* Fixes and cleanups for SMBIOS 3.0 DMI code - Ivan Khoronzhuk

* A new efi=debug command line option that enables debug output in the
    EFI boot stub and results in less verbose EFI memory map output by
    default - Borislav Petkov
 
  * Disable interrupts around EFI calls and use a more standard page
    table saving and restoring idiom when making EFI calls - Ingo Molnar
 
  * Reduce the number of memory allocations performed when allocating the
    FDT in EFI boot stub by retrieving size from the FDT header in the
    EFI config table - Ard Biesheuvel
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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi

Pull EFI updates from Matt Fleming:

 - Fixes and cleanups for SMBIOS 3.0 DMI code. (Ivan Khoronzhuk)

 - A new efi=debug command line option that enables debug output in the
   EFI boot stub and results in less verbose EFI memory map output by
   default. (Borislav Petkov)

 - Disable interrupts around EFI calls and use a more standard page
   table saving and restoring idiom when making EFI calls. (Ingo Molnar)

 - Reduce the number of memory allocations performed when allocating the
   FDT in EFI boot stub by retrieving size from the FDT header in the
   EFI config table. (Ard Biesheuvel)

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Documentation/kernel-parameters.txt

@@ -1036,7 +1036,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			Format: {"off" | "on" | "skip[mbr]"}
 
 	efi=		[EFI]
-			Format: { "old_map", "nochunk", "noruntime" }
+			Format: { "old_map", "nochunk", "noruntime", "debug" }
 			old_map [X86-64]: switch to the old ioremap-based EFI
 			runtime services mapping. 32-bit still uses this one by
 			default.
@@ -1044,6 +1044,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			boot stub, as chunking can cause problems with some
 			firmware implementations.
 			noruntime : disable EFI runtime services support
+			debug: enable misc debug output
 
 	efi_no_storage_paranoia [EFI; X86]
 			Using this parameter you can use more than 50% of

arch/x86/include/asm/efi.h

@@ -2,6 +2,8 @@
 #define _ASM_X86_EFI_H
 
 #include <asm/i387.h>
+#include <asm/pgtable.h>
+
 /*
  * We map the EFI regions needed for runtime services non-contiguously,
  * with preserved alignment on virtual addresses starting from -4G down
@@ -89,8 +91,8 @@ extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
 extern struct efi_scratch efi_scratch;
 extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 extern int __init efi_memblock_x86_reserve_range(void);
-extern void __init efi_call_phys_prolog(void);
+extern pgd_t * __init efi_call_phys_prolog(void);
-extern void __init efi_call_phys_epilog(void);
+extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
 extern void __init efi_unmap_memmap(void);
 extern void __init efi_memory_uc(u64 addr, unsigned long size);
 extern void __init efi_map_region(efi_memory_desc_t *md);

arch/x86/platform/efi/efi.c

@@ -85,12 +85,20 @@ static efi_status_t __init phys_efi_set_virtual_address_map(
 	efi_memory_desc_t *virtual_map)
 {
 	efi_status_t status;
+	unsigned long flags;
+	pgd_t *save_pgd;
 
-	efi_call_phys_prolog();
+	save_pgd = efi_call_phys_prolog();
+
+	/* Disable interrupts around EFI calls: */
+	local_irq_save(flags);
 	status = efi_call_phys(efi_phys.set_virtual_address_map,
 			       memory_map_size, descriptor_size,
 			       descriptor_version, virtual_map);
-	efi_call_phys_epilog();
+	local_irq_restore(flags);
+
+	efi_call_phys_epilog(save_pgd);
+
 	return status;
 }
 
@@ -491,7 +499,8 @@ void __init efi_init(void)
 	if (efi_memmap_init())
 		return;
 
