Merge tag 'efi-next-for-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "Again not a busy cycle for EFI, just some minor tweaks and bug fixes:

   - Enable boot graphics resource table (BGRT) on Xen/x86

   - Correct a misguided assumption in the memory attributes table
     sanity check

   - Start tagging efi_mem_reserve()'d regions as MEMBLOCK_RSRV_KERN

   - Some other minor fixes and cleanups"

* tag 'efi-next-for-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi/capsule-loader: fix incorrect sizeof in phys array reallocation
  efi: Tag memblock reservations of boot services regions as RSRV_KERN
  memblock: Permit existing reserved regions to be marked RSRV_KERN
  efi/memattr: Fix thinko in table size sanity check
  efi: libstub: fix type of fdt 32 and 64bit variables
  efi: Drop unused efi_range_is_wc() function
  efi: Enable BGRT loading under Xen
  efi: make efi_mem_type() and efi_mem_attributes() work on Xen PV

drivers/firmware/efi/capsule-loader.c

@@ -67,7 +67,7 @@ int __efi_capsule_setup_info(struct capsule_info *cap_info)
 	cap_info->pages = temp_page;
 
 	temp_page = krealloc(cap_info->phys,
-			     pages_needed * sizeof(phys_addr_t *),
+			     pages_needed * sizeof(phys_addr_t),
 			     GFP_KERNEL | __GFP_ZERO);
 	if (!temp_page)
 		return -ENOMEM;

drivers/firmware/efi/efi-bgrt.c

@@ -29,11 +29,12 @@ void __init efi_bgrt_init(struct acpi_table_header *table)
 	void *image;
 	struct bmp_header bmp_header;
 	struct acpi_table_bgrt *bgrt = &bgrt_tab;
+	int mem_type;
 
 	if (acpi_disabled)
 		return;
 
-	if (!efi_enabled(EFI_MEMMAP))
+	if (!efi_enabled(EFI_MEMMAP) && !efi_enabled(EFI_PARAVIRT))
 		return;
 
 	if (table->length < sizeof(bgrt_tab)) {
@@ -62,7 +63,9 @@ void __init efi_bgrt_init(struct acpi_table_header *table)
 		goto out;
 	}
 
-	if (efi_mem_type(bgrt->image_address) != EFI_BOOT_SERVICES_DATA) {
+	mem_type = efi_mem_type(bgrt->image_address);
+	if (mem_type != EFI_BOOT_SERVICES_DATA &&
+	    mem_type != EFI_ACPI_RECLAIM_MEMORY) {
 		pr_notice("Ignoring BGRT: invalid image address\n");
 		goto out;
 	}

drivers/firmware/efi/efi.c

@@ -600,7 +600,9 @@ void __init efi_mem_reserve(phys_addr_t addr, u64 size)
 		return;
 
 	if (!memblock_is_region_reserved(addr, size))
-		memblock_reserve(addr, size);
+		memblock_reserve_kern(addr, size);
+	else
+		memblock_reserved_mark_kern(addr, size);
 
 	/*
 	 * Some architectures (x86) reserve all boot services ranges
@@ -983,18 +985,12 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
  */
 u64 efi_mem_attributes(unsigned long phys_addr)
 {
-	efi_memory_desc_t *md;
+	efi_memory_desc_t md;
 
-	if (!efi_enabled(EFI_MEMMAP))
+	if (efi_mem_desc_lookup(phys_addr, &md))
 		return 0;
 
-	for_each_efi_memory_desc(md) {
-		if ((md->phys_addr <= phys_addr) &&
-		    (phys_addr < (md->phys_addr +
-		    (md->num_pages << EFI_PAGE_SHIFT))))
-			return md->attribute;
-	}
-	return 0;
+	return md.attribute;
 }
 
 /*
@@ -1007,18 +1003,15 @@ u64 efi_mem_attributes(unsigned long phys_addr)
  */
 int efi_mem_type(unsigned long phys_addr)
 {
-	const efi_memory_desc_t *md;
+	efi_memory_desc_t md;
 
-	if (!efi_enabled(EFI_MEMMAP))
+	if (!efi_enabled(EFI_MEMMAP) && !efi_enabled(EFI_PARAVIRT))
 		return -ENOTSUPP;
 
-	for_each_efi_memory_desc(md) {
-		if ((md->phys_addr <= phys_addr) &&
-		    (phys_addr < (md->phys_addr +
-				  (md->num_pages << EFI_PAGE_SHIFT))))
-			return md->type;
-	}
-	return -EINVAL;
+	if (efi_mem_desc_lookup(phys_addr, &md))
+		return -EINVAL;
+
+	return md.type;
 }
 
 int efi_status_to_err(efi_status_t status)

drivers/firmware/efi/libstub/fdt.c

@@ -32,8 +32,8 @@ static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
 {
 	int node, num_rsv;
 	int status;
-	u32 fdt_val32;
-	u64 fdt_val64;
+	fdt32_t fdt_val32;
+	fdt64_t fdt_val64;
 
 	/* Do some checks on provided FDT, if it exists: */
 	if (orig_fdt) {
@@ -100,13 +100,13 @@ static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
 	if (status)
 		goto fdt_set_fail;
 
-	fdt_val64 = U64_MAX; /* placeholder */
+	fdt_val64 = cpu_to_fdt64(U64_MAX); /* placeholder */
 
 	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
 	if (status)
 		goto fdt_set_fail;
 
