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>

4 files changed, 15 insertions, 10 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,