efi/libstub: Use stricter typing for firmware function pointers

We will soon remove another level of pointer casting, so let's make
sure all type handling involving firmware calls at boot time is correct.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-12-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

7 files changed, 28 insertions, 18 deletions

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 990b93379965..2733bc263c04 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -70,7 +70,8 @@ preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
 
 	size = romsize + sizeof(*rom);
 
-	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom);
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size,
+				(void **)&rom);
 	if (status != EFI_SUCCESS) {
 		efi_printk(sys_table, "Failed to allocate memory for 'rom'\n");
 		return status;
@@ -195,9 +196,9 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
 	struct setup_data *data, *new;
 	efi_status_t status;
 	u32 size = 0;
-	void *p;
+	apple_properties_protocol_t *p;
 
-	status = efi_call_early(locate_protocol, &guid, NULL, &p);
+	status = efi_call_early(locate_protocol, &guid, NULL, (void **)&p);
 	if (status != EFI_SUCCESS)
 		return;
 
@@ -212,7 +213,8 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
 
 	do {
 		status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
-					size + sizeof(struct setup_data), &new);
+					size + sizeof(struct setup_data),
+					(void **)&new);
 		if (status != EFI_SUCCESS) {
 			efi_printk(sys_table, "Failed to allocate memory for 'properties'\n");
 			return;
diff --git a/arch/x86/boot/compressed/eboot.h b/arch/x86/boot/compressed/eboot.h
index de13865dc7d2..b8d11928f528 100644
--- a/arch/x86/boot/compressed/eboot.h
+++ b/arch/x86/boot/compressed/eboot.h
@@ -12,9 +12,12 @@
 
 #define DESC_TYPE_CODE_DATA	(1 << 0)
 
-typedef union {
+typedef union efi_uga_draw_protocol efi_uga_draw_protocol_t;
+
+union efi_uga_draw_protocol {
 	struct {
-		void *get_mode;
+		efi_status_t (*get_mode)(efi_uga_draw_protocol_t *,
+					 u32*, u32*, u32*, u32*);
 		void *set_mode;
 		void *blt;
 	};
@@ -23,6 +26,6 @@ typedef union {
 		u32 set_mode;
 		u32 blt;
 	} mixed_mode;
-} efi_uga_draw_protocol_t;
+};
 
 #endif /* BOOT_COMPRESSED_EBOOT_H */
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index e188b7ce0796..d96953d9d4e7 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -385,7 +385,7 @@ static int __init efi_systab_init(void *phys)
 		tmp |= systab64->con_in;
 		efi_systab.con_out_handle = systab64->con_out_handle;
 		tmp |= systab64->con_out_handle;
-		efi_systab.con_out = systab64->con_out;
+		efi_systab.con_out = (void *)(unsigned long)systab64->con_out;
 		tmp |= systab64->con_out;
 		efi_systab.stderr_handle = systab64->stderr_handle;
 		tmp |= systab64->stderr_handle;
@@ -427,7 +427,7 @@ static int __init efi_systab_init(void *phys)
 		efi_systab.con_in_handle = systab32->con_in_handle;
 		efi_systab.con_in = systab32->con_in;
 		efi_systab.con_out_handle = systab32->con_out_handle;
-		efi_systab.con_out = systab32->con_out;
+		efi_systab.con_out = (void *)(unsigned long)systab32->con_out;
 		efi_systab.stderr_handle = systab32->stderr_handle;
 		efi_systab.stderr = systab32->stderr;
 		efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
index a04551ee5568..1abe455d926a 100644
--- a/arch/x86/xen/efi.c
+++ b/arch/x86/xen/efi.c
@@ -31,7 +31,7 @@ static efi_system_table_t efi_systab_xen __initdata = {
 	.con_in_handle	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 	.con_in		= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 	.con_out_handle	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
-	.con_out	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
+	.con_out	= NULL, 		  /* Not used under Xen. */
 	.stderr_handle	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 	.stderr		= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 	.runtime	= (efi_runtime_services_t *)EFI_INVALID_TABLE_ADDR,
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 1a814dc235ba..f91f4fdbe553 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -413,12 +413,13 @@ grow:
 	return status;
 }
 
-static efi_status_t efi_file_read(void *handle, unsigned long *size, void *addr)
+static efi_status_t efi_file_read(efi_file_handle_t *handle,
+				  unsigned long *size, void *addr)
 {
 	return efi_call_proto(efi_file_handle, read, handle, size, addr);
 }
 
-static efi_status_t efi_file_close(void *handle)
+static efi_status_t efi_file_close(efi_file_handle_t *handle)
 {
 	return efi_call_proto(efi_file_handle, close, handle);
 }
diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c
index eb9af83e4d59..d270acd43de8 100644
--- a/drivers/firmware/efi/libstub/tpm.c
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -69,11 +69,11 @@ void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg)
 	size_t log_size, last_entry_size;
 	efi_bool_t truncated;
 	int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
-	void *tcg2_protocol = NULL;
+	efi_tcg2_protocol_t *tcg2_protocol = NULL;
 	int final_events_size = 0;
 
 	status = efi_call_early(locate_protocol, &tcg2_guid, NULL,
-				&tcg2_protocol);
+				(void **)&tcg2_protocol);
 	if (status != EFI_SUCCESS)
 		return;
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index d8e987910853..880077639113 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -382,7 +382,11 @@ union efi_pci_io_protocol {
 		void *allocate_buffer;
 		void *free_buffer;
 		void *flush;
-		void *get_location;
+		efi_status_t (*get_location)(efi_pci_io_protocol_t *,
+					     unsigned long *segment_nr,
+					     unsigned long *bus_nr,
+					     unsigned long *device_nr,
+					     unsigned long *function_nr);
 		void *attributes;
 		void *get_bar_attributes;
 		void *set_bar_attributes;
@@ -730,6 +734,8 @@ typedef struct {
 	u32 tables;
 } efi_system_table_32_t;
 
+typedef union efi_simple_text_output_protocol efi_simple_text_output_protocol_t;
+
 typedef union {
 	struct {
 		efi_table_hdr_t hdr;
@@ -738,7 +744,7 @@ typedef union {
 		unsigned long con_in_handle;
 		unsigned long con_in;
 		unsigned long con_out_handle;
-		unsigned long con_out;
+		efi_simple_text_output_protocol_t *con_out;
 		unsigned long stderr_handle;
 		unsigned long stderr;
 		efi_runtime_services_t *runtime;
@@ -1337,8 +1343,6 @@ struct efivar_entry {
 	bool deleting;
 };
 
-typedef union efi_simple_text_output_protocol efi_simple_text_output_protocol_t;
-
 union efi_simple_text_output_protocol {
 	struct {
 		void *reset;