-	print_efi_memmap();
+	if (efi_enabled(EFI_DBG))
+		print_efi_memmap();
 }
 
 void __init efi_late_init(void)
@@ -939,6 +948,8 @@ static int __init arch_parse_efi_cmdline(char *str)
 {
 	if (parse_option_str(str, "old_map"))
 		set_bit(EFI_OLD_MEMMAP, &efi.flags);
+	if (parse_option_str(str, "debug"))
+		set_bit(EFI_DBG, &efi.flags);
 
 	return 0;
 }

arch/x86/platform/efi/efi_32.c

@@ -33,11 +33,10 @@
 
 /*
  * To make EFI call EFI runtime service in physical addressing mode we need
- * prolog/epilog before/after the invocation to disable interrupt, to
+ * prolog/epilog before/after the invocation to claim the EFI runtime service
- * claim EFI runtime service handler exclusively and to duplicate a memory in
+ * handler exclusively and to duplicate a memory mapping in low memory space,
- * low memory space say 0 - 3G.
+ * say 0 - 3G.
  */
-static unsigned long efi_rt_eflags;
 
 void efi_sync_low_kernel_mappings(void) {}
 void __init efi_dump_pagetable(void) {}
@@ -57,21 +56,24 @@ void __init efi_map_region(efi_memory_desc_t *md)
 void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
 void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
 
-void __init efi_call_phys_prolog(void)
+pgd_t * __init efi_call_phys_prolog(void)
 {
 	struct desc_ptr gdt_descr;
+	pgd_t *save_pgd;
 
-	local_irq_save(efi_rt_eflags);
+	/* Current pgd is swapper_pg_dir, we'll restore it later: */
-
+	save_pgd = swapper_pg_dir;
 	load_cr3(initial_page_table);
 	__flush_tlb_all();
 
 	gdt_descr.address = __pa(get_cpu_gdt_table(0));
 	gdt_descr.size = GDT_SIZE - 1;
 	load_gdt(&gdt_descr);
+
+	return save_pgd;
 }
 
-void __init efi_call_phys_epilog(void)
+void __init efi_call_phys_epilog(pgd_t *save_pgd)
 {
 	struct desc_ptr gdt_descr;
 
@@ -79,10 +81,8 @@ void __init efi_call_phys_epilog(void)
 	gdt_descr.size = GDT_SIZE - 1;
 	load_gdt(&gdt_descr);
 
-	load_cr3(swapper_pg_dir);
+	load_cr3(save_pgd);
 	__flush_tlb_all();
-
-	local_irq_restore(efi_rt_eflags);
 }
 
 void __init efi_runtime_mkexec(void)

arch/x86/platform/efi/efi_64.c

@@ -41,9 +41,6 @@
 #include <asm/realmode.h>
 #include <asm/time.h>
 
-static pgd_t *save_pgd __initdata;
-static unsigned long efi_flags __initdata;
-
 /*
  * We allocate runtime services regions bottom-up, starting from -4G, i.e.
  * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
@@ -78,17 +75,18 @@ static void __init early_code_mapping_set_exec(int executable)
 	}
 }
 
-void __init efi_call_phys_prolog(void)
+pgd_t * __init efi_call_phys_prolog(void)
 {
 	unsigned long vaddress;
+	pgd_t *save_pgd;
+
 	int pgd;
 	int n_pgds;
 
 	if (!efi_enabled(EFI_OLD_MEMMAP))
-		return;
+		return NULL;
 
 	early_code_mapping_set_exec(1);
-	local_irq_save(efi_flags);
 
 	n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
 	save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL);
@@ -99,24 +97,29 @@ void __init efi_call_phys_prolog(void)
 		set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
 	}
 	__flush_tlb_all();
+
+	return save_pgd;
 }
 
-void __init efi_call_phys_epilog(void)
+void __init efi_call_phys_epilog(pgd_t *save_pgd)
 {
 	/*
 	 * After the lock is released, the original page table is restored.
 	 */
-	int pgd;
+	int pgd_idx;
-	int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
+	int nr_pgds;
 
-	if (!efi_enabled(EFI_OLD_MEMMAP))
+	if (!save_pgd)
 		return;
 
-	for (pgd = 0; pgd < n_pgds; pgd++)
+	nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
-		set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
+
+	for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++)
+		set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
+
 	kfree(save_pgd);
+
 	__flush_tlb_all();
-	local_irq_restore(efi_flags);
 	early_code_mapping_set_exec(0);
 }
 

drivers/firmware/dmi_scan.c

@@ -17,7 +17,9 @@
  */
 static const char dmi_empty_string[] = "        ";
 
