @efi_rts_comp:	Struct used for handling completions
- */
-struct efi_runtime_work {
-	void *arg1;
-	void *arg2;
-	void *arg3;
-	void *arg4;
-	void *arg5;
-	efi_status_t status;
-	struct work_struct work;
-	enum efi_rts_ids efi_rts_id;
-	struct completion efi_rts_comp;
-};
+struct efi_runtime_work efi_rts_work;
 
 /*
  * efi_queue_work:	Queue efi_runtime_service() and wait until it's done
@@ -91,9 +59,13 @@ struct efi_runtime_work {
  */
 #define efi_queue_work(_rts, _arg1, _arg2, _arg3, _arg4, _arg5)		\
 ({									\
-	struct efi_runtime_work efi_rts_work;				\
 	efi_rts_work.status = EFI_ABORTED;				\
 									\
+	if (!efi_enabled(EFI_RUNTIME_SERVICES)) {			\
+		pr_warn_once("EFI Runtime Services are disabled!\n");	\
+		goto exit;						\
+	}								\
+									\
 	init_completion(&efi_rts_work.efi_rts_comp);			\
 	INIT_WORK_ONSTACK(&efi_rts_work.work, efi_call_rts);		\
 	efi_rts_work.arg1 = _arg1;					\
@@ -112,6 +84,8 @@ struct efi_runtime_work {
 	else								\
 		pr_err("Failed to queue work to efi_rts_wq.\n");	\
 									\
+exit:									\
+	efi_rts_work.efi_rts_id = NONE;					\
 	efi_rts_work.status;						\
 })
 
@@ -184,18 +158,16 @@ static DEFINE_SEMAPHORE(efi_runtime_lock);
  */
 static void efi_call_rts(struct work_struct *work)
 {
-	struct efi_runtime_work *efi_rts_work;
 	void *arg1, *arg2, *arg3, *arg4, *arg5;
 	efi_status_t status = EFI_NOT_FOUND;
 
-	efi_rts_work = container_of(work, struct efi_runtime_work, work);
-	arg1 = efi_rts_work->arg1;
-	arg2 = efi_rts_work->arg2;
-	arg3 = efi_rts_work->arg3;
-	arg4 = efi_rts_work->arg4;
-	arg5 = efi_rts_work->arg5;
+	arg1 = efi_rts_work.arg1;
+	arg2 = efi_rts_work.arg2;
+	arg3 = efi_rts_work.arg3;
+	arg4 = efi_rts_work.arg4;
+	arg5 = efi_rts_work.arg5;
 
-	switch (efi_rts_work->efi_rts_id) {
+	switch (efi_rts_work.efi_rts_id) {
 	case GET_TIME:
 		status = efi_call_virt(get_time, (efi_time_t *)arg1,
 				       (efi_time_cap_t *)arg2);
@@ -253,8 +225,8 @@ static void efi_call_rts(struct work_struct *work)
 		 */
 		pr_err("Requested executing invalid EFI Runtime Service.\n");
 	}
-	efi_rts_work->status = status;
-	complete(&efi_rts_work->efi_rts_comp);
+	efi_rts_work.status = status;
+	complete(&efi_rts_work.efi_rts_comp);
 }
 
 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
@@ -428,6 +400,7 @@ static void virt_efi_reset_system(int reset_type,
 			"could not get exclusive access to the firmware\n");
 		return;
 	}
+	efi_rts_work.efi_rts_id = RESET_SYSTEM;
 	__efi_call_virt(reset_system, reset_type, status, data_size, data);
 	up(&efi_runtime_lock);
 }
diff --git a/drivers/firmware/efi/test/efi_test.c b/drivers/firmware/efi/test/efi_test.c
index 41c48a1e8baa..769640940c9f 100644
--- a/drivers/firmware/efi/test/efi_test.c
+++ b/drivers/firmware/efi/test/efi_test.c
@@ -542,6 +542,30 @@ static long efi_runtime_get_nexthighmonocount(unsigned long arg)
 	return 0;
 }
 
+static long efi_runtime_reset_system(unsigned long arg)
+{
+	struct efi_resetsystem __user *resetsystem_user;
+	struct efi_resetsystem resetsystem;
+	void *data = NULL;
+
+	resetsystem_user = (struct efi_resetsystem __user *)arg;
+	if (copy_from_user(&resetsystem, resetsystem_user,
+						sizeof(resetsystem)))
+		return -EFAULT;
+	if (resetsystem.data_size != 0) {
+		data = memdup_user((void *)resetsystem.data,
+						resetsystem.data_size);
+		if (IS_ERR(data))
+			return PTR_ERR(data);
+	}
+
+	efi.reset_system(resetsystem.reset_type, resetsystem.status,
+				resetsystem.data_size, (efi_char16_t *)data);
+
+	kfree(data);
+	return 0;
+}
+
 static long efi_runtime_query_variableinfo(unsigned long arg)
 {
 	struct efi_queryvariableinfo __user *queryvariableinfo_user;
@@ -682,6 +706,9 @@ static long efi_test_ioctl(struct file *file, unsigned int cmd,
 
 	case EFI_RUNTIME_QUERY_CAPSULECAPABILITIES:
 		return efi_runtime_query_capsulecaps(arg);
+
+	case EFI_RUNTIME_RESET_SYSTEM:
+		return efi_runtime_reset_system(arg);
 	}
 
 	return -ENOTTY;
diff --git a/drivers/firmware/efi/test/efi_test.h b/drivers/firmware/efi/test/efi_test.h
index 9812c6a02b40..5f4818bf112f 100644
--- a/drivers/firmware/efi/test/efi_test.h
+++ b/drivers/firmware/efi/test/efi_test.h
@@ -81,6 +81,13 @@ struct efi_querycapsulecapabilities {
 	efi_status_t		*status;
 } __packed;
 
+struct efi_resetsystem {
+	int			reset_type;
+	efi_status_t		status;
+	unsigned long		data_size;
+	efi_char16_t		*data;
+} __packed;
+
 #define EFI_RUNTIME_GET_VARIABLE \
 	_IOWR('p', 0x01, struct efi_getvariable)
 #define EFI_RUNTIME_SET_VARIABLE \
@@ -108,4 +115,7 @@ struct efi_querycapsulecapabilities {
 #define EFI_RUNTIME_QUERY_CAPSULECAPABILITIES \
 	_IOR('p', 0x0A, struct efi_querycapsulecapabilities)
 
+#define EFI_RUNTIME_RESET_SYSTEM \
+	_IOW('p', 0x0B, struct efi_resetsystem)
+
 #endif /* _DRIVERS_FIRMWARE_EFI_TEST_H_ */