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>

10 files changed, 79 insertions, 52 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index bfcb1a62a7b4..01aa47d3b6ab 100644
--- a/Documentation/kernel-parameters.txt
+++ b/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
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 25bce45c6fc4..3738b138b843 100644
--- a/arch/x86/include/asm/efi.h
+++ b/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 void __init efi_call_phys_epilog(void);
+extern pgd_t * __init efi_call_phys_prolog(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);
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index dbc8627a5cdf..02744df576d5 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/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;
 }
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 40e7cda52936..ed5b67338294 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/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
- * claim EFI runtime service handler exclusively and to duplicate a memory in
- * low memory space say 0 - 3G.
+ * prolog/epilog before/after the invocation to claim the EFI runtime service
+ * handler exclusively and to duplicate a memory mapping in low memory space,
+ * 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)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 17e80d829df0..a0ac0f9c307f 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/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 n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
+        int pgd_idx;
+        int nr_pgds;
 
-        if (!efi_enabled(EFI_OLD_MEMMAP))
+        if (!save_pgd)
                 return;
 
-        for (pgd = 0; pgd < n_pgds; pgd++)
-                set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
+        nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
+
+        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);
 }
 
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 69fac068669f..c9cb725520c5 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/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",
-                                       dmi_ver >> 8, dmi_ver & 0xFF);
+                                pr_info("SMBIOS %d.%d%s present.\n",
+                                        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",
-                                dmi_ver >> 8, dmi_ver & 0xFF);
+                        pr_info("SMBIOS %d.%d.%d present.\n",
+                                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;
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index dcae482a9a17..e29560e6b40b 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/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,
-                                              (unsigned long *)&fdt_size);
+                                              ~0UL, &fdt_addr, &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");
         }
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 47437b16b186..e334a01cf92f 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/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,
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index 91da56c4fd54..ef5d764e2a27 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/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;
          }
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index cf7e431cbc73..af5be0368dec 100644
--- a/include/linux/efi.h
+++ b/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
 /*