-static u16 __initdata dmi_ver;
+static u32 dmi_ver __initdata;
+static u32 dmi_len;
+static u16 dmi_num;
 /*
  * Catch too early calls to dmi_check_system():
  */
@@ -78,7 +80,7 @@ static const char * __init dmi_string(const struct dmi_header *dm, u8 s)
  *	We have to be cautious here. We have seen BIOSes with DMI pointers
  *	pointing to completely the wrong place for example
  */
-static void dmi_table(u8 *buf, u32 len, int num,
+static void dmi_table(u8 *buf,
 		      void (*decode)(const struct dmi_header *, void *),
 		      void *private_data)
 {
@@ -89,7 +91,8 @@ static void dmi_table(u8 *buf, u32 len, int num,
 	 *	Stop when we see all the items the table claimed to have
 	 *	OR we run off the end of the table (also happens)
 	 */
-	while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
+	while ((i < dmi_num) && (data - buf + sizeof(struct dmi_header))
+		<= dmi_len) {
 		const struct dmi_header *dm = (const struct dmi_header *)data;
 
 		/*
@@ -98,9 +101,9 @@ static void dmi_table(u8 *buf, u32 len, int num,
 		 *  table in dmi_decode or dmi_string
 		 */
 		data += dm->length;
-		while ((data - buf < len - 1) && (data[0] || data[1]))
+		while ((data - buf < dmi_len - 1) && (data[0] || data[1]))
 			data++;
-		if (data - buf < len - 1)
+		if (data - buf < dmi_len - 1)
 			decode(dm, private_data);
 
 		/*
@@ -115,8 +118,6 @@ static void dmi_table(u8 *buf, u32 len, int num,
 }
 
 static phys_addr_t dmi_base;
-static u32 dmi_len;
-static u16 dmi_num;
 
 static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
 		void *))
@@ -127,7 +128,7 @@ static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
 	if (buf == NULL)
 		return -1;
 
-	dmi_table(buf, dmi_len, dmi_num, decode, NULL);
+	dmi_table(buf, decode, NULL);
 
 	add_device_randomness(buf, dmi_len);
 
@@ -198,7 +199,7 @@ static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
 	 * the UUID are supposed to be little-endian encoded.  The specification
 	 * says that this is the defacto standard.
 	 */
-	if (dmi_ver >= 0x0206)
+	if (dmi_ver >= 0x020600)
 		sprintf(s, "%pUL", d);
 	else
 		sprintf(s, "%pUB", d);
@@ -470,7 +471,7 @@ static void __init dmi_format_ids(char *buf, size_t len)
  */
 static int __init dmi_present(const u8 *buf)
 {
-	int smbios_ver;
+	u32 smbios_ver;
 
 	if (memcmp(buf, "_SM_", 4) == 0 &&
 	    buf[5] < 32 && dmi_checksum(buf, buf[5])) {
@@ -503,14 +504,16 @@ static int __init dmi_present(const u8 *buf)
 		if (dmi_walk_early(dmi_decode) == 0) {
 			if (smbios_ver) {
 				dmi_ver = smbios_ver;
-				pr_info("SMBIOS %d.%d present.\n",
+				pr_info("SMBIOS %d.%d%s present.\n",
-				       dmi_ver >> 8, dmi_ver & 0xFF);
+					dmi_ver >> 8, dmi_ver & 0xFF,
+					(dmi_ver < 0x0300) ? "" : ".x");
 			} else {
 				dmi_ver = (buf[14] & 0xF0) << 4 |
 					   (buf[14] & 0x0F);
 				pr_info("Legacy DMI %d.%d present.\n",
 				       dmi_ver >> 8, dmi_ver & 0xFF);
 			}
+			dmi_ver <<= 8;
 			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
 			printk(KERN_DEBUG "DMI: %s\n", dmi_ids_string);
 			return 0;
@@ -528,7 +531,8 @@ static int __init dmi_smbios3_present(const u8 *buf)
 {
 	if (memcmp(buf, "_SM3_", 5) == 0 &&
 	    buf[6] < 32 && dmi_checksum(buf, buf[6])) {
-		dmi_ver = get_unaligned_be16(buf + 7);
+		dmi_ver = get_unaligned_be32(buf + 6);
+		dmi_ver &= 0xFFFFFF;
 		dmi_len = get_unaligned_le32(buf + 12);
 		dmi_base = get_unaligned_le64(buf + 16);
 