-	fdt_val32 = U32_MAX; /* placeholder */
+	fdt_val32 = cpu_to_fdt32(U32_MAX); /* placeholder */
 
 	status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
 	if (status)
@@ -147,8 +147,8 @@ static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
 static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map)
 {
 	int node = fdt_path_offset(fdt, "/chosen");
-	u64 fdt_val64;
-	u32 fdt_val32;
+	fdt64_t fdt_val64;
+	fdt32_t fdt_val32;
 	int err;
 
 	if (node < 0)

drivers/firmware/efi/memattr.c

@@ -22,7 +22,6 @@ unsigned long __ro_after_init efi_mem_attr_table = EFI_INVALID_TABLE_ADDR;
 void __init efi_memattr_init(void)
 {
 	efi_memory_attributes_table_t *tbl;
-	unsigned long size;
 
 	if (efi_mem_attr_table == EFI_INVALID_TABLE_ADDR)
 		return;
@@ -40,22 +39,42 @@ void __init efi_memattr_init(void)
 		goto unmap;
 	}
 
+	/*
+	 * The EFI memory attributes table descriptors might potentially be
+	 * smaller than those used by the EFI memory map, as long as they can
+	 * fit a efi_memory_desc_t. However, a larger descriptor size makes no
+	 * sense, and might be an indication that the table is corrupted.
+	 *
+	 * The only exception is kexec_load(), where the EFI memory map is
+	 * reconstructed by user space, and may use a smaller descriptor size
+	 * than the original. Given that, ignoring this companion table is
+	 * still the right thing to do here, but don't complain too loudly when
+	 * this happens.
+	 */
+	if (tbl->desc_size < sizeof(efi_memory_desc_t) ||
+	    tbl->desc_size > efi.memmap.desc_size) {
+		pr_warn("Unexpected EFI Memory Attributes descriptor size %u (expected: %lu)\n",
+			tbl->desc_size, efi.memmap.desc_size);
+		goto unmap;
+	}
 
 	/*
-	 * Sanity check: the Memory Attributes Table contains up to 3 entries
-	 * for each entry of type EfiRuntimeServicesCode in the EFI memory map.
-	 * So if the size of the table exceeds 3x the size of the entire EFI
-	 * memory map, there is clearly something wrong, and the table should
-	 * just be ignored altogether.
+	 * Sanity check: the Memory Attributes Table contains multiple entries
+	 * for each EFI runtime services code or data region in the EFI memory
+	 * map, each with the permission attributes that may be applied when
+	 * mapping the region.  There is no upper bound for the number of
+	 * entries, as it could conceivably contain more entries than the EFI
+	 * memory map itself. So pick an arbitrary limit of 64k, which is
+	 * ludicrously high. This prevents a corrupted table from eating all
+	 * system RAM.
 	 */
-	size = tbl->num_entries * tbl->desc_size;
-	if (size > 3 * efi.memmap.nr_map * efi.memmap.desc_size) {
+	if (tbl->num_entries > SZ_64K) {
 		pr_warn(FW_BUG "Corrupted EFI Memory Attributes Table detected! (version == %u, desc_size == %u, num_entries == %u)\n",
 			tbl->version, tbl->desc_size, tbl->num_entries);
 		goto unmap;
 	}
 
-	tbl_size = sizeof(*tbl) + size;
+	tbl_size = sizeof(*tbl) + tbl->num_entries * tbl->desc_size;
 	memblock_reserve(efi_mem_attr_table, tbl_size);
 	set_bit(EFI_MEM_ATTR, &efi.flags);
 

include/linux/efi.h

@@ -832,27 +832,6 @@ extern int __init parse_efi_signature_list(
 	const void *data, size_t size,
 	efi_element_handler_t (*get_handler_for_guid)(const efi_guid_t *));
 
-/**
- * efi_range_is_wc - check the WC bit on an address range
- * @start: starting kvirt address
- * @len: length of range
- *
- * Consult the EFI memory map and make sure it's ok to set this range WC.
- * Returns true or false.
- */
-static inline int efi_range_is_wc(unsigned long start, unsigned long len)
-{
-	unsigned long i;
-
-	for (i = 0; i < len; i += (1UL << EFI_PAGE_SHIFT)) {
-		unsigned long paddr = __pa(start + i);
-		if (!(efi_mem_attributes(paddr) & EFI_MEMORY_WC))
-			return 0;
-	}
-	/* The range checked out */
-	return 1;
-}
-
 /*
  * We play games with efi_enabled so that the compiler will, if
  * possible, remove EFI-related code altogether.

include/linux/memblock.h

@@ -155,6 +155,7 @@ int memblock_mark_mirror(phys_addr_t base, phys_addr_t size);
 int memblock_mark_nomap(phys_addr_t base, phys_addr_t size);
 int memblock_clear_nomap(phys_addr_t base, phys_addr_t size);
 int memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t size);
+int memblock_reserved_mark_kern(phys_addr_t base, phys_addr_t size);
 int memblock_mark_kho_scratch(phys_addr_t base, phys_addr_t size);
 int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size);
 

mm/memblock.c

@@ -1115,6 +1115,21 @@ int __init_memblock memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t
 				    MEMBLOCK_RSRV_NOINIT);
 }
 
+/**
+ * memblock_reserved_mark_kern - Mark a reserved memory region with flag
+ * MEMBLOCK_RSRV_KERN
+ *
+ * @base: the base phys addr of the region
+ * @size: the size of the region
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+int __init_memblock memblock_reserved_mark_kern(phys_addr_t base, phys_addr_t size)
+{
+	return memblock_setclr_flag(&memblock.reserved, base, size, 1,
+				    MEMBLOCK_RSRV_KERN);
+}
+
 /**
  * memblock_mark_kho_scratch - Mark a memory region as MEMBLOCK_KHO_SCRATCH.
  * @base: the base phys addr of the region