@@ -545,8 +549,9 @@ static int __init dmi_smbios3_present(const u8 *buf)
 		dmi_num = dmi_len / 4;
 
 		if (dmi_walk_early(dmi_decode) == 0) {
-			pr_info("SMBIOS %d.%d present.\n",
+			pr_info("SMBIOS %d.%d.%d present.\n",
-				dmi_ver >> 8, dmi_ver & 0xFF);
+				dmi_ver >> 16, (dmi_ver >> 8) & 0xFF,
+				dmi_ver & 0xFF);
 			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
 			pr_debug("DMI: %s\n", dmi_ids_string);
 			return 0;
@@ -901,7 +906,7 @@ int dmi_walk(void (*decode)(const struct dmi_header *, void *),
 	if (buf == NULL)
 		return -1;
 
-	dmi_table(buf, dmi_len, dmi_num, decode, private_data);
+	dmi_table(buf, decode, private_data);
 
 	dmi_unmap(buf);
 	return 0;

drivers/firmware/efi/libstub/arm-stub.c

@@ -175,7 +175,7 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 	unsigned long initrd_addr;
 	u64 initrd_size = 0;
 	unsigned long fdt_addr = 0;  /* Original DTB */
-	u64 fdt_size = 0;  /* We don't get size from configuration table */
+	unsigned long fdt_size = 0;
 	char *cmdline_ptr = NULL;
 	int cmdline_size = 0;
 	unsigned long new_fdt_addr;
@@ -239,8 +239,7 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 	} else {
 		status = handle_cmdline_files(sys_table, image, cmdline_ptr,
 					      "dtb=",
-					      ~0UL, (unsigned long *)&fdt_addr,
+					      ~0UL, &fdt_addr, &fdt_size);
-					      (unsigned long *)&fdt_size);
 
 		if (status != EFI_SUCCESS) {
 			pr_efi_err(sys_table, "Failed to load device tree!\n");
@@ -252,7 +251,7 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 		pr_efi(sys_table, "Using DTB from command line\n");
 	} else {
 		/* Look for a device tree configuration table entry. */
-		fdt_addr = (uintptr_t)get_fdt(sys_table);
+		fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
 		if (fdt_addr)
 			pr_efi(sys_table, "Using DTB from configuration table\n");
 	}

drivers/firmware/efi/libstub/efistub.h

@@ -41,7 +41,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
 					    unsigned long fdt_addr,
 					    unsigned long fdt_size);
 
-void *get_fdt(efi_system_table_t *sys_table);
+void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size);
 
 void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
 		     unsigned long desc_size, efi_memory_desc_t *runtime_map,

drivers/firmware/efi/libstub/fdt.c

@@ -323,7 +323,7 @@ fail:
 	return EFI_LOAD_ERROR;
 }
 
-void *get_fdt(efi_system_table_t *sys_table)
+void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size)
 {
 	efi_guid_t fdt_guid = DEVICE_TREE_GUID;
 	efi_config_table_t *tables;
@@ -336,6 +336,11 @@ void *get_fdt(efi_system_table_t *sys_table)
 	for (i = 0; i < sys_table->nr_tables; i++)
 		if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) {
 			fdt = (void *) tables[i].table;
+			if (fdt_check_header(fdt) != 0) {
+				pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n");
+				return NULL;
+			}
+			*fdt_size = fdt_totalsize(fdt);
 			break;
 	 }
 

include/linux/efi.h

@@ -942,6 +942,7 @@ extern int __init efi_setup_pcdp_console(char *);
 #define EFI_64BIT		5	/* Is the firmware 64-bit? */
 #define EFI_PARAVIRT		6	/* Access is via a paravirt interface */
 #define EFI_ARCH_1		7	/* First arch-specific bit */
+#define EFI_DBG			8	/* Print additional debug info at runtime */
 
 #ifdef CONFIG_EFI
 /*